bluuebunny/crossref_metadata_2025 huggingface dataset:
A comprehensive study of extraction of hyperoside from Hypericum perforatum L. using CTAB reverse micelles
Authors: Zhou Xiaohua , Dong Lichun , Li Duanhua
Published: May 2008

BACKGROUND: Hyperoside is a valuable natural pharmaceutical that has many biomedical functions. By the traditional method of alcohol extraction, only hyperoside solution of very low concentration can be obtained, so a new method is urgently needed to produce pure hyperoside more effectively. Reverse micellar extraction has been widely used in the purification of biological macromolecules. Theoretically, this method could also be used to purify materials with small molecules. Therefore it would seem appropriate to consider the extraction of hyperoside, a material with small molecules, using reverse micelles. In this study the factors affecting hyperoside extraction using cetyl trimethylammonium bromide (CTAB) reverse micelles were comprehensively investigated.

RESULTS: The results showed that the partition coefficient increases with an increase in aqueous phase pH or CTAB concentration before reaching a saturated state. The existence of anions in the system can affect the extraction in several ways. For example, SO$_{4}^{2-}$ and PO$_{4}^{3-}$ ions can form hydrogen bonds with hyperoside and thereby improve the extraction significantly.

CONCLUSION: This study proved that extraction using CTAB reverse micelles is a very effective method to separate hyperoside from Hypericum perforatum L. Under optimal conditions the extraction efficiency can reach 68.3% and the single‐strip‐extraction efficiency can reach 85.9%. The proportion of hyperoside among the flavonoids left in the strip‐extract can reach 93.3 wt%. This finding is very significant, because it demonstrates that reverse micellar extraction is a promising way to separate and purify materials with small molecules. Copyright © 2008 Society of Chemical Industry
Sulfur dioxide non‐dispersive absorption in N,N‐dimethylaniline using a ceramic membrane contactor
Authors: Luis P , Garea A , Irabien A.
Published: May 2008

BACKGROUND: Removal of sulfur dioxide from gas emissions by selective absorption is a common method to separate and concentrate sulfur dioxide and to reduce air pollution and environmental risks. N,N‐dimethylaniline is an organic solvent used in some industrial applications for its sulfur dioxide affinity, leading to a regenerative process. However, the use of scrubbers and equipment in which direct contact between gas and liquid takes place leads to solvent losses due to evaporation and drops dragging.

RESULTS: In this work, an innovative procedure based on non‐dispersive absorption in a ceramic hollow fibre membrane contactor was studied in order to avoid drops dragging. The absorption efficiency ranged between 40 and 50%, showing the technical viability of the process. The sulfur dioxide flux through the membrane has a linear relationship with the concentration of SO2 in the gas stream and an overall mass transfer coefficient Koverall = (1.10 ± 0.11) × 10−5 m s−1 has been obtained.

CONCLUSIONS: The mass transfer behaviour of a ceramic hollow fibre membrane contactor for sulfur dioxide non‐dispersive absorption in N,N‐dimethylaniline has been studied. The main resistance is found to be the ceramic membrane and the effective diffusivity has been inferred. The mass transfer model and parameters allow the evaluation of equipment design for technical applications. Copyright © 2008 Society of Chemical Industry
COD fractionation and parameter estimation for combined sewers by respirometric tests
Authors: Zhou Zhen , Wu Zhichao , Wang Zhiwei , Tang Shujuan , Gu Guowei
Published: May 2008

This paper evaluates the effects of the pipeline retention time in sewer systems and the dilution by stormwater runoff on COD fractions and kinetic parameters of samples from two large‐scale wastewater treatment plants (WWTPs) fed with combined sewers, one collected from adjacent residential areas (Sewer Q) and the other undergoing long pipeline transportation (Sewer B). With four batch tests, COD fractions and kinetic parameters of two sewers were obtained by numerical computation based on activated sludge models (ASMs) modified by a dual hydrolysis mechanism. Long pipeline transportation significantly influenced the content and existence of heterotrophic biomass fractions in sewers, and the percentage of the fraction in Sewer B (17%) was higher than that in Sewer Q (9%). Compared with Sewer Q, long pipeline retention also resulted in lower concentrations of hydrolysable fractions and particulate inert COD in Sewer B, as well as an increase in the hydrolysis rate coefficient of particulate hydrolysable COD from 0.90 day−1 in Sewer Q to 1.83 day−1 in Sewer B. Results of samples from Sewer B during a typhoon event showed high variations of COD fractions and parameters, indicating the necessity for COD fractionation and parameter calibration before applying ASMs to wet weather cases. Copyright © 2008 Society of Chemical Industry
Preoperative sonography of nonreducible inguinal masses in girls
Authors: Narcı Adnan , Korkmaz Mevlit , Albayrak Ramazan , Sözübir Selami , Güvenç Bekir Haluk , Köken Reşit , Demir Tevfik , Doğru Ömer
Published: May 2008

Purpose.

Inguinal hernia is one of the most common surgical pathologies in childhood. Any of the abdominal organs can slide into the hernial sac and become incarcerated there. In girls, the fallopian tubes, ovaries, uterus, and—rarely—ovarian cysts can form the sliding component of an inguinal hernia. The aim of this study was to investigate the diagnostic value of preoperative sonographic examination in girls with nonreducible inguinal masses.

Methods.

Nine girls ranging in age from 2 months to 8 years who were admitted to our clinic with nonreducible inguinal masses were included in the study. All patients underwent sonographic examination followed by surgery on the day of admission.

Results.

A definitive diagnosis was obtained in 6 patients on preoperative sonographic evaluation, whereas 3 patients were misdiagnosed. One patient was diagnosed sonographically as having lymphadenopathy, but surgery revealed an ovarian cyst sliding into the hernial sac. A second patient was found to have an infected lymph node at surgery instead of a strangulated bowel loop as diagnosed on sonographic examination. In the third patient, the preoperative sonographic diagnosis was an ovarian cyst in the hernia sac, but surgery revealed a cyst of the canal of Nuck.

