bluuebunny/crossref_metadata_2025 huggingface dataset:
Additive Tuning of Redox Potential in Metallacarboranes by Sequential Halogen Substitution
Authors: González‐Cardoso Patricia , Stoica Anca‐Iulia , Farràs Pau , Pepiol Ariadna , Viñas Clara , Teixidor Francesc
Published: April 2010

The first artificially made set of electron acceptors is presented that are derived from a unique platform Cs[3,3′‐Co(C2B9H11)2], for which the redox potential of each differs from its predecessor by a fixed amount. The sequence of electron acceptors is made by substituting one, two, or more hydrogen atoms by chlorine atoms, yielding Cs[3,3′‐Co(C2B9H11−yCly)(C2B9H11−zClz)]. The higher the number of chlorine substituents, the more prone the platform is to be reduced. The effect is completely additive, so if a single substitution implies a reduction of 0.1 V of the redox potential of the parent complex, then ten substitutions imply a reduction of 1 V.
Rhodamine B Piperazinoacetohydrazine: A Water‐Soluble Spectroscopic Reagent for Pyruvic Acid Labeling
Authors: Jia Jia , Wang Ke , Shi Wen , Chen Suming , Li Xiaohua , Ma Huimin
Published: April 2010

A new water‐soluble reagent, rhodamine B piperazinoacetohydrazine (RBPH), with improved spectroscopic and reaction properties, has been developed and characterized for pyruvic acid labeling. The reagent RBPH is designed and synthesized by using rhodamine B as a spectroscopic unit, and hydrazine as a carbonyl‐specific labeling unit; the two units are connected by a well‐chosen linker of piperazine, which prohibits the formation of the nonfluorescent spirocyclic structure of rhodamine B, thereby keeping the spectroscopic response of the reagent in a stable state. Such a design enables RBPH not only to maintain its excellent spectroscopic properties over a wide pH range, but also to exist as a stable cation with high water solubility. Moreover, the hydrazino group of RBPH is expected to react selectively with carbonyl compounds under mild conditions through the rapid formation of hydrazones. These important features make RBPH of great potential use in the labeling of aldehydes or ketones in various biosystems, and such an application of RBPH as a precolumn derivatizing reagent has been successfully demonstrated on the analysis of pyruvic acid in human serum by high‐performance liquid chromatography with common UV/Vis detection.
The Electronic Structure and Photochemistry of Group 6 Bimetallic (Fischer) Carbene Complexes: Beyond the Photocarbonylation Reaction
Authors: Lage Marta L. , Fernández Israel , Mancheño María J. , Gómez‐Gallego Mar , Sierra Miguel A.
Published: April 2010

The UV spectra of Group 6 metal carbene complexes bearing a CpM(CO)3 (Cp=cyclopentadienyl) moiety bonded to the carbene carbon atom exhibit a redshift of the absorption maxima at higher wavelengths with respect to the parent monometallic complexes. This redshift is partly due to a higher occupation on the pz atomic orbital of the carbene carbon atom. Time‐dependent DFT calculations accurately assign this band to a metal‐to‐ligand charge‐transfer transition, thus showing that the presence of a second metal center does not affect the nature of the transition. However, the photochemical reactivity of Group 6 metal carbene complexes bearing a CpM(CO)3 moiety strongly depends on the nature of this metal fragment. A new photoslippage reaction leading to fulvenes occurs when Mn‐derived products 11 a, 11 b, and 12 a are irradiated (both Cr and W derivatives), whereas Re‐derived product 11 c behaves like standard Fischer complexes and yields the usual photocarbonylation products. A new photoreduction process occurring in the metallacyclopropanone intermediate is also observed for these complexes. Both computational and deuteration experiments support this unprecedented photoslippage process. The key to this differential photoreactivity seems to be the M–Cp back‐donation, which hampers the slippage process for Re derivatives and favors the carbonylation reaction.
Colloidal Noble‐Metal and Bimetallic Alloy Nanocrystals: A General Synthetic Method and Their Catalytic Hydrogenation Properties
Authors: Song Shuyan , Liu Ruixia , Zhang Yu , Feng Jing , Liu Dapeng , Xing Yan , Zhao Fengyu , Zhang Hongjie
Published: April 2010

A general single‐step strategy has been developed for the direct thermal decomposition of noble‐metal salts in octadecylamine to synthesize octahedron‐ and rod‐shaped noble‐metal aggregates and monodisperse noble‐metal or bimetallic alloy nanocrystals without introducing any additive into the system. It has presented a facile and economic way to fabricate these nanocrystals, especially alloy nanocrystals, which does not require a post‐synthesis solid‐state annealing process. The morphology of the nanocrystals can be easily controlled by tuning the synthetic temperature. Their ability to catalyze heterogeneous Suzuki coupling reactions has been investigated and showed satisfactory catalytic activity. The catalytic performance of the monometallic and bimetallic alloy nanocrystals were also evaluated in the selective hydrogenation of citral in a conventional organic solvent (toluene) and a green solvent (supercritical carbon dioxide, scCO2). Interestingly, the catalysts performed differently to each other when they were in scCO2 owing to the different morphology, which should be readily optimized for further use.
Hydrogels Composed of Organic Amphiphiles and α‐Cyclodextrin: Supramolecular Networks of Their Pseudorotaxanes in Aqueous Media
Authors: Taira Toshiaki , Suzaki Yuji , Osakada Kohtaro
Published: April 2010

