bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Antioxidant Activity of a New Class of Bis and Tris Heterocycles
Authors: Padmavathi Venkatapuram , Venkatesh Bhumireddy Chinnachennaiahgari , Muralikrishna Akkarapalli , Padmaja Adivireddy
Published: May 2012

A series of novel heterocycles, bisbenzoxazolyl/benzothiazolyl/benzimidazolyl pyrazoles/isoxazoles/pyrimidines were synthesized and evaluated for their antioxidant activity. The bisbenzoxazolylisoxazole 10 exhibited good antioxidant activity when compared with the standard ascorbic acid.
Synthesis, Cytotoxic Properties and Tubulin Polymerization Inhibitory Activity of Novel 2‐Pyrazoline Derivatives
Authors: Abdel‐Aziz Mohamed , Aly Omar M. , Khan Sabine S. , Mukherjee Kamalika , Bane Susan
Published: May 2012

A series of novel 1‐(3′,4′,5′‐trimethoxybenzoyl)‐3,5‐diarylpyrazoline derivatives were synthesized and evaluated for their cytotoxic properties on different cancer cell lines and tubulin polymerization inhibitory activity. Compounds 6d and 6e exhibited remarkable cytotoxic activity against different cancer cell lines with good tubulin polymerization inhibitory activity. Compound 6d exhibited moderate selectivity toward renal cancer and breast cancer subpanels with selectivity ratios of 3.06 and 5.11, respectively, at the cytostatic activity (TGI) level. Compounds 6e and 6d achieved good tubulin polymerization inhibitory activity with IC50 values of 17 and 40 µM, respectively. The photomicrographs made for compounds 6d and 6e on cellular microtubules indicated that the cytotoxicity of these compounds can be attributed to their ability to interfere with microtubule assembly. Molecular modeling studies involving compound 6e with the colchicine binding site of α,β‐tubulin revealed hydrogen‐bonding and hydrophobic interactions with several amino acids in the colchicine binding site of β‐tubulin.
Synthesis and Biological Evaluation of Andrographolide Derivatives as Potent Anti‐HIV Agents
Authors: Tang Chunlei , Liu Yajuan , Wang Bin , Gu Guolong , Yang Liumeng , Zheng Yongtang , Qian Hai , Huang Wenlong
Published: May 2012

In an attempt to develop potent anti‐HIV drugs, 20 andrographolide derivatives were designed, synthesized, and evaluated for their in vitro anti‐HIV activity. The screening results revealed that five compounds showed potent anti‐HIV activities with therapeutic indices (TI) above 10. The most promising compound 6f shows a significant TI close to 34.07, with the potency to be a new lead.
Comparative reaction engineering studies for succinic acid production from sucrose by metabolically engineered Escherichia coli in fed‐batch‐operated stirred tank bioreactors
Authors: Hoefel Torben , Faust Georg , Reinecke Liv , Rudinger Nicolas , Weuster‐Botz Dirk
Published: May 2012

This study presents a comparative reaction engineering analysis of metabolically engineered sucrose‐utilizing Escherichia coli derived from E. coli K12 MG1655 for the anaerobic production of succinic acid. Production capacities of 16 different recombinant strains were evaluated in 48 parallel fed‐batch‐operated milliliter‐scale stirred tank bioreactors (10 mL) with continuous CO2 sparging. The effects of recombinant sucrose‐utilization systems (csc‐operon or scr‐operon), enhancements of anaplerotic reactions (pck, ppc, maeA, maeB or heterologous pyc) and gene deletions (ldhA, adhE, ack‐pta and ptsG) were studied with respect to the overall process performances of the respective recombinant strains. Both sucrose‐utilization systems enabled the production of succinic acid from sucrose in E. coli K12 MG1655. Maximum succinate production was observed by overexpressing the pyruvate carboxylase from Corynebacterium glutamicum resulting in a succinate concentration of 26.8 g L–1 after 48 h and a cell‐specific productivity of 0.14 g g–1 h–1. Further experiments in a fed‐batch‐operated laboratory‐scale stirred tank bioreactor (2 L) showed that micro‐aerobic conditions preceding the anaerobic phase enhance succinic acid production of E. coli K12 MG1655‐derived strains. The work demonstrates the importance of parallel approaches within the scope of applied metabolic engineering studies.
Silica biotemplating by self‐assembling peptides via serine residues activated by the peptide amino terminal group
Authors: Kasotakis Emmanouil , Mitraki Anna
Published: May 2012

Self‐assembling biological materials increasingly serve as templates for the binding of inorganic materials and fabrication of composite nanowires, tubes, etc. with important applications in nanobiotechnology. We have previously reported the use of a self‐assembling octapeptide building block as scaffold for the systematic introduction of metal‐binding residues, namely cysteines, at the first two amino acids within the sequence (Kasotakis et al., Biopolymers 2009, 92, 164‐172). We have also reported unexpected behavior of serine within the octapeptide NH2NSGAITIGCONH2 (Asparagine‐Serine‐Glycine‐Alanine‐Isoleucine‐Threonine‐Isoleucine‐Glycine) in nucleating gold and platinum nanoparticles. Herein, we report that this serine residue is instrumental in nucleating silica nanoparticles on the surface of the self‐assembled fibrils from TEOS (tetraethyl orthosilicate) precursors. We carried out a systematic investigation of the adjacent functionalities and we propose that this serine residue is rendered abnormally nucleophilic through proton abstraction by the N‐terminal amino group of the peptide. Peptides with a threonine or a cysteine residue at position 2 are also able to nucleate silica nanoparticles. We propose that rationally designed self‐assembling peptides bearing hydroxyl groups adjacent to free amine functionalities could be used for targeted templating of biogenic and even nonbiogenic oxides. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 501–509, 2012.
Engineering biomaterials to integrate and heal: The biocompatibility paradigm shifts
Authors: Bryers James D. , Giachelli Cecilia M. , Ratner Buddy D.
Published: May 2012