Conclusion.

Inguinal masses in young girls must be carefully evaluated, because the sonographic preoperative diagnosis may be misleading. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Prenatal diagnosis of Pentalogy of Cantrell in the first trimester: Is 3‐dimensional sonography needed?
Authors: Peixoto‐Filho Fernando Maia , Carneiro do Cima Luciana , Nakamura‐Pereira Marcos
Published: May 2008

We report the prenatal diagnosis of 2 cases of Pentalogy of Cantrell in the first trimester. In case 1, sonographic evaluation revealed ectopia cordis, omphalocele, and cystic hygroma at 10 weeks' gestation. In case 2, sonographic assessment during the first trimester detected ectopia cordis and omphalocele at 11 weeks' gestation. In both cases, the patient opted for elective pregnancy termination, and Pentalogy of Cantrell was confirmed in 2 male fetuses. We discuss the role of Doppler imaging and 3‐dimensional sonography as complementary methods to conventional sonographic assessment of abdominal wall defects at early pregnancy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Anatomy and histochemistry of hindlimb flight posture in birds. I. The extended hindlimb posture of shorebirds
Authors: McFarland Joshua C. , Meyers Ron A.
Published: May 2008

Birds utilize one of two hindlimb postures during flight: an extended posture (with the hip and knee joints flexed, while the ankle joint is extended caudally) or a flexed posture (with the hip, knee, and ankle joints flexed beneath the body). American Avocets (Recurvirostra americana) and Black‐necked Stilts (Himantopus mexicanus) extend their legs caudally during flight and support them for extended periods. Slow tonic and slow twitch muscle fibers are typically found in muscles functioning in postural support due to the fatigue resistance of these fibers. We hypothesized that a set of small muscles composed of high percentages of slow fibers and thus dedicated to postural support would function in securing the legs in the extended posture during flight. This study examined the anatomy and histochemical profile of eleven hindlimb muscles to gain insight into their functional roles during flight. Contrary to our hypothesis, all muscles possessed both fast twitch and slow twitch or slow tonic fibers. We believe this finding is due to the versatility of dynamic and postural functions the leg muscles must facilitate, including standing, walking, running, swimming, and hindlimb support during flight. Whether birds use an extended or flexed hindlimb flight posture may be related to the aerodynamic effect of leg position or may reflect evolutionary history. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
False‐positive analysis of functional MRI during simulated deep brain stimulation: A phantom study
Authors: Liu Ho‐Ling , Chen Hsin‐Mei , Wu Yu‐Chien , Lim Siew‐Na , Huang Chih‐Mao , Hsu Yuan‐Yu , Wai Yau‐Yau , Wu Tony
Published: May 2008

Purpose

To investigate the false‐positive activations/deactivations in functional MRI (fMRI) of deep brain stimulation (DBS) using a phantom.

Materials and Methods

fMRI experiments were performed on a 1.5T scanner using a single‐shot gradient‐echo echo‐planar imaging (GE‐EPI) sequence (TR/TE/FA = 6000 msec/60 msec/90°) on an agar‐gel phantom inserted with DBS electrodes. During the experimental blocks, two‐second stimuli were delivered during the interscan waiting time (ISWT), which was adjusted by changing the number of slices acquired within the TR (3500 msec with 30 slices and 5160 msec with 10 slices). Data were analyzed using SPM2 software, and the false‐positive voxels were detected with five different P‐value thresholds.

Results

The number of false‐positive voxels in experimental conditions had no significant differences from those in control conditions with either long or short ISWT, which increased with the P‐value threshold from zero at P < 0.0001 to approximately 40 at P < 0.05. The pattern of increasing number of false‐positive reactions along with P‐value was similar between all conditions.

Conclusion

False‐positive findings from fMRI with similar experimental design can be well controlled with a statistical threshold of P < 0.001 or tighter. The short ISWT of 3500 msec did not increase false‐positive reactions compared to the long ISWT of 5160 msec. J. Magn. Reson. Imaging 2008;27:1439–1442. © 2008 Wiley‐Liss, Inc.
Assessment of tumor microcirculation with dynamic contrast‐enhanced MRI in patients with esophageal cancer: Initial experience
Authors: Oberholzer Katja , Pohlmann Andreas , Schreiber Wolfgang , Mildenberger Peter , Kunz Peter , Schmidberger Heinz , Junginger Theodor , Düber Cristoph
Published: May 2008

Purpose

To investigate the feasibility and impact of dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) on tumor characterization and response to radiochemotherapy (RCT) in patients with esophageal cancer.

Materials and Methods

A total of 48 patients underwent DCE‐MRI to assess tumor microcirculation based on a two‐compartment model function. Effects of RCT on kinetic parameters were studied in 12 patients with squamous cell carcinoma.

Results

Tumor microcirculation differs with respect to histological subtype: squamous cell carcinomas showed lower values of amplitude A (leakage space, P = 0.015) and higher contrast agent exchange rates (k21, P = 0.225) compared with adenocarcinomas. RCT led to a significant decrease of the contrast agent exchange rate (P = 0.005), while amplitude A increased moderately after therapy (P = 0.136).

Conclusion

DCE‐MRI is feasible in patients with esophageal cancer, reveals therapeutic effects, and may thus be useful in therapy management and monitoring. J. Magn. Reson. Imaging 2008;27:1296–1301. © 2008 Wiley‐Liss, Inc.
1.0‐M gadobutrol versus 0.5‐M gadoterate for peripheral magnetic resonance angiography: A prospective randomized controlled clinical trial
Authors: Szucs‐Farkas Zsolt , Froehlich Johannes M. , Ulrich Martin , Wuersten Hans‐Ueli , Guignard Dominique , Wyss Sandra , Braunschweig Marianne
Published: May 2008

Purpose

To perform a quantitative and qualitative comparison of gadobutrol and gadoterate in three‐station contrast enhanced magnetic resonance angiography (CE‐MRA) of the lower limbs.

