bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between polarity of template hydrogel and nanoporous structure replicated in sol–gel‐derived silica matrix
Authors: Kurumada K. , Suzuki A. , Baba S. , Otsuka E. 
Published: August 2009

AbstractWe replicated the nanoscopic network structure of acrylamide series hydrogels in silica matrix. In the replication, the mutual affinity of the template polymeric species to sol–gel‐derived silica matrix significantly affects the replicated porous structure formed in the silica matrix. In this work, we intended to fabricate nanoscopic replicas of hydrogels of acrylamides with various hydrophobic end groups. First, the alcoxy silane, tetraethylorthosilicate (TEOS) was hydrolyzed with the template hydrogel. Subsequently, the nanoporous silica solid structure was obtained by removing the hydrogel by calcination in air at 600°C. The nanoscopic structure of those replicas was estimated by transmission electron microscopy (TEM) and nitrogen adsorption/desorption at 77 K. Basically, the nanoscopic replication was possible using the examined hydrogels of polyacrylamides. As the template hydrogel became more nonpolar, the size of the nanopores in the silica replica increased. Thus, the contrast in the polarity between the template hydrogel and silica matrix leads to the enhanced driving force for the mutual segregation or phase separation to occur. The replicated nanoporous structure is considered as a type of a transient structure arrested on the way to the completion of the phase separation of the template polymeric species from the silica matrix. Therefore, the larger contract in the polarity between the structure directing hydrogel and solid matrix lead to the formation of the larger nanopores because of the enhancement in the driving force toward the segregation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of organically modified nanoclay on the performance of pineapple leaf fiber‐reinforced polypropylene nanocomposites
Authors: Biswal Manoranjan , Mohanty Smita , Nayak Sanjay K. 
Published: August 2009

AbstractPolypropylene/Pine apple leaf fiber (PP/PALF)‐reinforced nanocomposites were fabricated using melt blending technique in a twin‐screw extruder (Haake Rheocord 9000). Variation in mechanical properties, crystallization behavior, water absorption, and thermal stability with the addition of nanoclay in PP/PALF composites were investigated. It was observed that the tensile, flexural, and impact properties of PP increase with the increase in fiber loading from 10 to 30 wt %. Composites prepared using 30 wt % PALF and 5 wt % MA‐g‐PP exhibited optimum mechanical performance with an increase in tensile strength to 31%, flexural strength to 45% when compared with virgin PP. Addition of nanoclay results in a further increase in tensile and flexural strength of PP/PALF composites to 20 and 24.3%, which shows intercalated morphology. However, addition of nanoclay does not show any substantial increase in impact strength when compared with PP/PALF composites. Dynamic mechanical analysis tests revealed an increase in storage modulus (E′) and damping factor (tan δ), confirming a strong influence between the fiber/nanoclay and MA‐g‐PP. Differential scanning calorimetry, thermogravimetric analysis thermograms also showed improved thermal properties when compared with the virgin matrix. TEM micrographs also showed few layers of agglomerated clay galleries along with mixed nanomorphology in the nanocomposites. Wide angle X‐ray diffraction studies indicated an increase in d‐spacing from 22.4 Å in Cloisite 20A to 40.1 Å in PP/PALF nanocomposite because of improved intercalated morphology. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and mechanical properties of diimide‐hydrogenated natural rubber vulcanizates
Authors: Arayapranee Wanvimon , Rempel Garry L. 
Published: August 2009

AbstractHydrogenated natural rubber (HNR), providing an ethylene–propylene alternating copolymer, was prepared by the chemical modification of natural rubber latex (NRL) using diimide generated from hydrazine (N2H4) and hydrogen peroxide (H2O2), with copper sulfate (CuSO4) as catalyst. 1H‐NMR analysis indicated that 48% hydrogenation was performed with a mole ratio of N2H4/double bonds = 4 and H2O2/N2H4 = 1.5 at 50°C for 7 h. The obtained HNR was subjected to a sulfur cure by using a conventional milling process. The cure characteristics, mechanical properties before and after heat aging, and abrasion and ozone resistances of HNR vulcanizate were examined and compared with those of natural rubber (NR), ethylene propylene diene terpolymer (EPDM) and 50 : 50 NR/EPDM vulcanizates. The results indicated that the cure rate of 48% HNR showed no significant change when compare to both NR and 50 : 50 NR/EPDM blends, and offered a better processing advantage over EPDM. The mechanical properties and abrasion resistance of a 48% HNR vulcanizate were comparable to those of a NR vulcanizate. Additionally, its heat and ozone resistances were better than those of NR vulcanizate, due to a reduction in the amount of double bonds in the backbone chain. Thus, hydrogenation of NR can lead to a type of rubber that has improved heat and ozone resistances while still maintaining its good mechanical properties. Consequently, it improves the properties of NR for a wide range of applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Learning to lead: Self‐ and peer evaluation of team leaders in the human structure didactic block
Authors: Chen Laura P. , Gregory Jeremy K. , Camp Christopher L. , Juskewitch Justin E. , Pawlina Wojciech , Lachman Nirusha 
Published: August 2009