This article focuses on one of the major failure routes of implanted medical devices, the foreign body reaction (FBR)—that is, the phagocytic attack and encapsulation by the body of the so‐called “biocompatible” biomaterials comprising the devices. We then review strategies currently under development that might lead to biomaterial constructs that will harmoniously heal and integrate into the body. We discuss in detail emerging strategies to inhibit the FBR by engineering biomaterials that elicit more biologically pertinent responses. Biotechnol. Bioeng. 2012; 109:1898–1911. © 2012 Wiley Periodicals, Inc.
Network‐Assisted Investigation of Antipsychotic Drugs and Their Targets
Authors: Sun Jingchun , Xu Hua , Zhao Zhongming
Published: May 2012

Antipsychotic drugs are tranquilizing psychiatric medications primarily used in the treatment of schizophrenia and similar severe mental disorders. So far, most of these drugs have been discovered without knowing much on the molecular mechanisms of their actions. The available large amount of pharmacogenetics, pharmacometabolomics, and pharmacoproteomics data for many drugs makes it possible to systematically explore the molecular mechanisms underlying drug actions. In this study, we applied a unique network‐based approach to investigate antipsychotic drugs and their targets. We first retrieved 43 antipsychotic drugs, 42 unique target genes, and 46 adverse drug interactions from the DrugBank database and then generated a druggene network and a drugdrug interaction network. Through druggene network analysis, we found that seven atypical antipsychotic drugs tended to form two clusters that could be defined by drugs with different target receptor profiles. In the drugdrug interaction network, we found that three drugs (zuclopenthixol, ziprasidone, and thiothixene) tended to have more adverse drug interactions than others, while clozapine had fewer adverse drug interactions. This investigation indicated that these antipsychotics might have different molecular mechanisms underlying the drug actions. This pilot network‐assisted investigation of antipsychotics demonstrates that network‐based analysis is useful for uncovering the molecular actions of antipsychotics.
Enantio‐ and Chemoselective Differentiation of Protected α‐Amino Acids and β‐Homoamino Acids with a Single Copper(II) Host
Authors: Joyce Leo A. , Canary James W. , Anslyn Eric V.
Published: May 2012

The association between an achiral copper(II)‐containing host 1 and chiral carboxylates has been expanded beyond previous studies to new chiral carboxylate guests, both α‐amino acids and β‐homoamino acids. The observed exciton‐coupled circular dichroism (ECCD) signals for the enantiomers of each carboxylate were equal and opposite, and these signals differed in size and shape between the individual amino acids. Linear discriminant analysis (LDA) was applied as a statistical analysis technique to differentiate the amino acids, both enantioselectively and chemoselectively, giving the absolute configuration and identity of the amino acid. The identity of each of the α‐amino acids and β‐homoamino acids were determined independently by LDA, and then the two were considered together. Each of these analyses showed good differentiation of the amino acid guests with the use of only one host molecule.
Predicting Drug Metabolism by Cytochrome P450 2C9: Comparison with the 2D6 and 3A4 Isoforms
Authors: Rydberg Patrik , Olsen Lars
Published: May 2012

By the use of knowledge gained through modeling of drug metabolism mediated by the cytochrome P450 2D6 and 3A4 isoforms, we constructed a 2D‐based model for site‐of‐metabolism prediction for the cytochrome P450 2C9 isoform. The similarities and differences between the models for the 2C9 and 2D6 isoforms are discussed through structural knowledge from the X‐ray crystal structures and trends in experimental data. The final model was validated on an independent test set, resulting in an area under the curve value of 0.92, and a site of metabolism was found among the top two ranked atoms for 77 % of the compounds.
Review and perspective: neuromechanical considerations for predicting muscle activation patterns for movement
Authors: Ting Lena H. , Chvatal Stacie A. , Safavynia Seyed A. , Lucas McKay J.
Published: May 2012

Muscle coordination may be difficult or impossible to predict accurately based on biomechanical considerations alone because of redundancy in the musculoskeletal system. Because many solutions exist for any given movement, the role of the nervous system in further constraining muscle coordination patterns for movement must be considered in both healthy and impaired motor control. On the basis of computational neuromechanical analyses of experimental data combined with modeling techniques, we have demonstrated several such neural constraints on the temporal and spatial patterns of muscle activity during both locomotion and postural responses to balance perturbations. We hypothesize that subject‐specific and trial‐by‐trial differences in muscle activation can be parameterized and understood by a hierarchical and low‐dimensional framework that reflects the neural control of task‐level goals. In postural control, we demonstrate that temporal patterns of muscle activity may be governed by feedback control of task‐level variables that represent the overall goal‐directed motion of the body. These temporal patterns then recruit spatially‐fixed patterns of muscle activity called muscle synergies that produce the desired task‐level biomechanical functions that require multijoint coordination. Moreover, these principles apply more generally to movement, and in particular to locomotor tasks in both healthy and impaired individuals. Overall, understanding the goals and organization of the neural control of movement may provide useful reduced dimension parameter sets to address the degrees‐of‐freedom problem in musculoskeletal movement control. More importantly, however, neuromechanical analyses may lend insight and provide a framework for understanding subject‐specific and trial‐by‐trial differences in movement across both healthy and motor‐impaired populations. Copyright © 2012 John Wiley & Sons, Ltd.
Well‐being, Positivity and Mental Health: An Introduction to the Special Issue
Authors: MacLeod Andrew K.
Published: May 2012

Enhancing well‐being, as opposed to reducing distress, has traditionally not been a focus for clinical practice. There are differences in views about the nature of well‐being, but enhancing well‐being in clinical settings is a straightforward goal whatever concept of well‐being is adopted. Reasons for adopting a well‐being enhancing, as well as a distress‐reducing, focus include the fact that many psychological problems do not fit the simple acute treatment model of disorder, that positive experience inhibits negative experience, and that people can benefit from therapists seeing them as more than the sum of their problems. In recent years, well‐being has been of increasing interest to researchers and clinicians, and enhancing well‐being is emerging as a potentially valuable element of effective clinical practice. Copyright © 2012 John Wiley & Sons, Ltd.