Materials and Methods

In this prospective randomized controlled trial, 52 patients with leg ischemia were randomly assigned to one of two groups receiving either gadobutrol (1.0 mmol Gd/mL, 15 mL) or gadoterate (0.5 mmol Gd/mL, 30 mL). Three‐station 3D CE‐MRAs from the pelvis to the ankles were performed with moving‐table technique on a 1.5T MR scanner. Injection time was identical in both groups. Signal‐to‐noise (SNR) and contrast‐to‐noise ratios (CNR) were calculated for 816 arteries. Contrast quality in 1196 vessel segments was evaluated separately by two blinded readers on a three‐point scale.

Results

Mean SNR (61.8 ± 7.8 for gadobutrol vs. 61.9 ± 9.1 for gadoterate, P = 0.257), CNR (52.8 ± 9.1 vs. 52.8 ± 10.7, P = 0.154), and qualitative ranking (1.41 vs. 1.44, P = 0.21) for all vessels did not differ significantly between the two patient groups. The overall quality was good in 90.4% with gadoterate and 94.2% with gadobutrol (P = 0.462).

Conclusion

High‐concentration gadobutrol allows neither a higher CNR nor any qualitative advantage over the ordinary unspecific Gd agent gadoterate when the same Gd load and injection times are used in multistation CE‐MRA of the peripheral arteries. J. Magn. Reson. Imaging 2008;27:1399–1405. © 2008 Wiley‐Liss, Inc.
Robust GRAPPA reconstruction and its evaluation with the perceptual difference model
Authors: Huo Donglai , Wilson David L.
Published: May 2008

Purpose

To develop and optimize a new modification of GRAPPA (generalized autocalibrating partially parallel acquisitions) MR reconstruction algorithm named “Robust GRAPPA.”

Materials and Methods

In Robust GRAPPA, k‐space data points were weighted before the reconstruction. Small or zero weights were assigned to “outliers” in k‐space. We implemented a Slow Robust GRAPPA method, which iteratively reweighted the k‐space data. It was compared to an ad hoc Fast Robust GRAPPA method, which eliminated (assigned zero weights to) a fixed percentage of k‐space “outliers” following an initial estimation procedure. In comprehensive experiments the new algorithms were evaluated using the perceptual difference model (PDM), whereby image quality was quantitatively compared to the reference image. Independent variables included algorithm type, total reduction factor, outlier ratio, center filling options, and noise across multiple image datasets, providing 10,800 test images for evaluation.

Results

The Fast Robust GRAPPA method gave results very similar to Slow Robust GRAPPA, and showed significant improvements as compared to regular GRAPPA. Fast Robust GRAPPA added little computation time compared with regular GRAPPA.

Conclusion

Robust GRAPPA was proposed and proved useful for improving the reconstructed image quality. PDM was helpful in designing and optimizing the MR reconstruction algorithms. J. Magn. Reson. Imaging 2008;27:1412–1420. © 2008 Wiley‐Liss, Inc.
4D time‐resolved MR angiography with keyhole (4D‐TRAK): More than 60 times accelerated MRA using a combination of CENTRA, keyhole, and SENSE at 3.0T
Authors: Willinek Winfried A. , Hadizadeh Dariusch R. , von Falkenhausen Marcus , Urbach Horst , Hoogeveen R. , Schild Hans H. , Gieseke Jürgen
Published: May 2008

Purpose

To present a new 4D method that is designed to provide high spatial resolution MR angiograms at subsecond temporal resolution by combining different techniques of view sharing with parallel imaging at 3.0T.

Materials and Methods

In the keyhole‐based method, a central elliptical cylinder in k‐space is repeated n times (keyhole) with a random acquisition (CENTRA), and followed by the readout of the periphery of k‐space. 4D‐MR angiography with CENTRA keyhole (4D‐TRAK) was combined with parallel imaging (SENSE) and partial Fourier imaging. In total, a speed‐up factor of 66.5 (6.25 [CENTRA keyhole] × 8 [SENSE] × 1.33 [partial Fourier imaging]) was achieved yielding a temporal resolution of 608 ms and a spatial resolution of (1.1 × 1.4 × 1.1) mm3 with whole‐brain coverage 4D‐TRAK was applied to five patients and compared with digital subtraction angiography (DSA).

Results

4D‐TRAK was successfully completed with an acceleration factor of 66.5 in all five patients. Sharp images were acquired without any artifacts possibly created by the transition of the central cylinder and the reference dataset. MRA findings were concordant with DSA.

Conclusion

4D time‐resolved MRA with keyhole (4D‐TRAK) is feasible using a combination of CENTRA, keyhole, and SENSE at 3.0T and allows for more than 60 times accelerated MRA with high spatial resolution. J. Magn. Reson. Imaging 2008;27:1455–1460. © 2008 Wiley‐Liss, Inc.
Comparison of single‐sequence T1w TFE MRI with multisequence MRI for the quantification of lipid‐rich necrotic core in atherosclerotic plaque
Authors: Cappendijk Vincent C. , Heeneman Sylvia , Kessels Alfons G.H. , Cleutjens Kitty B.J.M. , Schurink Geert Willem H. , Welten Rob J.Th.J. , Mess Werner H. , van Suylen Robert‐Jan , Leiner Tim , Daemen Mat J.A.P. , van Engelshoven Jos M.A. , Kooi M. Eline
Published: May 2008

Purpose

To prospectively determine the accuracy of semiquantitative analysis of the amount of lipid‐rich necrotic core (LRNC) in atherosclerotic plaque using multi‐ as well as single‐sequence T1‐weighted (w) turbo field echo (TFE) MRI. Histology served as a reference standard.

