bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of tsunami inundation by coastal forests in Yogyakarta, Indonesia: a numerical study
Authors: Ohira W. , Honda K. , Harada K.
Published: January 2012

Abstract. Coastal forests are known to protect coastal areas from environmental degradation. In this paper, we examined another important role of coastal forests – to mitigate tsunami devastations to coastal areas. Using a two-dimensional numerical model (Harada and Imamura model, 2005), we evaluated the damping effects of a coastal forest to resist tsunami inundation in Yogyakarta, Indonesia. In the simulations, we set up a two-km long control forest with a representative topography of the study site and experimented its damping performance sensitivity under various width configurations, e.g. 20, 40, 60, 80, 100 and 200 m. The initial tsunami wave was set such that the inundation depth at the front edge of the forest would not exceed 4 m (tree fragility limit). The forest variables such as species, density, DBH, height and canopy size were determined from a typical forest of the site (Casuarina plantation, 4 trees/100 m2, Diameter at Breast Height = 0.20 m). The results showed that coastal forest with 100 m width reduced inundation flux, depth and area by 17.6, 7.0 and 5.7%, respectively. Exponential models were found to describe the relationships between forest width and tsunami inundation transmission. An additional experiment was performed using actual topography and a forest plantation plan with 100 m width for 2.46 km2. In this experiment, the results showed that the plan would reduce inundation flux by 10.1%, while the exponential model estimated it to be 10.6%, close to the numerical model results. It suggests that statistical models of forest width and damping effects are useful tools for plantation planning, as it allows for quicker evaluation of the impact of coastal forest without simulation modeling that requires a lot of data, time and computing power.
Thiolated Carboxymethyl-Hyaluronic-Acid-Based Biomaterials Enhance Wound Healing in Rats, Dogs, and Horses
Authors: Yang Guanghui , Prestwich Glenn D. , Mann Brenda K.
Published: January 2012

The progression of wound healing is a complicated but well-known process involving many factors, yet there are few products on the market that enhance and accelerate wound healing. This is particularly problematic in veterinary medicine where multiple species must be treated and large animals heal slower, oftentimes with complicating factors such as the development of exuberant granulation tissue. In this study a crosslinked-hyaluronic-acid (HA-) based biomaterial was used to treat wounds on multiple species: rats, dogs, and horses. The base molecule, thiolated carboxymethyl HA, was first found to increase keratinocyte proliferation in vitro. Crosslinked gels and films were then both found to enhance the rate of wound healing in rats and resulted in thicker epidermis than untreated controls. Crosslinked films were used to treat wounds on forelimbs of dogs and horses. Although wounds healed slower compared to rats, the films again enhanced wound healing compared to untreated controls, both in terms of wound closure and quality of tissue. This study indicates that these crosslinked HA-based biomaterials enhance wound healing across multiple species and therefore may prove particularly useful in veterinary medicine. Reduced wound closure times and better quality of healed tissue would decrease risk of infection and pain associated with open wounds.
Phenotypic Plasticity and Adaptation in a Holometabolous Insect: The Chironomid Midge
Authors: McLachlan Athol John
Published: January 2012

Attention is currently shifting from a gene-centred view of evolution to a more phenotype-focussed one. Here, I attempt to test this new paradigm against a diverse and ecologically prominent taxon, the chironomid midge. I conclude that putting phenotypic and developmental flexibility at the forefront helps resolve some persistent difficulties in understanding the process of adaptation.
Evaluation of the Immune Response of Individuals Infected withMycobacterium tuberculosisand Patients with Active Tuberculosis
Authors: Guimarães Tânia Mara Pinto Dabés , de Toledo Vicente de Paulo Coelho Peixoto , Abreu Mery Natali , Dantas Nayanne Gama Teixeira , Spíndola de Miranda Silvana
Published: January 2012

This study reports the association betweenMycobacterium tuberculosisand the immune response to pulmonary tuberculosis (TB). Three groups were analyzed: (a) symptomatic patients with pulmonary tuberculosis (PTB), HIV-negative; (b) healthy individuals, tuberculin skin test reactive (TST+); (c) asymptomatic individuals, TST nonreactive (TST−). Groups B and C presented a negative bacilloscopic smear, normal chest radiographs, and negative HIV. The ELISA was used for IFN-γ, IL-10, TNF-α, and IgG quantification and lymph proliferative assay (LPA) to evaluate the cellular immune response. IgG and LPA increased in all study groups as well as IFN-γand TNF-α, but IL-10 remained low in all study groups. There was an association between LPA and IFN-γin group B. It was demonstrated an association between IgG and IL-10 and between IFN-γand IL-10 in group A. There were direct and significant correlations between LPA and IgG, TNF-αand IFN-γ, IL-10 and IgG, and between IL-10 and IFN-γ, but an inverse relationship was observed between IFN-γand LPA.
Development of Rotary Magnetoferrite Treatment with Stirrers for Waste Water Treatment Plants to Reduce Excess Sludge
Authors: Kabir Mahmudul , Suzuki Masafumi , Yoshimura Noboru
Published: January 2012