Key Practitioner Message

Enhancing well-being has been relatively neglected as a therapeutic goal.

There are good reasons for seeing well‐being enhancement as a valuable goal for clinical practice, alongside the more traditional goal of distress‐reduction.

Useful work is emerging in this area from clinicians and clinical researchers.
Ethanol‐induced locomotor activity in adolescent rats and the relationship with ethanol‐induced conditioned place preference and conditioned taste aversion
Authors: Acevedo María Belén , Nizhnikov Michael E. , Spear Norman E. , Molina Juan C. , Pautassi Ricardo M.
Published: May 2012

Adolescent rats exhibit ethanol‐induced locomotor activity (LMA), which is considered an index of ethanol's motivational properties likely to predict ethanol self‐administration, but few studies have reported or correlated ethanol‐induced LMA with conditioned place preference (CPP) by ethanol at this age. The present study assessed age‐related differences in ethanol's motor stimulating effects and analyzed the association between ethanol‐induced LMA and conventional measures of ethanol‐induced reinforcement. Experiment 1 compared ethanol‐induced LMA in adolescent and adult rats. Subsequent experiments analyzed ethanol‐induced CPP and conditioned taste aversion (CTA) in adolescent rats evaluated for ethanol‐induced LMA. Adolescent rats exhibit a robust LMA after high‐dose ethanol. Ethanol‐induced LMA was fairly similar across adolescents and adults. As expected, adolescents were sensitive to ethanol's aversive reinforcement, but they also exhibited CPP. These measures of ethanol reinforcement, however, were not related to ethanol‐induced LMA. Spontaneous LMA in an open field was, however, negatively associated with ethanol‐induced CTA. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 429–442, 2013
Synaptotagmin‐1 promotes the formation of axonal filopodia and branches along the developing axons of forebrain neurons
Authors: Greif Karen F. , Asabere Nana , Lutz Gordon J. , Gallo Gianluca
Published: May 2012

Synaptotagmin‐1 (syt1) is a Ca2+‐binding protein that functions in regulation of synaptic vesicle exocytosis at the synapse. Syt1 is expressed in many types of neurons well before synaptogenesis begins both in vivo and in vitro. To determine if expression of syt1 has a functional role in neuronal development before synapse formation, we examined the effects of syt1 overexpression and knockdown on the growth and branching of the axons of cultured primary embryonic day 8 chicken forebrain neurons. In vivo these neurons express syt1, and most have not yet extended axons. We present evidence that syt1 plays a role in regulating axon branching, while not regulating overall axon length. To study the effects of overexpression of syt1, we used adenovirus‐mediated infection to introduce a syt1‐YFP construct, or control GFP construct, into neurons. Syt1 levels were reduced using RNA interference. Overexpression of syt1 increased the formation of axonal filopodia and branches. Conversely, knockdown of syt1 decreased the number of axonal filopodia and branches. Time‐lapse analysis of filopodial dynamics in syt1‐overexpressing cells demonstrated that elevation of syt1 levels increased both the frequency of filopodial initiation and their lifespan. Taken together these data indicate that syt1 regulates the formation of axonal filopodia and branches before engaging in its conventional functions at the synapse. © 2011 Wiley Periodicals, Inc. Develop Neurobiol, 2013
Highly Efficient Dehydrogenation of 5‐Benzyl‐3‐phenyl‐2‐thioxoimidazolidin‐4‐one: Microwave versus Flash Vacuum Pyrolysis Conditions
Authors: Pepino Ana J. , Peláez Walter J. , Moyano Elizabeth L. , Argüello Gustavo A.
Published: May 2012

5‐Benzyl‐3‐phenyl‐2‐thioxoimidazolidin‐4‐one underwent thermal dehydrogenation to afford 5‐benzylidene‐2‐thioxoimidaxolidin‐4‐one under microwave and flash vacuum pyrolysis conditions. A high predominance of the Z‐isomer over the E‐isomer of the imidazolidinone product was achieved. By using DFT and NBO calculations, the mechanism of the dehydrogenation and the selectivity were also explored.
Solid‐Phase Synthesis of 5′‐O‐[N‐(Acyl)sulfamoyl]adenosine Derivatives
Authors: Redwan Itedale Namro , Ingemyr Hanna Jacobson , Ljungdahl Thomas , Lawson Christopher P. , Grøtli Morten
Published: May 2012

The solid‐phase synthesis of 5′‐O‐[N‐(acyl)sulfamoyl]adenosine derivatives is described. The use of a Rink amide polystyrene solid support together with an appropriately protected ribo‐purine starting material allowed for the development of a highly reliable and practical route for the solid‐phase synthesis of 5′‐O‐[N‐(acyl)sulfamoyl]adenosines. The developed procedure enables the efficient parallel synthesis of the target compounds in high yields. These compounds are non‐hydrolysable isosteres of acyl‐adenylates, which play an important role in a range of different metabolic pathways such as ribosomal and non‐ribosomal peptide synthesis, fatty acid oxidation or enzyme regulation; some adenylate‐forming enzymes are potential drug targets.
Planar‐Chiral Bis‐silanols and Diols as H‐Bonding Asymmetric Organocatalysts
Authors: Beemelmanns Christine , Husmann Ralph , Whelligan Daniel K. , Özçubukçu Salih , Bolm Carsten
Published: May 2012