AbstractIncreasing emphasis on leadership in medical education has created a need for developing accurate evaluations of team leaders. Our study aimed to compare the accuracy of self‐ and peer evaluation of student leaders in the first‐year Human Structure block (integrated gross anatomy, embryology, and radiology). Forty‐nine first‐year medical students at Mayo Medical School were assigned to learning teams of three or four members. Teams worked together on daily laboratory dissection, clinical projects, embryology presentations, and daily group quizzes. Student team leaders were responsible for leading laboratory dissection, reviewing radiographic findings, and organizing group assignments. Weekly electronic surveys were administered to evaluate team leaders on altruism, compassion, respect, integrity, responsibility, commitment to excellence, and self‐reflection. Results demonstrated that team leaders rated themselves lower than their peers rated them in multiple aspects of leadership. Peer evaluation of team leaders was statistically higher than self‐evaluation in all traits measured except respect. Female leaders were rated higher by their peers in the areas of responsibility and self‐reflection compared to male leaders. This study demonstrates the need for increased communication between team leaders and members, along with creation of a mutually respectful environment, to improve leader awareness of their abilities and foster team success. Anat Sci Educ 2:210–217, 2009. © 2009 American Association of Anatomists.
Regulation of GCL activity and cellular glutathione through inhibition of ERK phosphorylation
Authors: Chen Zhi‐Hua , Saito Yoshiro , Yoshida Yasukazu , Niki Etsuo , Noguchi Noriko 
Published: August 2009

AbstractExtracellular signal‐regulated protein kinase (ERK), one of the mitogen‐activated protein kinase, has been known to be involved in diverse cellular functions. In this work, we found that basically inhibition of this kinase in cultured cells markedly increased the γ‐glutamate‐cysteine ligase (GCL; EC 6.3.2.2) activity, but without any considerable induction of the GCL genes. The increased GCL activity consequently elevated the cellular GSH level and eventually enhanced the cellular antioxidant capacity. Genetic inhibition of B‐Raf, the upstream of ERK, also resulted in increased GCL activity and GSH level. Recent evidence also suggests that chronic pro‐oxidant exposure results in the loss of ERK phosphorylation in vivo. Therefore, the findings in the present study suggest that inhibition of B‐Raf/MEK/ERK pathway might be a promising physiological approach to up‐regulate GCL activity and GSH. This study would also help us to understand the comprehensive role of the Raf/MEK/ERK pathway in overall physio/pathological conditions.
Effect of quercetin on oxidative nuclear and mitochondrial DNA damage
Authors: Potenza Lucia , Calcabrini Cinzia , De Bellis Roberta , Mancini Umberto , Cucchiarini Luigi , Dachà Marina 
Published: August 2009

AbstractQuercetin is a well‐investigated antioxidant known to protect cells against oxidative nuclear DNA damage. There is no knowledge regarding its effect on oxidative mitochondrial DNA damage. In this study we investigated the effect of quercetin on oxidatively‐injured DNA. Cell‐free and cell studies were performed. Cell‐free analyses carried out on plasmidic DNA showed that quercetin protects from all oxidative challenges used. Cellular studies were carried out on NCTC 2544 cells which were insulted with hydrogen peroxide and UVC radiations. Nuclear and mitochondrial DNAs were analysed by measuring DNA damage with a quantitative polymerase chain reaction. Quercetin supplementation showed significant genoprotective activity on mitochondrial DNA when hydroperoxide was used. The evidence of the protection afforded by quercetin suggests that this flavonoid may play an important role on mitochondrial genome stability.
Inhibition of cellular invasive parameters in influenza A virus‐infected MDCK and vero cells by a nutrient mixture
Authors: Roomi M.W. , Jariwalla R.J. , Kalinovsky T. , Roomi N. , Niedzwiecki A. , Rath M. 
Published: August 2009

