bluuebunny/crossref_metadata_2025 huggingface dataset:
Small‐strain heterogeneous elastoplasticity revisited
Authors: Francfort Gilles A. , Giacomini Alessandro
Published: April 2012

The elastoplastic quasi‐static evolution of a multiphase material—a material with a pointwise varying yield surface and elasticity tensor, together with interfaces between the phases—is revisited in the context of conservative globally minimizing movements. Existence is shown, and classical evolutions are recovered under natural constraints on the plastic dissipation potential. Special attention is paid to the interfaces where the correct dissipation has to be enforced on the interfaces. Further, the evolution is shown to be a limit of that obtained for a model with linear isotropic hardening as the hardening becomes vanishingly small. The duality between plastic strains and admissible stresses is also revisited for Lipschitz boundaries, and its role in deriving a classical evolution is circumscribed. © 2012 Wiley Periodicals, Inc.
Photoinduced Electron Transfer in a Ferrocene–Distyryl BODIPY Dyad and a Ferrocene–Distyryl BODIPY–C60 Triad
Authors: Liu Jian‐Yong , El‐Khouly Mohamed E. , Fukuzumi Shunichi , Ng Dennis K. P.
Published: April 2012

A ferrocene–distyryl BODIPY dyad and a ferrocene–distyryl BODIPY–C60 triad are synthesized and characterized. Upon photoexcitation at the distyryl BODIPY unit, these arrays undergo photoinduced electron transfer to form the corresponding charge‐separated species. Based on their redox potentials, determined by cyclic voltammetry, the direction of the charge separation and the energies of these states are revealed. Femtosecond transient spectroscopic studies reveal that a fast charge separation (kCS=1.0×1010 s−1) occurs for both the ferrocene–distyryl BODIPY dyad and the ferrocene–distyryl BODIPY–C60 triad, but that a relatively slow charge recombination is observed only for the triad. The lifetime of the charge‐separated state is 500 ps. Charge recombination of the dyad and triad leads to population of the triplet excited sate of ferrocene and the ground state, respectively.
Opportunistic channel allocation decision making in cognitive radio communications
Authors: Shatila Hazem , Khedr Mohamed , Reed Jeffrey H.
Published: April 2012

The global spread of wireless devices with mobile Internet access and the increasing demand of multimedia‐based applications are fueling the need for wireless broadband networks. IEEE 802.16 and 802.20 are standards for a broadband wireless access with promising cognitive radio features to support mobile Internet access. However, because of the fast changing radio environment and the demand for dynamic spectrum allocation mechanisms, these standards must continuously readjust different radio parameters. The cognitive radio makes decisions based on its built‐in inference engine, which also in time can adapt itself to different situations through the process of learning from experience. In this paper we present an automated opportunistic decision making and learning process for cognitive radio based on uncertainty reasoning algorithms. This novel approach is well suited in fast changing wireless environments with vague, incomplete, and heterogeneous information. Theory and simulations prove that decision making and learning of the cognitive radio based on the proposed approach cope with the changes in the radio environment. In this work we use fuzzy logic for the learning and decision making of the cognitive radio. Simulation also show that our approach provides accurate and precise decisions on allocating spectrum to mobile Internet users even in fast varying radio conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Host plant defense signaling in response to a coevolved herbivore combats introduced herbivore attack
Authors: Woodard Anastasia M. , Ervin Gary N. , Marsico Travis D.
Published: April 2012

Defense‐free space resulting from coevolutionarily naïve host plants recently has been implicated as a factor facilitating invasion success of some insect species. Host plants, however, may not be entirely defenseless against novel herbivore threats. Volatile chemical‐mediated defense signaling, which allows plants to mount specific, rapid, and intense responses, may play a role in systems experiencing novel threats. Here we investigate defense responses of host plants to a native and exotic herbivore and show that (1) host plants defend more effectively against the coevolved herbivore, (2) plants can be induced to defend against a newly‐associated herbivore when in proximity to plants actively defending against the coevolved species, and (3) these defenses affect larval performance. These findings highlight the importance of coevolved herbivore‐specific defenses and suggest that naïveté or defense limitations can be overcome via defense signaling. Determining how these findings apply across various host–herbivore systems is critical to understand mechanisms of successful herbivore invasion.
Phylogenetic analysis of cryptic speciation in the polychaete Pygospio elegans
Authors: Kesäniemi J. E. , Rawson P. D. , Lindsay S. M. , Knott K. E.
Published: April 2012

Development in marine invertebrate species can take place through a variety of modes and larval forms, but within a species, developmental mode is typically uniform. Poecilogony refers to the presence of more than one mode of development within a single species. True poecilogony is rare, however, and in some cases, apparent poecilogony is actually the result of variation in development mode among recently diverged cryptic species. We used a phylogenetic approach to examine whether poecilogony in the marine polychaete worm, Pygospio elegans, is the result of cryptic speciation. Populations of worms identified as P. elegans express a variety of developmental modes including planktonic, brooded, and intermediate larvae; these modes are found both within and among populations. We examined sequence variation among partial mitochondrial cytochrome c oxidase subunit I sequences obtained for 279 individual worms sampled across broad geographic and environmental scales. Despite a large number of unique haplotypes (121 haplotypes from 279 individuals), sequence divergence among European samples was low (1.7%) with most of the sequence variation observed within populations, relative to the variation among regions. More importantly, we observed common haplotypes that were widespread among the populations we sampled, and the two most common haplotypes were shared between populations differing in developmental mode. Thus, our results support an earlier conclusion of poecilogony in P elegans. In addition, predominantly planktonic populations had a larger number of population‐specific low‐frequency haplotypes. This finding is largely consistent with interspecies comparisons showing high diversity for species with planktonic developmental modes in contrast to low diversity in species with brooded developmental modes.
A comparison of four methods for detecting weak genetic structure from marker data
Authors: Jones Owen R. , Wang Jinliang
Published: April 2012

