bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Interleg BP Difference with Overall and Cardiovascular Mortality in Hemodialysis
Authors: Chen Szu-Chia , Chang Jer-Ming , Tsai Yi-Chun , Tsai Jer-Chia , Su Ho-Ming , Hwang Shang-Jyh , Chen Hung-Chun
Published: August 2012

Background and objectives

An interarm BP difference has been associated with atherosclerosis and adverse cardiovascular outcomes. This study investigated whether an interleg BP difference was associated with peripheral vascular disease and overall and cardiovascular mortality in hemodialysis patients.

Design, setting, participants, & measurements

This study enrolled 210 hemodialysis patients from December 2006 to January 2007. Bilateral leg BPs were measured simultaneously by an ankle-brachial index (ABI)–form device before hemodialysis.

Results

The mean follow-up period was 4.4±1.5 years. ABI <0.9 and high brachial-ankle pulse wave velocity were independently associated with an interleg difference in systolic BP of ≥15 mmHg or diastolic BP of ≥10 mmHg. Furthermore, this difference was an independent predictor for overall mortality (hazard ratio [HR], 3.36; 95% confidence interval [CI], 1.68–6.72; P<0.01) and cardiovascular mortality (HR, 4.84; 95% CI, 1.84–12.71; P<0.01) after adjustment for demographic, clinical, and biochemical parameters. After further adjustment for ABI <0.9 and brachial-ankle pulse wave velocity, the relation remained significant to overall mortality (HR, 2.91; 95% CI, 1.28–6.64; P=0.01) and cardiovascular mortality (HR, 3.15; 95% CI, 1.05–9.44; P=0.04).

Conclusions

A difference in systolic BP of ≥15 mmHg or diastolic BP of ≥10 mmHg between legs was associated with peripheral vascular disease and increased risk for overall and cardiovascular mortality in hemodialysis patients. Detection of an interleg BP difference may identify hemodialysis patients at increased risk of peripheral vascular disease and overall and cardiovascular mortality.
Urinary Biomarkers in Obstructive Nephropathy
Authors: Trnka Peter , Ivanova Larissa , Hiatt Michael J. , Matsell Douglas G.
Published: August 2012

Background and objectives

Obstructive nephropathy is a leading cause of CKD in children. The assessment of severity of renal impairment and the prediction of which children will progress to renal failure are, however, challenging.

Design, Setting, Participants, & Measurements

This case-control study measured the urinary excretion of candidate biomarkers in 27 prevalent case-patients with posterior urethral valves (PUVs) and 20 age-matched controls, correlated their urinary concentration with GFR, and analyzed receiver-operating characteristic (ROC) curve and regression analyses to assess their performance as tests for low GFR.

Results

The median urinary protein-to-creatinine ratio was higher in children with PUV (45 g/mol; range, 5–361 g/mol) than in controls (7 g/mol; range, 3–43 g/mol) (P<0.01) and correlated inversely with renal function (r = −0.44; P<0.05). In whole urine, excretion of aquaporin-2 was significantly decreased, whereas that of TGFβ and L1 cell adhesion molecule (L1CAM) was significantly increased. Whole-urine TGFβ excretion correlated inversely with GFR (r = −0.53; P<0.05). As tests for low GFR, whole-urine TGFβ, L1CAM, and urinary protein-to-creatinine ratio performed best, with areas under the ROC curves of 0.788, 0.795, and 0.814, respectively. By linear regression analysis, whole-urine TGFβ, L1CAM, and urinary protein-to-creatinine ratio were associated with low GFR in the case-patients.

Conclusions

Candidate biomarkers of obstructive nephropathy can be readily measured in whole urine and in urine exosomes. In boys with PUV, these biomarkers correlate with GFR.
Three-dimensional finite element analysis of occlusal stress distribution in the human skull with premolar extraction
Authors: Choi Dong-Soon , Cha Bong-Kuen , Jang Insan , Kang Kyung-Hwa , Kim Sang-Cheol
Published: August 2012

Objective:

To analyze the effect of orthodontic treatment with premolar extraction on the stress distribution of the occlusal force in the human skull.

Materials and Methods:

A three-dimensional finite element (3D FE) model was constructed based on computed tomography scan data, and it served as the pretreatment model. For the extraction model simulating postorthodontic occlusion, the first premolar was removed in the pretreatment model, and the anterior and posterior segments were repositioned. Stress distribution was evaluated by 3D FE analysis in both models under the simulation of 1000 N for occlusal forces and 400 N for masseter muscle force.

Results:

The occlusal stresses were concentrated at the alveolar bone near the teeth, the infrazygomatic crest, the frontal process, the temporal process of the zygomatic bone, the infraorbital rim, the pyriform aperture region, and the pterygoid plate in both models. The von Mises stress at the pterygoid plate area was lower in the extraction model (3.53 MPa) than in the pretreatment model (5.57 MPa), while the stress at the frontal process of the maxilla was higher in the extraction model (2.32 MPa) than in the pretreatment model (2.16 MPa).

Conclusions:

The results indicated that the occlusal forces were transferred through the maxillonasal, maxillozygomatic, and maxillopterygoid stress trajectories and that stress distribution moved more “forward” with the orthodontic treatment with premolar extraction.
Three-dimensional motion of the uncovertebral joint during head rotation
Authors: Nagamoto Yukitaka , Ishii Takahiro , Iwasaki Motoki , Sakaura Hironobu , Moritomo Hisao , Fujimori Takahito , Kashii Masafumi , Murase Tsuyoshi , Yoshikawa Hideki , Sugamoto Kazuomi
Published: August 2012

Object

The uncovertebral joints are peculiar but clinically important anatomical structures of the cervical vertebrae. In the aged or degenerative cervical spine, osteophytes arising from an uncovertebral joint can cause cervical radiculopathy, often necessitating decompression surgery. Although these joints are believed to bear some relationship to head rotation, how the uncovertebral joints work during head rotation remains unclear. The purpose of this study is to elucidate 3D motion of the uncovertebral joints during head rotation.