Materials and Methods

Sixty‐four symptomatic patients with carotid stenosis ≥70% were included and underwent endarterectomy after an MRI scan. Two MRI readers classified relative signal intensities in regions of interest in the vessel wall. The amount of LRNC was determined semiquantitatively using an algorithm based on fixed combinations of multiple MR pulse sequences as well as solely based on T1w TFE images. Interreader agreement was expressed by intraclass correlation coefficients (ICCs). Agreement between MRI and histology was determined by linear regression (R).

Results

Interreader reproducibility for quantification of LRNC was high (ICC, 95% confidence interval [CI]): multisequence 0.86 (0.77–0.94), and single sequence 0.91 (0.85–0.95). There was good agreement between MRI and histology for both MR readers for quantification based on multisequence as well as single sequence MRI, 0.80 ≤ R ≤ 0.85 (P < 0.0001).

Conclusion

The amount of LRNC using single‐sequence T1w TFE MRI is a reproducible, accurate, and fast way to quantify LRNC in carotid atherosclerotic plaque. J. Magn. Reson. Imaging 2008;27:1347–1355. © 2008 Wiley‐Liss, Inc.
Characterization of three‐dimensional myocardial deformation in the mouse heart: An MR tagging study
Authors: Zhong Jia , Liu Wei , Yu Xin
Published: May 2008

Purpose

To develop a 3D MR tagging method that combines harmonic phase (HARP) and homogeneous strain analysis methods for quantification of regional myocardial wall motion in mice.

Materials and Methods

3D tagged images were acquired from seven C57BL/6 mice. Intersecting tag points were reconstructed and 3D strains were quantified at apical, midventricular, and basal levels. Circumferential and radial strains quantified with 2D MR tagging were compared with those calculated from 3D tagged images.

Results

Our data showed significant heterogeneity in radial, circumferential, and shear strains. Longitudinal strain was more homogeneous. The circumferential‐longitudinal shear strain, a unitless measure of ventricular torsion, was positive throughout the left ventricle. There were strong correlations between 2D and 3D studies at the basal and midventricular levels.

Conclusion

This work demonstrates the feasibility of 3D characterization of cardiac function in mouse via the combination of HARP and homogeneous strain analysis. J. Magn. Reson. Imaging 2008;27:1263–1270. © 2008 Wiley‐Liss, Inc.
ADC value and diffusion tensor imaging of prostate cancer: Changes in carbon‐ion radiotherapy
Authors: Takayama Yukihisa , Kishimoto Riwa , Hanaoka Shouhei , Nonaka Hiroi , Kandatsu Susumu , Tsuji Hiroshi , Tsujii Hirohiko , Ikehira Hiroo , Obata Takayuki
Published: May 2008

Purpose

To assess the apparent diffusion coefficient (ADC) value and diffusion tensor image (DTI) including fractional anisotropy (FA) of the noncancerous prostate and prostate cancer before and after carbon‐ion radiotherapy (CIRT).

Materials and Methods

Nine patients with biopsy‐proven prostate cancer underwent 1.5T magnetic resonance (MR) examinations. One patient with benign prostatic hypertrophy and one healthy volunteer were also examined as references. The changes in ADC values and DTI of the entire prostate calculated from b‐values of 0 and 700 (s/mm2) were estimated between before and after CIRT.

Results

ADC values of prostate cancer significantly increased after CIRT by paired t‐test (P < 0.01) but those of noncancerous inner gland (IG) and peripheral zone (PZ) showed no significant change. By analysis of variance, significant differences in ADC values were observed among prostate cancer and noncancerous IG and PZ before CIRT (P < 0.05). After CIRT, those significant differences had disappeared. FAs showed no significant differences in any comparisons. DTI showed changes in the direction of the main axis of the tensor in prostate cancer after CIRT.

Conclusion

There were changes in ADC and DTI in prostate cancer after CIRT. They may be useful for monitoring prostatic structural changes under radiotherapy. J. Magn. Reson. Imaging 2008;27:1331–1335. © 2008 Wiley‐Liss, Inc.
Tumor‐liver contrast and subjective tumor conspicuity of respiratory‐triggered T2‐weighted fast spin‐echo sequence compared with T2*‐weighted gradient recalled‐echo sequence for ferucarbotran‐enhanced magnetic resonance imaging of hepatic malignant tumors
Authors: Ishiyama Koichi , Hashimoto Manabu , Izumi Jun‐ichi , Watarai Jiro , Shibata Satoshi , Sato Tsutomu , Yamamoto Yuzo
Published: May 2008

Purpose

To compare respiratory‐triggered T2‐weighted fast spin‐echo (RTT2W‐FSE) and gradient T2*‐weighted recalled‐echo (T2*W‐GRE) images for visualization of malignant hepatic tumors using ferucarbotran‐enhanced magnetic resonance (MR) imaging.

Materials and Methods

Ferucarbotran‐enhanced RTT2W‐FSE and breath‐hold long‐TE 2D‐fast spoiled gradient recalled acquisition in the steady state (FSPGR) images as T2*W‐GRE were used to evaluate 128 malignant hepatic tumors (77 metastases, 37 hepatocellular carcinomas, 14 other) in 62 patients. Tumor‐to‐liver contrast (TLC) was quantitatively compared using the paired Student's t‐test, and the score of lesion conspicuity was qualitatively compared using Wilcoxon's signed rank test.

Results

The mean TLC of RTT2W‐FSE was significantly higher than that of FSPGR (1.10 ± 0.82 vs. 2.54 ± 1.42) in all malignant tumors. The score of lesion conspicuity of RTT2W‐FSE was significantly higher than that of FSPGR (4.84 ± 0.52 vs. 4.52 ± 0.99) in all malignant tumors.