Genetic structure is ubiquitous in wild populations and is the result of the processes of natural selection, genetic drift, mutation, and gene flow. Genetic drift and divergent selection promotes the generation of genetic structure, while gene flow homogenizes the subpopulations. The ability to detect genetic structure from marker data diminishes rapidly with a decreasing level of differentiation among subpopulations. Weak genetic structure may be unimportant over evolutionary time scales but could have important implications in ecology and conservation biology. In this paper we examine methods for detecting and quantifying weak genetic structures using simulated data. We simulated populations consisting of two putative subpopulations evolving for up to 50 generations with varying degrees of gene flow (migration), and varying amounts of information (allelic diversity). There are a number of techniques available to detect and quantify genetic structure but here we concentrate on four methods: FST, population assignment, relatedness, and sibship assignment. Under the simple mating system simulated here, the four methods produce qualitatively similar results. However, the assignment method performed relatively poorly when genetic structure was weak and we therefore caution against using this method when the analytical aim is to detect fine‐scale patterns. Further work should examine situations with different mating systems, for example where a few individuals dominate reproductive output of the population. This study will help workers to design their experiments (e.g., sample sizes of markers and individuals), and to decide which methods are likely to be most appropriate for their particular data.
Structural and DFT Studies of Dibromine and Diiodine Adducts of a Sulfur‐Rich Thiocarbonyl Donor
Authors: Mancini Annalisa , Pala Luca , Aragoni M. Carla , Arca Massimiliano , Devillanova Francesco A. , Hursthouse Michael B. , Light Mark E. , Skabara Peter J. , Bricklebank Neil
Published: April 2012

4,5‐Bis(benzoylthio)‐1,3‐dithiole‐2‐thione (1) forms molecular adducts with dibromine (2) and diiodine (3), which display a range of complementary primary X–X and S–X and secondary S···X and X···X bonding interactions. Compounds 2 and 3 were characterised by X‐ray diffraction analysis and FT‐Raman spectroscopy. Compound 2, which is derived from the additive dibromine oxidation of 1, features a near linear Br–S–Br moiety that is coplanar with the dithiole‐2‐thione heterocycle. The S–Br bonds in 2 are asymmetric; the asymmetry arises mainly through a combination of intramolecular S···Br bonds between the Br atoms and the thioether S atoms of the donor, and an intermolecular S···Br contact between one of the bromine atoms and the hypervalent S atom of an adjacent molecule. DFT calculations carried out on 2 with different functionals agree and show that the geometry featuring the SBr2 moiety coplanar with the heterocycle is more stable by about 9 kcal mol–1 than that with the SBr2 unit perpendicular to the plane of the heterocycle. DFT calculations indicate that the formation of 2 can be explained based on the charge distribution on the hypothetical cationic intermediate [1–Br]+. Diiodine complex 3 is a molecular charge‐transfer species, with an almost linear S–I–I moiety. The unit cell contains two molecules of donor 1, related by a centre of inversion, which form a dimer pair held together by two intermolecular S···S and two S···O contacts. The packing of the dimers generates various cavities that are able to accommodate I2 molecules as “guests”, in one case the guest diiodine molecule bonds with the sulfur atoms of the benzoylthio‐groups and acts as a bridge between adjacent dimers, in another the diiodine is disordered along the channel‐like cavity. The terminal iodine atom of each S–I–I fragment interacts with two additional I2 molecules leading to infinite chains in the [01–1] direction.
Catalysis of C–C Cross‐Coupling Reactions in Aqueous Solvent by Bis‐ and Tris(ferrocenyltriazolylmethyl)arene–β‐Cyclodextrin‐Stabilized Pd0 Nanoparticles
Authors: Liang Liyuan , Diallo Abdou K. , Salmon Lionel , Ruiz Jaime , Astruc Didier
Published: April 2012

Mono‐, bis‐, and tris(4‐ferrocenyl‐1,2,3‐triazolylmethyl)arene–β‐cyclodextrin adducts have been used to prepare new Pd0 nanoparticle (PdNP) catalysts for C–C cross‐coupling reactions in EtOH/H2O. The results show that these catalysts work well in Miyaura–Suzuki and Heck reactions with iodoarenes at 25 and 80 °C, respectively, with turnover numbers (TONs) of up to 31000 for standard Miyaura–Suzuki reactions of PhI when 10 ppm of the Pd catalyst (5 nm PdNPs) were used. The results show the benefit for PdNP catalysis of encapsulating hydrophobic catalytic systems between peripheral water‐solubilizing cyclodextrins as bolamphiphile‐like materials because the open monoferrocenyltriazolylmethylbenzene system shows a considerably reduced catalytic efficiency compared with bis‐ and tris(4‐ferrocenyl‐1,2,3‐triazolylmethyl)arene–β‐cyclodextrin adducts.
Copper(I)‐Dioxygen Reactivity in a Sterically Demanding Tripodal Tetradentate tren Ligand: Formation and Reactivity of a Mononuclear Copper(II) End‐On Superoxo Complex
Authors: Kobayashi Yuki , Ohkubo Kei , Nomura Takashi , Kubo Minoru , Fujieda Nobutaka , Sugimoto Hideki , Fukuzumi Shunichi , Goto Kei , Ogura Takashi , Itoh Shinobu
Published: April 2012

