bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical Assembly of Organic/Inorganic Building Molecules with π–π Interactions
Authors: Yang Lu , Peng Huisheng , Huang Kun , Mague Joel T. , Li Hexing , Lu Yunfeng
Published: May 2008

Hierarchical assemblies of perylenetetracarboxylic diimide bridged silsesquioxane (PDBS) with controlled structure at multi‐length scale are studied using both experimental and computational methods. The organization process spans multi‐length scales and includes three continuous steps: 1) stacking of the preprogrammed molecules into small clusters, 2) growing of the small clusters into nanoscale building blocks with various sizes and shapes depending on the experimental conditions, and 3) aggregation of nanoscale building blocks into micro‐ or macro‐scale assemblies. The main factors determining the assembly morphology are the second and third steps, which can be controlled by varying the experimental conditions, such as solution drying rate, solvent composition, and PDBS concentration. Despite the different morphologies, all of these assemblies possess highly ordered lamellar structure. It is found that incorporating perylenetetracarboxylic diimide (PD) moieties into the highly ordered silica network endows the PD components with high thermal and mechanical stability, as well as improved optical and electronic properties.
Computer evaluation of hydrogel‐based systems for diabetes closed loop treatment
Authors: Sánchez‐Chávez Irma Y. , Martínez‐Chapa Sergio O. , Peppas Nicholas A.
Published: May 2008

Hydrogels provide the multifunctionality of smart materials and the applicability to medical regulatory systems. Hydrogel membranes that incorporate glucose oxidase for the closed loop treatment of type 1 diabetes mellitus are characterized and modeled. The Sorensen compartmental model is extended to represent the treatment system of a diabetic patient. The performance of the system closed by a hydrogel‐based device is explored and compared to the dynamic behavior of a conventional scheme with an explicit controller element. Anionic and cationic hydrogels are discussed for insulin delivery application. Simulations demonstrate limitations in the range of swelling and contraction of hydrogels in a physiological environment due to the Donnan equilibrium effect. Results show the reduction of peak glucose levels and a basal insulin delivery from a hydrogel membrane system. The evaluation of ionic hydrogel membrane macrosystems prompts the consideration of detected pros and cons using different hydrogels, structures and scales. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Patterns of occurrence and concordance between subjective and objective hot flashes among Muslim and Hindu women in Sylhet, Bangladesh
Authors: Sievert Lynnette Leidy , Begum Khurshida , Sharmeen Taniya , Chowdhury Osul , Muttukrishna Shanthi , Bentley Gillian
Published: May 2008

This study examined the pattern of occurrence and the rate of concordance between objective hot flashes measured by sternal skin conductance and the subjective experience of “gorom vap laga” (feeling steaming hot) among Muslim and Hindu women living in Sylhet, Bangladesh. Participants were aged 40–55, not pregnant or lactating, not using hormone therapy, and with no history of hysterectomy. Thirty women wore an ambulatory hot flash monitor for 8 h on average, from mid‐morning to early evening. True positive, false negative, and false positive measures of hot flashes were examined in relation to demographic, reproductive, and lifestyle variables. On body diagrams, women were most likely to indicate hot flashes on the top of their head (64%) and upper chest (68%). The greatest number of objective hot flashes occurred during the hour of 17:00, perhaps due to the heat of the day, and the clothing and activity associated with prayer. Muslim participants demonstrated more objective hot flashes per woman than Hindu participants (1.5 vs. 0.1, P < 0.05), and Muslims had more false positive measures (86%) compared with Hindu participants (0%, P = 0.06). Among all women who reported subjective hot flashes (n = 19), the proportion of true positive scores was 19%. Overall, the frequency of objective hot flashes was low compared with reports from studies in the United States. The pattern of sweating assessed by body diagrams was not associated with variation in hot flash experience. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
A possible link between the pubertal growth of girls and ovarian cancer in their daughters
Authors: Barker David J. P. , Osmond Clive , Thornburg Kent L. , Kajantie Eero , Eriksson Johan G.
Published: May 2008