Conclusion

For ferucarbotran‐enhanced MR imaging, compared to FSPGR images, RTT2W‐FSE images provide greater TLC and subjective conspicuity for malignant tumors. J. Magn. Reson. Imaging 2008;27:1322–1326. © 2008 Wiley‐Liss, Inc.
Posttreatment with the Ca2+‐Mg2+‐dependent endonuclease inhibitor aurintricarboxylic acid abolishes genotoxic agent‐induced nuclear condensation and DNA fragmentation and decreases death of astrocytes
Authors: Lu Huafei , Wei Gangwei , Wang Dongmin , Yung Patrick , Ying Weihai
Published: May 2008

DNA fragmentation and nuclear condensation are important nuclear changes in apoptosis. In this study we determined whether DNA fragmentation and nuclear condensation occur in astrocytes treated with 100–200 μM of the genotoxic agent M‐nitroso‐N‐nitroguanidine (MNNG). Our study also investigated the roles of Ca2+‐Mg2+‐dependent endonuclease (CME) in the MNNG‐induced nuclear changes. We found that MNNG induced profound ATP depletion as well as marked nuclear condensation and DNA fragmentation in the cells. Both the nuclear condensation and the DNA fragmentation were abolished by posttreatment of the cells with the CME inhibitor aurintricarboxylic acid (ATA). The ATA posttreatment also significantly, but only partially, decreased MNNG‐induced cell death. In contrast, pretreatment plus cotreatment with ATA did not affect either MNNG‐induced nuclear condensation or cell death. Our study further suggests that ATA does not decrease the cytotoxicity of MNNG by directly inhibiting poly(ADP‐ribose) polymerases. Collectively, our observations suggest that MNNG can induce both DNA fragmentation and nuclear condensation in astrocytes by a CME‐dependent mechanism, which partially contributes to the genotoxic agent‐induced cell death. Published 2008 Wiley‐Liss, Inc.
Evaluation of fungicidal activity of extracellular filtrates of cyanobacteria – possible role of hydrolytic enzymes
Authors: Prasanna Radha , Nain Lata , Tripathi Ravindramani , Gupta Vishal , Chaudhary Vidhi , Middha Sheetal , Joshi Monica , Ancha Radhika , Kaushik Brahma D.
Published: May 2008

A set of seventy axenised and unicyanobacterial isolates belonging to the genus Anabaena were evaluated for biocidal activity against a set of phytopathogenic fungi. Among them, 35 Anabaena strains showed zone of inhibition against one or more fungi. The extracellular filtrates from 4 and 8 weeks old cultures of these Anabaena strains were further evaluated in terms of hydrolytic enzymes, proteins and IAA employing standard methods. Significant differences were also observed among the strains in terms of their FPase, chitosanase and xylanase activity, while low and relatively similar values of CMCase, cellobiase and protease activity were recorded in the strains analyzed. IAA production was also observed in all the strains. Comparative evaluation of activity of hydrolytic enzymes and antifungal activity revealed that such enzymes may contribute to the fungicidal activity of the cyanobacterial strains, besides other bioactive compounds, including IAA, which are established promising traits for biocontrol agents. This study is a first time report on the production of hydrolytic enzymes by these oxygenic photosynthetic prokaryotes, which can be potential candidates for the development of biocontrol agent(s) against selected phytopathogenic fungi. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isolation, characterization of heavy metal resistant strain of Pseudomonas aeruginosa isolated from polluted sites in Assiut city, Egypt
Authors: Hassan S. H. A. , Abskharon R. N. N. , Gad El‐Rab S. M. F. , Shoreit A. A. M.
Published: May 2008

Sixty six isolates of Pseudomonas spp. were isolated from wastewater of El‐Malah canal located in Assiut, Egypt and were checked for their heavy metal tolerance. One isolate has tested for its multiple metal resistances and found to be plasmid mediated with molecular weight 27 Kb for nickel and lead. It was identified as Pseudomonas aeruginosa ASU 6a. Its minimal inhibitory concentration (MIC) for Cu2+, Co2+, Ni2+, Zn2+, Cr3+, Cd2+and Pb2+ were 6.3, 5.9, 6.8, 9.2, 5.8, 4.4, and 3.1 mM, respectively. Growth kinetics and the maximum adsorption capacities were determined under Ni2+ and Pb2+ stress. The latter heavy metals induced potassium efflux and were used as indicator for plasma membrane permeabilization. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production of an extracellular thermohalophilic lipase from a moderately halophilic bacterium, Salinivibrio sp. strain SA‐2
Authors: Amoozegar Mohammad Ali , Salehghamari Ensieh , Khajeh Khosro , Kabiri Mahbube , Naddaf Saied
Published: May 2008

Fifty strains of moderately halophilic bacteria were isolated from various salty environments in Iran. A strain designated as SA‐2 was shown to be the best producer of extracellular lipase and was selected for further studies. Biochemical and physiological characterization along with 16S rDNA sequence analysis placed SA‐2 in the genus Salinivibrio. The optimum salt, pH, temperature and aeration for enzyme production were 0.1 M KCl, pH 8, 35 °C and 150 rpm, respectively. The enzyme production was synchronized bacterial growth and reached a maximum level during the early‐stationary phase in the basal medium containing 1 M NaCl. Triacylglycerols enhanced lipase production, while carbohydrates had inhibitory effects on it. The maximum lipase activity was obtained at pH 7.5, 50 °C and CaCl2 concentration of 0.01 M. The enzyme was stable at pH range of 7.5–8 and retained 90% of its activity at 80 °C for 30 min. Different concentrations of NaNO3, Na2SO4, KCl and NaCl had no affect on lipase stability for 3 h. These results suggest that the lipase secreted by Salinivibrio sp. strain SA‐2 is industrially important from the perspective of its tolerance to a broad temperature range, its moderate thermoactiviy and its high tolerance to a wide range of salt concentrations (0–3 M NaCl). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prehistoric rock crystal artefacts from Lower Silesia (Poland)
Authors: Sachanbiński M. , Girulski R. , Bobak D. , Łydżba‐Kopczyńska B.
Published: May 2008