Reaction of a copper(I) complex supported by a sterically demanding tripodal tetradentate ligand, HIPT3tren, and O2 gave a mononuclear copper(II) end‐on superoxo complex. Spectroscopic (UV/Vis, resonance Raman, ESR, and 1H‐NMR) and DFT studies have been performed. The O2‐binding process as well as the reaction toward external substrates have been investigated kinetically to demonstrate the unique behavior of the copper(II) end‐on superoxo complex, which may occur as a result of the existence of the hydrophobic core around the copper coordination sphere created by the HIPT3tren ligand.
Stormwater input of pyrethroid insecticides to an urban river
Authors: Weston Donald P. , Lydy Michael J.
Published: April 2012

The American River flows for nearly 50 km through highly urbanized lands surrounding Sacramento, California, USA. Twenty-three streams, drainage canals, or pumping stations discharge urban runoff to the river, with the cumulative effect of nearly doubling the river's flow during rain events. During winter storms, the water column in the most downstream 13-km reach of the river exhibited toxicity to the standard testing species, Hyalella azteca, in 52% of samples, likely because of the pyrethroid insecticide bifenthrin. The compound is heavily used by professional pest controllers, either as a liquid perimeter treatment around homes or as granules broadcast over landscaped areas. It was found in 11 of 12 runoff sources examined, at concentrations averaging five times the H. azteca 96-h EC50. Quantified inputs of bifenthrin should have been sufficient to attain peak concentrations in the river twice those actually observed, suggesting loss by sedimentation of particulates and pesticide adsorption to the substrate and/or vegetation. Nevertheless, observed bifenthrin concentrations in the river were sufficient to cause water column toxicity, demonstrated during six storms studied over three successive winters. Toxicity and bifenthrin concentrations were greatest when river flow was low (<23 m3/s) but persisted even at atypically high flows (585 m3/s). Environ. Toxicol. Chem. 2012; 31: 1579–1586. © 2012 SETAC
Association between diabetes, family history of diabetes, and risk of nonalcoholic steatohepatitis and fibrosis
Authors: Loomba Rohit , Abraham Maria , Unalp Aynur , Wilson Laura , Lavine Joel , Doo Ed , Bass Nathan M.
Published: April 2012

Previous studies have shown familial aggregation of insulin resistance and nonalcoholic fatty liver disease (NAFLD). Therefore, we aimed to examine whether family history of diabetes mellitus (DM) is associated with nonalcoholic steatohepatitis (NASH) and fibrosis in patients with NAFLD. This was a cross-sectional analysis in participants of the NAFLD Database study and PIVENS trial who had available data on family history of DM. One thousand and sixty-nine patients (63% women), with mean age of 49.6 (± 11.8) years and body mass index (BMI) of 34.2 (± 6.4) kg/m2, were included. Thirty percent had DM, and 56% had a family history of DM. Both personal history of DM and family history of DM were significantly associated with NASH, with an odds ratio (OR) of 1.93 (95% confidence interval [CI]: 1.37–2.73;

P

<0.001) and 1.48 (95% CI: 1.11–1.97;

P

= 0.01) and any fibrosis with an OR of 3.31 (95% CI: 2.26–4.85;

P

< 0.001) and 1.66 (95% CI: 1.25–2.20;

P

< 0.001), respectively. When the models were adjusted for age, sex, BMI, ethnicity, and metabolic traits, the association between diabetes and family history of DM with NASH showed an increased adjusted OR of 1.76 (95% CI: 1.13–2.72;

P

< 0.001) and 1.34 (95% CI: 0.99–1.81;

P

= 0.06), respectively, and with any fibrosis with a significant adjusted OR of 2.57 (95% CI: 1.61–4.11;

P

< 0.0001) and 1.38 (95% CI: 1.02–1.87;

P

= 0.04), respectively. After excluding patients with personal history of diabetes, family history of DM was significantly associated with the presence of NASH and any fibrosis with an adjusted OR of 1.51 (95% CI: 1.01–2.25;

P

= 0.04) and 1.49 (95% CI: 1.01–2.20;

P

= 0.04), respectively.

Conclusions:

Diabetes is strongly associated with risk of NASH, fibrosis, and advanced fibrosis. Family history of diabetes, especially among nondiabetics, is associated with NASH and fibrosis in NAFLD.
Antagonism of sphingosine 1-phosphate receptor 2 causes a selective reduction of portal vein pressure in bile duct-ligated rodents
Authors: Kageyama Yuko , Ikeda Hitoshi , Watanabe Naoko , Nagamine Masakazu , Kusumoto Yoshika , Yashiro Mitsuru , Satoh Yumiko , Shimosawa Tatsuo , Shinozaki Koji , Tomiya Tomoaki , Inoue Yukiko , Nishikawa Takako , Ohtomo Natsuko , Tanoue Yasushi , Yokota Hiromitsu , Koyama Takatoshi , Ishimaru Kazuhiro , Okamoto Yasuo , Takuwa Yoh , Koike Kazuhiko , Yatomi Yutaka
Published: April 2012