A large amount of excess sludge is being produced in the waste water treatment plants (WWTPs), which is a serious problem in terms of economical and environmental problems. So, the experiments on reduction of excess sludge are carried out. We have introduced a new approach for reduction of excess sludge by using ferrite particles and permanent magnets. A rotary treatment plant was introduced which showed good possibilities of this method for application in the WWTPs. Stirrers hold a very important role in rotary magnetoferrite treatment as they directly get in touch with ferrite particles and sludge. In this paper, we have shown the relationship between the ferrite particles and stirrers. Again, the treatment was carried out for different amounts of activated sludge which shows that the smaller the amount, the better the treatment of sludge. This knowledge may pave the way for the reduction of excess sludge in WWTPs in practical fields.
Cell Proliferation in Cutaneous Malignant Melanoma: Relationship with Neoplastic Progression
Authors: Piérard G. E.
Published: January 2012

The establishment of the diagnosis of cutaneous malignant melanoma (CMM) always calls for histopathological confirmation. Further to the recognition of the CMM aspects, immunohistochemistry is helpful, in particular, in determining the size of the replicative compartment and the activity in each of the cell cycle phases (G1, S, G2, M). The involvement of cancer stem cells and transient amplifier cells in CMM genesis is beyond doubt. The proliferation activity is indicative of the neoplastic progression and is often related to the clinical growth rate of the neoplasm. It allows to distinguish high-risk CMM commonly showing a high growth rate, from those CMMs of lower malignancy associated with a more limited growth rate. The recruitment and progression of CMM cells in the cell cycle of proliferation depend on mitogen-activated protein kinase (MAPK) pathway and result from a loss of control normally involving a series of key regulatory cyclins. In addition, the apoptotic pathways potentially counteracting any excess in proliferative activity are out of the dependency of specific regulatory molecular mechanisms. Key molecular components involved in the deregulation of the growth fraction, the cell cycle phases of proliferation, and apoptosis are presently described in CMM.
Patterns of compartment involvement in tibiofemoral osteoarthritis in men and women and in whites and African Americans
Authors: Wise Barton L. , Niu Jingbo , Yang Mei , Lane Nancy E. , Harvey William , Felson David T. , Hietpas Jean , Nevitt Michael , Sharma Leena , Torner Jim , Lewis C. E. , Zhang Yuqing ,   Multicenter Osteoarthritis (MOST) Group
Published: January 2012

Objective

We conducted a cross‐sectional study to describe the prevalence of tibiofemoral joint space narrowing (JSN) in medial and lateral compartments and assess whether it differs by sex and ethnic groups, and, if it does, to what extent such a difference is accounted for by knee malalignment.

Methods

The Multicenter Osteoarthritis Study is an observational study of persons ages 50–79 years with either symptomatic knee osteoarthritis or high risk of disease. Knee radiographs were assessed for JSN in each tibiofemoral compartment. Mechanical axis angle was measured using full‐extremity films. We compared the proportion of knees with medial compartment JSN and with lateral JSN between men and women, as well as between whites and African Americans, using a logistic regression model adjusting for covariates (race or sex and body mass index, age, education, and clinic site). We used generalized estimating equations to account for correlation between 2 knees within a person.

Results

Of 5,202 knees (2,652 subjects), 1,532 (29.5%) had medial JSN and 427 (8.2%) had lateral JSN. Lateral JSN was more prevalent in the knees of women than in men (odds ratio [OR] 1.9, 95% confidence interval [95% CI] 1.5–2.4) and was also higher in the knees of African Americans than in whites (OR 2.4, 95% CI 1.7–3.3). Further adjustment for malalignment attenuated the OR for sex but not the OR for race.

Conclusion

Women and African Americans are more likely to have lateral JSN than men and whites, respectively. Valgus malalignment may contribute to the higher prevalence in women.
On dark energy and accelerated reference frames
Authors: Ulhoa S.C.
Published: January 2012

The paper is devoted to an explanation of the accelerated rate of expansion of the Universe. Usually the acceleration of the Universe, which is described by FRW metric, is due to dark energy. It is shown that this effect may be considered as a manifestation of torsion tensor for a flat Universe in the realm of Teleparallel gravity. An observer with radial field velocity obey Hubble's Law. As a consequence it is established that this is radial acceleration in a flat Universe. In Eq. (35) the acceleration is written in terms of the deceleration parameter, the Hubble’s constant and the proper distance. This may be interpreted as an acceleration of the Universe.
Mechanism of multi‐metal(loid) methylation and hydride generation by methylcobalamin and cob(I)alamin: a side reaction of methanogenesis
Authors: Wuerfel Oliver , Thomas Frank , Schulte Marcel Sven , Hensel Reinhard , Diaz‐Bone Roland Arturo
Published: January 2012