Methods

Study participants were 10 healthy volunteers who underwent 3D MRI of the cervical spine in 11 positions during head rotation: neutral (0°) and 15° increments to maximal head rotation on each side (left and right). Relative motions of the cervical spine were calculated by automatically superimposing a segmented 3D MR image of the vertebra in the neutral position over images of each position using the volume registration method. The 3D intervertebral motions of all 10 volunteers were standardized, and the 3D motion of uncovertebral joints was visualized on animations using data for the standardized motion. Inferred contact areas of uncovertebral joints were also calculated using a proximity mapping technique.

Results

The 3D animation of uncovertebral joints during head rotation showed that the joints alternate between contact and separation. Inferred contact areas of uncovertebral joints were situated directly lateral at the middle cervical spine and dorsolateral at the lower cervical spine. With increasing angle of rotation, inferred contact areas increased in the middle cervical spine, whereas areas in the lower cervical spine slightly decreased.

Conclusions

In this study, the 3D motions of uncovertebral joints during head rotation were depicted precisely for the first time.
Effects of N, P, K and S application on yield and quality of white jute (Corchorus capsularis L.) var. BJC-2197
Authors: Khanom Sayma , Hosssain Sonia , Hossain Shahid Akhtar
Published: August 2012

A field experiment was conducted at Bangladesh Jute Research Institute (BJRI) to observe the response of N, P, K and S on a pre?released white jute (Corchorus capsularis) var. BJC?2197. The experiment was carried out by applying N, P, K, S fertilizers in ten combinations including control. From the experiment it was observed that all the treatments had significant positive effect over control on growth, yield and quality parameters. The highest fiber yield (3.21 t/ha) and stick yield (6.58 t/ha) were recorded with N90P5K30S10 kg/ha treatment. However, the best quality fiber was found with combination of N90P15K30S10 kg/ha treatment. From the economic analysis point of view, it was found that combination of N90P5K30S10 kg/ha was higher (2.30) than N90P15K30S10 kg/ha (2.04). So the former can be considered as the best combination for var. BJC?2197 in terms of BCR, yield and quality. Dhaka Univ. J. Biol. Sci. 21(2): 109?116, 2012 (July) DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11508
Relationships between soil physico-chemical properties and total viable bacterial counts in Sunderban mangrove forests, Bangladesh
Authors: Hossain Mohammad Zabed , Aziz Chaman Binta , Saha Mihir Lal
Published: August 2012

Although soil bacterial communities are one of the important biotic components that influence decomposition and nutrient mineralization in the terrestrial ecosystems, factors driving this biotic community in the Sunderban mangrove forests are not well studied. The present study examined the importance of soil physico?chemical properties in driving soil bacterial communities in the Sunderban mangrove forests, Bangladesh. Soils were collected from 12 locations under four sites, namely Koromjal, Kotka, Hironpoint, and Dublarchar of Sunderban forests. Results showed a large range of variation in total bacterial colony counts (7.65 × 104 ? 14.5 × 104 cfu/g soil), soil moisture (9.0 ? 27.0%), total nitrogen (0.057 ? 0.158%), available nitrogen (0.504 ? 2.016 ?g/g soil), soil salinity (20.99 ? 34.99 mg chloride/g soil), and organic carbon (0.460 ? 0.885%). Data of the present study revealed that the number of total viable bacterial count was significantly and positively correlated only with total nitrogen content in soil indicating that total nitrogen content is the major driving factor of bacterial communities in the Sunderban mangrove forest soils.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11515 Dhaka Univ. J. Biol. Sci. 21(2): 169-175, 2012 (July)
Plankton composition, abundance and diversity in hilsa (Tenualosa ilisha) migratory rivers of Bangladesh during spawning season
Authors: Ahsan Dewan Ali , Kabir AKM Nazrul , Rahman Md Mofizur , Mahabub Shahad , Yesmin Rumana , Faruque Md Hasan , Naser Md Niamul
Published: August 2012

Hilsa (Tenualosa ilisha) is one of the flagship diadromous fish species of Bangladesh that migrate only through the Ganges?Meghna river system route. The biological profile of plankton from the Padma, Meghna and Tetulia reference river sites during 2011 spawning season of hilsa showed that in total of 58 taxa of plankton were present. Of which, 19 taxa (32.76%) were of phytoplankton and 39 taxa (67.24%) of zooplankton. Phytoplankton group belonged to Cyanophyceae (6 taxa), Chlorophyceae (7 taxa) and Bacillariophyceae (6 taxa) while zooplankton including Protozoa (10 taxa), Rotifera (19 taxa), Copepoda (4 taxa), Cladocera (5 taxa) and Ostracoda (1 taxon). The average abundance of plankton was recorded as 194.05 ± 82.58 indiv/l. The highest abundance of total plankton (692 indiv/l) was observed in Godagari, Rajshahi (Station 3) and was lowest (4.00 indiv/l) in Charghat, Rajshahi (Station 2). The highest abundance (49 indiv/l) of total zooplankton was observed in Godagari and lowest (1 indiv/l) in Charghat with mean value of 19.46 ± 4.12 indiv/l. The highest species richness (SR = 45) was observed in Daulotkhan, Vhola (Station 9) and the lowest (SR = 3) in Charghat (Station 2), with mean value of 17.10±4.408. Shannon?Weiner species diversity index (H?) ranged from 3.334 in Daulotkhan (Station 9) to 1.5 in Charghat, (Station 2) with mean value of 2.717 ± 0.147. Based on the plankton profile it may be concluded that the biological quality of hilsa migratory river was not alike throughout the route which may restrict the migration up to up steam and spontaneous spawning of hilsa.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11516 Dhaka Univ. J. Biol. Sci. 21(2): 177-189, 2012 (July)
Whole Farm Net Greenhouse Gas Abatement from Establishing Kikuyu-Based Perennial Pastures in South-Western Australia
Authors: Thomas Dean T. , Sanderman Jonathan , Eady Sandra J. , Masters David G. , Sanford Paul
Published: August 2012