At puberty, the distance between the iliac crests of the female pelvis, measured by the intercristal and interspinous diameters, increases rapidly. This is mainly controlled by estrogens. We have followed up 6,370 women who were born in Helsinki during 1934–1944, and whose mothers' pelvic bones were measured during routine antenatal care. We have previously reported that women whose mothers had larger intercristal diameters had higher rates of breast cancer. We postulated that large intercristal diameters are markers of high circulating concentrations of estrogen, which are established at puberty, persist through reproductive life and cause genetic instability in differentiating breast cells in female embryos. We now report on ovarian cancer in the same cohort. Our hypothesis was that the risk of this cancer would also be higher in women whose mothers had broader hips. We found that, when compared with all other women, the hazard ratio for ovarian cancer was 3.3 (95% CI 1.6–7.0, P = 0.004) in the daughters of mothers whose interspinous diameter was greater than 27 cm. Among mothers who had an early menarche, each measure of broad hips was associated with increased risk of ovarian cancer in their daughters. We postulate that ovarian cancer is initiated by exposure of the fetal ovary to maternal sex hormones. Concentrations of these hormones may be higher in mothers who had an early menarche. The maternal sex hormone profile that initiates ovarian cancer may be the product of poor nutrition and growth in early childhood followed by catch‐up pre‐pubertal growth. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Morphological, electrical, and mechanical properties of multiwall carbon nanotube/polysilsesquioxane composite
Authors: Yuen Siu‐Ming , Ma Chen‐Chi M.
Published: May 2008

Multiwalled carbon nanotube (MWCNT) was modified with mixed acid. Diglycidyl ether of bisphenol A (DGEBA)‐bridged polyorganosiloxanes was prepared. The multiwalled carbon nanotube/diglycidyl ether of bisphenol A‐bridged polysilsesquioxane (MWCNT/DGEBA‐PSSQ) composites was fabricated. The improvement of the affinity between MWCNT and the polymer matrix by acid modification was studied. SEM and TEM microphotographs confirm that acid‐modified MWCNT exhibits better dispersion than the unmodified MWCNT in DGBEA‐PSSQ. The mechanical and electrical properties of acid‐modified MWCNT/DGBEA‐PSSQ composites have been investigated. The tensile strength of the material increased 150.6% (with 1.0 wt % acid‐modified MWCNT). The flexural strength of the PSSQ increased 68.4% (with 0.6 wt % acid‐modified MWCNT). The Young's modulus of the material increased 189.3% (with 1.0 wt % acid‐modified MWCNT). The flexural modulus of the PSSQ increased 219.1% (with 0.8 wt % acid‐modified MWCNT). The surface and volume electrical resistivities of MWCNT/DGEBA‐PSSQ composites decreased 6 orders when 2.0 wt % of unmodified MWCNT was added to the PSSQ matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization of an alkali‐treated grass fiber by thermogravimetric and X‐ray crystallographic analysis
Authors: De Debasish , De Debapriya
Published: May 2008

The thermal behavior of grass fiber was characterized by means of thermogravimetric analysis and differential scanning calorimetry analysis. The results proved that the removal of water‐soluble matter improved the thermal behavior of grass fiber over that of unleached fiber, and this was further enhanced by an alkali treatment of the grass fiber. The isothermal weight loss of the grass‐fiber specimens was analyzed at 100, 200, and 300°C for different time periods. Accelerated aging of the grass‐fiber samples was carried out to determine the effect of aging on the tensile strength. Partially delignified grass fiber showed maximum thermal stability. X‐ray diffraction analysis was also performed to verify the composition and to correlate the change in the tensile strength due to the water leaching and alkali treatment. The processing of grass fiber with NaOH and NaClO2 reduced the amorphous fraction in the fiber sample. This may have been a result of the loss of the amorphous noncellulosic components of the fibers and the degradation of the unordered regions of the grass fiber. However, mercerization of the grass fiber revealed an increase in the amorphous fraction after a certain time exposure, confirming the decrease in the crystallinity. The morphology of the water‐leached and alkali‐treated grass fiber was studied with scanning electron microscopy © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Phenol–furfural resins to elaborate composites reinforced with sisal fibers—Molecular analysis of resin and properties of composites
Authors: Oliveira Franciéli B. , Gardrat Christian , Enjalbal Christine , Frollini Elisabete , Castellan Alain
Published: May 2008