AbstractInfluenza, a long‐standing common infection, poses a serious health problem causing significant morbidity and mortality, and imposing substantial economic costs. To date there are no effective antiviral therapies. A unique nutrient mixture (NM), containing lysine, proline, ascorbic acid, green tea extract, N‐acetyl cysteine and selenium among other micro nutrients, has been shown to exert a wide range of biochemical and pharmacological effects, among them anti‐carcinogenic and anti‐atherogenic activity both in vitro and in vivo. In a previous study, NM was found to significantly inhibit influenza virus A associated neuraminidase enzyme as well as production of NP antigen in a dose‐dependent manner. Influenza virus A not only infects pulmonary areas, but also manifests in extrapulmonary areas, which require basement membrane disruption by matrix metalloproteinases capable of degrading collagen type IV. This prompted us to study the effect of NM on cellular invasive parameters of virus‐infected and non‐infected MDCK and Vero cells. NM inhibited extracellular invasive parameters such as MMP‐2 and MMP‐9 secretion and Matrigel invasion. Results indicated that the relatively non‐toxic nutrient mixture tested in this investigation has potential in influenza treatment by not only decreasing viral multiplication in infected cells but also by blocking the enzymatic degradation of the extracellular matrix.
Expression of ß‐carotene 15,15′‐monooxygenase gene and retinol status in type 2 diabetic Goto‐kakizaki rats
Authors: Takitani Kimitaka , Miyazaki Hiroshi , Takaya Ryuzo , Tamai Hiroshi 
Published: August 2009

AbstractThe vitamin A status has been studied in type 2 diabetes and it is known that plasma retinol levels of patients with type 2 diabetes are elevated. However, the details of vitamin A metabolism in type 2 diabetes are unclear. ß‐Carotene exhibits biological activity as provitamin A and ß‐carotene 15,15′‐monooxygenase (BCM) cleaves ß‐carotene to form retinal. We studied BCM gene expression in type 2 diabetic Goto‐Kakizaki (GK) rats.BCM gene expression was analyzed in the liver, intestine, and testis of 8‐ and 13‐week‐old GK rats and Wistar rats (control). The plasma and liver retinol levels were measured, and plasma retinol‐binding protein (RBP) was detected. BCM gene expression in the liver, intestine and testis of GK rats was increased compared with that in controls. Plasma retinol levels and RBP levels were increased in GK rats, but hepatic retinol levels did not differ between GK rats and controls. BCM gene expression in the liver and intestine might affect retinol levels in type 2 diabetes. Conversion of ß‐carotene to retinal might be accelerated in the presence of insulin resistance status, so that plasma retinol levels are increased in type 2 diabetes.
Effects of a nutrient mixture on infectious properties of the highly pathogenic strain of avian influenza virus A/H5N1
Authors: Deryabin Petr G. , Lvov Dmitry K. , Botikov Andrey G. , Ivanov Vadim , Kalinovsky Tatiana , Rath Matthias , Niedzwiecki Aleksandra 
Published: August 2009

AbstractNumerous outbreaks of avian influenza virus infection (A/H5N1) have occurred recently, infecting domestic birds, chicken and ducks. The possibility of the emergence of a new strain of influenza virus capable of causing a pandemic in humans is high and no vaccine effective against such a strain currently exists. A unique nutrient mixture (NM), containing lysine, proline, ascorbic acid, green tea extract, N‐acetyl cysteine, selenium among other micro nutrients, has been shown to exert a wide range of biochemical and pharmacological effects, including an inhibitory effect on replication of influenza virus and HIV. This prompted us to investigate the potential anti‐viral activity of a nutrient mixture (NM) and its components on avian influenza virus A/H5N1at viral dosages of 1.0, 0.1 and 0.01 TCID50. Antiviral activity was studied in cultured cell lines PK, BHK‐21, and Vero‐E6. Virus lysing activity was determined by co‐incubation of virus A/H5N1 with NM for 0–60 min, followed residual virulence titration in cultured SPEV or BHK‐21 cells. NM demonstrated high antiviral activity evident even at prolonged periods after infection. NM antiviral properties were comparable to those of conventional drugs (amantadine and oseltamivir); however, NM had the advantage of affecting viral replication at the late stages of the infection process.
Insulin like growth factor‐1 and insulin like growth factor binding proteins in the cerebrospinal fluid and serum from patients with Alzheimer's disease
Authors: Salehi Zivar , Mashayekhi Farhad , Naji Mohammad 
Published: August 2009