Metal(loid)s are subject to many transformation processes in the environment, such as oxidation, reduction, methylation and hydride generation, predominantly accomplished by prokaryotes. Since these widespread processes affect the bioavailability and toxicity of metal(loid)s to a large extent, the investigation of their formation is of high relevance. Methanogenic Archaea are capable of methylating and hydrogenating Group 15 and 16 metal(loid)s arsenic, selenium, antimony, tellurium, and bismuth due to side reactions between central methanogenic cofactors, methylcobalamin (CH3Cob(III)) and cob(I)alamin (Cob(I)). Here, we present systematic mechanistic studies on methylation and hydride generation of Group 15 and 16 metal(loid)s by CH3Cob(III) and Cob(I). Pentavalent arsenical species showed neither methylation nor reduction as determined by using a newly developed oxidation state specific hydride generation technique, which allows direct determination of tri‐ and pentavalent arsenic species in a single batch. In contrast, efficient methylation of trivalent species without a change in oxidation state indicated that the methyl transfer does not proceed via a Challenger‐like oxidative methylation, but via a non‐oxidative methylation. Our findings also point towards a similar mechanism for antimony, bismuth, selenium, and tellurium. Overall, we suggest that the transfer of a methyl group does not involve a free reactive species, such as a radical, but instead is transferred either in a concerted nucleophilic substitution or in a caged radical mechanism. For hydride generation, we propose the intermediate formation of hydridocobalamin, transferring a hydride ion to the metal(loid)s. Copyright © 2012 John Wiley & Sons, Ltd.
Recruiting patients into randomized clinical trials in surgery
Authors: Blazeby J M
Published: January 2012

Surgeons can do better
Impact of nationwide centralization of pancreaticoduodenectomy on hospital mortality
Authors:   for the Dutch Pancreatic Cancer Group, de Wilde R F , Besselink M G H , van der Tweel I , de Hingh I H J T , van Eijck C H J , Dejong C H C , Porte R J , Gouma D J , Busch O R C , Molenaar I Q
Published: January 2012

Background

The impact of nationwide centralization of pancreaticoduodenectomy (PD) on mortality is largely unknown. The aim of this study was to analyse changes in hospital volumes and in-hospital mortality after PD in the Netherlands between 2004 and 2009.

Methods

Nationwide data on International Classification of Diseases, ninth revision (ICD-9) code 5-526 (PD, including Whipple), patient age, sex and mortality were retrieved from the independent nationwide KiwaPrismant registry. Based on established cut-off points of annually performed PDs, hospitals were categorized as very low (fewer than 5), low (5–10), medium (11–19) or high (at least 20) volume. A subgroup analysis based on a cut-off age of 70 years was also performed.

Results

Some 2155 PDs were included. The number of hospitals performing PD decreased from 48 in 2004 to 30 in 2009 (P = 0·011). In these specific years, the proportion of patients undergoing PD in a medium- or high-volume centre increased from 52·9 to 91·2 per cent (P < 0·001). Nationwide mortality rates after PD decreased from 9·8 to 5·1 per cent (P = 0·044). The mortality rate during the 6-year period was 14·7, 9·8, 6·3 and 3·3 per cent in very low-, low-, medium- and high-volume hospitals respectively (P < 0·001). The difference in mortality between medium- and high-volume centres was statistically significant (P = 0·004). The volume–outcome relationship was not influenced by age (P = 0·467). The mortality rate after PD in patients aged at least 70 years was 10·4 per cent compared with 4·4 per cent in younger patients (P < 0·001).

Conclusion

With nationwide centralization of PD, the in-hospital mortality rate after this procedure decreased. Further centralization of PD is likely to decrease mortality further, especially in the elderly.
Natural and Engineered Plasmin Inhibitors: Applications and Design Strategies
Authors: Swedberg Joakim E. , Harris Jonathan M.
Published: January 2012

The serine protease plasmin is ubiquitously expressed throughout the human body in the form of the zymogen plasminogen. Conversion to active plasmin occurs through enzymatic cleavage by plasminogen activators. The plasminogen activator/plasmin system has a well‐established function in the removal of intravascular fibrin deposition through fibrinolysis and the inhibition of plasmin activity; this has found widespread clinical use in reducing perioperative bleeding. Increasing evidence also suggests diverse, although currently less defined, roles for plasmin in a number of physiological and pathological processes relating to extracellular matrix degradation, cell migration and tissue remodelling. In particular, dysregulation of plasmin has been linked to cancer invasion/metastasis and various chronic inflammatory conditions; this has prompted efforts to develop inhibitors of this protease. Although a number of plasmin inhibitors exist, they commonly suffer from poor potency and/or specificity of inhibition that either results in reduced efficacy or prevents clinical use. Consequently, there is a need for further development of high‐affinity plasmin inhibitors that maintain selectivity over other serine proteases. This review summarises clearly defined and potential applications for plasmin inhibition. The properties of naturally occurring and engineered plasmin inhibitors are discussed in the context of current knowledge regarding plasmin structure, specificity and function. This includes design strategies to obtain the potency and specificity of inhibition in addition to controlled temporal and spatial distribution tailored for the intended use.
Seasonally Accumulation of Microcystins in the Various Tissues of an Endemic and Protected Fish Species (Rutilus panosi) with Different Sizes
Authors: Papadimitriou Theodoti , Kagalou Ifigenia , Leonardos Ioannis D.
Published: January 2012

The present study was undertaken to investigate the accumulation of microcystins (MCYST) in the various tissues of an endemic and protected fish species (Rutilus panosi). We also tried to identify any differences in sensitivity and accumulation of MCYST, for various specimens of the same fish species related to body length. MCYST concentrations in lake water and fish tissues were determined by a commercial Microcystin ELISA kit. Results showed that considerable amount of toxins were found to be accumulated in tissues of R. panosi throughout the year. Among them, liver had the highest MCYST concentrations (407.97 ± 32.43 ng/g). This study confirmed the accumulation of high MCYST concentrations in fish brain (308.75 ± 26.49 ng/g). Our results suggest, that MCYST accumulation in R. panosi tissues is size depended. High MCYST concentration in the muscle of the fish increases the risk of unsafe consumption, thus threatening human health.
Physiological and anatomical evidence for an inhibitory trigemino‐oculomotor pathway in the cat
Authors: May Paul J. , Vidal Pierre‐Paul , Baker Harriet , Baker Robert
Published: January 2012