Resol type resins were prepared in alkaline conditions (potassium hydroxide or potassium carbonate) using furfural obtained by acid hydrolysis of abundant renewable resources from agricultural and forestry waste residues. The structures of the resins were fully determined by 1H, 13C, and 2D NMR spectrometries with the help of four models compounds synthesized specially for this study. MALDI‐Tof mass spectrometry experiments indicated that a majority of linear oligomers and a minority of cyclic ones constituted them. Composites were prepared with furfural–phenol resins and sisal fibers. These fibers were chosen mainly because they came from natural lignocellulosic material and they presented excellent mechanical properties. Thermal analyses (dTG and DSC) and electron microscopy images indicated that the composites displayed excellent adhesion between resin and fibers. Impact strength measurement showed that mild conditions were more suitable to prepare thermosets. Nevertheless, mild conditions induced a high‐diffusion coefficient for water absorption by composites. Composites with good properties could be prepared using high proportion of materials obtained from biomass without formaldehyde. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence to the performance of cellulose acetate reverse osmosis membranes by fibers addition
Authors: Duarte A.P. , Bordado J.C. , Cidade M.T.
Published: May 2008

The asymmetric membranes based on cellulose acetate are mainly applied for separations in aqueous systems and in reverse osmosis processes, although they can also be used in the so‐called salinity process of energy generation. These applications require membranes with considerable water permeability and high salt rejection. In this paper the improvements resulting from the addition of two different types of fibers on the permeability performance of the membranes (water permeability and salt rejection) as well as on mechanical properties are presented. Concerning the water permeability and salt rejection, the influence of four different contents of cellulosic fibers (CF) and anionic diethylaminoethyl cellulose (DEAE) fibers has been studied and the optimum value was chosen after measuring water permeability and salt rejection of the membranes. To study the mechanical performance, membranes with six different contents of these two types of fibers were produced. Both permeability and mechanical test results obtained for membranes with different contents of fibers were compared with the ones for the membranes produced from the same solution but without fibers. In terms of permeability tests, the membranes with 0.5 wt % CF fibers present the best results, with water permeability 22.8% higher than the membrane without fibers, while the salt rejection only decreases by 7.3%. Concerning the mechanical properties, the best membrane would be the one with 3 wt % CF fibers, however the membrane with 0.5 wt % CF fibers still present a toughness 18.9% higher than the membrane without fibers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Peripheral Muscle Targets and Central Projections of the Mesencephalic Trigeminal Nucleus in Macaque Monkeys
Authors: Wang Niping , May Paul J.
Published: May 2008

The mesencephalic trigeminal nucleus (MesV) contains the somata of primary afferent neurons that innervate muscle spindles in masticatory muscles and mechanoreceptors in the periodontal ligaments. There are conflicting reports about additional peripheral targets of MesV, such as the extraocular muscles, as well as about its central targets. In addition, only limited primate data are available. Consequently, we examined MesV projections in macaque monkeys. The retrograde tracer wheat germ agglutinin‐conjugated horseradish peroxidase (WGA‐HRP) was injected into masticatory or extraocular muscles to define the peripheral targets of the primate MesV. Numerous labeled neurons were found in ipsilateral MesV after masticatory muscle injections. The scattered distribution of labeled cells, and their presence among clusters of unlabeled cells, suggests the muscle representations overlap. Just a few MesV neurons were labeled after extraocular muscle injections. This correlates with the small number of muscle spindles present in macaque extraocular muscles, suggesting MesV cells supplying extraocular muscle spindles may contribute a minor component to oculomotor proprioception. To examine the central connections of MesV, biotinylated dextran amine (BDA) was injected into the spinal trigeminal nucleus (Vs). The presence of retrogradely labeled MesV cells indicated a projection to Vs from MesV. These injections also anterogradely labeled terminals that lay in close association with MesV cells, suggesting an ascending projection from Vs to MesV. Finally, a small number of MesV neurons were labeled after WGA‐HRP injections into the upper cervical spinal cord. This pattern of central connections indicates MesV and Vs information is combined to guide mastication. Anat Rec, 291:974–987, 2008. © 2008 Wiley‐Liss, Inc.
Electromagnetic conductivity mapping for site prediction in meandering river floodplains
Authors: Conyers Lawrence B. , Ernenwein Eileen G. , Grealy Michael , Lowe Kelsey M.
Published: May 2008