Sinusoidal vasoconstriction, in which hepatic stellate cells operate as contractile machinery, has been suggested to play a pivotal role in the pathophysiology of portal hypertension. We investigated whether sphingosine 1-phosphate (S1P) stimulates contractility of those cells and enhances portal vein pressure in isolated perfused rat livers with Rho activation by way of S1P receptor 2 (S1P2). Rho and its effector, Rho kinase, reportedly contribute to the pathophysiology of portal hypertension. Thus, a potential effect of S1P2 antagonism on portal hypertension was examined. Intravenous infusion of the S1P2 antagonist, JTE-013, at 1 mg/kg body weight reduced portal vein pressure by 24% without affecting mean arterial pressure in cirrhotic rats induced by bile duct ligation at 4 weeks after the operation, whereas the same amount of S1P2 antagonist did not alter portal vein pressure and mean arterial pressure in control sham-operated rats. Rho kinase activity in the livers was enhanced in bile duct-ligated rats compared to sham-operated rats, and this enhanced Rho kinase activity in bile duct-ligated livers was reduced after infusion of the S1P2 antagonist. S1P2 messenger RNA (mRNA) expression, but not S1P1 or S1P3, was increased in bile duct-ligated livers of rats and mice and also in culture-activated rat hepatic stellate cells. S1P2 expression, determined in

S1P

Symbol
mice, was highly increased in hepatic stellate cells of bile duct-ligated livers. Furthermore, the increase of Rho kinase activity in bile duct-ligated livers was observed as early as 7 days after the operation in wildtype mice, but was less in

S1P

Symbol
mice.

Conclusion

: S1P may play an important role in the pathophysiology of portal hypertension with Rho kinase activation by way of S1P2. The S1P2 antagonist merits consideration as a novel therapeutic agent for portal hypertension. (Hepatology 2012)
Intraductal papillary neoplasm of the bile duct: A biliary equivalent to intraductal papillary mucinous neoplasm of the pancreas?
Authors: Rocha Flavio G. , Lee Hwajeong , Katabi Nora , DeMatteo Ronald P. , Fong Yuman , D'Angelica Michael I. , Allen Peter J. , Klimstra David S. , Jarnagin William R.
Published: April 2012

Intraductal papillary neoplasm of the bile duct (IPNB) is a variant of bile duct carcinoma characterized by intraductal growth and better outcome compared with the more common nodular-sclerosing type. IPNB is a recognized precursor of invasive carcinoma, but its pathogenesis and natural history are ill-defined. This study examines the clinicopathologic features and outcomes of IPNB. A consecutive cohort of patients with bile duct cancer (hilar, intrahepatic, or distal) was reviewed, and those with papillary histologic features identified. Histopathologic findings and immunohistochemical staining for tumor markers and for cytokeratin and mucin proteins were used to classify IPNB into subtypes. Survival data were analyzed and correlated with clinical and pathologic parameters. Thirty-nine IPNBs were identified in hilar (23/144), intrahepatic (4/86), and distal (12/113) bile duct specimens between 1991 and 2010. Histopathologic examination revealed 27 pancreatobiliary, four gastric, two intestinal, and six oncocytic subtypes; results of cytokeratin and mucin staining were similar to those of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. Invasive carcinoma was seen in 29/39 (74%) IPNBs. Overall median survival was 62 months and was not different between IPNB locations or subtypes. Factors associated with a worse median survival included presence and depth of tumor invasion, margin-positive resection, and expression of MUC1 and CEA.

Conclusion

: IPNBs are an uncommon variant of bile duct cancer, representing approximately 10% of all resectable cases. They occur throughout the biliary tract, share some histologic and clinical features with IPMNs of the pancreas, and may represent a carcinogenesis pathway different from that of conventional bile duct carcinomas arising from flat dysplasia. Given their significant risk of harboring invasive carcinoma, they should be treated with complete resection. (Hepatology 2012)
Sustained telomere length in hepatocytes and cholangiocytes with increasing age in normal liver
Authors: Verma Suman , Tachtatzis Phaedra , Penrhyn-Lowe Sue , Scarpini Cinzia , Jurk Diana , Von Zglinicki Thomas , Coleman Nick , Alexander Graeme J. M.
Published: April 2012

Telomeres, a validated biomarker of aging, comprise multiple nucleotide repeats capping chromosomes that shorten with each cell cycle until a critical length is achieved, precipitating cell senescence. Only two previous studies focused on the effect of aging in “normal” liver tissue, but these studies were compromised by small sample size, limited age range, tissue derived from individuals with an increased risk of senescence, and the use of liver homogenates. We developed a robust large-volume, four-color quantitative fluorescent

in situ

hybridization technique to measure telomere length in large numbers of hepatocytes, Kupffer cells, hepatic stellate cells, CD4-positive and CD8-positive lymphocytes, and cholangiocytes. Following validation against the gold standard (Southern blotting), the technique was applied to normal archived paraffin-embedded liver tissue obtained following reperfusion of implanted donor liver. We studied 73 highly selected donors aged 5-79 years with a short medical illness preceding death and no history of liver disease, reperfusion injury, or steatosis and normal graft function 1-year posttransplantation. Cholangiocytes had significantly longer telomeres compared with all other intrahepatic lineages over a wide age range (

P

< 0.05). Age-related telomere attrition was restricted to sinusoidal cells (i.e., Kupffer cells [

P

= 0.0054] and stellate cells [

P

= 0.0001]). Cholangiocytes and hepatocytes showed no age-related telomere shortening.