During blink down‐phase, the levator palpebrae superioris (levator) muscle is inactivated, allowing the orbicularis oculi muscle to act. For trigeminal reflex blinks, the excitatory connections from trigeminal sensory nuclei to the facial nucleus have been described, but the pathway whereby the levator is turned off have not. We examined this question by use of both physiological and anatomical approaches in the cat. Intracellular records from antidromically activated levator motoneurons revealed that periorbital electrical stimulation produced bilateral, long latency inhibitory postsynaptic potentials (IPSPs). Central electrical stimulation of the principal trigeminal nucleus produced shorter latency IPSPs. Intracellular staining revealed that these motoneurons reside in the caudal central subdivision and have 10 or more poorly branched dendrites, which extend bilaterally into the surrounding supraoculomotor area. Axons penetrated in this region could be activated from periorbital and central electrodes. Neurons labeled from tracer injections into the caudal oculomotor complex were distributed in a crescent‐shaped band that lined the ventral and rostral aspects of the pontine trigeminal sensory nucleus. Double‐label immunohistochemical procedures demonstrated that these cells were not tyrosine hydroxylase‐positive cells in the Kölliker‐Fuse area. Instead, supraorbital nerve afferents displayed a similar crescent‐shaped distribution, suggesting they drive these trigemino‐oculomotor neurons. Anterograde labeling of the trigemino‐oculomotor projection indicates that it terminates bilaterally, in and above the caudal central subdivision. These results characterize a trigemino‐oculomotor pathway that inhibits levator palpebrae motoneurons in response to blink‐producing periorbital stimuli. The bilateral distributions of trigemino‐oculomotor afferents, levator motoneurons, and their dendrites supply a morphological basis for conjugate lid movements. J. Comp. Neurol. 520:2218–2240, 2012. © 2012 Wiley Periodicals, Inc.
(±)3,4‐methylenedioxymethamphetamine (“ecstasy”) treatment modulates expression of neurotrophins and their receptors in multiple regions of adult rat brain
Authors: Hemmerle Ann M. , Dickerson Jonathan W. , Herring Nicole R. , Schaefer Tori L. , Vorhees Charles V. , Williams Michael T. , Seroogy Kim B.
Published: January 2012

(±)3,4‐Methylenedioxymethamphetamine (MDMA), a widely used drug of abuse, rapidly reduces serotonin levels in the brain when ingested or administered in sufficient quantities, resulting in deficits in complex route‐based learning, spatial learning, and reference memory. Neurotrophins are important for survival and preservation of neurons in the adult brain, including serotonergic neurons. In this study, we examined the effects of MDMA on the expression of brain‐derived neurotrophic factor (BDNF) and neurotrophin‐3 (NT‐3) and their respective high‐affinity receptors, tropomyosin receptor kinase (trk)B and trkC, in multiple regions of the rat brain. A serotonergic‐depleting dose of MDMA (10 mg/kg × 4 at 2‐hour intervals on a single day) was administered to adult Sprague‐Dawley rats, and brains were examined 1, 7, or 24 hours after the last dose. Messenger RNA levels of BDNF, NT‐3, trkB, and trkC were analyzed by using in situ hybridization with cRNA probes. The prefrontal cortex was particularly vulnerable to MDMA‐induced alterations in that BDNF, NT‐3, trkB, and trkC mRNAs were all upregulated at multiple time points. MDMA‐treated animals had increased BDNF expression in the frontal, parietal, piriform, and entorhinal cortices, increased NT‐3 expression in the anterior cingulate cortex, and elevated trkC in the entorhinal cortex. In the nigrostriatal system, BDNF expression was upregulated in the substantia nigra pars compacta, and trkB was elevated in the striatum in MDMA‐treated animals. Both neurotrophins and trkB were differentially regulated in several regions of the hippocampal formation. These findings suggest a possible role for neurotrophin signaling in the learning and memory deficits seen following MDMA treatment. J. Comp. Neurol. 520:2459–2474, 2012. © 2012 Wiley Periodicals, Inc.
Lack of robust LGN label following transneuronal rabies virus injections into macaque area V4
Authors: Lyon David C. , Rabideau Cameron
Published: January 2012