Spatial mapping using electromagnetic (EM) conductivity can quickly define past sedimentary environments within meandering river floodplain settings and, most important, those most likely to include archaeological materials. Natural levee and uplifted fluvial terrace environments would have been the most likely areas for people to place permanent settlements, as these topographically high areas would have remained dry during most annual floods. The spatial patterning of high and low electrical conductivity regions, when combined with geological core and auger information, can define a number of depositional environments in floodplains including channels, point bars, natural levees and oxbow lakes. Conductivity maps can then be used to predict the locations of prehistoric floodplain environments, and therefore the most likely locations for archaeological remains. Suitable areas can then be further tested for archaeological features using detailed geophysical surveys and other archaeological survey methods. Case studies are presented from California, Texas and Mississippi that integrate these methods for depositional environment mapping as a way of accessing the archaeological potential in meandering river floodplains. Copyright © 2008 John Wiley & Sons, Ltd.
Rapid and sensitive magnetometer surveys of large areas using SQUIDs – the measurement system and its application to the Niederzimmern Neolithic double‐ring ditch exploration
Authors: Schultze Volkmar , Linzen Sven , Schüler Tim , Chwala Andreas , Stolz Ronny , Schulz Marco , Meyer Hans‐Georg
Published: May 2008

A geomagnetic field measurement system for the detection of archaeological signatures in the subsoil is presented based on the superconducting quantum interference device (SQUID). The system provides fast mapping of large areas with high magnetic field gradient resolution as well as lateral precision. The acquired data are geographically referenced and also the altitude profile is given. The properties of the system were tested intensively at the large Neolithic double‐ring ditch enclosure of Niederzimmern near Weimar, Germany. Differences of the signal acquisition compared with caesium magnetometers are discussed. In the Niederzimmern double‐ring ditch enclosure, with an area of 27 ha, archaeological patterns were found only near the gates. These SQUID measurements, together with accompanying excavations, provide a complex picture of the double‐ring ditch enclosure, dated about 5600 years old. Copyright © 2008 John Wiley & Sons, Ltd.
Growth inhibition of Monodus subterraneus by free fatty acids
Authors: Bosma R. , Miazek K. , Willemsen S.M. , Vermuë M.H. , Wijffels R.H.
Published: May 2008

Monodus subterraneus is a microalga, which is known for its high eicosapentaenoic acid (EPA; 20:5ω3) content. To produce EPA commercially, high volumetric productivities of microalgae are required. These high productivities can be reached in flat panel photobioreactors with small optical paths that have to be operated at high cell densities (>10 g/L). However, at these cell densities a reduction of productivity is observed. This growth inhibition is probably caused by growth inhibitors released by the microalgae, which have been suggested to be fatty acids. Our aim was to investigate if free fatty acids produced by M. subterraneus inhibited growth of this species. Therefore a bioassay was developed and saturated, unsaturated and poly‐unsaturated fatty acids occurring in Monodus were tested on their growth inhibiting properties. Growth of M. subterraneus was completely inhibited at a saturated concentration (96 µM) of palmitoleic acid (16:1ω7). But, the saturated fatty acid palmitic acid (16:0) and the mono‐saturated oleic acid (18:1ω9) were much stronger inhibitors. Growth was inhibited for 50% already at concentrations of 0.4 µM 16:0 and 3 µM 18:1ω9, respectively. These fatty acids probably cause the growth inhibition in high cell density cultures of M. subterraneus. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Simultaneous saccharification and fermentation of Kanlow switchgrass pretreated by hydrothermolysis using Kluyveromyces marxianus IMB4
Authors: Suryawati Lilis , Wilkins Mark R. , Bellmer Danielle D. , Huhnke Raymond L. , Maness Niels O. , Banat Ibrahim M.
Published: May 2008