Mixtures of N‐alkyl pyridinium compounds [py‐N‐(CH2)nOC6H3‐3,5‐(OMe)2]+(X−) (1bCl: n=10, X=Cl; 1cBr: n=12, X=Br) and α‐cyclodextrin (α‐CD) form supramolecular hydrogels in aqueous media. The concentrations of the two components influences the sol–gel transition temperature, which ranges from 7 to 67 °C. Washing the hydrogel with acetone or evaporation of water left the xerogel, and 13C CP/MAS NMR measurements, powder X‐ray diffraction (XRD), and scanning electron microscopy (SEM) revealed that the xerogel of 1bCl (or 1cBr) and α‐CD was composed of pseudorotaxanes with high crystallinity. 13C{1H} and 1H NMR spectra of the gel revealed the detailed composition of the components. The gel from 1bCl and α‐CD contains the corresponding [2]‐ and [3]pseudorotaxanes, [1b⋅(α‐CD)]Br and [1b⋅(α‐CD)2]Br, while that from 1cBr and α‐CD consists mainly of [3]pseudorotaxane [1c⋅(α‐CD)2]Br. 2D ROESY 1H NMR measurements suggested intermolecular contact of 3,5‐dimethoxyphenyl and pyridyl end groups of the axle component. The presence of the [3]pseudorotaxane is indispensable for gel formation. Thus, intermolecular interaction between the end groups of the axle component and that between α‐CDs of the [3]pseudorotaxane contribute to formation of the network. The supramolecular gels were transformed into sols by adding denaturing agents such as urea, C6H3‐1,3,5‐(OH)3, and [py‐N‐nBu]+(Cl−).
Tuning the Magnetic Moment of [Ru2(DPhF)3(O2CMe)L]+ Complexes (DPhF=N,N′‐Diphenylformamidinate): A Theoretical Explanation of the Axial Ligand Influence
Authors: Barral M. Carmen , Casanova David , Herrero Santiago , Jiménez‐Aparicio Reyes , Torres M. Rosario , Urbanos Francisco A.
Published: April 2010

The magnetic behaviour of the compounds containing the [Ru2(DPhF)3(O2CMe)]+ ion (DPhF−=N,N′‐diphenylformamidinate) shows a strong dependence on the nature of the ligand bonded to the axial position. The new complexes [Ru2(DPhF)3(O2CMe)(OPMe3)][BF4]⋅0.5 CH2Cl2 (1⋅ 0.5 CH2Cl2) and [Ru2(DPhF)3(O2CMe)(4‐pic)][BF4] (2) (4‐pic=4‐methylpyridine) clearly display this influence. Complex 1⋅0.5 CH2Cl2 shows a magnetic moment corresponding to a S=3/2 system affected by the common zero‐field splitting (ZFS) and a weak antiferromagnetic interaction, whereas complex 2 displays an intermediate behaviour between S=3/2 and S=1/2 systems. The experimental data of complex 1 are fitted with a model that considers the ZFS effect using the Hamiltonian ĤD=S⋅D⋅S. The weak antiferromagnetic coupling is introduced as a perturbation, using the molecular field approximation. DFT calculations demonstrate that, in the [Ru2(O2CMe)(DPhF)3(L)]+ complexes, the energy level of the metal–metal molecular orbitals is strongly dependent on the nature of the axial ligand (L). This study reveals that the increase in the π‐acceptor character of L leads to a greater split between the π* and δ* HOMO orbitals. The influence of the axial ligand in the relative energy between the doublet and quartet states in this type of complexes was also analysed. This study was performed on the new complexes 1⋅0.5 CH2Cl2 and 2. The previously isolated [Ru2(DPhF)3(O2CMe)(OH2)][BF4]⋅0.5 CH2Cl2 (3⋅ 0.5 CH2Cl2) and [Ru2(DPhF)3(O2CMe)(CO)][BF4]⋅CH2Cl2 (4⋅CH2Cl2) complexes were also included in this study as representative examples of spin‐admixed and low‐spin configurations, respectively. The [Ru2(DPhF)3(O2CMe)]+ (5) unit was used as a reference compound. These theoretical studies are in accordance with the different magnetic behaviour experimentally observed.
Total Synthesis of Punctaporonin C by a Regio‐ and Stereoselective [2+2]‐Photocycloaddition
Authors: Fleck Martin , Bach Thorsten
Published: April 2010

The unique sesquiterpene punctaporonin C was synthesized starting from commercially available 7‐tert‐butoxynorbornadiene in a linear sequence of 29 steps and with an overall yield of 0.65 %. Key step of the synthesis was an intramolecular [2+2]‐photocycloaddition, in which the two vinylic double bonds in a 1,3‐divinyl‐2‐cyclopentyl tetronate were differentiated by reaction with the photoexcited tetronate. The reaction gave regio‐ and diastereoselective access to the tricyclic core skeleton of punctaporonin C in 63 % yield. Additional studies related to the tetronate [2+2]‐photocycloaddition revealed that even diastereotopic vinylic double bonds in a 1,3‐divinyl‐2‐cyclopentyl tetronate can be differentiated (d.r. up to 78:22). In the further course of the total synthesis the complete tetracyclic oxatetracyclo[6.3.2.01, 4.05, 12]tridecane skeleton of punctaporonin C was established by an intramolecular aldol reaction, closing a seven‐membered oxepane ring. The nucleophilic methyl ketone employed in this step was generated by Wacker oxidation of the vinylic double bond, which was not involved in the [2+2]‐photocycloaddition. Several reactions employed in the synthetic sequence required adaptation to the rigid skeleton of punctaporonin C, for example, the reduction of a mesylate, the alkylation of a cyclobutane carboxylate, or the methyl addition to a prostereogenic carbonyl group.
Synthesis and application of 3‐substituted (S)‐BINOL as chiral ligands for the asymmetric ethylation of aldehydes
Authors: Zhang Zhi‐Guang , Dong Zhi‐Bing , Li Jin‐Shan
Published: April 2010