The successful development of planar‐chiral bis‐silanols 3a–d and their application as asymmetric organocatalysts in hetero‐Diels–Alder (HDA) reactions is described. All precursors were easily prepared by addition of commerically available silyl electrophiles to a dilithiated [2.2]paracyclophane derivative followed by silane oxidations. The analogous bis‐carbinols 7a–c have been prepared by addition of suitable Grignard reagents to bis‐methoxycarbonyl derivative 6. Both racemic as well as enantiopure planar‐chiral bis‐silanols and bis‐carbinols were obtained in good yields. The catalytic activities of the bis‐silanols were analyzed by monitoring HDA reactions between Rawal's diene and aldehydes by in situ IR spectroscopy and comparing the resulting data with those obtained in catalyses with the corresponding bis‐carbinol derivatives. The results show for the first time that planar‐chiral bis‐silanols with hydrogen‐bonding capabilities can be applied as asymmetric organocatalysts leading to enantiomerically enriched products.
Depression subtypes and 5‐year risk of dementia and Alzheimer disease in patients aged 70 years
Authors: Vilalta‐Franch Joan , López‐Pousa Secundino , Llinàs‐Reglà Jordi , Calvó‐Perxas Laia , Merino‐Aguado Javier , Garre‐Olmo Josep
Published: May 2012

Objective

The objective of this study was to estimate several subtypes of depressive disorders as risk factors for dementia and Alzheimer disease (AD) specifically.

Methods

This is a population‐based cohort study using a sample of 451 non‐demented older people. Adjusted Cox proportional hazard models were calculated to determine the association of depression with dementia or AD development after 5 years. Baseline evaluation included the Cambridge Mental Disorders of the Elderly Examination (CAMDEX). Depressive disorders (major episode [MD] and minor depressive disorders [MDDIS]) were assessed following DSM‐IV criteria and further classified according to the age at onset (early versus late onset). In turn, all late‐onset depressions were grouped as with or without depression‐executive dysfunction syndrome (DEDS). Dementia (and dementia subtypes) diagnoses were made using the CAMDEX. When the patients were deceased, the Retrospective Collateral Dementia Interview was used.

Results

Late‐onset depressions (both MD and MDDIS) were associated with increased dementia (hazard ratio [HR] = 2.635; 95% CI = 1.153–6.023; and HR = 2.517; 95% CI = 1.200–5.280, respectively), and AD (HR = 6.262; 95% CI = 2.017–19.446; and HR = 4.208; 95% CI = 1.828–9.685, respectively) after adjustment by age, gender, marital status, education, cognitive impairment, executive function and stroke history. A second model revealed that only late‐onset depressions with DEDS increased the risk for both dementia (late‐onset MD with DEDS: HR = 6.262; 95% CI = 2.017–19.446; late‐onset MDDIS with DEDS: HR = 4.208; 95% CI = 1.828–9.685) and AD (late‐onset MD with DEDS: HR = 7.807; 95% CI = 1.567–38.894; late‐onset MDDIS with DEDS: HR = 6.099; 95% CI = 2.123–17.524).

Conclusions

Late‐onset depressive episodes with DEDS are risk factors for dementia and AD development, regardless of the severity of the depression. Copyright © 2012 John Wiley & Sons, Ltd.
The diagnosis of depression and use of antidepressants in nursing home residents with and without dementia
Authors: van Asch Iris F. M. , Nuyen Jasper , Veerbeek Marjolein A. , Frijters Dinnus H. M. , Achterberg Wilco P. , Pot Anne Margriet
Published: May 2012

Objective

To compare the prevalence of diagnosed depressive disorders, depressive symptoms and use of antidepressant medication between nursing home residents with and without dementia.

Methods

This cross‐sectional study used Minimal Data Set of the Resident Assessment Instrument 2.1 data collected in seven nursing homes located in an urbanized region in the Netherlands. Trained nurse assistants recorded all medical diagnoses made by a medical specialist, including dementia and depressive disorder, and medication use. Depressive symptoms were measured with the Depression Rating Scale. Multivariate logistic regression analysis was used to compare data between residents with and without dementia.

Results

Included in the study were 1885 nursing home residents (aged 65 years or older), of which 837 had dementia. There was no significant difference in the prevalence of diagnosed depressive disorder between residents with (9.6%) and without dementia (9.8%). Residents with dementia (46.4%) had more depressive symptoms than residents without dementia (22.6%). Among those with depressive symptoms, residents with dementia had the same likelihood of being diagnosed with a depressive disorder as residents without dementia. Among residents with a diagnosed depressive disorder, antidepressant use did not differ significantly between residents with dementia (58.8%) and without dementia (57.3%). The same holds true for residents with depressive symptoms, where antidepressant use was 25.3% in residents with dementia and 24.6% in residents without dementia.