A thermotolerant yeast strain named Kluyveromyces marxianus IMB4 was used in a simultaneous saccharification and fermentation (SSF) process using Kanlow switchgrass as a feedstock. Switchgrass was pretreated using hydrothermolysis at 200°C for 10 min. After pretreatment, insoluble solids were separated from the liquid prehydrolyzate by filtration and washed with deionized water to remove soluble sugars and inhibitors. Insoluble solids were then hydrolyzed using a commercial cellulase preparation and the released glucose was fermented to ethanol by K. marxianus IMB4 in an SSF process. SSF temperature was 37, 41, or 45°C and pH was 4.8 or 5.5. SSF was conducted for 7 days. Results were compared with a control of Saccharomyces cerevisiae D5A at 37°C and pH 4.8. Fermentation by IMB4 at 45 and 41°C ceased after 3 and 4 days, respectively, when a pH 4.8 citrate buffer was used. Fermentation continued for all 7 days using IMB4 at 37°C and the control. When pH 5.5 citrate buffer was used, fermentation ceased after 96 h using IMB4 at 45°C, and ethanol yield was greater than when pH 4.8 citrate buffer was used (78% theoretical). Ethanol yield using IMB4 at 45°C, pH 5.5 was greater than the control after 48, 72, and 96 h (P < 0.05). Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Cost analysis of biomarker testing for mismatch repair deficiency in node-positive colorectal cancer
Authors: Barrow E , McMahon R , Evans D G , Levine E , Hill J
Published: May 2008

Background

Microsatellite instability (MSI) in colorectal cancer is caused by defective DNA mismatch repair (MMR). It is present in 15 per cent of sporadic colorectal cancers owing to epigenetic mutL homologue 1 (MLH1) inactivation. The evidence suggests that patients with tumours caused by defective DNA MMR do not benefit from 5-fluorouracil (5-FU)-based chemotherapy.

Methods

The proportion of cancers with defective DNA MMR identified by MSI analysis or immunohistochemistry was calculated from published data. The cost of analysis was compared with the potential savings if 5-FU-based chemotherapy was not administered to these patients.

Results

Some 16·3 per cent of sporadic colorectal cancers had defective DNA MMR. Immunostaining for MLH1 and mutS homologue 2 (MSH2) had a sensitivity of 92·4 per cent and a specificity of 99·6 per cent for identifying MSI-high tumours. The strongest predictive variable was right-sidedness, with positive and negative predictive values of 0·329 and 0·948 respectively. If 5-FU-based chemotherapy were not administered, potential savings of up to £1·2 million per 1000 patients tested could be made. Costs would be higher if alternative chemotherapeutic regimens were substituted as a result of testing.

Conclusion

Knowledge of MMR status may enable participation in trials of non-5-FU-based chemotherapy. The cost of MMR testing may be offset by more efficient use of chemotherapy.
Significant association of ABCG5 604Q and ABCG8 D19H polymorphisms with gallstone disease
Authors: Kuo K-K , Shin S-J , Chen Z-C , Yang Y-H C , Yang J-F , Hsiao P-J
Published: May 2008

Background

Adenosine triphosphate-binding cassette (ABC) transporters ABCG5 and ABCG8 are sterol export pumps regulating biliary cholesterol excretion. The formation of gallstones, supersaturated with cholesterol in bile, is determined by genetic and environmental factors. The interaction of susceptible gene polymorphisms with age, sex and body mass index in gallstone disease is unclear.

Methods

In a cross-sectional study, 979 subjects (880 men and 99 women, mean(s.d.) age 47·7(10·4) years) were recruited from a hospital-based population. Of these, 74 were diagnosed with gallstone disease by abdominal ultrasonography. Five non-synonymous polymorphisms, E604Q (ABCG5), D19H, C54Y, T400K and A632V (ABCG8), were analysed using the TaqMan® genotyping assay.