A series of (S)‐BINOL ligands substituted at the 3 position with some five‐membered nitrogen‐containing aromatic heterocycles were effectively prepared and their catalytic abilities were evaluated in the asymmetric addition of diethylzinc to benzaldehyde in the presence of titanium tetraisopropoxide. Under the optimized reaction conditions, titanium complex of (S)‐3‐(1H‐benzimidazol‐1‐yl)‐1,1′‐bi‐2‐naphthol was found to be the most efficient catalyst for asymmetric ethylation of various aldehydes to generate the corresponding secondary alcohols in up to 99% yield and 91% ee. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
(S)‐6‐Bromo‐BINOL‐based phosphoramidite ligand with C1 symmetry for enantioselective hydrogenation and allylic substitution
Authors: Gavrilov Konstantin N. , Benetsky Eduard B. , Boyko Vladimir E. , Rastorguev Eugenie A. , Davankov Vadim A. , Schäffner Benjamin , Börner Armin
Published: April 2010

(S)‐6‐Br‐BINOL‐derived phosphoramidite, a simple monodentate ligand with a stereogenic center at the phosphorus atom, was synthesized for the first time. This stereoselector generated a high level of enantioselectivity (80–95% ee) in the rhodium‐catalyzed hydrogenation of α‐dehydrocarboxylic acid esters and was also successfully employed in the asymmetric palladium‐catalyzed allylic substitution of (E)‐1,3‐diphenylallyl acetate. The optical yield also showed significant dependence with reaction type: up to 70% ee for allylic amination, up to 75% ee for allylic sulfonylation, and up to 90% ee for allylic alkylation. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
Highly enantiomeric reduction of acetophenone and its derivatives by locally isolated Rhodotorula glutinis
Authors: Zilbeyaz Kani , Kurbanoglu Esabi B.
Published: April 2010

Ninety isolates of microorganisms belonging to different taxonomical groups (30 bacteria, 20 yeast, and 40 fungi) were previously isolated from various samples. These isolates were screened as reducing agents for acetophenone 1a to phenylethanol 2a. It was found that the isolate EBK‐10 was the most effective biocatalyst for the enantioselective bioreduction of acetophenone. This isolate was identified as Rhodotorula glutinis by the VITEK 2 Compact system. The various parameters (pH 6.5, temperature 32°C, and agitation 200 rpm) of the bioreduction reaction was optimized, which resulted in conversions up to 100% with >99% enantiomeric excesses (ee) of the S‐configuration. The preparative scale bioreduction of acetophenone 1a by R. glutinis EBK‐10 gave (S)‐1‐phenylethanol 2a in 79% yield, complete conversion, and >99% ee. In addition, R.glutinis EBK‐10 successfully reduced various substituted acetophenones. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
Stereospecific pharmacodynamics and chiral inversion of NG‐nitro‐arginine in the beagle dogs
Authors: Xin Yan‐Fei , Gu Li‐Qiang , Zhang Sheng , Bai Yun‐Sheng , Zhou Guo‐Liang , You Zhen‐Qiang , Xuan Yao‐Xian
Published: April 2010

In the present study, we analyzed the stereospecific pharmacodynamics and inversion of NG‐nitro‐arginine by an intravenous blous injection of L‐NG‐nitro‐arginine (L‐NNA) or D‐NG‐nitro‐arginine (D‐NNA) (10 mg/kg) in beagle dogs. Significant pressor responses were observed for both substances, though a similar maximum response induced by L‐NNA was reached at 120 min slower as compared with D‐NNA. The rise in mean arterial pressure (MAP) of D‐NNA dogs was also shown to be slower than the L‐NNA group. Our data showed that D‐NNA had no impact on MAP within 60 min after its injection. Plasma L‐NNA started to appear after 45 min posterior to the i.v. bolus injection of D‐NNA. This chiral inversion is unidirectional because no D‐NNA was not produced from L‐NNA. The pressor response in the D‐NNA‐injected dogs was well parallel to the plasma L‐NNA concentration. Similar disposition of NG‐nitro‐arginine enantiomers and 4% of chiral inversion ratio from D‐NNA to L‐NNA was found in the beagle dogs. Given thatD‐amino acid oxidase (DAAO) is the essential enzyme in chiral inversion of D‐NNA, we further compared the enzymatic activity of the renal DAAO between dogs and rats. Our data showed that dogs had a significantly lower enzymatic activity than rats, thus supported a lower inversion ratio of D‐NNA in dogs. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
Changes in the plasma concentrations ofD‐kynurenine and kynurenic acid in rats after intraperitoneal administration of tryptophan enantiomers
Authors: Ishii Kana , Ogaya Tadahiro , Song Ziyu , Iizuka Hideaki , Fukushima Takeshi
Published: April 2010

An aqueous solution of enantiomerically pure tryptophan (Trp), namely,D‐Trp orL‐Trp (100 mg/kg), was administered intraperitoneally to male Sprague‐Dawley rats. The time‐course profiles of the rat plasma concentrations ofD‐kynurenine (KYN),L‐KYN, and kynurenic acid (KYNA), which are metabolites ofD‐ orL‐Trp, were investigated using high‐performance liquid chromatography (HPLC) systems that were reported in our previous study. The plasmaD‐KYN concentration increased after the administration ofD‐Trp, but this increase was not observed after the administration ofL‐Trp. The plasmaL‐KYN concentration increased after the administration ofL‐Trp, but no significant change was observed after the administration ofD‐Trp. The plasma KYNA concentration drastically increased in the case of rats administeredD‐Trp and those administeredL‐Trp. Additionally, an inhibitor ofD‐amino acid oxidase (DAAO), 5‐methylpyrazole‐3‐carboxylic acid (MPC) (50 mg/kg), was administrated to the rats 30 min before the administration ofD‐Trp. The preadministration of MPC remarkably increased theD‐KYN concentration and suppressed the production of KYNA. These results suggest that DAAO may contribute to the metabolism ofD‐KYN to KYNA in vivo. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
NMR diffusion measurements under chemical exchange between sites involving a large chemical shift difference
Authors: Leclerc S. , Guendouz L. , Retournard A. , Canet D.
Published: April 2010