AbstractInsulin like growth factor‐1 (IGF‐1) is ubiquitously expressed growth factor that has profound effects on the growth and differentiation of many cell types and tissues, including cells of the central nervous system (CNS). IGF‐1 is produced by a wide variety of cells and is found in many biological fluids including cerebrospinal fluid (CSF). IGF‐1 plays important role during CNS development and repair. IGF‐1 has broad range neuroprotective effects and is a therapeutic candidate for Huntington's disease (HD). IGF‐1 protects striatal neurons from the toxicity of mutated Huntington in vitro and improves neuronal survival in vivo in a phenotypic model of HD. Alzheimer's disease (AD) is an age‐dependent dementia characterized by progressive loss of cognitive functions and by characteristic pathological changes in the brain: the formation of aggregates extracellularly by ß‐amyloid (AB) peptide and intracellularly by tau proteins. Since cerebrospinal fluid (CSF) is in contact with the extracellular space of the brain, biochemical brain modifications could be reflected in the CSF. IGFs in circulation and other physiological fluids are associated with a group of high‐affinity binding proteins insulin like growth factor binding proteins (IGFBPs) that specifically bind and modulate their bioactivity at the cellular level. The aim of this study was to determine the level of CSF and serum IGF‐1 and IGFBPs concentrations in the patients with AD. CSF was obtained by lumbar puncture. The presence of IGF‐1 and IGFBPs in the CSF and serum samples was confirmed by Western blot using anti‐IGF‐1 and IGFBPs antibodies. Using enzyme linked immunosorbent assay (ELISA), it was shown that the concentration of CSF and serum IGF‐1 and IGFBPs in the patients with AD is higher than in normal control. The data from this study indicate that IGF‐1 is a constant component of human CSF. It is also concluded that high levels of CSF IGF‐1 may be partly related to AD pathophysiology.
Withaferin A induces apoptosis and inhibits adipogenesis in 3T3‐L1 adipocytes
Authors: Park Hea Jin , Rayalam Srujana , Della‐Fera Mary Anne , Ambati Suresh , Yang Jeong‐Yeh , Baile Clifton A. 
Published: August 2009

AbstractWithaferin A (WA), a highly oxygenated steroidal lactone that is found in the medicinal plant Withania somnifera (also called ashwagandha) has been reported to have anti‐tumor, anti‐angiogenesis, and pro‐apoptotic activity. We investigated the effects of WA on viability, apoptosis and adipogenesis in 3T3‐L1 adipocytes. Pre‐ and post‐confluent preadipocytes and mature adipocytes were treated with WA (1–25 μM) up to 24 hrs. Viability and apoptosis were measured by CellTiter‐Blue® Cell Viability Assay and single strand DNA ELISA Assay, respectively. WA decreased viability and induced apoptosis in all stages of cells. Induction of apoptosis by WA in mature adipocytes was mediated by increased ERK1/2 phosphorylation and altered Bax and Bcl2 protein expression. The effect of WA on adipogenesis was examined by Adipo Red Assay after treating with WA (0.1–1 μM) during the differentiation period. WA decreased lipid accumulation in a dose‐dependent manner and decreased the expression of peroxisome proliferator‐activated receptor γ, CCAAT/enhancer binding protein α and adipocyte fatty acid binding protein. The effects on apoptosis and lipid accumulation were also confirmed with Hoechst staining and Oil Red O staining, respectively. These results show that WA acts on adipocytes to reduce cell viability and adipogenesis and also induce apoptosis.
Effect of mono‐(2‐ethylhexyl) phthalate (MEHP) on resumption of meiosis, in vitro maturation and embryo development of immature mouse oocytes
Authors: Dalman A. , Eimani H. , Ashtiani S.K. , Valojerdi M.R. , Eftekhari‐Yazdi P. , Shahverdi A. , Sepehri H. 
Published: August 2009