Results

The serum total cholesterol and both low- and high-density lipoprotein cholesterol levels were significantly lower in subjects with gallstones than in those without. 604Q (CC) and D19H (GC) genotypes were significantly associated with gallstone disease, even when adjusted for age, sex and body mass index. The genetic risk of developing gallstone disease was further stratified by age. The risk was greatly increased in subjects younger than 50 years with the D19H genotype and those of 50 years or more with the 604Q genotype.

Conclusion

Carriers of ABCG5 604Q or ABCG8 D19H polymorphisms have an increased risk of gallstone disease independent of age, sex and body mass index.
Incorporating ObjectStab library and fuzzy logic toolbox for design of power system damping controller
Authors: Ngamroo Issarachai , Somritvanitcha Boonrat , Hongesombut Komsan
Published: May 2008

ObjectStab is a general purpose simulation tool for power system stability studies developed by Modelica which is an object‐oriented modeling language. It provides enough modeling flexibility to allow addition or modification of new power system components. This article describes an incorporated use of ObjectStab library and fuzzy logic toolbox in Matlab/Simulink to enhance the application of this library into fuzzy control design environment. The example provided here is the modeling of the static synchronous series compensator (SSSC) which is the new device developed in the ObjectStab. In addition, the interface of ObjectStab with Matlab/Simulink for an SSSC damping controller design by fuzzy logic toolbox is explained step by step. In fuzzy control design, a simple approach to extract membership functions and fuzzy logic control rules based on observed signals is presented. Simulation studies in a two‐area four‐generator power system confirm the effectiveness of the fuzzy controller of SSSC designed by the incorporated use of ObjectStab and fuzzy logic toolbox. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 243–255, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20126
Regulation of the Near‐IR Spectral Properties of Individually Dissolved Single‐Walled Carbon Nanotubes in Aqueous Solutions of dsDNA
Authors: Noguchi Yuichi , Fujigaya Tsuyohiko , Niidome Yasuro , Nakashima Naotoshi
Published: May 2008

Two different single‐walled carbon nanotubes (SWNTs), the so‐called HiPco and CoMoCAT, have been individually dissolved in aqueous solutions of double‐stranded DNA (dsDNA). Atomic force microscopy (AFM) revealed the fine structures of the dsDNA‐wrapped SWNTs. The near‐IR absorption and photoluminescence (PL) spectra of aqueous solutions of dsDNA‐wrapped SWNTs were recorded and, in pure water, we observed only a single two‐dimensional PL spot from (6,5) SWNTs for both HiPco and CoMoCAT. In sharp contrast, when Tris‐EDTA (TE) buffer was used in place of pure water, the PL‐mapping images of the solutions showed chirality indices of (6,5), (7,5), (7,6), (8,4), (9,4), and (10,2) for HiPco‐SWNTs, and (6,5) and (7,5) for CoMoCAT‐SWNTs. The first semiconducting bands in the near‐IR absorption spectra of solutions of dsDNA‐wrapped SWNTs are different. To explain the observed differences in the near‐IR absorption and PL behavior we conducted several experiments and found that the near‐IR optical properties of the SWNTs can be modulated by changing the pH of the solutions. The pH break‐points for near‐IR absorption bleaching and PL quenching are different and the phenomena are explained by differences in the numbers of holes generated on the SWNTs. These findings are important from both fundamental and applied viewpoints.
π‐Face Donor Properties of N‐Heterocyclic Carbenes in Grubbs II Complexes
Authors: Leuthäußer Steffen , Schmidts Volker , Thiele Christina M. , Plenio Herbert
Published: May 2008