This study concerns the thallium‐205 cation in aqueous solution in the presence of a calixarene molecule. Although the measurement of the self‐diffusion coefficient of pure thallium (without calixarene in the aqueous solution) does not pose any particular problem, major difficulties are encountered with the standard method using gradient strength increment as soon as thallium is partly complexed by calixarene. With static magnetic field gradients, the NMR signal is so weak that it prevents any reliable measurement, whereas radio frequency (rf) field gradients lead to an unrealistic value of the diffusion coefficient. This failure is explained by the fact that thallium is in fast exchange between two sites (complexed and free thallium) thus exhibiting a single NMR signal although, in the course of the experiment, two signals, with an important difference in resonance frequencies (due to the large thallium chemical shift range), are effectively involved. With the objective to understand these quite unexpected observations, the theory underlying NMR diffusion experiments is first reviewed, and criteria of fast exchange are discussed for three parameters: chemical shifts, relaxation rates, and diffusion coefficients. It turns out that off‐resonance effects are responsible for unwanted defocusing due to rf pulses in the static magnetic field gradient method and for time‐dependent gradients in the rf field gradient method. Concerning the latter, a remedy is proposed which consists in applying the stronger gradient and incrementing the gradient pulse durations. After correction for relaxation, the expected value of the diffusion coefficient is retrieved. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 127–137, 2010.
Analysis of electric field gradient tensors at quadrupolar nuclei in common structural motifs
Authors: Autschbach Jochen , Zheng Shaohui , Schurko Robert W.
Published: April 2010

This article is concerned with the analysis of electric field gradients (EFGs) using first–principles theory along with model calculations. Simple atomic orbital (AO )models for the EFG are developed in the spirit of the Townes–Dailey (TD) analysis and applied to various sets of spn hybrid orbitals and to atomic d orbital shells. These AO models are then combined with modern analysis methods rooted in first principles theory which provide accurate localized molecular orbital contributions to the EFG. It is shown by density functional computations how such analyses of the EFG for a variety of typical structural motifs can provide an intuitive way of understanding the chemical origin of the magnitude and the sign of EFG tensors at atomic nuclei, as well as of their orientation with respect to the molecular coordinate frame. The utility of graphical visualizations of EFG tensors is also emphasized. The systems that are investigated span the range from very small molecules (carbon and sulfur EFGs in CO, CS, OCS) to small‐ and medium‐sized molecules (nitrogen and aluminum EFGs in ammonia, methyl‐cyanide and ‐isocyanide, aluminum AlX3 model systems and various alumino‐organic systems), to the metal atom field gradient in transition metal complexes with Ru and Nb and a variety of ligands. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 84–126, 2010.
Diagnostic and therapeutic delays among a multiethnic sample of breast and cervical cancer survivors
Authors: Ashing‐Giwa Kimlin T. , Gonzalez Patricia , Lim Jung‐Won , Chung Cathie , Paz Benjamin , Somlo George , Wakabayashi Mark T.
Published: April 2010

BACKGROUND:

Several publications reporting on health disparities document that ethnic minorities disproportionately experience delays in healthcare access, delivery, and treatment. However, few studies examine factors underlying access and receipt of healthcare among cancer survivors from the patient perspective. This study explores diagnostic and therapeutic care delays among a multiethnic sample of breast and cervical cancer survivors and examines contextual factors influencing diagnostic and therapeutic care delays.

METHODS:

Population‐based sampling and a cross‐sectional design were used to recruit 1377 survivors (breast cancer, n = 698; cervical cancer, n = 679). This multiethnic sample included 449 European American, 185 African American, 468 Latina American, and 275 Asian American survivors.

RESULTS:

Latina Americans were more likely to report diagnostic delays (P = .003), whereas African Americans were more likely to report therapeutic delays (P = .007). In terms of cancer type, cervical cancer survivors were more likely to report diagnostic (P = .004) and therapeutic delays (P = .000) compared with breast cancer survivors. “Fear of finding cancer” was the most frequently cited reason for diagnostic delays, and “medical reasons” were most frequently cited for therapeutic delays.

CONCLUSIONS:

Due in part to a higher proportion of diagnostic and therapeutic delays, ethnic minorities endure greater cancer burden, including poorer survival and survivorship outcomes. The medical community must recognize the impact of existing psychological and cultural dimensions on diagnostic care, as well as the personal and healthcare system level barriers that contribute to therapeutic delays. Cancer 2010. © 2010 American Cancer Society.
Invasive intraductal papillary mucinous neoplasm versus sporadic pancreatic adenocarcinoma
Authors: Wasif Nabil , Bentrem David J. , Farrell James J. , Ko Clifford Y. , Hines Oscar J. , Reber Howard A. , Tomlinson James S.
Published: April 2010

BACKGROUND:

Although invasive intraductal papillary mucinous neoplasm (IPMN) of the pancreas is thought to be more indolent than sporadic pancreatic adenocarcinoma (PAC), the natural history remains poorly defined. The authors compared survival and identify prognostic factors after resection for invasive IPMN versus stage‐matched PAC.

METHODS:

The Surveillance, Epidemiology, and End Results database (1991‐2005) was used to identify 729 patients with invasive IPMN and 8082 patients with PAC who underwent surgical resection.