Conclusions

Regarding the prevalence rates of diagnosed depressive disorder and antidepressant use found in this study, our findings demonstrate that there is room for improvement not only for the detection of depression but also with regard to its treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis and Anti‐HIV Activity of Triazolo‐Fused 3′,5′‐Cyclic Nucleoside Analogues Derived from an Intramolecular Huisgen 1,3‐Dipolar Cycloaddition
Authors: Sun Jingbo , Liu Xinyu , Li Hongming , Duan Ronghui , Wu Jinchang
Published: May 2012

Triazolo‐fused 3′,5′‐cyclic nucleoside analogues were synthesized by an intramolecular 1,3‐dipolar cycloaddition of nucleoside‐derived azido‐alkynes in a regio‐ and stereospecific manner. The thymine nucleoside base in these target compounds was transformed successfully into the corresponding 5‐methylcytosine component. The synthesized compounds were examined in a MAGI assay for exploring the anti‐HIV activity and in a H9 T lymphocytes assay for measuring the cell toxicity.
Chemical Composition of the Volatile Oil from the Roots of Selinum tenuifoliumWall.
Authors: Chauhan Rajendra S. , Nautiyal Mohan C. , Tava Aldo , Mella Mariella
Published: May 2012

The essential oil from the underground parts of Selinum tenuifolium Wall. (Apiaceae) was extracted by hydrodistillation using a Clevenger‐type apparatus, and analyzed by GC/FID and GC/MS. Nine constituents, representing 97.7% of the total oil, were identified, five of which belong to the class of polyacetylenes. The structures of the compounds 1–5 were elucidated by using IR, MS, and 1H‐ and 13C‐NMR data after purification by column chromatography. The major constituent detected was nona‐3,5‐diyne (1; 85.6% of the total volatiles), followed by nona‐3,5‐diyn‐2‐one (2), nona‐4,6‐diyn‐3‐one (3), nona‐3,5‐diyn‐2‐ol (4), and nona‐4,6‐diyn‐3‐ol (5), accounting for 3.0, 2.5, 2.2, and 3.1% of the total volatiles, respectively. The latter four polyacetylenes, 2–5, were never reported in plants so far, and, therefore should be regarded as novel compounds.
A Convenient Synthesis of 2‐Sulfanylbenzoselenazole Derivatives via the Reaction of 2‐Lithiophenyl Isothiocyanates with Selenium
Authors: Kobayashi Kazuhiro , Yokoi Yuki
Published: May 2012

The title compounds have been prepared from 2‐bromophenyl isothiocyanates 1. Thus, 2‐lithiophenyl isothiocyanates 2, obtained from 1 and BuLi through Br/Li exchange, reacted with Se at −78° to form lithium benzoselenazole‐2‐thiolates 3, which, upon aqueous workup, afforded benzoselenazole‐2(3H)‐thiones 4. The thiolates 3 were alkylated with reactive alkyl halides and acylated with carboxylic acid chlorides to give 2‐(alkylsulfanyl)benzoselenazoles 5 and S‐(benzoselenazol‐2‐yl) thiocarboxylates 6, respectively.
Examination and parameterization of the root water uptake model from stem water potential and sap flow measurements
Authors: Yang Yuting , Guan Huade , Hutson John L. , Wang Hailong , Ewenz Caecilia , Shang Songhao , Simmons Craig T.
Published: May 2012

A simple field‐based method for directly parameterizing root water uptake models is proposed. Stem psychrometers and sap flow meters are used to measure stem water potential and plant transpiration rate continuously and simultaneously. Predawn stem water potential is selected as a surrogate for root zone soil water potential to examine and parameterize the root water uptake–water stress response functions. The method is applied to two drooping sheoak (Allocasuarina verticillata) trees for a period of 80 days, covering both a dry season and a wet season. The results indicate that the S‐shape function is more appropriate than the Feddes piecewise linear function for drooping sheoak to represent the effect of soil moisture stress on its root water uptake performance. Besides, the water stress function is found to be not only a function of soil moisture but also dependent of the atmospheric demand. As a result, the water stress function is corrected for the effect of atmospheric conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Molecular genetic analysis of MSUD from India reveals mutations causing altered protein truncation affecting the C‐termini of E1α and E1β
Authors: Bashyam Murali D. , Chaudhary Ajay K. , Sinha Manjari , Nagarajaram H.A. , Devi A. Radha Rama , Bashyam Leena , Reddy E. Chandrakanth , Dalal Ashwin
Published: May 2012

Maple Syrup Urine Disease is a rare metabolic disorder caused by reduced/absent activity of the branched chain α‐Ketoacid dehydrogenase enzyme complex. Mutations in BCKDHA, BCKDHB, and DBT, that encode important subunits of the enzyme complex namely E1α, E1β, and E2, are the primary cause for the disease. We have performed the first molecular genetic analysis of MSUD from India on nine patients exhibiting classical MSUD symptoms. BCKDHA and BCKDHB mutations were identified in four and five patients, respectively including seven novel mutations namely the BCKDHA c.1249delC, c.1312T>C, and c.1561T>A and the BCKDHB c.401T>A, c.548G>A, c.964A>G, and c.1065delT. The BCKDHB c.970C>T (p.R324X) mutation was shown to trigger nonsense mediated decay‐based degradation of the transcript. Seven of the total 11 mutations resulted in perturbations in the E1α or E1β C‐termini either through altered termination or through an amino acid change; these are expected to result in disruption of E1 enzyme complex assembly. Our study has therefore revealed that BCKDHA and BCKDHB mutations might be primarily responsible for MSUD in the Indian population. J. Cell. Biochem. 113: 3122–3132, 2012. © 2012 Wiley Periodicals, Inc.
Observations during development of an internal medicine residency training program in cardiovascular limited ultrasound examination
Authors: Kimura Bruce J. , Amundson Stan A. , Phan James N. , Agan Donna L. , Shaw David J.
Published: May 2012

BACKGROUND:

Despite the future potential of using ultrasound stethoscopes to augment the bedside cardiac physical, few data exist on a general cardiovascular imaging protocol that can be taught to physicians on a perpetual basis as a curriculum in graduate medical education.