On-farm activities that reduce GHG emissions or sequester carbon from the atmosphere to compensate for anthropogenic emissions are currently being evaluated by the Australian Government as carbon offset opportunities. The aim of this study was to examine the implications of establishing and grazing Kikuyu pastures, integrated as part of a mixed Merino sheep and cropping system, as a carbon offset mechanism. For the assessment of changes in net greenhouse gas emissions, results from a combination of whole farm economic and livestock models were used (MIDAS and GrassGro). Net GHG emissions were determined by deducting increased emissions from introducing this practice change (increased methane and nitrous oxide emissions due to higher stocking rates) from the soil carbon sequestered from growing the Kikuyu pasture. Our results indicate that livestock systems using perennial pastures may have substantially lower net GHG emissions, and reduced GHG intensity of production, compared with annual plant-based production systems. Soil carbon accumulation by converting 45% of arable land within a farm enterprise to Kikuyu-based pasture was determined to be 0.80 t CO2-e farm ha−1 yr−1 and increased GHG emissions (leakage) was 0.19 t CO2-e farm ha−1 yr−1. The net benefit of this practice change was 0.61 t CO2-e farm ha−1 yr−1 while the rate of soil carbon accumulation remains constant. The use of perennial pastures improved the efficiency of animal production almost eight fold when expressed as carbon dioxide equivalent emissions per unit of animal product. The strategy of using perennial pasture to improve production levels and store additional carbon in the soil demonstrates how livestock should be considered in farming systems as both sources and sinks for GHG abatement.
Challenges and Opportunities in Developing Sustainable Communities in the North West of England
Authors: Maliene Vida , Durney-Knight Natalie , Sertyesilisik Begum , Malys Naglis
Published: August 2012

Origins of sustainable communities lie in agendas set in a motion passed by the United Nations nearly forty years ago. As part of a sustainable development strategy and to tackle negative aspects of post industrial cities, in 2003, the UK government launched a Sustainable Communities Plan, accompanied by regional action plans, of which a major objective has been to implement regeneration projects aiming to improve quality of life in several areas of England, including the North West. This paper aims to review sustainable development agendas and to establish what needs to be done to improve quality of life indicators for communities of Stockbridge Village (SV), Murdishaw (M) and Halton Brook (HB) in Knowsley Metropolitan Borough (MBC) and Halton Borough Councils (BC), which have been identified as the most deprived post industrial areas in the North West of England. An investigation has been carried out by comparing the economic, social, physical and environmental indicators. Study findings reveal existing challenges and highlight problems that need to be addressed when implementing sustainable development strategy.
[KDy(Hptc)3(H3ptc)]n·2n(Hbipy)·5n(H2O), a Layered Coordination Polymer Containing DyO6N3 Tri-Capped Trigonal Prisms (H3ptc = Pyridine 2,4,6-Tricarboxylic Acid, C8H5NO6; Bipy = 2,2'-Bipyridine, C10H8N2)
Authors: Anwar Shoaib , Mariam Irfana , Khan Islam Ullah , Ejaz  , Harrison William T. A. , Anwar Sohail
Published: August 2012

The synthesis, structure and properties of the bimetallic layered coordination polymer, [KDy(C8H3NO6)3(C8H5NO6)]n·2n(C10H9N2)·5n(H2O) = [KDy(Hptc)3(H3ptc)]n·2n(Hbipy)·5n(H2O), are described. The Dy3+ ion is coordinated by three O,N,O-tridentate doubly-deprotonated pyridine tri-carboxylate (Hptc) ligands to generate a fairly regular DyO6N3 tri-capped trigonal prism, with the N atoms acting as the caps. The potassium ion is coordinated by an O,N,O-tridentate H3ptc molecule as well as monodentate and bidentate Hptc ligands to result in an irregular KNO9 coordination geometry. The ligands bridge the metal-atom nodes into a bimetallic, layered, coordination polymer, which extends as corrugated layers in the (010) plane, with the mono-protonated bipyridine cations and water molecules occupying the inter-layer regions: Unlike related structures, there are no dysprosium–water bonds. Many O–HLO and N–HLO hydrogen bonds consolidate the structure. Characterization and bioactivity data are described. Crystal data: C52H42DyKN8O29, Mr = 1444.54, triclinic, (No. 2), Z = 2, a = 9.188(2) Å, b = 15.7332(17) Å, c = 19.1664(19) Å, α = 92.797(6)°, β = 92.319(7)°, γ = 91.273(9)°, V = 2764.3(7) Å3, R(F) = 0.029, wR(F2) = 0.084.
Neuroprotective Effects of Germinated Brown Rice against Hydrogen Peroxide Induced Cell Death in Human SH-SY5Y Cells
Authors: Ismail Norsharina , Ismail Maznah , Farhana Fathy Siti , Asma Musa Siti Nor , Umar Imam Mustapha , Foo Jhi Biau , Iqbal Shahid
Published: August 2012