The analysis of inclusions utilising optical methods and micro‐Raman spectroscopy was used to address a question of provenance of prehistoric rock‐crystal artefacts excavated in Lower Silesia (SW Poland). The nature and spectroscopic features of inclusions in rock crystal from three Lower Silesian deposits were established and compared with the ones identified in the rock‐crystal artefacts. A characteristic inclusion assemblage in rock crystal from the Jegłowa–Krzywina deposit consists of anatase, kaolinite, and chlorite. Quartz from granitic pegmatites of the Jelenia Góra Valley displays the presence of dusty hematite coating. Frequent inclusions of goethite are typical of rock crystal from cavities in volcanic rocks near Kłodzko. The study established that raw material used to manufacture 16 of the artefacts investigated comes from the Jegłowa–Krzywina quartz deposit. One tool was made of the material obtained from granitic pegmatites that occur near Karpniki (Jelenia Góra Valley). Two other artefacts contain inclusions not found in crystals from any of the investigated Lower Silesian deposits. Copyright © 2008 John Wiley & Sons, Ltd.
Anti‐influenza virus activity of extract of Japanese wasabi leaves discarded in summer
Authors: Mochida Kyo , Ogawa Tetsuro
Published: May 2008

BACKGROUND: Japanese wasabi (Wasabia japonica) is now habitually used as a spice in some kinds of Japanese foods, and its pungent taste and flavor are preferred. Generally, rhizomes and winter leaves are used as a spice and for processed foods such as pickled wasabi. Since the leaf area of summer leaves is far greater than that of winter leaves, they are not used for food, and are discarded. Thus, we need to develop an effective use for summer leaves. We investigated anti‐influenza virus activity in these summer leaves as a new function.

RESULTS: Seventy percent ethanol extracts of leaves harvested in July exhibited a high replication inhibition rate (98% or higher) in the type A strain (AH1N1, A/shimane/48/2002), its subtype (AH3N2, A/shimane/122/2002), and type B strain (B/shimane/2/2002). The extracts of summer leaves exhibited the same anti‐influenza virus activity as winter leaves, and showed a stronger activity than stems, roots, and rhizomes.

CONCLUSION: A potent anti‐influenza virus activity was discovered in summer leaves of Japanese wasabi. The ethanol extracts inhibited influenza virus replication regardless of the hemagglutinin antigen type. Therefore, such extracts are expected to be a promising source of a novel anti‐influenza virus agent. Copyright © 2008 Society of Chemical Industry
Effects of amounts of HMW glutenin subunits determined by capillary electrophoresis on technological properties in wheat doubled haploids
Authors: Salmanowicz Bolesław P , Surma Maria , Adamski Tadeusz , Rębarz Michał
Published: May 2008

BACKGROUND: Knowledge of the types and amounts of individual HMW glutenin subunits (HMW‐GS) is important for predicting technological quality. In this study, 228 wheat doubled haploids were compared in respect of HMW‐GS composition, seed protein content, flour yield, rheological properties of dough, and loaf properties. The quantitative and qualitative composition of particular HMW‐GS was determined by CE. The relative amounts of x‐type and y‐type subunits encoded by individual Glu‐1 loci were considered.

RESULTS: The results show that the amounts of some pairs x + y of HMW‐GS are correlated with technological properties. The importance of quantities of particular pairs of HMW‐GS for technological values depends on allele compositions in all the Glu‐1 loci. Positive correlation was found between the amount of subunits Ax1, Ax2*, Bx7 + By8 or Dx5 + Dy10 and loaf volume (r = 0.215–0.618, P < 0.05). The influence of an increasing amount of Ax1 was positively correlated with dough softening (r = 0.451, P < 0.01) and negatively with dough development time (r = − 0.209, P < 0.05) and stability (r = − 0.351, P < 0.01), whereas for subunit Ax2* these associations were opposite.

CONCLUSION: The results confirm the occurrence of epistatic interactions between alleles of Glu‐1 loci. The effects of amounts of HMW subunits on bread‐making quality should be considered only within glutenin subunit compositions. Copyright © 2008 Society of Chemical Industry
Photopolymerized Injectable RGD‐Modified Fumarated Poly(ethylene glycol) Diglycidyl Ether Hydrogels for Cell Growth
Authors: Akdemir Z. Seden , Akçakaya Handan , Kahraman M. Vezir , Ceyhan Taşkın , Kayaman‐Apohan Nilhan , Güngör Atilla
Published: May 2008

In this study, photopolymerized hydrogels of fumarated poly(ethylene glycol) diglycidyl‐co‐ poly(ethylene glycol) diacrylate have been synthesized and modified with cell adhesion peptide, Arg‐Gly‐Asp (RGD). The structural and mechanical properties of the hydrogels are found to be poly(ethylene glycol) diacrylate (PEGDA) dependent. The percentage of gelation is increased from 72 to 89 wt.‐% when the amount of the crosslinker co‐monomer (PEGDA) in the hydrogel formulation is increased from 20 to 40 wt.‐%. In the present case, the equilibrium mass swelling is decreased from 216 to 93%. The viscosities of the uncured formulations have also been measured and likewise, the results were influenced by the increasing amount of PEGDA that reduced the value from 83 to 36 cP. The compressive modulus of the prepared hydrogels was improved with the addition of the PEGDA. Cell growth experiments have been performed by comparing the properties of the hydrogels with and without RGD units. The results show that RGD units enhance the adhesion of cells to the surface of the hydrogels. SEM‐EDS studies reveal that nitrogen and calcium are produced on the osteoblast‐seeded surface of the scaffold within the culture time period.