METHODS:

During the past decade, we developed and integrated a cardiovascular limited ultrasound training program within the confines of an internal medicine residency. The evidence‐based rationale for the exam, the teaching methods, and curriculum are delineated, and subsequent observations regarding program requirements, proficiency, and academic outcomes are explored. Analysis of variance and linear regression assessed for relationships between academic scores, chief resident selection, and gender to proficiency in ultrasound.

RESULTS:

A brief, 5‐minute cardiovascular limited ultrasound exam (CLUE) was taught using both didactic and bedside methods, and practiced primarily within the cardiology consult, outpatient clinic, and intensive care rotations. Program costs were minimized by employing readily available institutional resources. After a 2‐year lead‐in training phase, the subsequent 4 years of senior resident performance (n = 41 residents) showed an 81% pass rate in CLUE competency. Resident ultrasound performance did not relate to academic scores (r = 0.05, P = 0.75), chief resident selection, nor gender. Observations regarding resident pitfalls in CLUE practice and increased participation in extracurricular research are described.

CONCLUSIONS:

We report our initial experience in developing and implementing a training program for bedside cardiovascular ultrasound examination that employed evidence‐based techniques, set proficiency goals, and assessed resident performance. It may be feasible to teach future internist–hospitalists the technique of bedside ultrasound during residency. Journal of Hospital Medicine 2012;. © 2012 Society of Hospital Medicine
Impact of in‐hospital enteroviral polymerase chain reaction testing on the clinical management of children with meningitis
Authors: Lyons Todd W. , McAdam Alexander J. , Cohn Keri A. , Monuteaux Michael C. , Nigrovic Lise E.
Published: May 2012

BACKGROUND:

Enteroviral meningitis is a common cause of meningitis in children which requires only supportive care.

OBJECTIVE:

To evaluate the impact of implementing an in‐hospital enteroviral polymerase chain reaction (EVPCR) testing protocol on the clinical management of children with meningitis.

DESIGN:

Retrospective cohort study.

POPULATION:

Children <19 years old with meningitis.

INTERVENTION:

EVPCR testing differed by time period: send‐out testing protocol from July 1, 2006–June 23, 2008 (pre‐period) versus in‐house testing protocol from June 24, 2008–June 30, 2010 (post‐period).

MEASUREMENTS:

Test turnaround time, test utilization, length of stay, and duration of parenteral antibiotics.

RESULTS:

Of the 441 study patients, 216 (49%) presented during the post‐period. Median age was 2.9 months (interquartile range, 1.5–96 months). Test turnaround time decreased with the in‐house test (53 hours pre vs 13 hours post, P < 0.001), and test utilization increased (28% pre vs 62% post, P < 0.001). Among children with a positive EVPCR test, both length of stay (44 hours pre vs 28 hours post, P = 0.005) and duration of parenteral antibiotics (48 hours pre vs 36 hours post, P = 0.04) decreased in the post‐period. No change in either of these outcomes was observed in children with meningitis and a negative EVPCR test.

CONCLUSION:

In‐house EVPCR testing reduced test turnaround time, increased test utilization, and reduced both length of stay and duration of parenteral antibiotics for children with a positive result. Clinicians caring for children with meningitis should have access to in‐hospital EVPCR testing. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
Which is the best MRI marker of malignancy for atypical cirrhotic nodules: Hypointensity in hepatobiliary phase alone or combined with other features? Classification after Gd‐EOB‐DTPA administration
Authors: Golfieri Rita , Grazioli Luigi , Orlando Emanuela , Dormi Ada , Lucidi Vincenzo , Corcioni Beniamino , Dettori Ernesto , Romanini Laura , Renzulli Matteo
Published: May 2012

Purpose:

To investigate whether the malignancy of atypical nodules in cirrhosis can be identified at gadoxetic‐acid‐disodium(Gd‐EOB‐DTPA)‐MRI by their hypointensity in the hepatobiliary(HB)‐phase alone or combined with any other MR imaging features.

Materials and Methods:

One hundred eleven atypical nodules detected in 77 consecutive Gd‐EOB‐DTPA‐MRIs were divided, based on arterial‐phase behavior, into: Class I, isovascular (n = 82), and Class II, hypervascular without portal/delayed washout (n = 29). The two classes were further grouped based on HB‐phase intensity (A/B/C hypo/iso/hyperintensity). Portal/venous/equilibrium‐phase behavior and T2w features were also collected. Histology was the gold standard. Per‐nodule sensitivity, specificity, negative and positive predictive values (NPV/PPV), and diagnostic accuracy were calculated for HB‐phase hypointensity alone, and combined with vascular patterns and T2w hyperintensity.

Results:

Histology detected 60 benign and 51 malignant/premalignant nodules [10 overt hepatocellular carcinomas (HCCs) and 41 high‐grade dysplastic nodules (HGDN)/early HCC]. Class IA contained 31 (94%) malignancies, IB one (3%), and IC only benign lesions. Class IIA had 100% malignancies, IIB three (37.5%) and IIC only two (28.5%). HB‐phase hypointensity alone (Classes I–IIA) had 88% sensitivity, 91% NPV, and 93% diagnostic accuracy, superior (P < 0.05, P < 0.006, and P < 0.05, respectively) to any other MR imaging feature alone or combined.

Conclusion:

In atypical cirrhotic nodules, HB‐phase hypointensity by itself is the strongest marker of malignancy. J. Magn. Reson. Imaging 2012;36:648–657. © 2012 Wiley Periodicals, Inc.
Rectal Cancer: MR imaging of the mesorectal fascia and effect of chemoradiation on assessment of tumor involvement
Authors: Oberholzer Katja , Junginger Theodor , Heintz Achim , Kreft Andreas , Hansen Torsten , Lollert André , Ebert Maren , Düber Christoph
Published: May 2012

Purpose:

To evaluate the impact of chemoradiation on the reliability of MRI in assessing tumor involvement of the mesorectal fascia in patients with rectal cancer.