The neuroprotective and antioxidative effects of germinated brown rice (GBR), brown rice (BR) and commercially available γ-aminobutyric acid (GABA) against cell death induced by hydrogen peroxide (H2O2) in human neuroblastoma SH-SY5Y cells have been investigated. Results show that GBR suppressed H2O2-mediated cytotoxicity and induced G0/G1 phase cell cycle arrest in SH-SY5Y cells. Moreover, GBR reduced mitochondrial membrane potential (MMP) and prevented phosphatidylserine (PS) translocation in SH-SY5Y cells, key features of apoptosis, and subsequent cell death. GBR exhibited better neuroprotective and antioxidative activities as compared to BR and GABA. These results indicate that GBR possesses high antioxidative activities and suppressed cell death in SH-SY5Y cells by blocking the cell cycle re-entry and apoptotic mechanisms. Therefore, GBR could be developed as a value added functional food to prevent neurodegenerative diseases caused by oxidative stress and apoptosis.
Molecular Dynamic Simulation Insights into the Normal State and Restoration of p53 Function
Authors: Fu Ting , Min Hanyi , Xu Yong , Chen Jianzhong , Li Guohui
Published: August 2012

As a tumor suppressor protein, p53 plays a crucial role in the cell cycle and in cancer prevention. Almost 50 percent of all human malignant tumors are closely related to a deletion or mutation in p53. The activity of p53 is inhibited by over-active celluar antagonists, especially by the over-expression of the negative regulators MDM2 and MDMX. Protein-protein interactions, or post-translational modifications of the C-terminal negative regulatory domain of p53, also regulate its tumor suppressor activity. Restoration of p53 function through peptide and small molecular inhibitors has become a promising strategy for novel anti-cancer drug design and development. Molecular dynamics simulations have been extensively applied to investigate the conformation changes of p53 induced by protein-protein interactions and protein-ligand interactions, including peptide and small molecular inhibitors. This review focuses on the latest MD simulation research, to provide an overview of the current understanding of interactions between p53 and its partners at an atomic level.
Trypanocidal Action of (−)-Elatol Involves an Oxidative Stress Triggered by Mitochondria Dysfunction
Authors: Desoti Vânia Cristina , Lazarin-Bidóia Danielle , Sudatti Daniela Bueno , Pereira Renato Crespo , Alonso Antonio , Ueda-Nakamura Tania , Dias Filho Benedito Prado , Nakamura Celso Vataru , De Oliveira Silva Sueli
Published: August 2012

Natural compounds have shown good potential for the discovery of new chemotherapeutics for the treatment of Chagas’ disease. Recently, our group reported the effective trypanocidal activity of (−)-elatol, extracted from the red macroalgae Laurencia dendroidea present in the Brazilian coast against Trypanosoma cruzi. However, the mechanism of action of this compound has remained unclear. There are only hypotheses concerning its action on mitochondrial function. Here, we further investigated the mechanisms of action of (−)-elatol on trypomastigotes of T. cruzi. For this, we evaluated some biochemical alterations in trypomastigotes treated with (−)-elatol. Our results show that (−)-elatol induced depolarization of the mitochondrial membrane, an increase in the formation of mitochondrial superoxide anion and loss of cell membrane and DNA integrity. Additionally, (−)-elatol induced formation of autophagic vacuoles and a decrease in cell volume. All together, these results suggest that the trypanocidal action of (−)-elatol involves multiple events and mitochondria might be the initial target organelle. Our hypothesis is that the mitochondrial dysfunction leads to an increase of ROS production through the electron transport chain, which affects cell membrane and DNA integrity leading to different types of parasite death.
Insights on Cytochrome P450 Enzymes and Inhibitors Obtained Through QSAR Studies
Authors: Sridhar Jayalakshmi , Liu Jiawang , Foroozesh Maryam , Stevens Cheryl L. Klein
Published: August 2012

The cytochrome P450 (CYP) superfamily of heme enzymes play an important role in the metabolism of a large number of endogenous and exogenous compounds, including most of the drugs currently on the market. Inhibitors of CYP enzymes have important roles in the treatment of several disease conditions such as numerous cancers and fungal infections in addition to their critical role in drug-drug interactions. Structure activity relationships (SAR), and three-dimensional quantitative structure activity relationships (3D-QSAR) represent important tools in understanding the interactions of the inhibitors with the active sites of the CYP enzymes. A comprehensive account of the QSAR studies on the major human CYPs 1A1, 1A2, 1B1, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and a few other CYPs are detailed in this review which will provide us with an insight into the individual/common characteristics of the active sites of these enzymes and the enzyme-inhibitor interactions.
Synthesis and Characterization of New Thiazolidinones Containing Coumarin Moieties and Their Antibacterial and Antioxidant Activities
Authors: Hamdi Naceur , Al-Ayed Abdullah Sulaiman , Ben Said Ridha , Fabienne Alary
Published: August 2012