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Synthesis of Fluorescent Polyisoprene Nanoparticles and their Uptake into Various Cells
Authors: Lorenz Myriam R. , Kohnle Maria‐Verena , Dass Martin , Walther Paul , Höcherl Anita , Ziener Ulrich , Landfester Katharina , Mailänder Volker
Published: May 2008

Fluorescent polyisoprene nanoparticles were synthesized by the miniemulsion technique as marker particles for cells. The uptake of the non‐functionalized polyisoprene nanoparticles, without any transfection agents, into different adherent (HeLa) and also suspension (Jurkat) cell lines is strikingly efficient and fast compared to other polymeric particles, and leads to high loading of the cells. The intracellular polyisoprene particles are localized as single particles in endosomes distributed throughout the entire cytoplasm. The uptake kinetics shows that particle internalization starts during the first minutes of incubation and is finished after 48 h of incubation. Since (unfunctionalized) polystyrene particles show a comparable, low uptake behavior in cells, the uptake rates can be tuned by the amount of polystyrene in polyisoprene/polystyrene copolymer particles. As polyisoprene nanoparticles are internalized by different cell lines that are relevant for biomedical applications, they can be used to label these cells efficiently if a marker is incorporated in the particles. As polyisoprene is not or is hardly biodegradable the particles should be suited for long‐term applications.

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Fibrinolytic Poly(dimethyl siloxane) Surfaces
Authors: Chen Hong , Wang Liang , Zhang Yanxia , Li Dan , McClung W. Glenn , Brook Michael A. , Sheardown Heather , Brash John L.
Published: May 2008

PDMS surfaces have been modified to confer both resistance to non‐specific protein adsorption and clot lyzing properties. The properties and chemical compositions of the surfaces have been investigated using water contact angle measurements, ATR FT‐IR spectroscopy, and XPS. The ability of the PEG component to suppress non‐specific protein adsorption was assessed by measurement of radiolabeled fibrinogen uptake from buffer. The adsorption of plasminogen from human plasma to the various surfaces was studied. In vitro experiments demonstrated that lysine‐immobilized surfaces with free ε‐amino groups were able to dissolve fibrin clots, following exposure to plasma and tissue plasminogen activator.

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Poly(glycerol sebacate) Nanofiber Scaffolds by Core/Shell Electrospinning
Authors: Yi Feng , LaVan David A.
Published: May 2008

The novel biomaterial poly(glycerol sebacate) (PGS) holds great promise for tissue engineering and regenerative medicine. PGS is a rubbery, degradable polymer much like elastin; however, it has been limited to cast structures. This work reports on the formation of PGS nanofibers in random non‐woven mats for use as tissue engineering scaffolds by coaxial core/shell electrospinning. PGS nanofibers are an inexpensive and synthetic material that mimics the chemical and mechanical environment provided by elastin fibers. Poly(lactide) was used as the shell material to constrain the PGS during the curing process and was removed before cell seeding. Human microvascular endothelial cells from skin (HDMEC) were used to evaluate the in‐vitro cellular compatibility of the PGS nanofiber scaffolds.

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Macromol. Chem. Phys. 11/2008
Authors: Losio Simona , Boccia Antonella C. , Sacchi Maria Carmela
Published: May 2008

Cover: Ethylene/4‐methyl‐1‐pentene copolymers were synthesized by [Me2Si(η5‐Me4C5)‐(η1‐N‐tBu)TiCl2] and MAO catalyst and analyzed by 13C NMR. The set of assignments so far available was remarkably improved, as can be seen on the cover: in particular, all the sequences containing regio‐ and stereoerrors have been assigned for the first time. Further details can be found in the article by S. Losio, A. C. Boccia, and M. C. Sacchi* on page 1115.
Modification of Polymer Surfaces by Click Chemistry
Authors: Fleischmann Sven , Hinrichs Karsten , Oertel Ulrich , Reichelt Senta , Eichhorn Klaus‐Jochen , Voit Brigitte
Published: May 2008

Silicon substrates were coated with well‐defined glycidyl and alkyne groups containing terpolymer that was synthesized by NMRP. The polymer was successfully tethered on silicon wafers and the resulting solvent stable, homogeneous, smooth thin films were characterized by means of atomic force microscopy (AFM), spectroscopic ellipsometry in the visible (Vis), and infrared (IR) spectral range. Subsequently, the films were modified in a heterogeneous reaction, converting the alkyne groups of the surface efficiently and quantitatively with azides by click chemistry. Appropriate film analysis allowed to directly verify the reaction of the alkyne groups with the azides and revealed that the chemical and physical properties of the thin films have changed while their morphology and topography is preserved.

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Broadband Dielectric Relaxation Spectroscopy in Polymer Nanocomposites
Authors: Pissis Polycarpos , Fragiadakis Daniel , Kanapitsas Athanasios , Delides Kostas
Published: May 2008

Summary: Dielectric spectroscopy in the frequency domain and thermally stimulated depolarization currents techniques, covering together a broad frequency range (10−4–109 Hz), were employed to investigate molecular dynamics in relation to structure and morphology in polymeric nanocomposites. Several systems were investigated, three of them with the same epoxy resin matrix and different inclusions (modified smectite clay, conducting carbon nanoparticles and diamond nanoparticles) and two with silica nanofiller (styrene‐butadiene rubber/silica and polyimide/silica nanocomposites). Special attention was paid to the investigation of segmental dynamics associated with the glass transition of the polymer matrix, in combination also with differential scanning calorimetry measurements. Effects of nanoparticles on local (secondary) relaxations and on the overall dielectric behavior were, however, also investigated. Several interesting results were obtained and discussed for each of the particular systems. Two opposite effects seem to be common to the nanocomposites studied and dominate their behavior: (1) immobilization/reduction of mobility of a fraction of the chains at the interface to the inorganic nanoparticles, due to chemical or physical bonds with the particles, and (2) loosened molecular packing of the chains, due to tethering and geometrical confinement, resulting in an increase of free volume and of molecular mobility.
Temperature Effect on Drying and Swelling of Kappa Carrageenan Gels: A Steady State Fluorescence Study
Authors: Tarı Ozlem , Pekcan Onder
Published: May 2008