Materials and Methods:

Presurgical MRI was performed in 150 patients; among them 85 had received neoadjuvant long‐course chemoradiation. A standardized imaging protocol (1.5 Tesla [T] system, image voxel size 0.6 × 0.4 × 3 mm3), standardized surgery, and histopathological examination were applied for the entire patient population. Images were analyzed to identify potential tumor involvement of the mesorectal fascia (minimum tumor distance to fascia ≤1 mm) and compared with histopathology as the reference standard. Results of nonirradiated and irradiated patients were compared to define the impact of chemoradiation on imaging reliability.

Results:

In nonirradiated patients, MRI was reliable in predicting or excluding tumor involvement of the mesorectal fascia, positive predictive value 80%, negative predictive value 89%. The frequency of overestimating tumor involvement was significantly higher in irradiated patients (P = 0.005, positive predictive value 42%).

Conclusion:

Discussions about MRI assessment of tumor involvement of the mesorectal fascia as a basis for recommending neoadjuvant chemoradiation should focus on investigations that excluded irradiated patients, because MRI is less reliable after chemoradiation and tends to overestimate mesorectal tumor involvement. J. Magn. Reson. Imaging 2012;36:658–663. © 2012 Wiley Periodicals, Inc.
EFFECTS OF CONVERTING FOREST TO AVOCADO ORCHARDS ON TOPSOIL PROPERTIES IN THE TRANS‐MEXICAN VOLCANIC SYSTEM, MEXICO
Authors: Bravo‐Espinosa M. , Mendoza M. E. , CarlóN Allende T. , Medina L. , Sáenz‐Reyes J. T. , Páez R.
Published: May 2012

In the present work, land cover and land use changes between 2003 and 2008 were assessed in the Cupatitzio River sub‐basin located in the Trans‐Mexican Volcanic System and Balsas Depression in Mexico. The effects of land cover conversion from temperate forest to avocado orchards on soil properties were determined. Land cover and land use databases were built for the years 1975, 2003, and 2008 using available cartographic information and interpretation of panchromatic SPOT images for the year 2008. Additionally, soil sampling was carried out in 16 representative sites in the higher parts of the sub‐basin, where avocado plantation dynamics have caused important changes in areas covered by temperate forests. Results show that (i) temperate coniferous and tropical low deciduous forests were reduced at an annual rate of 0·9 per cent (1, 001 ha y−1) between 1975 and 2008; (ii) cropland areas expanded at an annual rate of 0·7 per cent between 1975 and 2008, representing a growth of 553 ha y−1; (iii) wet soil aggregate stability, mechanical resistance to penetration and nitrate (N‐NO3) concentration in the topsoil layer of Andosols were significantly affected by land use conversion to avocado orchards. Other soil properties such as organic matter, interchangeable K, and available P showed degradation tendencies. These results suggest the importance of implementing strategies for mitigating the accelerated process of transformation and degradation of natural resources in the Cupatitzio River sub‐basin. The implementation of programs for deforestation reduction should be a priority in the restoration strategy. Copyright © 2012 John Wiley & Sons, Ltd.
Degradation and stabilization of an aromatic polyurethane coating during an artificial aging test viaFTIR spectroscopy
Authors: Rashvand M. , Ranjbar Z.
Published: May 2012

In this investigation nano‐zinc oxide‐containing polyurethane‐based coatings were prepared by incorporating 3 wt% nano‐ZnO in the electrocoating composition. The paint films were deposited on phosphated steel panels through electrodeposition. The films were then rinsed by DI water and baked for 20 min at 165 °C in an electrical laboratory oven. The cured films were exposed to ultraviolet (UV) radiation under humid condition. Variation of chemical nature, color, surface roughness, gloss, and corrosion resistance of the coatings were investigated as a function of UV exposure period. It was found that in presence of nano‐ZnO particles, photodegradation reactions of the aromatic polyurethane network are delayed for a longer time. Specular gloss and surface roughness values of the exposed films are in accordance to this observation too. It was found that deep cracks are formed in the films in which no nano‐ZnO is present. The higher electrical resistance value of the nano‐ZnO stabilized films was found to be due to the protective effect of the particles against photodegradation of the polyurethane binder.
Effects of water vapour and oxygen partial pressures on low carbon steel oxidation in N2–H2–H2O mixtures
Authors: Yin H. , Yuen W. Y. D. , Young D. J.
Published: May 2012

A low carbon, low silicon steel was oxidised at temperatures of 900–1000 °C in flowing N2–H2–H2O gas mixtures in which oxygen and water vapour partial pressures were varied independently. Scales of dense, single‐phase, coarse grained wüstite grew rapidly, according to parabolic kinetics. Both the scaling rate and the oxide grain growth increased with $p_{{\rm O}_{2} } $ at constant $p_{{\rm H}_{2} {\rm O}} $, and also with $p_{{\rm H}_{2} {\rm O}} $ at constant $p_{{\rm O}_{2} } $. An inert marker experiment showed that significant oxygen transport but majority metal transport supported scale growth. Gas composition effects are interpreted using point defect models involving formation of hydroxyl species on anion sites as well as cation vacancies.
Effect of ternary element addition on the corrosion behaviour of NiTi shape memory alloys
Authors: Kassab E. , Neelakantan L. , Frotscher M. , Swaminathan S. , Maaß B. , Rohwerder M. , Gomes J. , Eggeler G.
Published: May 2012