New coumarin derivatives, namely (2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-phenylthiazolidin-3-yl)acetamide, N-(2-(3-methoxyphenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide, 2-(4-methyl-2-oxo-2H-chromen-7-yloxy)-N-(4-oxo-2-(2,3,4trimethoxyphenyl)thiazolidin-3-yl)acetamide and N-(2-(4-bromophenyl)-4-oxothiazolidin-3-yl)-2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetamide) were synthesized starting from 4-methyl-7-hydroxycoumarin. The structures of the obtained compounds were confirmed by analytical IR and NMR spectra to elucidate the different positions of protons and carbons and as well as theoretical studies (DFT/B3LYP). The new compounds were screened for antibacterial activity. Most of them are more active against E. coli S. aureus and B. subtilis than standard references.
A Convenient Ultrasound-Promoted Synthesis of Some New Thiazole Derivatives Bearing a Coumarin Nucleus and Their Cytotoxic Activity
Authors: Gomha Sobhi M. , Khalil Khaled D.
Published: August 2012

Successful implementation of ultrasound irradiation for the rapid synthesis of a novel series of 3-[1-(4-substituted-5-(aryldiazenyl)thiazol-2-yl)hydrazono)ethyl]-2H-chromen-2-ones 5a–h, via reactions of 2-(1-(2-oxo-2H-chromen-3-yl)ethylidene) thiosemicarbazide (2) and the hydrazonoyl halides 3(4), was demonstrated. Also, a new series of 5-arylidene-2-(2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinyl)thiazol-4(5H)-ones 10a–d were synthesized from reaction of 2 with chloroacetic acid and different aldehydes. Moreover, reaction of 2-cyano-N'-(1-(2-oxo-2H-chromen-3-yl)ethylidene)-acetohydrazide (12) with substituted benzaldehydes gave the respective arylidene derivatives 13a–c under the conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data. Also, the cytototoxic activities of the thiazole derivative 5a was evaluated against HaCaT cells (human keratinocytes). It was found that compound 5a possess potent cytotoxic activity.
Induction of Apoptosis by Ethanolic Extract of Corchorus olitorius Leaf in Human Hepatocellular Carcinoma (HepG2) Cells via a Mitochondria-Dependent Pathway
Authors: Li Chia-Jung , Huang Shang-Yu , Wu Meng-Yu , Chen Yu-Ching , Tsang Shih-Fang , Chyuan Jong-Ho , Hsu Hsue-Yin
Published: August 2012

Corchorus olitorius L., is a culinary and medicinal herb, widely used as a vegetable in several countries in Asia. Many studies have shown that C. olitorius contains several antioxidants and exhibits anti-inflammatory and anti-proliferative activities in various in vitro and in vivo settings. Recently, C. olitorius has been approved for its antitumor activity; however, the underlying molecular mechanisms remain unclear. The goal of this study was to investigate the effects of ethanol extract of C. olitorius (ECO) on the growth of human hepatocellular carcinoma (HepG2) cells and gain some insights into the underlying mechanisms of its action. We found that HepG2 cells, treated with ECO for 24 h at a concentration higher than 12.5 μg/mL, displayed a strong reduction in cell viability, whereas normal FL83B hepatocytes were not affected. DNA fragmentation and nuclear condensation were evidenced by the increased subG1 population of ECO-treated HepG2 cells. ECO triggered the activation of procaspases-3 and -9 and caused the cleavage of downstream substrate, poly ADP-ribose polymerase (PARP), followed by down-regulation of the inhibitor of caspase-activated DNase (ICAD) signaling. Moreover, the increased release of cytochrome c from mitochondria with decreased membrane potential demonstrated the apoptosis induced through the caspases cascade. Our findings indicated that ECO might be effective against hepatocellular carcinoma through induction of apoptosis via mitochondria-dependent pathway.
Improvement in the Water Retention Characteristics of Sandy Loam Soil Using a Newly Synthesized Poly(acrylamide-co-acrylic Acid)/AlZnFe2O4 Superabsorbent Hydrogel Nanocomposite Material
Authors: Shahid Shaukat Ali , Qidwai Ansar Ahmad , Anwar Farooq , Ullah Inam , Rashid Umer
Published: August 2012

The use of some novel and efficient crop nutrient-based superabsorbent hydrogel nanocomposites (SHNCs), is currently becoming increasingly important to improve the crop yield and productivity, due to their water retention properties. In the present study a poly(Acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite was synthesized and its physical properties characterized using Energy Dispersive X-ray (EDX), FE-SEM and FTIR spectroscopic techniques. The effects of different levels of SHNC were studied to evaluate the moisture retention properties of sandy loam soil (sand 59%, silt 21%, clay 19%, pH 7.4, EC 1.92 dS/m). The soil amendment with 0.1, 0.2, 0.3 and 0.4 w/w% of SHNC enhanced the moisture retention significantly at field capacity compared to the untreated soil. Besides, in a separate experiment, seed germination and seedling growth of wheat was found to be notably improved with the application of SHNC. A delay in wilting of seedlings by 5–8 days was observed for SHNC-amended soil, thereby improving wheat plant growth and establishment.
Pedestrian Navigation Based on a Waist-Worn Inertial Sensor
Authors: Alvarez Juan Carlos , Alvarez Diego , López Antonio , González Rafael C.
Published: August 2012

We present a waist-worn personal navigation system based on inertial measurement units. The device makes use of the human bipedal pattern to reduce position errors. We describe improved algorithms, based on detailed description of the heel strike biomechanics and its translation to accelerations of the body waist to estimate the periods of zero velocity, the step length, and the heading estimation. The experimental results show that we are able to support pedestrian navigation with the high-resolution positioning required for most applications.
Numerical and Experimental Study on the Development of Electric Sensor as for Measurement of Red Blood Cell Deformability in Microchannels
Authors: Tatsumi Kazuya , Katsumoto Yoichi , Fujiwara Ryoji , Nakabe Kazuyoshi
Published: August 2012