In primates, retinal inputs are relayed through the magno‐ and parvocells of the lateral geniculate nucleus (LGN) indirectly to extrastriate visual cortex. The most direct pathway identified to the extrastriate cortex is a disynaptic one that provides robust magno‐ and parvocellular inputs to the middle temporal area (MT). The inclusion of parvocells in this projection is somewhat surprising because of their importance for color and form vision, whereas MT is more strictly tuned to velocity. This raises the question of whether areas more involved in color and form processing, such as V4, receive similar projections. We report here on experiments that use rabies virus injections into V4 to retrogradely label mono‐ and disynaptic inputs. We find only a small number of labeled neurons in the LGN in a pattern consistent with monosynaptic labeling of koniocells, rather than disynaptic labeling of magno‐ and parvocells. The lack of robust magno‐ and parvocellular label was not due to ineffective viral transport because in the same cases we find hundreds of neurons labeled in the thalamic reticular nucleus, a structure that can only be labeled disynaptically from the cortex. We also find a complete absence of neurons labeled in V1, but thousands in adjacent areas V2 and V3. This result helps explain the absence of labeled magno‐ and parvocells in the LGN because disynaptic transport from an extrastriate visual area should require a relay through V1. Taken together, these results suggest that ascending magno/parvocellular inputs to V4 are more hierarchically organized than the relatively direct inputs to MT. J. Comp. Neurol. 520:2500–2511, 2012. © 2012 Wiley Periodicals, Inc.
Comparative Study of the Semiconducting Properties of Benzothiadiazole and Benzobis(thiadiazole) Derivatives Using Computational Techniques
Authors: Thomas Anup , Bhanuprakash Kotamarthi
Published: January 2012

Recent literature reports indicate that derivatives of benzothiadiazole (BT) and benzobis(thiadiazole) (BBT), which differs from BT by an extra thiadiazole ring, exhibit good semiconducting properties, such as high electron mobility and low‐lying lowest unoccupied molecular‐orbital (LUMO) levels. In this study herein, computational techniques like density functional theory (DFT), spin‐flip DFT and valence‐bond methods are used to analyze the semiconducting properties of these molecules. Calculations at the B3LYP/cc‐pVTZ level reveal that all the BBT molecules, including the bare BBT ring, have lower lying LUMO energies (3.70–4.11 eV) compared to the BT derivatives (2.56–3.41 eV) with similar substitution. The reorganization energies (λ+/λ−) obtained at this level of theory of the BT derivatives are around (225–333)/(246–315) meV, while BBT derivatives have much smaller reorganization energies and these are in the range of (129–259)/(150–230) meV. We observe that the different behavior of BBT is due to the inherited biradicaloid character from the parent molecule tetramethylenebenzene (TMB), a disjoint non‐Kekule biradical having non‐bonding molecular orbitals (NBMOs) as the highest occupied molecular orbital (HOMO) and LUMO. Additionally, the perturbation of the orbitals of the biradical TMB to obtain BBT is the major cause for the BBT derivatives to have a larger electron affinity (EA) and a smaller HOMO–LUMO gap (HLG) compared to BT derivatives.
The Use of Environmental Policy Instruments for Urban Wastewater Control: Evidences from an International Survey
Authors: Xenarios Stefanos , Bithas Kostas
Published: January 2012

The use of environmental policy instruments as an effective approach for wastewater management has been of increasing debate. The relevant literature is mainly directed to the role of these instruments for the mitigation of air emissions, although occasionally policy implications for wastewater are noted. Empirical evidence regarding the performance of environmental instruments in wastewater management is scarce. There is thus often a discrepancy between the design and application stages of an instrument by a failure to attain the pursued targets in wastewater policy. This paper investigates the appropriateness of major applied environmental instruments and of combinatory options for wastewater pollution control. The research is based on an international survey of experienced experts and decision‐makers in developed urban wastewater systems. The results suggest a strong preference for taxes and, to a lesser extent, for command‐and‐control approaches. The country origin of the respondents appears to be a significant factor for the preference of particular instruments. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Pyridocarbazole‐Rhodium(III) Complexes as Protein Kinase Inhibitors
Authors: Dieckmann Sandra , Riedel Radostan , Harms Klaus , Meggers Eric
Published: January 2012

Inert metal complexes are sophisticated structural scaffolds for the design of enzyme inhibitors. Whereas previous work from our laboratory was predominantly based on ruthenium(II), this study evaluates the suitability of rhodium in the +3 oxidation state to serve as a structural centre for the design of inert metal‐based enzyme inhibitors. Based on our established staurosporine‐inspired metallo‐pyridocarbazole scaffold, strategies for the convenient synthesis of rhodium(III)‐pyridocarbazole complexes were developed and applied to the synthesis of protein kinase inhibitors. The structures of several rhodium complexes were investigated by X‐ray crystallography. A stability study confirmed the high kinetic inertness of such rhodium complexes under biologically relevant conditions, such as the presence of millimolar concentrations of thiols. Finally, an extremely potent, picomolar rhodium inhibitor for the protein kinase Pim1 was discovered. Thus, it can be concluded that rhodium(III) expands the toolbox for the design of inert metal complexes with biological activity.
Thermal stability of some flavonoids and phenolic acids in sheep tallow olein
Authors: Elhamirad Amir Hosein , Zamanipoor Mohammad Hasan
Published: January 2012

In this study, the thermal stability of some phenolic antioxidants including flavonoids (quercetin and catechin) and phenolic acids (gallic acid, tannic acid, ellagic acid and caffeic acid) in tallow olein was investigated. Tallow olein fractionated from sheep tallow fat was used as a medium to study the antioxidant activity at 120, 140, 160 and 180°C. In order to extract tallow olein, a three‐stage fractionation method was performed on sheep tallow fat at the constant temperatures of 25, 15 and 5°C using acetone as a solvent. The results suggested that quercetin and ellagic acid had the highest thermal stability amongst others, while gallic acid and caffeic acid exhibited the least thermal stability.