The goal of this study is to compare the corrosion behaviour of selected ternary nickel titanium (NiTi)‐based alloys (Ni45Ti50Cu5, Ni47Ti50Fe3 and Ni39Ti50Pd11) with a binary, pseudoelastic Ni50.7Ti49.3 alloy. We examine the influence of the ternary elements on the corrosion behaviour using standard electrochemical techniques. All measurements were done in a physiological solution (0.9% NaCl) simulating a body temperature of 37 ± 1 °C. The influence of Cu and Pd addition on the surface oxide film was characterised by X‐ray photoelectron spectroscopy (XPS). The results revealed that, the localised corrosion resistance of these ternary alloys is lower than the binary NiTi alloy. By comparing the different NiTi‐based alloys, the following relation has been proposed for their localised corrosion resistances: NiTiCu < NiTiFe < NiTiPd < NiTi. Depth profiling by XPS showed that the surface oxide film on all the investigated NiTi‐based alloys is mainly of TiO2, however, the NiTiPd and NiTiCu alloys showed metallic ternary element distributed within TiO2 layer.
CPW‐fed miniaturized split ring‐loaded slot antenna
Authors: Mitra Debasis , Chaudhuri Sekhar Ranjan Bhadra
Published: May 2012

In this article, a simple and an efficient approach for antenna miniaturization of split ring‐loaded slot antenna fed by the CPW line has been proposed. It has been shown that the fundamental resonant frequency has been lowered considerably by properly loading a pair of split ring resonator (SRR) rings at the edge of the half‐wavelength slot. A 26% miniaturization is achieved in comparison to slot antenna without SRR loading. The radiation pattern is also seen to be unaffected by the presence of the SRR. The overall antenna size is 0.5λ0 × 0.5λ0 × 0.017λ0. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1907–1911, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26926
A CPW‐FED planar dual band‐notched ultra‐wideband antenna by etching an S‐shaped SIR slot on the feed line
Authors: Mao Chun‐Xu , Chu Qing‐Xin
Published: May 2012

A novel planar ultra‐wideband antenna with 3.6/5.5 GHz dual band‐notched characteristics is proposed in this article. By etching an S‐shaped step‐impedance resonator slot on the feed line, antenna with dual band‐stopped filtering properties in the world interoperability for microwave access/wireless local‐area network bands are achieved. The proposed antenna consists of a beveled rectangular metal patch and a 50 Ω coplanar waveguide transmission line. The antenna is successfully designed, simulated, and measured, which exhibits broadband impedance matching and stable radiation patterns. The mechanism of this dual band‐notched antenna is also discussed in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1998–2001, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26940
V‐band low phase‐noise oscillator based on a cavity resonator integrated in the silicon substrate of the MCM‐D platform
Authors: Dancila D. , Rottenberg X. , John A. , Tilmans H. A. C. , De Raedt W. , Huynen I.
Published: May 2012

In this article, we present a V‐band low‐phase‐noise oscillator stabilized by a silicon integrated cavity resonator (SiCR). The SiCR is realized in a multi chip module‐deposited thin‐film technology platform. The high resistivity silicon substrate is thinned to 100 μm and through silicon vias are available. The resonator is formed by a double row of through silicon vias defining a TM010 cylindrical cavity resonator. The area on top of the resonator is reused for flip‐chip mounting the active device, a MMIC chip realized in BiCMOS technology, implementing SiGe heterojunction bipolar transistors. A lower phase noise is demonstrated for the oscillator using SiCR in comparison with an idle oscillator using the same active device but a shorted CPW line as resonator. In the best case, the phase‐noise of the oscillator with SiCR is reduced to −102 dBc/Hz at 1‐MHz carrier offset, fosc = 54 GHz, from −89 dBc/Hz at 1 MHz carrier offset, fosc = 47.3 GHz, corresponding to the idle oscillator, using the CPW resonator. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1788–1792, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26946
Broadband E‐shaped microstrip antenna with dipole RE‐radiators
Authors: Makarov E. S. , Fedorov S. M.
Published: May 2012

New design of microstrip patch antenna with coaxial feed is proposed in this article. The proposed construction includes additional dipole radiators placed over main patch and exhibits enhanced broadbandness comparing to classical E‐shaped patch antenna. Also, gain of proposed antenna is highly stable in the broad frequency band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1785–1788, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26947
A tri‐band, small size radio frequency identification tag antenna with U‐shaped slots
Authors: Aliakbari Hanieh , Mallahzadeh Alireza , Nezhad Sajad Mohammad Ali
Published: May 2012

A new multiband, small size antenna for passive radio frequency identification (RFID) tags is presented. Placement of three U‐shaped slots can create three independent resonances within the RFID range: 0.953, 2.45, and 5.8 GHz, whereas in each resonance, particular inductive input impedance will be achieved by a simple technique to be conjugately matched with the capacitive impedance of the chosen electronic chip. The proposed simple structural antenna is flexibly tunable to be matched with other chips in RFID frequencies. It is shown that the matching and forward patterns of tag antenna in each band are desirable, simultaneously. Details of the proposed antenna design and measured results are presented. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1975–1978, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26949
Internal cellular handset antenna with a curved metal pattern for decreased near‐field radiation
Authors: Wong Kin‐Lu , Chang Hsuan‐Jui
Published: May 2012

Near‐field radiation characteristics of an internal cellular handset antenna with a curved metal pattern are studied.The antenna's metal pattern comprises a simple strip monopole for the GSM1800/1900 operation. The strip monopole is smoothly curved to avoid right‐angle or abrupt bendings such that smooth variations of the excited surface currents thereon can be obtained. In this case, it is expected that the antenna's near‐field radiation can be decreased. When compared with a corresponding monopole antenna with one or more right‐angle bendings, the obtained results show that the proposed antenna can have lower specific absorption rate values by at least 1.0 dB, which is mainly owing to the decreased near‐field radiation. Detailed results are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1927–1932, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26958