The electron‐donating properties of eighteen N‐heterocyclic carbenes (N,N′‐bis(2,6‐dimethylphenyl)imidazol)‐2‐ylidene and the respective dihydro ligands) with 4,4′‐R substituted aryl rings (4,4′‐R = NEt2, OMe, Me, H, SMe, F, Cl, Br, I) in the respective Grubbs II complexes were studied using electrochemical techniques. The nature of the 4‐R substituent has a strong influence on the RuII/III redox potentials ranging between ΔE1/2=+0.196 and +0.532 V. Three unsymmetrical Grubbs II complexes with 4‐R ≠ 4‐R′ were also synthesized. Dynamic NMR spectroscopy revealed the restricted rotation around the (NHC)CRu bond (ΔG = 89 kJ mol−1 at 333 K) resulting in two atropisomers, respectively, with an isomer ratio close to unity. Each of the isomers, that is the two orientations of the 4‐R/4‐R′ substituted mesityl ring with respect to the RCHPh unit, gives rise to different redox potentials (4‐R = NEt2, 4‐R′ = Br: ΔE1/2=+0.232 and +0.451 V). In the oxidized Grubbs II complex (4‐R = NEt2, H) and in the cathodic isomer the electron rich aryl ring is located above the RuCHPh unit. This orientational effect provides clear evidence for strong π–π through‐space interactions in the RuIII complexes, assuming that the alternative through‐bond transfer of electron density is equally efficient in both isomers.
An Hg2+‐Gated Chiral Molecular Switch Created by Using Binaphthalene Molecules with Two Anthracene Units and Two 1,3‐Dithiole‐2‐thione (1,3‐Dithiole‐2‐one) Units
Authors: Wang Cheng , Zhang Deqing , Zhang Guanxin , Xiang Junfeng , Zhu Daoben
Published: May 2008

By integrating the features of anthracene, 1,3‐dithiole‐2‐thione, and binaphthalene units, (S)‐1 and its analogue (S)‐2, which contains two 1,3‐dithiole‐2‐one units instead of 1,3‐dithiole‐2‐thione, were studied for creating a new molecular regulation system and building a gated chiral molecular switch. The results show that the photodimerization is controlled by the remote functional‐group transformation of CS into CO, thus providing an elegant example of molecular regulation. The photodimerization of two anthracene units induces circular dichroism (CD) spectral variation. Overall, the CD spectrum can be remotely modulated by Hg2+ in (S)‐1, which leads to an Hg2+‐gated chiral molecular switch.
Phase 2 trial of pemetrexed disodium and gemcitabine in advanced urothelial cancer (E4802)
Authors: Dreicer Robert , Li Hailun , Cooney Matthew M. , Wilding George , Roth Bruce J.
Published: May 2008

BACKGROUND.

There is a need to identify active new regimens in patients with advanced urothelial cancer. Pemetrexed and gemcitabine are active agents in advanced urothelial cancer. A phase 2 trial of the combination of these 2 agents was performed in patients with advanced urothelial cancer who were previously untreated for metastatic disease.

METHODS.

Forty‐six patients with advanced urothelial carcinoma received pemetrexed disodium 500 mg/m2 and gemcitabine 1000 mg/m2 intravenously on Day 1, with gemcitabine repeated on Day 8. Cycles were repeated every 3 weeks for a maximum of 6 cycles.

RESULTS.

Two patients attained a complete response, and 12 patients attained a partial response for an overall response rate of 31.8% (90% confidence interval, 20.4%–45.2%). The median time to disease progression was 5.8 months, and the median overall survival was 13.4 months. Thirty‐three patients (75%) experienced grade ≥3 neutropenia, and 5 patients (11%) had febrile neutropenia. There were 2 therapy‐related deaths.

CONCLUSIONS.

The combination of pemetrexed and gemcitabine had moderate antitumor activity in previously untreated patients with advanced urothelial cancer at the expense of significant myelosuppression. Cancer 2008. © 2008 American Cancer Society.
How many sentinel lymph nodes are enough during sentinel lymph node dissection for breast cancer?
Authors: Yi Min , Meric‐Bernstam Funda , Ross Merrick I. , Akins Jeri S. , Hwang Rosa F. , Lucci Anthony , Kuerer Henry M. , Babiera Gildy V. , Gilcrease Michael Z. , Hunt Kelly K.
Published: May 2008

BACKGROUND.