Practical applications: The sheep tallow fat has been primarily used in soap manufacturing and its application as an edible fat has been limited due to its high content of saturated fatty acids. Extraction of the liquid phase of tallow fat (tallow olein) by fractionation reduces its long‐chain saturated fatty acid content to an acceptable level for edible consumption. The fractionation process, as negatively affects the stability to autoxidation, should be followed by stabilisation with antioxidants. The recent interest in natural antioxidants encouraged the authors to investigate the thermal stability of phenolic antioxidants in tallow olein. It is necessary to determine the thermal stability of antioxidants to predict their appropriateness to be used in high‐temperature applications such as deep frying. Fractionation and stabilisation with appropriate antioxidants are the important steps to utilise tallow olein as an edible oil for different applications in salad formulations, cooking and frying.
An Efficient Multigram Synthesis of Alkannin and Shikonin
Authors: Wang Rubing , Zhou Shanshan , Jiang Hudagula , Zheng Xiaogang , Zhou Wen , Li Shaoshun
Published: January 2012

The concise and efficient total syntheses of alkannin (1) and shikonin (2), based on the resolution of a key acid intermediate, are achieved with excellent enantiomeric excesses and high overall yields (99 % ee, 15.6 % for 1 and 99.8 % ee, 11.9 % for 2). The key steps of the synthetic strategy involve the convenient synthesis and separation of a pair of amide diastereoisomers and the mild hydrolysis of the amide to remove the amine chiral auxiliary, together with an efficient deprotection sequence of the methyl protecting groups.
An Electrochemical Transducer Based on a Pentacene Double‐Gate Thin‐Film Transistor
Authors: Göllner Martin , Glasbrenner Georg , Nickel Bert
Published: January 2012

We report an electrochemical transducer based on an organic double‐gate transistor. The bottom‐gate is given by a p‐doped silicon substrate, which is covered by 300 nm thermal oxide. A 20 nm pentacene film acts as the semiconducting layer, and a 50 nm tetratetracontane (TTC) alkane film is used as a top‐gate dielectric. An aqueous ionic solution acts as top‐gate. We record the transistor transfer characteristics by variation of the electrolyte potential via a Ag/AgCl electrode for various bottom‐gate settings. A change of the electrolyte potential results in a change of the transistor current and the characteristic behaviour of the device is in good agreement with the expected behaviour of a double‐gate transistor. The top‐gate capacitance of the alkane layer is as high as 2.6×10−8 F cm−2 determined by impedance measurements, indicating that TTC is a good choice as an organic top‐gate dielectric. The suitability of this transducer configuration for sensing in aqueous media is demonstrated by the detection of hexanoic acid and stearic acid molecules adsorbing to the alkane interface, respectively. We show that the transducer easily achieves a concentration sensitivity in the range of 100 nM.
Recent Trends for (Bio)Chemical Impedance Sensor Electronic Interfaces
Authors: Crescentini Marco , Bennati Marco , Tartagni Marco
Published: January 2012

A large class of chemical and biological sensors have been based on electrical characterization of interfaces where sensing is often related to the characterization of interfaces between ion‐based and electron‐based conductive materials by means of typical electric variables such as voltage, current and charge. Integrated electronics has started a revolution in this field allowing very complex electronic systems to be shrunk to millimeter square sizes. This paper will introduce some recent trends in integrated sensor interface design, showing how progress in electronic devices and signal processing would enhance performance and applications of biochemical sensors.
Biofuel Cells for Self‐Powered Electrochemical Biosensing and Logic Biosensing: A Review
Authors: Zhou Ming , Wang Joseph
Published: January 2012

This article reviews recent advances and progress in developing electrochemical (EC) biosensing and logic biosensing systems based on self‐powered biofuel cells (BFCs). BFCs that exploit enzymes and microbes have attracted a considerable recent interest owing to their unique ability to provide sustainable energy from renewable fuel source under mild conditions. This review focuses on recently introduced novel concepts for using BFCs as the basic element for EC‐biosensing and especially EC‐logic biosensing applications. The fabrication and design of such self‐powered EC‐biosensing and EC‐logic biosensing are described along and different new approaches for BFCs‐based EC‐biosensing and EC‐logic biosensing involving substrate effects, inhibition effects, blocking effects and gene regulation effects. Latest advances in coupling a self‐powered diagnostic operation with logic‐activated drug release functionality are discussed. We conclude with the implications of the new self‐powered biosensing/logic‐biosensing platforms along with future prospects and challenges.
Rock fall dynamics and deposition: an integrated analysis of the 2009 Ahwiyah Point rock fall, Yosemite National Park, USA
Authors: Zimmer Valerie L. , Collins Brian D. , Stock Greg M. , Sitar Nicholas
Published: January 2012