Conclusion:

In normal liver and over a broad age range, cholangiocytes have longer telomeres than all other intrahepatic lineages. Age-related telomere length decline is restricted to Kupffer cells and stellate cells. (Hepatology 2012)
Revisiting concepts of visceral nociception in irritable bowel syndrome
Authors: Keszthelyi D. , Troost F.J. , Simrén M. , Ludidi S. , Kruimel J.W. , Conchillo J.M. , Masclee A.A.
Published: April 2012

Background and Objective

Irritable bowel syndrome (IBS) is a common disorder characterized by abdominal pain related to defecation with a change in bowel habit. Patients with IBS often exhibit increased visceral sensitivity, which can be tested clinically by rectal balloon distension procedures. This paper aims to give an overview of mechanisms involved in visceral hypersensitivity in IBS by reviewing recent literature.

Databases and Data Treatment

A literature search in the electronic databases Pubmed and MEDLINE was executed using the search terms ‘visceral pain’ or ‘visceral nociception’ or ‘visceral hypersensitivity’ and ‘irritable bowel syndrome.’ Both original articles and review articles were considered for data extraction.

Results

Recent advances in molecular neurophysiology provide knowledge to better understand the underlying mechanism in pain generation in the human gut, in particular, in IBS patients. Sensitization of peripheral nociceptive afferents, more specifically high‐threshold afferents, has been proposed as one of the principle mechanism in the development of visceral hypersensitivity. On the other hand, central mechanisms also play an important role. In terms of clinical testing of visceral perception, considerable discrepancies remain, however, across different centres.

Conclusion

Alterations in the modulatory balance of pro‐ and antinociceptive central processing of noxious peripheral input may serve as in integrative hypothesis for explaining visceral hypersensitivity in IBS. Nevertheless, it remains troublesome to estimate the contribution of central and peripheral factors in visceral hypersensitivity, posing a challenge in determining effective therapeutic entities.
Cognitive‐Behavioral Conjoint Therapy for Posttraumatic Stress Disorder: Application to a Couple's Shared Traumatic Experience
Authors: Brown‐Bowers Amy , Fredman Steffany J. , Wanklyn Sonya G. , Monson Candice M.
Published: April 2012

Cognitive‐behavioral conjoint therapy for posttraumatic stress disorder (CBCT for PTSD) is designed to improve PTSD symptoms and enhance intimate relationship adjustment. Phase 1 includes psychoeducation about the reciprocal influences of PTSD symptoms and relationship functioning, exercises to promote positive affect and behaviors, and conflict management skills. In Phase 2, behavioral methods are used to address avoidance and emotional numbing and to increase relationship satisfaction. Couples engage in activities to promote approaching, rather than avoiding, feared situations. Phase 3 focuses on specific trauma appraisals and here‐and‐now cognitions that maintain PTSD and relationship problems. This article provides an overview of the treatment, a review of the outcome research, and a case illustration of a couple with a shared trauma (a stillborn child).
Family Consultation for Psychiatrically Complicated Health Problems
Authors: Rohrbaugh Michael J. , Kogan Anya V. , Shoham Varda
Published: April 2012

We describe a social cybernetic view of health behavior problems and a team‐based family consultation (FAMCON) format for strategic intervention based on that view. This approach takes relationships rather than individuals as the primary unit of analysis and attaches more importance to problem maintenance than to etiology. Treatment aims to interrupt two types of interpersonal problem maintenance—ironic processes and symptom‐system fit (conceptualized, respectively, as positive and negative feedback cycles)—and to mobilize communal coping as a relational resource for change. A case example features a depressed husband and bipolar wife complaining of severe communication difficulties related to the husband's kidney cancer and diabetes. Over 6 consultation sessions, strategic interventions focused on interrupting ironic interpersonal patterns resolved the presenting complaint. Although cost‐effectiveness is an open question, FAMCON may offer a useful alternative to psychoeducational and cognitive‐behavioral treatments in the framework of stepped care.
Covalent attachment of P15 peptide to titanium surfaces enhances cell attachment, spreading, and osteogenic gene expression
Authors: Liu Qinyi , Limthongkul Worawat , Sidhu Gursukhmandeep , Zhang Jun , Vaccaro Alexander , Shenck Ryan , Hickok Noreen , Shapiro Irving , Freeman Theresa
Published: April 2012

P15, a synthetic 15 amino acid peptide, mimics the cell‐binding domain within the alpha‐1 chain of human collagen is being tested in clinical trials to determine if it enhances bone formation in spinal fusions. We hypothesize that covalent attachment of P15 to titanium implants may also serve to promote osseointegration. To test this hypothesis, we measured osteoblast and mesenchymal cell adhesion, proliferation, and maturation on P15 tethered to a titanium (Ti‐P15) surface. P15 peptide was covalently bonded to titanium alloy surfaces and incubated with osteoblast like cells. Cell toxicity, adhesion, spreading, and differentiation was then evaluated. Real‐time quantitative PCR, Western blot analysis, and fluorescent immunohistochemistry was performed to measure osteoblast gene expression and differentiation. There was no evidence of toxicity. Significant increases in early cell attachment, spreading, and proliferation were observed on the Ti‐P15 surface. Increased filapodial attachments, α2 integrin expression, and phosphorylated focal adhesion kinase immunostaining indicated activation of integrin signaling pathways. qRT‐PCR analysis indicated there was significant increase in osteogenic differentiation markers in cells grown on Ti‐P15 compared to control‐Ti. Western blotting confirmed these findings. Surface modification of titanium with P15 significantly increased cell attachment, spreading, osteogenic gene expression, and differentiation. Results of this study suggest that Ti‐P15 has the potential to safely enhance bone formation and promote osseointegration of titanium implants. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1626–1633, 2012
The role of systematic reviews of qualitative evidence in evaluating interventions: a case study
Authors: Lorenc Theo , Pearson Mark , Jamal Farah , Cooper Chris , Garside Ruth
Published: April 2012