A microsensor that can continuously measure the deformability of a single red blood cell (RBC) in its microchannels using microelectrodes is described in this paper. The time series of the electric resistance is measured using an AC current vs. voltage method as the RBC passes between counter-electrode-type micro-membrane sensors attached to the bottom wall of the microchannel. The RBC is deformed by the shear flow created in the microchannel; the degree of deformation depends on the elastic modulus of the RBC. The resistance distribution, which is unique to the shape of the RBC, is analyzed to obtain the deformability of each cell. First, a numerical simulation of the electric field around the electrodes and RBC is carried out to evaluate the influences of the RBC height position, channel height, distance between the electrodes, electrode width, and RBC shape on the sensor sensitivity. Then, a microsensor was designed and fabricated on the basis of the numerical results. Resistance measurement was carried out using samples of normal RBCs and rigidified (Ca2+-A23186 treated) RBCs. Visualization measurement of the cells’ behavior was carried out using a high-speed camera, and the results were compared with those obtained above to evaluate the performance of the sensor.
Resolution in QCM Sensors for the Viscosity and Density of Liquids: Application to Lead Acid Batteries
Authors: Cao-Paz Ana María , Rodríguez-Pardo Loreto , Fariña José , Marcos-Acevedo Jorge
Published: August 2012

In battery applications, particularly in automobiles, submarines and remote communications, the state of charge (SoC) is needed in order to manage batteries efficiently. The most widely used physical parameter for this is electrolyte density. However, there is greater dependency between electrolyte viscosity and SoC than that seen for density and SoC. This paper presents a Quartz Crystal Microbalance (QCM) sensor for electrolyte density-viscosity product measurements in lead acid batteries. The sensor is calibrated in H2SO4 solutions in the battery electrolyte range to obtain sensitivity, noise and resolution. Also, real-time tests of charge and discharge are conducted placing the quartz crystal inside the battery. At the same time, the present theoretical “resolution limit” to measure the square root of the density-viscosity product ( ) of a liquid medium or best resolution achievable with a QCM oscillator is determined. Findings show that the resolution limit only depends on the characteristics of the liquid to be studied and not on frequency. The QCM resolution limit for measurements worsens when the density-viscosity product of the liquid is increased, but it cannot be improved by elevating the work frequency.
19F MRI Tracer Preserves in Vitro and in Vivo Properties of Hematopoietic Stem Cells
Authors: Helfer Brooke M. , Balducci Anthony , Sadeghi Zhina , O'hanlon Charles , Hijaz Adonis , Flask Chris A. , Wesa Amy
Published: August 2012

Hematopoietic stem cells (HSCs) have numerous therapeutic applications including immune reconstitution, enzyme replacement, regenerative medicine, and immunomodulation. The trafficking and persistence of these cells after administration is a fundamental question for future therapeutic applications of HSCs. Here, we describe the safe and efficacious labeling of human CD34+ HSCs with a novel, self-delivering perfluorocarbon 19F magnetic resonance imaging (MRI) tracer, which has recently been authorized for use in a clinical trial to track therapeutic cells. While various imaging contrast agents have been used to track cellular therapeutics, the impact of this MRI tracer on HSC function has not previously been studied. Both human CD34+ and murine bone marrow (BM) HSCs were effectively labeled with the MRI tracer, with only a slight reduction in viability, relative to mock-labeled cells. In a pilot study, 19F MRI enabled the rapid evaluation of HSC delivery/retention following administration into a rat thigh muscle, revealing the dispersal of HSCs after injection, but not after surgical implantation. To investigate effects on cell functionality, labeled and unlabeled human HSCs were tested in in vitro colony forming unit (CFU) assays, which resulted in equal numbers of total CFU as well as individual CFU types, indicating that labeling did not alter multipotency. Cobblestone assay forming cell precursor frequency was also unaffected, providing additional evidence that stem cell function was preserved after labeling. In vivo tests of multipotency and reconstitution studies in mice with murine BM containing labeled HSCs resulted in normal development of CFU in the spleen, compared to unlabeled cells, and reconstitution of both lymphoid and myeloid compartments. The lack of interference in these complex biological processes provides strong evidence that the function and therapeutic potential of the HSCs are likely maintained after labeling. These data support the safety and efficacy of the MRI tracer for clinical tracking of human stem cells.
Effects of inbreeding and interpopulation crosses on performance and plasticity of two generations of offspring of a declining grassland plant
Authors: Walisch Tania J. , Colling Guy , Poncelet Myriam , Matthies Diethart
Published: August 2012

• Premise of the study: Inbreeding depression is a major evolutionary force and an important topic in conservation genetics because habitat fragmentation leads to increased inbreeding in the populations of many species. Crosses between populations may restore heterozygosity, resulting in increased performance (heterosis), but may also lead to the disruption of coadapted gene complexes and to decreased performance (outbreeding depression).

• Methods: We investigated the effects of selfing and of within and between population crosses on reproduction and the performance of two generations of offspring of the declining grassland plant Saxifraga granulata (Saxifragaceae). We also subjected the first generation of offspring to a fertilization and two stress treatments (competition and defoliation) to investigate whether the effects of inbreeding and interpopulation gene flow depend on environmental conditions.

• Key results: Inbreeding depression affected all traits in the F1 generation (δ = 0.07–0.55), but was stronger for traits expressed late during development and varied among families. The adaptive plasticity of offspring from selfing and from interpopulation crosses in response to nutrient addition was reduced. Outbreeding depression was also observed in response to stress. Multiplicative fitness of the F2 generation after serial inbreeding was extremely low (δ > 0.99), but there was heterosis after crossing inbred lines. Outbreeding depression was not observed in the F2.