RESULTS:

Patients with resected invasive IPMN experienced improved overall survival when compared with resected PAC (median survival, 21 vs 14 months; P < .001). Stratification by nodal status demonstrated no difference in survival among lymph node‐positive patients; however, median survival of resected, lymph node‐negative, invasive IPMN was significantly improved compared with lymph node‐negative PAC (34 vs 18 months; P < .001). On multivariate analysis, PAC histology was an adverse predictor of overall survival (hazard ratio [HR], 1.31; 95% confidence interval [CI], 1.15‐1.50) compared with invasive IPMN. For patients with invasive IPMN, positive lymph nodes (HR, 1.98; 95% CI, 1.50‐2.60), high tumor grade (HR, 1.74; 95% CI, 1.31‐2.31), tumor size >2 cm (HR, 1.50; 95% CI, 1.04‐2.19), and age >66 years (HR, 1.33; 95% CI, 1.03‐1.73) were adverse predictors of survival.

CONCLUSIONS:

Although lymph node‐negative invasive IPMN showed improved survival after resection compared with lymph node‐negative PAC, the natural history of lymph node‐positive invasive IPMN mimicked that of lymph node‐positive PAC. The authors also identified adverse predictors of survival in invasive IPMN to guide discussions regarding use of adjuvant therapies and prognosis after resection of invasive IPMN. Cancer 2010. © 2010 American Cancer Society.
Ethnicity and management of colon cancer in New Zealand
Authors: Hill Sarah , Sarfati Diana , Blakely Tony , Robson Bridget , Purdie Gordon , Dennett Elizabeth , Cormack Donna , Dew Kevin , Ayanian John Z. , Kawachi Ichiro
Published: April 2010

BACKGROUND:

Racial and ethnic inequalities in colon cancer treatment have been reported in the United States but not elsewhere. The authors of this report compared cancer treatment in a nationally representative cohort of Maori (indigenous) and non‐Maori New Zealanders with colon cancer.

METHODS:

On the basis of cancer registry data, 301 Maori patients and 329 randomly selected non‐Maori patients were identified who were diagnosed with colon cancer between 1996 and 2003. Medical notes were reviewed, and surgical and oncology treatments were compared by indigenous status.

RESULTS:

Maori and non‐Maori patients had similar rates of surgical resection, although Maori patients were less likely to undergo extensive lymph node clearance and were more likely to die during the postoperative period. Maori patients were significantly less likely to receive chemotherapy for stage III disease (relative risk [RR], 0.69; 95% confidence interval [CI], 0.53‐0.91) and were more likely to experience a delay of at least 8 weeks before starting chemotherapy (RR, 1.98; 95%CI, 1.23‐3.16). Treatment disparities were not explained by differences in tumor characteristics or patient comorbidity.

CONCLUSIONS:

Maori New Zealanders with colon cancer were less likely to receive adjuvant chemotherapy and experienced a lower quality of care compared with non‐Maori patients. The authors concluded that attention to health system factors is needed to ensure equal access and quality of cancer treatment for indigenous and ethnic minority populations. Cancer 2010. © 2010 American Cancer Society.
Evaluation of trends in the use of intensity‐modulated radiotherapy for head and neck cancer from 2000 through 2005
Authors: Guadagnolo B. Ashleigh , Liu Chih‐Chin , Cormier Janice N. , Du Xianglin L.
Published: April 2010

BACKGROUND:

The current study was conducted to evaluate trends in utilization of intensity‐modulated radiotherapy (IMRT) for head and neck cancer (HNC).

METHODS:

Identified were 5487 patients from the Surveillance, Epidemiology, and End Results (SEER) ‐Medicare linked database with a diagnosis of HNC (aged ≥65 years) between 2000 and 2005, who received any type of radiotherapy (RT). Multivariate logistic regression analyses were performed to assess the influence of patient, tumor, treatment, and sociodemographic characteristics on receipt of IMRT versus conventional radiotherapy techniques.

RESULTS:

Overall, 21.3% of patients in the cohort received IMRT as the technique of irradiation. The use of IMRT increased significantly, with 1.3% of patients receiving it in 2000 compared with 46.1% in 2005 (P <.0001 for trend). Patients treated with RT in 2005 were 68 times more likely to receive IMRT than those treated in 2000. There was significant geographic variation observed in use of IMRT, ranging from 11.3% of cases in Kentucky to 40.4% of cases in Hawaii. Patients in the census tracks comprising the lowest quartile for socioeconomic status were 33% less likely to receive IMRT than patients in the highest quartile, even when adjusting for geographic area and year of diagnosis.

CONCLUSIONS:

The use of IMRT has rapidly become widespread for the delivery of RT for patients with HNC. However, there was significant geographic variation noted in the utilization of IMRT. Patients in census tracks comprising the lowest socioeconomic quartile were less likely to receive IMRT than their more affluent counterparts. Cancer 2010. © 2010 American Cancer Society.
RC oscillator admits negative frequency
Authors: Williamsen Mark S.
Published: April 2010

The humble resistance–capacitance (RC) oscillator has held our attention for nearly seven decades. During that time many improvements have been made to enhance the performance and the range of applicability. In this letter we consider further refinements that extend the frequency range to include zero, and even negative frequencies. This allows the frequency to be swept through zero with no discontinuity in phase or amplitude. We then suggest an addition to the well‐known automatic level control (ALC) circuits to linearize the control function, with attendant benefits in modeling, simulation, and implementation. Closed‐loop dynamics for the improved ALC circuit are predicted, then verified by experiment. Copyright © 2010 John Wiley & Sons, Ltd.
Neurosurgical management of spina bifida: Research issues
Authors: Bowman Robin M. , McLone David G.
Published: April 2010