Systematic reviews of qualitative evidence have been widely used to provide information on the context and implementation of interventions, and their potential barriers and facilitators. However, such reviews face a number of methodological challenges, and there are ongoing debates as to how qualitative evidence can best be used to inform our understanding of interventions. In this paper, we use a case study of two systematic reviews of qualitative evidence on the prevention of skin cancer to explore these issues. We find that qualitative evidence not directly related to interventions is likely to be of value for such reviews, that it is often not possible to construct fully comprehensive search strategies, and that there are diminishing returns to the synthesis, in terms of added value or insight, from the inclusion of large numbers of primary studies. We conclude that there are a number of ways in which systematic reviews of qualitative evidence can be utilised in conjunction with evidence on intervention effectiveness, without compromising the rigour of the review process. In particular, the use of theory to inform frameworks for synthesis is a promising way to integrate a broader range of qualitative evidence. Copyright © 2012 John Wiley & Sons, Ltd.
An investigation of the transmission and attenuation of intense pulsed light on samples of human Achilles tendon and surrounding tissue
Authors: Hutchison A.M. , Beard D.J. , Bishop J. , Pallister I. , Davies W.
Published: April 2012

Background

Light therapy is a common mode of treatment for musculoskeletal injuries but the depth of penetration of light radiation is controversial. Evidence exists for the efficacy of intense pulsed light (IPL) treatment for the rejuvenation of skin (superficial tissue) but it is not known if the IPL can penetrate deeper. If the IPL can penetrate to the depth of the Achilles tendon it may provide a potential management options in the treatment of a chronic mid‐body Achilles tendinopathy.

Objectives

To examine if any optical radiation produced by an IPL transmits to the depth of the Achilles tendon when applied cutaneously to excised samples of human Achilles tissue. A secondary aim was to establish the relative amount of optical radiation that was attenuated within the tendon.

Materials and Methods

Three samples of human Achilles tendon and surrounding tissue were harvested following elective lower limb amputation operations. Each sample was irradiated 2–6 cm above the insertion into the calcaneus (area of an Achilles tendinopathy) with IPL (model iPulse; Cyden Ltd, Wales, UK) set at a single pulse of 25 millisecond, wavelength range 530–1,110 nm and fluence of 13 J/cm2. The transmission of light radiation was evaluated using (a) standard SLR digital camera, (b) spectrometer, and (c) an external energy meter.

Results

Light radiation was found to have transmitted through each of the three tissue samples by all three instruments. There were observable differences in the color of light detected for the control photo and the IPL irradiated tissue samples photographs. The percentage of fluence that was detected to have transmitted through the tissue samples by the energy meter was 4–8.1% and wavelengths between 645 and 843 nm were detected to have transmitted through the tissue by the spectrometer. In addition, the percentage of light radiation that attenuated with the tendon was 10.2–17.32%.

Conclusion

The results of this study provides evidence that IPL penetrates to the depth of the Achilles tendon and attenuates with the tendon. IPL has potential to produce physiological effects in the treatment of patients with a chronic mid‐body Achilles tendinopathy. Lasers Surg. Med. 44: 397–405, 2012. © 2012 Wiley Periodicals, Inc.
Proofs with monotone cuts
Authors: Jeřábek Emil
Published: April 2012

Atserias, Galesi, and Pudlák have shown that the monotone sequent calculus MLK quasipolynomially simulates proofs of monotone sequents in the full sequent calculus LK (or equivalently, in Frege systems). We generalize the simulation to the fragment MCLK of LK which can prove arbitrary sequents, but restricts cut‐formulas to be monotone. We also show that MLK as a refutation system for CNFs quasipolynomially simulates LK.
A reliable study for extensions of the Bratu problem with boundary conditions
Authors: Wazwaz Abdul‐Majid
Published: April 2012

In this paper, we present a reliable study on extensions of the Bratu problem with boundary conditions. The work rests mainly on Adomian decomposition method and Padé approximants. The study shows a variety of approximations, one for each extension. The work highlights the effect of the extensions on the structure of the approximate solutions. Copyright © 2012 John Wiley & Sons, Ltd.
Chemical shift encoded water–fat separation using parallel imaging and compressed sensing
Authors: Sharma Samir D. , Hu Houchun H. , Nayak Krishna S.
Published: April 2012