AbstractThe purpose of this study was to evaluate the effect of MEHP on in vitro maturation of mouse oocytes and resulting embryo development.Denuded oocytes (DO) were cultured in maturation medium supplemented with 0, 50, 100,200 and 400 μM levels of MEHP for 24 h. The matured oocytes then were fertilized and cultured for 4 days.The percentage of Germinal Vesicle (GV) stage oocytes were significantly higher in 200 and 400 μM MEHP treatment comparing to the control (P < 0.05). The proportion of oocytes that progressed to the metaphase II (MII) stage was significantly decreased by adding of MEHP in a dose related pattern. The 2‐cell embryo formation was significantly decreased with 400 μM treatments than the control. Moreover with further culture in experimental groups none of the embryos comparing to that of the control group were developed to morulla stage (P < 0.05).These results indicate that MEHP could negatively modulate mouse oocyte meiotic maturation in vitro and embryo development, suggesting possible risks for human and other mammalians reproductive health.
Bilberry inhibits angiogenesis in chick chorioallontoic membrane
Authors: Ozgurtas Taner , Aydin Ibrahim , Tapan Serkan , Avci Ozgur , Erbil M. Kemal 
Published: August 2009

AbstractAngiogenesis is the process of generating new blood vessels from preexisting vessels and is considered essential in many pathological conditions. Bilberry has been traditionally used as a folk medicine for some countries. The purpose of the present study was to evaluate the effect of bilberry in chick chorioallantoic membrane angiogenesis modelin vivo.In this well characterized model, bilberry inhibited angiogenesis in a concentration‐dependent manner. Compared with the normal group, bilberry group has significant decreased vessels proliferation. These results provide evidence that bilberry inhibits angiogenesis and may be useful for treating angiogenesis‐dependent human diseases.
A nutrient mixture suppresses hepatic metastasis in athymic nude mice injected with murine B16FO melanoma cells
Authors: Roomi M. W. , Kalinovsky T. , Roomi N. W. , Monterrery J. , Rath M. , Niedzwiecki A. 
Published: August 2009

AbstractHighly metastatic melanoma is resistant to existing therapies. A unique micronutrient mixture (NM) containing ascorbic acid, amino acids, green tea extract has been shown to exhibit anticancer activity in vivo and in vitro in a number of cancer cell lines including human and murine melanoma cells lines. In this study we examined the effect of dietary NM supplementation on hepatic metastasis of intrasplenic injection of B16FO melanoma cells in athymic nude mice. Athymic nude mice (n = 10), 10–12 weeks of age, received 106 B16FO melanoma cells by injection into the spleen and divided into two groups. The Control group of mice received Purina mouse chow and the NM group received the regular diet supplemented with NM 0.5%. After two weeks, animals were sacrificed and spleens, livers, kidneys and lungs were excised from all animals, examined, weighed and processed for histology. The Control mice developed large black spleens and livers indicating growth in the spleen and metastasis to the liver. However, the mice supplemented with NM not only showed less tumor growth in the spleen as the Control mice, but also drastically reduced metastasis to the liver. In all groups, no metastasis to the kidneys and lungs was evident. In conclusion, these results suggest that NM has potential in suppression of tumor metastasis.
Cacao procyanidins reduce plasma cholesterol and increase fecal steroid excretion in rats fed a high‐cholesterol diet
Authors: Yasuda Akiko , Natsume Midori , Sasaki Kazue , Baba Seigo , Nakamura Yuko , Kanegae Minoru , Nagaoka Satoshi 
Published: August 2009

AbstractCocoa powder is rich in polyphenols, such as catechins and oligomeric procyanidins, and has a hypocholesterolemic effect in humans. This study evaluated the principal active components and potential mechanism(s) for the hypocholesterolemic effect of polyphenolic substances from cocoa powder in rats. Male Wistar rats were fed a 1% high‐cholesterol diet (HC) or a high‐cholesterol diet containing 1% polyphenol extract from cocoa powder (PE) or a mixture of 0.024% catechin and 0.058% epicatechin (CE) for 4 weeks. We also examined the effects of these polyphenolic substances on micellar cholesterol solubility in vitro. The PE group had significantly lower plasma cholesterol concentrations, and had significantly greater fecal cholesterol and total bile acids excretion than the HC group. The CE group diet did not influence plasma cholesterol concentrations, or fecal cholesterol or total bile acids excretion. Micellar solubility of cholesterol in vitro was significantly lower for procyanidin B2 (dimer), B5 (dimer), C1 (trimer) and A2 (tetramer), which are the main components of polyphenol extract from cocoa powder, compared to catechin and epicatechin. These results suggest that oligomeric procyanidins from cocoa powder are the principal active components responsible for the hypocholesterolemic effect, and inhibit the intestinal absorption of cholesterol and bile acids through the decrease in micellar cholesterol solubility.