We analyzed a combination of airborne and terrestrial LiDAR, high‐resolution photography, seismic, and acoustic data in order to gain insights into the initiation, dynamics, and talus deposition of a complex rock fall. A large (46 700 m3) rock fall originated from near Ahwiyah Point in eastern Yosemite Valley and fell a total of 730 m to the valley floor on 28 March 2009. Analyses of remote sensing, seismic, and acoustic data were integrated to reconstruct the rock fall, which consisted of (1) the triggering of a 25 400 m3 rock block in an area of intersecting and sometimes highly weathered joint planes, (2) the sliding and subsequent ballistic trajectory of the block from a steeply dipping ledge, (3) dislodging of additional rock from the cliff surface from beneath the rock fall source area, (4) a mid‐cliff ledge impact that detached a volume of rock nearly equivalent in volume to the initial block, (5) sliding of the deteriorating rock mass down the remainder of the cliff, and (6) final impact at the base of the cliff that remobilized the existing talus downward and outward and produced an airblast that knocked down hundreds of trees. The depositional geomorphology indicates that the porosity of the fresh talus is significantly lower than that expected for typical blocky talus slopes, likely because the rock debris from this event was pulverized into smaller, more poorly sorted fragments and densified via dynamic compaction when compared to less energetic, fragmental‐type rock falls. These results suggest that accumulation of individual rock‐fall boulders tends to steepen talus slopes, whereas large, energetic rock falls tend to flatten them. Detachment and impact signals were recorded by seismic and acoustic instruments and highlight the potential use of this type of instrumentation for generalized rock fall monitoring, while LiDAR and photography data were able to quantify the cliff geometry, rock fall volume, source and impact locations, and geomorphological changes to the cliff and talus. Published in 2012. This article is a US Government work and is in the public domain in the USA.
Genome-wide DNA methylation profiles in hepatocellular carcinoma
Authors: Shen Jing , Wang Shuang , Zhang Yu-Jing , Kappil Maya , Wu Hui-Chen , Kibriya Muhammad G. , Wang Qiao , Jasmine Farzana , Ahsan Habib , Lee Po-Huang , Yu Ming-Whei , Chen Chien-Jen , Santella Regina M.
Published: January 2012

Alterations in DNA methylation frequently occur in hepatocellular cancer (HCC). We have previously demonstrated that hypermethylation in candidate genes can be detected in plasma DNA before HCC diagnosis. To identify, with a genome-wide approach, additional genes hypermethylated in HCC that could be used for more accurate analysis of plasma DNA for early diagnosis, we analyzed tumor and adjacent nontumor tissues from 62 Taiwanese HCC cases using Illumina methylation arrays (Illumina, Inc., San Diego, CA) that screen 26,486 autosomal CpG sites. After Bonferroni adjustment, a total of 2,324 CpG sites significantly differed in methylation level, with 684 CpG sites significantly hypermethylated and 1,640 hypomethylated in tumor, compared to nontumor tissues. Array data were validated with pyrosequencing in a subset of five of these genes; correlation coefficients ranged from 0.92 to 0.97. Analysis of plasma DNA from 38 cases demonstrated that 37%-63% of cases had detectable hypermethylated DNA (≥5% methylation) for these five genes individually. At least one of these genes was hypermethylated in 87% of the cases, suggesting that measurement of DNA methylation in plasma samples is feasible.

Conclusion:

The panel of methylated genes indentified in the current study will be further tested in a large cohort of prospectively collected samples to determine their utility as early biomarkers of HCC.
A fibrous stromal component in hepatocellular carcinoma reveals a cholangiocarcinoma-like gene expression trait and epithelial-mesenchymal transition
Authors: Seok Jae Yeon , Na Deuk Chae , Woo Hyun Goo , Roncalli Massimo , Kwon So Mee , Yoo Jeong Eun , Ahn Ei Yong , Kim Gwang Il , Choi Jin-Sub , Kim Young Bae , Park Young Nyun
Published: January 2012

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the major primary liver cancers in adults. The phenotypic overlap between HCC and CC has been shown to comprise a continuous liver cancer spectrum. As a proof of this concept, a recent study demonstrated a genomic subtype of HCC that expressed CC-like gene expression traits, such as CC-like HCC, which revealed the common genomic trait of stem-cell–like properties and aggressive clinical outcomes. Scirrhous HCC (S-HCC), a rare variant of HCC, is characterized by abundant fibrous stroma and has been known to express several liver stem/progenitor cell markers. This suggests that S-HCC may harbor common intermediate traits between HCC and CC, including stem-cell traits, which are similar to those of CC-like HCC. However, the molecular and pathological characteristics of S-HCC have not been fully evaluated. By performing gene-expression profiling and immunohistochemical evaluation, we compared the morphological and molecular features of S-HCC with those of CC and HCC. S-HCC expresses both CC-like and stem-cell–like genomic traits. In addition, we observed the expression of core epithelial-mesenchymal transition (EMT)-related genes, which may contribute to the aggressive behavior of S-HCC. Overexpression of transforming growth factor beta (TGF-β) signaling was also found, implying its regulatory role in the pathobiology of S-HCC.

Conclusion:

We suggest that the fibrous stromal component in HCC may contribute to the acquisition of CC-like gene-expression traits in HCC. The expression of stem-cell–like traits and TGF-β/EMT molecules may play a pivotal role in the aggressive phenotyping of S-HCC.
High-mobility group box 1 activates caspase-1 and promotes hepatocellular carcinoma invasiveness and metastases
Authors: Yan Wei , Chang Ying , Liang Xiaoyan , Cardinal Jon S. , Huang Hai , Thorne Stephen H. , Monga Satdarshan P.S. , Geller David A. , Lotze Michael T. , Tsung Allan
Published: January 2012