Chemical shift encoded techniques have received considerable attention recently because they can reliably separate water and fat in the presence of off‐resonance. The insensitivity to off‐resonance requires that data be acquired at multiple echo times, which increases the scan time as compared to a single echo acquisition. The increased scan time often requires that a compromise be made between the spatial resolution, the volume coverage, and the tolerance to artifacts from subject motion. This work describes a combined parallel imaging and compressed sensing approach for accelerated water–fat separation. In addition, the use of multiscale cubic B‐splines for B0 field map estimation is introduced. The water and fat images and the B0 field map are estimated via an alternating minimization. Coil sensitivity information is derived from a calculated k‐space convolution kernel and l1‐regularization is imposed on the coil‐combined water and fat image estimates. Uniform water–fat separation is demonstrated from retrospectively undersampled data in the liver, brachial plexus, ankle, and knee as well as from a prospectively undersampled acquisition of the knee at 8.6x acceleration. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Selective homonuclear polarization transfer for spectroscopic imaging of GABA at 7T
Authors: Pan J. W. , Duckrow R. B. , Spencer D. D. , Avdievich N. I. , Hetherington H. P.
Published: April 2012

We develop and implement a selective homonuclear polarization transfer method for the detection of 3.0 ppm C‐4 GABA resonance by spectroscopic imaging in the human brain at 7T. This single shot method is demonstrated with simulations and phantoms, which achieves comparable efficiency of detection to that of J‐difference editing. The macromolecule resonance that commonly co‐edits with GABA is suppressed at 7T through use of a narrow band preacquisition suppression pulse. This technique is implemented in humans with an eight channel transceiver array and high degree B0 shimming to measure supplementary motor area and thalamic GABA in controls (n = 8) and epilepsy patients (n = 8 total). We find that the GABA/N‐acetyl aspartate ratio in the thalamus of control volunteers, well controlled and poorly controlled epilepsy patients are 0.053 ± 0.012 (n = 8), 0.090 ± 0.012 (n = 2), and 0.038 ± 0.009 (n = 6), respectively. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
A new method for detecting exchanging amide protons using chemical exchange rotation transfer
Authors: Zu Zhongliang , Janve Vaibhav A. , Xu Junzhong , Does Mark D. , Gore John C. , Gochberg Daniel F.
Published: April 2012

In this study, we introduce a new method for amide proton transfer imaging based on chemical exchange rotation transfer. It avoids several artifacts that plague conventional chemical exchange saturation transfer approaches by creating label and reference scans based on varying the irradiation pulse rotation angle (π and 2π radians) instead of the frequency offset (3.5 and −3.5 ppm). Specifically, conventional analysis is sensitive to confounding contributions from magnetic field (B0) inhomogeneities and, more problematically, inherently asymmetric macromolecular resonances. In addition, the lipid resonance at −3.5 ppm complicates the interpretation of the reference scan and decreases the resulting contrast. Finally, partial overlap of the amide signal by nearby amines and hydroxyls obscure the results. By avoiding these issues, our new method is a promising approach for imaging endogenous protein and peptide content and mapping pH. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
PEO‐like Plasma Polymers Prepared by Atmospheric Pressure Surface Dielectric Barrier Discharge
Authors: Gordeev Ivan , Choukourov Andrei , Šimek Milan , Prukner Václav , Biederman Hynek
Published: April 2012

This work investigates the properties of poly(ethylene oxide)‐like plasma polymers prepared by amplitude‐modulated AC surface dielectric barrier discharge at atmospheric pressure. The discharge was driven in argon with admixtures of di(ethylene glycol) vinyl ether and special attention was paid to optimization of the experimental parameters for fabrication of thin films with enhanced retention of ether structure. Chemical composition of the plasma polymers was studied by XPS and FTIR whereas their non‐fouling properties were tested in terms of adsorption of fibrinogen. Under investigated range of discharge conditions, plasma polymers with up to 70% retention of the poly(ethylene oxide) character and with non‐fouling properties were obtained.

magnified image
Mutagenesis of the bovSERPINA3‐3 demonstrates the requirement of aspartate‐371 for intermolecular interaction and formation of dimers
Authors: Blanchet X. , Péré‐Brissaud A. , Duprat N. , Pinault E. , Delourme D. , Ouali A. , Combet C. , Maftah A. , Pélissier P. , Brémaud L.
Published: April 2012

The family of serpins is known to fold into a metastable state that is required for the proteinase inhibition mechanism. One of the consequences of this conformational flexibility is the tendency of some mutated serpins to form polymers, which occur through the insertion of the reactive center loop of one serpin molecule into the A‐sheet of another. This “A‐sheet polymerization” has remained an attractive explanation for the molecular mechanism of serpinopathies. Polymerization of serpins can also take place in vitro under certain conditions (e.g., pH or temperature). Surprisingly, on sodium dodecyl sulfate/polyacrylamide gel electrophoresis, bovSERPINA3‐3 extracted from skeletal muscle or expressed in Escherichia coli was mainly observed as a homodimer. Here, in this report, by site‐directed mutagenesis of recombinant bovSERPINA3‐3, with substitution D371A, we demonstrate the importance of D371 for the intermolecular linkage observed in denaturing and reducing conditions. This residue influences the electrophoretic and conformational properties of bovSERPINA3‐3. By structural modeling of mature bovSERPINA3‐3, we propose a new “non‐A‐sheet swap” model of serpin homodimer in which D371 is involved at the molecular interface.
Graphene coupling to circularly polarized photons
Authors: Kibis O. V.
Published: April 2012

We have demonstrated theoretically that the Dirac electron spectrum of graphene leads to the strong electron in‐teraction with circularly polarized photons for low light intensities. This results in bound electron‐photon states (charged quasiparticles) which should be considered as a substantially new kind of light‐matter coupling.