• Conclusions: Continuous inbreeding may drastically reduce the fitness of plants, but effects may be environment‐dependent. When assessing the genetic effects of fragmentation and interpopulation crosses, the possible effects on the mean performance of offspring and on its adaptive plasticity should be considered.
Variation in ploidy level and phenology can result in large and unexpected differences in demography and climatic sensitivity between closely related ferns
Authors: de Groot G. Arjen , Zuidema Pieter A. , de Groot Harry , During Heinjo J.
Published: August 2012

• Premise of the study: Current environmental changes may affect the dynamics and viability of plant populations. This environmental sensitivity may differ between species of different ploidy level because polyploidization can influence life history traits. We compared the demography and climatic sensitivity of two closely related ferns: the tetraploid Polystichum aculeatum and one of its diploid parents, Polystichum setiferum.

• Methods: Matrix models were used to assess the effects of life history variation on population dynamics under varying winter conditions. We analyzed the contributions of all key aspects of the fern life cycle to population growth. Our study is the first to also include the gametophyte generation.

• Key results: Projected population growth rate (λ) was much higher for the tetraploid P. aculeatum (1.516) than for P. setiferum (1.071) under normal winter conditions. During a year with harsh winter conditions, population growth of P. aculeatum was strongly reduced. This finding contradicts our expectation that the winter‐hardy fronds of this species would allow high survival of harsh winters. Differences in λ between species and between years with different winter conditions were mostly caused by variation in gametophyte‐related recruitment rates, a finding that shows the importance of including gametophytes in fern demographic studies.

• Conclusions: Our results indicate that populations of closely related ferns can show large differences in population performance, mainly related to recruitment rates and frond phenology, and that these differences may depend greatly on climatic conditions. Our findings provide a first indication that (allo)polyploidization in ferns can have a significant effect on population dynamics.
The fossil record of Eucalyptus in Patagonia
Authors: Hermsen Elizabeth J. , Gandolfo María A. , Zamaloa María del Carmen
Published: August 2012

• Premise of the study: Herein, we name, describe, and illustrate new macrofossil material representing Eucalyptus (Myrtaceae: Myrtoideae, Eucalypteae) from the diverse early Eocene Laguna del Hunco (LH) flora of Chubut Province, Patagonia, Argentina. We explore the significance of these fossils in light of understanding the fossil record of eucalypts and the biogeography of the Eucalypteae.

• Methods: Fossils representing vegetative and reproductive organs were collected from multiple LH localities over several field seasons. These specimens were prepared, photographed, and compared to extant Eucalyptus. Additional historical collections of Patagonian fossil Eucalyptus were also examined.

• Key results: Vegetative and reproductive organs representing five different Eucalyptus taxa were identified in the LH paleoflora. One new taxon each representing leaves, flower buds, and infructescences with co‐occurring, isolated capsules are described and named as new Eucalyptus species. Additionally, two flower types cf. Eucalyptus, represented by one specimen each, are illustrated and briefly described. The fossil species have unique characteristics that independently suggest each belongs within the Eucalypteae. The reproductive material is most similar morphologically to extant Eucalyptus, although it also shares many similarities to the closely related genus Corymbia.

• Conclusions: The LH fossil Eucalyptus material is among the few eucalypt macrofossils that have recently been named and described and are the oldest macrofossils that can presently be definitively ascribed to the Eucalypteae. They also represent the only credible description of Eucalyptus fossils occurring outside of Australasia and suggest a once broader geographic distribution for this group.
Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism
Authors: Hlawacek Gregor , Veligura Vasilisa , Lorbek Stefan , Mocking Tijs F , George Antony , van Gastel Raoul , Zandvliet Harold J W , Poelsema Bene
Published: August 2012

Background: Helium ion microscopy is a new high-performance alternative to classical scanning electron microscopy. It provides superior resolution and high surface sensitivity by using secondary electrons.

Results: We report on a new contrast mechanism that extends the high surface sensitivity that is usually achieved in secondary electron images, to backscattered helium images. We demonstrate how thin organic and inorganic layers as well as self-assembled monolayers can be visualized on heavier element substrates by changes in the backscatter yield. Thin layers of light elements on heavy substrates should have a negligible direct influence on backscatter yields. However, using simple geometric calculations of the opaque crystal fraction, the contrast that is observed in the images can be interpreted in terms of changes in the channeling probability.

Conclusion: The suppression of ion channeling into crystalline matter by adsorbed thin films provides a new contrast mechanism for HIM. This dechanneling contrast is particularly well suited for the visualization of ultrathin layers of light elements on heavier substrates. Our results also highlight the importance of proper vacuum conditions for channeling-based experimental methods.
The oriented and patterned growth of fluorescent metal–organic frameworks onto functionalized surfaces
Authors: Zhuang Jinliang , Friedel Jasmin , Terfort Andreas
Published: August 2012

A metal–organic framework (MOF) material, [Zn2(adc)2(dabco)] (adc = anthracene-9,10-dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]­octane), the fluorescence of which depends on the loading of its nanopores, was synthesized in two forms: as free-flowing nanocrystals with different shapes and as surface-attached MOFs (SURMOFs). For the latter, we used self-assembled monolayers (SAMs) bearing functional groups, such as carboxylate and pyridyl groups, capable of coordinating to the constituents of the MOF. It could be demonstrated that this directed coordination also orients the nanocrystals deposited at the surface. Using two different patterning methods, i.e., microcontact printing and electron-beam lithography, the lateral distribution of the functional groups could be determined in such a way that the highly localized deposition of the SURMOF films became possible.
Synthesis of a library of tricyclic azepinoisoindolinones
Authors: Miller Bettina , Mao Shuli , Rosenker Kara M George , Pierce Joshua G , Wipf Peter
Published: August 2012