Hypoxia is often found in solid tumors and is associated with tumor progression and poor clinical outcomes. The exact mechanisms related to hypoxia-induced invasion and metastasis remain unclear. We elucidated the mechanism by which the nuclear-damage–associated molecular pattern molecule, high-mobility group box 1 (HMGB1), released under hypoxic stress, can induce an inflammatory response to promote invasion and metastasis in hepatocellular carcinoma (HCC) cells. Caspase-1 activation was found to occur in hypoxic HCC cells in a process that was dependent on the extracellular release of HMGB1 and subsequent activation of both Toll-like receptor 4 (TLR4)- and receptor for advanced glycation endproducts (RAGE)-signaling pathways. Downstream from hypoxia-induced caspase-1 activation, cleavage and release of proinflammatory cytokines interleukin (IL)-1β and -18 occurred. We further demonstrate that overexpression of HMGB1 or treatment with recombinant HMGB1 enhanced the invasiveness of HCC cells, whereas stable knockdown of HMGB1 remarkably reduced HCC invasion. Moreover, in a murine model of HCC pulmonary metastasis, stable knockdown of HMGB1 suppressed HCC invasion and metastasis.

Conclusion:

These results suggest that in hypoxic HCC cells, HMGB1 activates TLR4- and RAGE-signaling pathways to induce caspase-1 activation with the subsequent production of multiple inflammatory mediators, which, in turn, promote cancer invasion and metastasis.
Adrenocortical dysfunction in liver disease: A systematic review
Authors: Fede Giuseppe , Spadaro Luisa , Tomaselli Tania , Privitera Graziella , Germani Giacomo , Tsochatzis Emmanuel , Thomas Michael , Bouloux Pierre-Marc , Burroughs Andrew K. , Purrello Francesco
Published: January 2012

In patients with cirrhosis, adrenal insufficiency (AI) is reported during sepsis and septic shock and is associated with increased mortality. Consequently, the term “hepato-adrenal syndrome” was proposed. Some studies have shown that AI is frequent in stable cirrhosis as well as in cirrhosis associated with decompensation other than sepsis, such as bleeding and ascites. Moreover, other studies showed a high prevalence in liver transplant recipients immediately after, or some time after, liver transplantation. The effect of corticosteroid therapy in critically ill patients with liver disease has been evaluated in some studies, but the results remain controversial. The 250-μg adreno-cortico-tropic-hormone stimulation test to diagnose AI in critically ill adult patients is recommended by an international task force. However, in liver disease, there is no consensus on the appropriate tests and normal values to assess adrenal function; thus, standardization of normal ranges and methodology is needed. Serum total cortisol assays overestimate AI in patients with cirrhosis, so that direct free cortisol measurement or its surrogates may be useful measurements to define AI, but further studies are needed to clarify this. In addition, the mechanisms by which liver disease leads to adrenal dysfunction are not sufficiently documented. This review evaluates published data regarding adrenal function in patients with liver disease, with a particular focus on the potential limitations of these studies as well as suggestions for future studies. (Hepatology 2012)
Two‐photon confocal imaging study: Cell uptake of two photon dyes‐labeled PAMAM dendrons in HeLa cells
Authors: Tsai Hsieh‐Chih , Imae Toyoko , Calderó Gabriela , Solans Conxita
Published: January 2012

A two‐photon excitation difluoroboron dye activated in the near infrared region for biological image analysis was synthesized in this study. Cell affinity, membrane interaction, and the endocytosis pathway of PAMAM dendrons were investigated using only covalent two‐photon dyes (TPD) at the periphery of the PAMAM dendrons. Generation 3 TPD‐labeled PAMAM dendrons (BG3) exhibited multivalency binding on the HeLa cell membranes from the cell affinity study in the fixation of HeLa cells. Photo‐stimulation on the membrane of the living HeLa cell was observed by confocal optical imaging in situ, using the two‐photon model, when incubated with BG3. Analyses of cell membrane integrity via lactate dehydrogenase (LDH) assay confirmed membrane damage at two photon excitation model. However, no variation in the cell was observed using the one‐photon excitation model. These results indicated a high degree of dendrons uptake by cells through binding to the cell membrane following the endocytotic pathway. Furthermore, the wide excitation fluorescence spectrum of difluoroboron dye provides dual imaging with which to study the endocytosis of TPD‐labeled PAMAM dendrons using a single near infrared laser. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Endothelial cell adhesion and proliferation to PEGylated polymers with covalently linked RGD peptides
Authors: Wang Xin , Heath Daniel E. , Cooper Stuart L.
Published: January 2012

A nonfouling peptide grafted polymer was synthesized that can promote endothelial cell (EC) binding. The polymer was composed of hexyl methacrylate, methyl methacrylate, poly(ethylene glycol) methacrylate, and CGRGDS peptide. The peptide was incorporated into the polymer system either by a chain transfer reaction or by coupling to an acrylate‐PEG‐N‐hydroxysuccinimide (NHS) comonomer. The introduction of PEG chains minimizes protein adsorption. Human umbilical vein ECs and endothelial colony forming cells were cultured on these surfaces in short term and long‐term studies. A difference in number and morphology of ECs was observed depending on the method of peptide incorporation. Both cell types adhered better to polymer films containing NHS coupled RGD peptide after 2 h even in the presence of albumin but significant cell detachment occurred after 4 days. Polymer solutions were electrospun into fibrous scaffolds. Both nonfouling and peptide binding characteristics were retained after processing. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.