The energy spectrum of the quasiparticles is of dielectric type, that leads to the photon‐induced metal‐insulator transition in graphene. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallization of hydrogenated amorphous‐nanocrystalline silicon films under high‐pressure annealing
Authors: Tyschenko Ida , Volodin Vladimir , Misiuk Andrzej
Published: April 2012

Crystallization of the hydrogen ion implanted silicon‐on‐insulator (SOI) layers under conditions of high‐pressure (10.5 kbar) annealing at the temperature Ta = 450‐1000 °C was investigated by Raman spectroscopy. The as‐implanted films had composite structure consisted of the Si nanocrystals surrounded by the hydrogenated amorphous silicon. The retardation of hydrogenated Si crystallization was obtained under high‐pressure annealing at the temperature higher than 600 °C. The SOI layers remained to be nanocrystalline up to the annealing temperature of 1000 °C. The average size of the nanocrystals and the crystalline volume fraction were estimated from the Raman spectra as a function of the annealing temperature. The origin of the pressure effect on the crystallization of hydrogenated silicon is discussed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aqueous bromine etching of InP: a specific surface chemistry
Authors: Causier A. , Bouttemy M. , Gérard I. , Aureau D. , Vigneron J. , Etcheberry A.
Published: April 2012

The n ‐InP behaviour in HBr (0.1‐1.0 M)/Br2 (1.25 × 10‐2M) aqueous solutions is studied by AAS, XPS and SEM‐FEG. Indium AAS‐titrations of the HBr/Br2 solutions demonstrate that InP undergoes an etching mechanism whatever the HBr/Br2 formulation. The etching process is always linear with time but its rate depends on the HBr concentration. XPS analyses permit to link the apparent slow‐down of the dissolution process when decreasing the HBr molarity from 1.0 M to 0.1 M to the presence of a mixed (In,P)ox oxide layer on the surface. Therefore, the dissolution process of InP in HBr/Br2 solution appears to be ruled by the surface chemical state (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Confinement of electrons in a geometrically patterned non‐circular two‐dimensional semiconductor quantum dot
Authors: Ciftja Orion , Rasco Torrance , Vargas Guillermo , Dunn Stevonnise
Published: April 2012

Semiconductor quantum dots are artificial nanoscale systems in which charge carriers, such as electrons, are usually confined in a small two‐dimensional (2D) region of space. In many occasions the confinement potential of the electrons is considered to be circularly symmetric with the parabolic form as the most commonly used one. Despite the variety of other confinement potentials with both infinite and finite range, all these choices share the property that the potential is circular in space. While these confinement models can be very good in many circumstances, there are situations in which the experimental setup in a semiconductor quantum dot involves application of several gate potentials which have very sharp geometric features. In these experimental instances, the area depleted of electrons, that represents the confining region is not circular and many times is better approximated as square or rectangular in shape. In this work we introduce a confinement potential that describes the confinement of electrons in a non‐circular2D semiconductor quantum dot in which the domain where the electrons are confined has a square or rectangular geometric shape. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Balancing the atomic waistline: Isodensity‐based scrf radii for main‐group elements and transition metals
Authors: Tao Jia‐Yuan , Mu Wei‐Hua , Chass Gregory Adam , Tang Ting‐Hua , Fang De‐Cai
Published: April 2012

Toward cracking the problem of understanding, characterizing, and predicting “solvent‐effect” while the world awaits an effective explicit solvent model, we introduce and justify herein a novel set of atomic radii to be used within the most commonly used continuum reaction field, the polarizable continuum model (PCM). The radial values emerge from a quantitative description of the elemental electronic density distribution and are shown to be accurate in such a self‐consistent reaction field (SCRF); labeled accordingly as isodensity‐based SCRF (IDSCRF) radii. Transition row elements with dynamic oxidation states are addressed through an averaging of the electronic properties from all states in the determination of their effective radii. All results for nonmetal elements have been verified with Guthrie's SAMPLE1 test set and are in quantitative agreement with experimental values from the literature and self‐consistent isodensity polarizable continuum model (SCIPCM) calculations. For the compounds with transition metal elements, our IDSCRF results have been verified with SCIPCM results as there are rarely experimental results available. Finally, explicit solvent particles “solvating” Pd‐ and Ni‐containing homogeneous catalysts are also shown to be in close agreement with the IDSCRF radii calculations. © 2012 Wiley Periodicals, Inc.
Quantum chemical study on molecular‐level affinity of DJ‐1 binding compounds
Authors: Shigemitsu Yasuhiro
Published: April 2012

The computationally evaluated binding free energies of DJ‐1, a clue protein to Parkinson's disease, with three potential curative agents are presented and discussed. The simple docking analysis offered fair absolute agreements of the calculated and the experimental binding energies while it failed to predict the binding affinity rank among the candidates. Computationally demanding analysis based on molecular dynamics and quantum chemical calculations unexpectedly worsen the gap between theory and experiment. The failure presumably comes from the inaccurate enthalpy terms owing to the basis set quality limitation and dispersion energy uncertainties, as well as from the inaccuracies of the entropy terms. The interfragment interaction analysis elucidated the driving force of the receptor–ligand affinity, which is not driven by Cys106 (the active site) but by the surrounding residues. © 2012 Wiley Periodicals, Inc.