Hydrozirconation of 1-hexyne, the addition to in situ prepared N-acyliminium species, and ring-closing metathesis (RCM) were key steps in the preparation of a tricyclic isoindolinone scaffold. An unusual alkene isomerization process during the RCM was identified and studied in some detail. Chemical diversification for library synthesis was achieved by a subsequent alkene epoxidation and zinc-mediated aminolysis reaction. The resulting library products provided selective hits among a large number of high-throughput screens reported in PubChem, thus illustrating the utility of the novel scaffold.
Asymmetric total synthesis of smyrindiol employing an organocatalytic aldol key step
Authors: Enders Dieter , Fronert Jeanne , Bisschops Tom , Boeck Florian
Published: August 2012

The first organocatalytic asymmetric synthesis of smyrindiol, by using an (S)-proline catalyzed enantioselective intramolecular aldol reaction as the key step, is described. Smyrindiol was synthesized from commercially available 2,4-dihydroxybenzaldehyde in 15 steps, with excellent stereoselectivity (de = 99%, ee = 99%). In the course of this total synthesis a new and mild coumarin assembly was developed.
Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity
Authors: De Zotti Marta , Biondi Barbara , Peggion Cristina , De Poli Matteo , Fathi Haleh , Oancea Simona , Toniolo Claudio , Formaggio Fernando
Published: August 2012

Backbone modification is a common chemical tool to control the conformation of linear peptides and to explore potentially useful effects on their biochemical and biophysical properties. The thioamide, ψ[CS-NH], group is a nearly isosteric structural mimic of the amide (peptide) functionality. In this paper, we describe the solution synthesis, chemical characterization, preferred conformation, and membrane and biological activities of three, carefully selected, peptide analogues of the lipopeptaibiotic [Leu11-OMe] trichogin GA IV. In each analogue, a single thioamide replacement was incorporated. Sequence positions near the N-terminus, at the center, and near the C-terminus were investigated. Our results indicate that (i) a thioamide linkage is well tolerated in the overall helical conformation of the [Leu11-OMe] lipopeptide analogue and (ii) this backbone modification is compatible with the preservation of its typical membrane leakage and antibiotic properties, although somewhat attenuated.
Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41
Authors: Haney Evan F , Nguyen Leonard T , Schibli David J , Vogel Hans J
Published: August 2012

A number of physicochemical characteristics have been described which contribute to the biological activity of antimicrobial peptides. This information was used to design a novel antimicrobial peptide sequence by using an intrinsically inactive membrane-associated peptide derived from the HIV glycoprotein, gp41, as a starting scaffold. This peptide corresponds to the tryptophan-rich membrane-proximal region of gp41, which is known to interact at the interfacial region of the viral membrane and adopts a helical structure in the presence of lipids. Three synthetic peptides were designed to increase the net positive charge and amphipathicity of this 19-residue peptide. Ultimately, the peptide with the greatest degree of amphipathicity and largest positive charge proved to be the most potent antimicrobial, and this peptide could be further modified to improve the antimicrobial activity. However, the other two peptides were relatively ineffective antimicrobials and instead proved to be extremely hemolytic. This work demonstrates a novel approach for the design of unexplored antimicrobial peptide sequences but it also reveals that the biological and cytotoxic activities of these polypeptides depend on a number of interrelated factors.
Palladium-catalyzed substitution of (coumarinyl)methyl acetates with C-, N-, and S-nucleophiles
Authors: Chattopadhyay Kalicharan , Fenster Erik , Grenning Alexander J , Tunge Jon A
Published: August 2012

The palladium-catalyzed nucleophilic substitution of (coumarinyl)methyl acetates is described. The reaction proceeds though a palladium π-benzyl-like complex and allows for many different types of C-, N-, and S-nucleophiles to be regioselectively added to the biologically active coumarin motif. This new method was utilized to prepare a 128-membered library of aminated coumarins for biological screening.
Photochemistry with laser radiation in condensed phase using miniaturized photoreactors
Authors: Bremus-Köbberling Elke , Gillner Arnold , Avemaria Frank , Réthoré Céline , Bräse Stefan
Published: August 2012

Miniaturized microreactors enable photochemistry with laser irradiation in flow mode to convert azidobiphenyl into carbazole with high efficiency.
Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica
Authors: Zou Lu , Zheng Ruixiang Blake , Lowary Todd L
Published: August 2012

A series of methoxy and deoxy derivatives of mannopyranose-1-phosphate (Manp-1P) were chemically synthesized, and their ability to be converted into the corresponding guanosine diphosphate mannopyranose (GDP-Manp) analogues by a pyrophosphorylase (GDP-ManPP) from Salmonella enterica was studied. Evaluation of methoxy analogues demonstrated that GDP-ManPP is intolerant of bulky substituents at the C-2, C-3, and C-4 positions, in turn suggesting that these positions are buried inside the enzyme active site. Additionally, both the 6-methoxy and 6-deoxy Manp-1P derivatives are good or moderate substrates for GDP-ManPP, thus indicating that the C-6 hydroxy group of the Manp-1P substrate is not required for binding to the enzyme. When taken into consideration with other previously published work, it appears that this enzyme has potential utility for the chemoenzymatic synthesis of GDP-Manp analogues, which are useful probes for studying enzymes that employ this sugar nucleotide as a substrate.