The neurosurgical goal when treating children with spina bifida (predominantly myelomeningocele) is to maintain stable neurological functioning throughout the patient's life time. Unfortunately, few long‐term outcome studies are available to help direct the neurosurgical care of a child born with myelomeningocele and often treatment relies more heavily upon the experience of senior practitioners. This article reviews the current literature regarding neurosurgical treatment strategies, with recommendations concerning including prenatal diagnosis, in utero treatment and delivery modes, and postnatal management. Given the overall declining prevalence of open neural tube defects world‐wide, research collaboration amongst practitioners through multicenter trial are essential to improving the lives of people born with this most complex congenital anomaly. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:82–87.
The cognitive phenotype of spina bifida meningomyelocele
Authors: Dennis Maureen , Barnes Marcia A.
Published: April 2010

A cognitive phenotype is a product of both assets and deficits that specifies what individuals with spina bifida meningomyelocele (SBM) can and cannot do and why they can or cannot do it. In this article, we review the cognitive phenotype of SBM and describe the processing assets and deficits that cut within and across content domains, sensory modality, and material, including studies from our laboratory and other investigations. We discuss some implications of the SBM cognitive phenotype for assessment, rehabilitation, and research. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:31–39.
Optimizing health care for children with spina bifida
Authors: Liptak Gregory S. , El Samra Ahmad
Published: April 2010

The health care needs of children with spina bifida are complex. They need specialists, generalists, and an integrated system to deliver this complex care and to align and inform all the providers. Most research in spina bifida has been focused on narrow medical outcomes; it has been noncollaborative, based on small samples of convenience, with no comparison groups, and without consistent standards of measurement. Models of health, like the World Health Organization International Classification of Functioning, Disability, and Health Model can help to broaden the scope of future research. Using methods from other pediatric conditions like the patient registry (cystic fibrosis), gene bank (autism), and collaborative research (leukemia), researchers can improve the quality of future studies. Research questions related to the process of care and to specific nonsurgical conditions associated with spina bifida are reviewed in this article. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:66–75.
Urologic management of spina bifida
Authors: Clayton Douglass B. , Brock John W. , Joseph David B.
Published: April 2010

The urologist plays an important role in the multidisciplinary team of physicians who provide care for patients with spina bifida. We review common strategies for managing the urinary tract in these patients. The primary objective in all phases of life is protecting kidney function by minimizing bladder hostility and establishing a good capacity, low‐pressure urinary reservoir. Ensuring adequate bladder and bowel continence is also paramount for enhancing self‐esteem and independence. Medical therapy incorporating clean intermittent catheterization and antimuscarinic medication is the cornerstone of neurogenic bladder management and often the only intervention required to achieve the above goals. Others may require formal lower urinary tract reconstruction to prevent urinary tract deterioration. As will be shown, current management, while effective, is not supported by strong evidence‐based protocols; and the impact of any intervention upon quality of life, while subjectively seen as positive, does not have objective validation. These limitations are recognized and currently the subject of urologic investigation. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:88–95.
Quality of life in individuals with spina bifida: A research update
Authors: Sawin Kathleen J. , Bellin Melissa H.
Published: April 2010

Quality of life (QOL) is an important concept for individuals with chronic health conditions. Measuring and supporting QOL in children, adolescents, and adults with spina bifida (SB) may be especially unique given the broad range of complex health and rehabilitative challenges they encounter. This article provides a research update on (a) conceptual and methodological considerations in measuring QOL and a related construct, health‐related quality of life (HRQOL); (b) the state of the science in QOL and HRQOL for individuals with SB; and (c) gaps in the evidence and implications for future research. A synthesis of the literature was limited by the use of 17 different QOL and HRQOL instruments to measure these constructs and notable weaknesses in the most frequently used condition‐specific HRQOL instrument. However, a tentative pattern of lower scores on the physical domain of HRQOL measures in individuals with SB in comparison to peers emerged, while discrepancies in emotional, social, and school domains varied by study. Recommendations for future research include using a lifespan approach to expand QOL studies to older adults with SB and focusing on intervention research to prevent or treat decreased HRQOL. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:47–59.
Orthopedic management of spina bifida
Authors: Thomson Jeffrey D. , Segal Lee S.
Published: April 2010

The management of orthopedic problems in spina bifida has seen a dramatic change over the past 10 years. The negative effects of spasticity, poor balance, and the tethered cord syndrome on ambulatory function are better appreciated. There is less emphasis on the hip radiograph and more emphasis on the function of the knee and the prevention of knee pain. The importance of the hip abductor muscle and its influence on gait and knee function has been realized. Important developments in the treatment of spinal deformity include the use of pedicle screws which allow better correction. The role of anterior‐only spinal surgery has been defined, which allows motion at the lumbo‐sacral junction and has a lower postoperative infection rate than posterior surgery. Functional outcome assessments provide better feedback for surgeons and families in regards to which patients may benefit most from surgery. Overall, the past 10 years has seen the increased use of functional outcome measures such as Motion Analysis, oxygen consumption, and patient‐based outcome assessments rather than traditional radiographic measures (e.g., hip dislocation or subluxation). This progress has resulted in a better understanding of spina bifida and, more importantly, improved outcomes for our patients. Additional research is likely to further enhance outcomes by establishing additional evidence‐based interventions. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:96–103.
Optimizing health care for adults with spina bifida
Authors: Webb Thomas S.
Published: April 2010