Summary: A novel technique based on in situ steady state fluorescence (SSF) measurements is introduced for studying drying and swelling of κ‐ carrageenan (kappa carrageenan) gels at various temperatures. κ‐ carrageenan gels were completely dried and then swelled in water vapor. Pyranine was embedded in κ‐ carrageenan and used as a fluorescence probe. Scattered light intensities, Isc and fluorescence intensities, I were monitored during the drying and swelling of κ‐ carrageenan gels. It was observed that the fluorescence intensity decreased linearly as drying time was increased. A simple model consisting of Case II diffusion was used to quantify the drying processes of the κ‐ carrageenan gels. This moving boundary model provided packing constant, k0. During swelling, fluorescence intensity increased exponentially as time is increased. The increase in I, was modeled using Li‐Tanaka equation from which swelling time constants, τc and cooperative diffusion coefficients, Dc were determined. It was observed that swelling time constants, τc decreased and diffusion coefficients, Dc increased as the swelling temperature was increased. Activation energies for drying and swelling were also obtained and found to be 53.9 and 47.2 kJ mol−1, respectively.
Vibrational Dynamics of Polyaniline Pernigraniline Base Form: A Conducting Polymer
Authors: Mishra Abhishek Kumar , Tandon Poonam , Gupta V. D.
Published: May 2008

Summary: Polyaniline is unique among conducting polymers in that its electrical properties can be reversibly controlled both by the oxidation state of the main chain and by protonation. In the present communication we report normal modes and their dispersion in polyaniline pernigraniline base (PANI PNB) form using Urey ‐ Bradely force field which in addition to valence force field accounts for the non‐bonded interactions in the gem and cis configurations and tension terms. Some of the distinguished features of the dispersion curves such as cross‐over and Von Hove type of singularities are discussed and possible explanations are given in terms of symmetry considerations. Several new assignments, which are missing in earlier work, are reported.
ESR ‐ Spin Probe Method in Studying Natural Rubber: an Effect of the Probe Incorporation Temperature
Authors: Didović Mirna , Klepac Damir , Valić Srećko
Published: May 2008

Summary: Natural rubber (NR) latex containing 62 wt.% of solid phase was dried by evaporating the liquid phase at room temperature. 4‐hydroxy‐2,2,6,6‐tetramethyl‐ piperidine‐1‐oxyl free radical, used as the spin probe, was incorporated into the NR matrix by swelling the samples in toluene probe solution at 4 °C, 24 °C and 37 °C. The probe incorporation temperatures were constant for each set of samples. When the solvent was slowly removed, all samples were annealed at 60 °C during 72 hours. Composite ESR spectra observed in the vicinity of T5mT show a significant influence of the probe incorporation temperature on the spectral shape. More precisely, the amount of the broad component in a composite ESR spectrum increases with the increasing probe incorporation temperature. A simple model which describes the probe distribution inside the inhomogeneous NR matrix is proposed.
Micro Raman Spectroscopy of Silica Nanoparticles Treated with Aminopropylsilanetriol
Authors: Volovšek V. , Furić K. , Bistričić L. , Leskovac M.
Published: May 2008

Summary: Micro Raman spectroscopy was used to investigate the structures formed at the surface of amorphous pirogenic silica Aerosil 200. Nanoparticles were treated with 25% water solution of aminopropylsilanetriol and dried in laboratory atmosphere and under vacuum of about 5 mbar. Spectra of pure silica nanoparticles and treated nanoparticles were recorded in the frequency range 20–1700 cm−1 and 2500–3800 cm−1. Comparative analysis reveals the existance of different structures formed at the surface of silica nanoparticles depending on drying conditions.
Thermal Degradation of Poly(ε‐caprolactone), Poly(L‐lactic acid) and their Blends with Poly(3‐hydroxy‐butyrate) Studied by TGA/FT‐IR Spectroscopy
Authors: Vogel Christian , Siesler Heinz W.
Published: May 2008

Summary: The thermal degradation behavior of poly(ε‐caprolactone) (PCL) and poly(L‐lactic acid) (PLA) have been studied in different environment. It was found that these polymers undergo completely different degradation processes in nitrogen and oxygen atmosphere. In oxygen environment PCL and PLA mainly decompose to CO2, CO, water and short‐chain acids. In nitrogen atmosphere PCL releases 5‐hexenioc acid, CO2, CO and ε‐caprolactone, whereas PLA decomposes to acetaldehyde, CO2, CO and lactide. The polymer blends of poly(3‐hydroxybutyrate) (PHB) with PCL and PLA decompose similar to the individual homopolymers with crotonic acid as the initial decomposition product of PHB.
In situ ATR‐FTIR Spectroscopy of Poly(ethylene terephthalate) Subjected to High‐Temperature Methanol
Authors: Andanson Jean‐Michel , Kazarian Sergei G.
Published: May 2008

Summary: In situ ATR‐FTIR (attenuated total reflection Fourier transform infrared) spectroscopy combined with a high‐pressure cell has been applied to measure IR spectra of polymers subjected to superheated or near‐critical methanol (100– 200 °C). Spectra of poly(ethylene terephthalate) (PET) have been measured under exposure to high temperature methanol using this ATR‐FTIR approach to understand at a molecular level the recycling process of PET. The evolution of the structure and the morphology of the polymer has been studied during the methanolysis. The quantity of trans PET conformer is generally used as a tracer of the crystallinity of PET. During depolymerisation of PET the evolution of crystallinity and of trans conformer appears to be different. The dependence of the rate constant on reaction temperature was correlated by Arrhenius plot, which shows activation energy of 5.8 kJ/mol.
Infrared Intensity Studies in Fluorinated Macromolecules
Authors: Radice S. , Canil G. , Toniolo P. , Guarda P.A. , Petricci S. , Milani A. , Tommasini M. , Castiglioni C. , Zerbi G.
Published: May 2008

Summary: Functionalized perfluoropolyethers are investigated by infrared spectroscopy with the aim to give a quantitative estimate of the carboxylic acid groups species; since hydrogen bonded moieties have been observed, also the relative distribution of the associated species has been determined. The study is based both on measured and on theoretically predicted infrared intensities, as obtained by density functional theory (DFT) calculations on model systems.