Survival into adulthood for individuals with spina bifida has significantly improved over the last 40 years with the majority of patients now living as adults. Despite this growing population of adult patients who have increased medical needs compared to the general population, including spina bifida (SB)‐specific care, age‐related secondary disabilities, and general adult medical needs, there is little published information about the natural history of SB in adulthood. There are few published studies of medical conditions, interventions, or long‐term complications in this population. This article will provide a review of the medical issues of adults with SB, highlighting areas that are different than pediatric care, and areas of needed research. © 2010 Wiley‐Liss, Inc. Dev Disabil Res Rev 2010;16:76–81.
Spontaneous kicking in full‐term and preterm infants with and without white matter disorder
Authors: Fetters Linda , Sapir Inbal , Chen Yu‐ping , Kubo Masayoshi , Tronick Ed
Published: April 2010

Early damage to white matter of the brain may have developmental consequences for prematurely born infants including the coordination of leg movements. Our perspective is that white matter damage initiates an ontogenetic course that may lead to movement dysfunction leading to disability. In this study, spontaneous kicking in the human infant is a “window” for evaluating the potential consequences of perinatal brain damage for sensori‐motor coordination. We compare the intra‐limb coordination patterns of 5‐month‐old premature infants with white matter damage (PTWMD) to a group of prematurely born infants without WMD (PT) and a group of full‐term (FT) infants. The PT group demonstrates advanced kicking patterns in comparison to both the PTWMD and FT groups. The PTWMD group has less mature patterns than the FT group on some, but not all measures. The movement challenge for PTWMD infants may be in the transition from spontaneous kicking to movements with the legs that require decoupling of intralimb joints. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 524–536, 2010.
Pax2 is expressed in a subpopulation of Müller cells in the central chick retina
Authors: Boije Henrik , Ring Henrik , López‐Gallardo Meritxell , Prada Carmen , Hallböök Finn
Published: April 2010

Müller cells in the chick retina are generally thought to be a homogeneous population. We show that the transcription factor Pax2 is expressed by Müller cells in the central chick retina and its expression was first observed at stage 32 (embryonic day [E] 7.5). Birth‐dating indicated that the majority of Pax2‐positive Müller cells are generated between stage 29 and 33 (E5.5–E8). At stage 42 (E16), several Müller cell markers, such as Sox2 and 2M6, had reached the peripheral retina, while the Pax2 labeling extended approximately half‐way. A similar pattern was maintained in the 6‐month‐old chicken. Neither the Pax2‐positive nor the Pax2‐negative Müller cells could be specifically associated to proliferative responses in the retina induced by growth factors or N‐methyl‐D‐aspartate. Pax2 was not detected in Müller cells in mouse, rat, guinea‐pig, rabbit, or pig retinas; but the zebrafish retina displayed a similar pattern of central Pax2‐expressing Müller cells. Developmental Dynamics 239:1858–1866, 2010. © 2010 Wiley‐Liss, Inc.
c‐Jun activating binding protein 1 binds to the IgA receptor and modulates protein levels of FcαRI and FcRγ‐chain
Authors: Bakema Jantine E. , Hiemstra Ida H. , Bakker Johanna , de Haij Simone , Kok Yvonne , Adema Gosse , van Egmond Marjolein , Coffer Paul J. , van de Winkel Jan G. J. , Leusen Jeanette H. W.
Published: April 2010

The receptor for IgA, FcαRI or CD89, is expressed on myeloid cells and can trigger phagocytosis, tumor cell lysis, and release of inflammatory mediators. These functions critically depend on the associated FcR γ‐chain; however, some biological functions, like receptor internalization, are solely mediated by FcαRI α‐chain. Little is known as to how FcαRI regulates these processes and the FcαRI intracellular domain does not contain recognized signalling motifs. We searched for associating proteins and identified c‐Jun activating binding protein 1 (JAB1) as a binding partner specifically for FcαRI. We found increased FcαRI surface expression after ectopic expression of JAB1 as well as diminished protein levels of total FcR γ‐chain levels after JAB1 knock‐down. These data functionally link JAB1 with controlling protein expression levels of FcαRI‐FcR γ‐chain protein complex.
Highly avid, oligoclonal, early‐differentiated antigen‐specific CD8+ T cells in chronic HIV‐2 infection
Authors: Leligdowicz Aleksandra , Onyango Clayton , Yindom Louis‐Marie , Peng YanChun , Cotten Matthew , Jaye Assan , McMichael Andrew , Whittle Hilton , Dong Tao , Rowland‐Jones Sarah
Published: April 2010

HIV‐1‐specific CD8+ T cells are present in most HIV‐1‐infected people and play an important role in controlling viral replication, but the characteristics of an effective HIV‐specific T‐cell response are largely unknown. The majority of HIV‐2‐infected people behave as long‐term non‐progressors while those who progress to AIDS do so in a manner indistinguishable from HIV‐1. A detailed study of HIV‐2 infection may identify protective immune responses. Robust gag p26‐specific T‐cell responses are elicited during HIV‐2 infection and correlate with control of viremia. In this study, we analyzed features of an HLA‐B*3501‐restricted T‐cell response to HIV‐2 p26 that may contribute to virus control. In contrast to HIV‐1, HIV‐2‐specific T cells are at an early stage of differentiation (CD27+CD28+), a finding that relates directly to CD4+ T‐cell levels and inversely to immune activation. The cells demonstrate IFN‐γ secretion, oligoclonal T‐cell receptor Vβ gene segment usage, exceptional avidity and secretion of pro‐inflammatory cytokines. Despite the potentially strong selection pressure imposed on the virus by these cells, there was no evidence of HIV‐2 sequence evolution. We propose that in chronic HIV‐2 infection, the maintenance of early‐differentiated, highly avid CD8+ T cells could account for the non‐progressive course of disease. Such responses may be desirable from an HIV vaccine.
Modulating numbers and phenotype of CD8+ T cells in secondary immune responses
Authors: Wirth Thomas C. , Harty John T. , Badovinac Vladimir P.
Published: April 2010

Prime‐boost regimens are frequently used to increase the number of memory CD8+ T cells and thus the protective capacity of experimental vaccinations; however, it is currently unknown how the frequency and phenotype of primary (1°) memory CD8+ T cells impact the quantity and phenotype of secondary (2°) memory CD8+ T‐cell populations. Here, we show that 2° infections of mice that received different 1° infections and/or immunizations generated similar numbers of 2° effector and memory CD8+ T cells. Remarkably, this result was independent of the numbers and phenotype of 1° memory CD8+ T cells present at the time of rechallenge. However, after adoptive transfer of low numbers of 1° memory CD8+ T cells, a linear correlation between 1° memory CD8+ T‐cell input and 2° memory CD8+ T‐cell numbers was observed. These data suggest that, above a very low threshold, boosting of 1° memory CD8+ T‐cell populations elicits 2° immune responses of similar magnitude. Therefore, our study has important implications for the design of prime‐boost regimens that aim to generate protective CD8+ T‐cell‐mediated immunity.
Gender and age differences in the distribution of the HDL subclasses among the Chinese population
Authors: Tian Li , Yang Yuye , Fu Mingde , Xu Yanhua
Published: April 2010

Background and aims: to analyze the gender and age differences in the distribution of the high‐density lipoprotein (HDL) subclasses among the Chinese population, and to clarify the mechanism of these changes. Methods and results: the apoA‐I contents of the plasma HDL subclasses were determined by 2‐DE coupled with immunodetection in 324 men (including 186 normolipidemic subjects) and 186 women (including 114 normolipidemic subjects). The contents of preβ1‐HDL and HDL3 (HDL3c, HDL3b, HDL3a) were significantly lower, whereas the contents of HDL2a and HDL2b were higher for women than for men in the <50 years age group. Moreover, the contents of preβ1‐HDL and HDL3 were higher for female subjects; the HDL2a and HDL2b contents were lower for both female and male subjects in the 50–59, 60–69, and ≥70 years age groups versus the subjects of the same gender in the <50 years age group. When compared to the normolipidemic premenopausal women, preβ1‐HDL, HDL3b, and HDL3a increased while HDL2b decreased significantly in normolipidemic men and postmenopausal women. Conclusions: the contents of the large‐sized HDL particles HDL2b were higher, but the contents of the small‐sized HDL particles (preβ1‐HDL, HDL3b, HDL3a) were lower for women versus men in the <50 years age group. Meanwhile, the gender difference in distribution of the HDL subclass narrowed obviously with advancing age. Moreover, the characteristics of the HDL subclass distribution profile for the normolipidemic postmenopausal women resembled those for the normolipidemic men.
Easy mass spectrometry for metabolomics and quality control of vegetable and animal fats
Authors: Riccio Maria Francesca , Saraiva Sérgio A. , Marques Lygia Azevedo , Alberici Rosana , Haddad Renato , Moller Jens C. , Eberlin Marcos N. , Catharino Rodrigo Ramos
Published: April 2010

Easy ambient sonic spray ionization (EASI), a novel desorption/ionization technique for ambient mass spectrometry analysis, is shown to permit the characterization of different types of vegetable and animal fats. The taxonomic markers of the oils, mainly fatty acids and phenols, are extracted with methanol/water (1:1) solution and made alkaline with NH4OH, then placed and dried on the surface of a glass tip and directly analyzed by EASI‐MS in the negative‐ion mode. EASI provides a supersonic cloud of charged droplets that causes efficient desorption and ionization of the oil markers directly from the surface of the glass tip. As proof‐of‐principle cases, EASI(−)‐MS was applied to genuine samples of olive oil, hazelnut oil, soybean oil, grape seed oil, canola oil, butter, and lard. Characteristic metabolomics EASI(−)‐MS profiles of fatty acids and eventually phenols were obtained.
Effects of tocopherols and tocotrienols on the inhibition of autoxidation of conjugated linoleic acid
Authors: Ko Soon‐Nam , Kim Chul‐Jin , Kim Chong‐Tai , Kim Yangha , Kim In‐Hwan
Published: April 2010

The effect of eight vitamin E homologues, i.e. α‐, β‐, γ‐, and δ‐tocopherol and α‐, β‐, γ, and δ‐tocotrienol, on the inhibition of autoxidation of conjugated linoleic acid (CLA) were investigated. The oxidation was carried out in the dark for 21 days at 50 °C and monitored by peroxide values (PV) and TBA values. The levels of the individual vitamin E homologues in CLA during storage were determined by HPLC. γ‐Tocopherol exhibited the highest antioxidant activity among the homologues tested in this study when the antioxidant activities of the individual homologues in CLA were compared by PV. The order of antioxidant activity of eight homologues was γ‐tocopherol > δ‐tocopherol = δ‐tocotrienol ≥ γ‐tocotrienol > β‐tocopherol = β‐tocotrienol > α‐tocopherol = α‐tocotrienol. The degradation rates of α‐tocopherol and α‐tocotrienol were faster than those of the other homologues, whereas δ‐tocopherol had the highest stability in CLA during storage. All homologues exhibited an antioxidant activity by inhibiting the formation of secondary oxidation products. It appears that α‐tocotrienol and β‐tocotrienol have significantly higher antioxidant activities for secondary oxidation in CLA than α‐tocopherol and β‐tocopherol. Meanwhile, the other homologues, namely γ‐tocopherol, γ‐tocotrienol, δ‐tocopherol, and δ‐tocotrienol, exhibited similar antioxidant activity for secondary oxidation in CLA.