It remains unclear how many sentinel lymph nodes (SLNs) must be removed to accurately predict lymph node status during SLN dissection in breast cancer. The objective of this study was to determine how many SLNs need to be removed for accurate lymph node staging and which patient and tumor characteristics influence this number.

METHODS.

The authors reviewed data for all patients in their prospective database with clinical tumor, lymph node, metastasis (TNM) T1 through T3, N0, M0 breast cancer who underwent lymphatic mapping at their institution during the years 1994 through 2006. There were 777 patients who had at least 1 SLN that was positive for cancer. Simple and multiple quantile regression analyses were used to determine which patient and tumor characteristics were associated with the number of positive SLNs. The baseline number of SLNs that needed to be dissected for detection of 99% of positive SLNs in the total group of patients also was determined.

RESULTS.

The mean number of SLNs removed in the 777 lymph node‐positive patients was 2.9 (range, 1‐13 SLNs). Greater than 99% of positive SLNs were identified in the first 5 lymph nodes removed. On univariate analysis, tumor histology, patient race, tumor location, and tumor size significantly affected the number of SLNs that needed to be removed to identify 99% of all positive SLNs. On multivariate analysis, mixed ductal and lobular histology, Caucasian race, inner quadrant tumor location, and T1 tumor classification significantly increased the number of SLNs that needed to be removed to achieve 99% recovery of all positive SLNs.

CONCLUSIONS.

In general, the removal of a maximum of 5 SLNs at surgery allowed for the recovery of >99% of positive SLNs in patients with breast cancer. The current findings indicated that tumor histology, patient race, and tumor size and location may influence this number. Cancer 2008. © 2008 American Cancer Society.
Histologic grade is correlated with outcome after resection of hepatic neuroendocrine neoplasms
Authors: Cho Clifford S. , Labow Daniel M. , Tang Laura , Klimstra David S. , Loeffler Agnes G. , Leverson Glen E. , Fong Yuman , Jarnagin William R. , D'Angelica Michael I. , Weber Sharon M. , Blumgart Leslie H. , DeMatteo Ronald P.
Published: May 2008

BACKGROUND.

The behavior of neuroendocrine neoplasms is poorly defined, and predictors of outcome after surgical resection have yet to be identified. Consequently, guidelines for treatment remain unclear. Current pathologic classification systems do not permit meaningful discrimination of hepatic neuroendocrine neoplasms.

METHODS.

The authors reviewed prospectively maintained databases from 2 institutions of patients who underwent hepatic resection for neuroendocrine neoplasms between 1990 and 2006. Patient, tumor, and operative characteristics were analyzed to identify factors associated with overall survival, progression‐free survival, and symptom control. Hepatic neoplasms were stratified by using a 3‐tier pathologic classification system based on the number of mitotic figures and the presence of tumor necrosis that was recently validated for pancreatic neuroendocrine neoplasms.

RESULTS.

Seventy patients were identified from the databases. Low‐grade, intermediate‐grade, and high‐grade neoplasms were identified in 53%, 37%, and 10% of patients, respectively. After a median follow‐up of 51 months, the median overall survival for all patients was 91 months, and it was 108 months when 7 patients with high‐grade neuroendocrine carcinomas were excluded. Progressive disease was eventually observed in 81% of patients, and the median progression‐free survival was 17 months. The median time to the onset of symptoms was 39 months for patients who presented with hormonal symptoms and 80 months for all patients. Histologic grade was associated with poorer overall and progression‐free survival.

CONCLUSIONS.

When performed in a context of aggressive multimodality therapy, long‐term outcomes after partial hepatectomy for hepatic neuroendocrine neoplasms were favorable; however, disease progression was eventually observed in the majority of patients. Several oncologic variables were associated with significant differences in survival after resection. A novel pathologic classification system appears to enhance prognostic stratification of patients with hepatic neuroendocrine neoplasms. Cancer 2008. © 2008 American Cancer Society.
Normalization of bone markers is associated with improved survival in patients with bone metastases from solid tumors and elevated bone resorption receiving zoledronic acid
Authors: Lipton Allan , Cook Richard , Saad Fred , Major Pierre , Garnero Patrick , Terpos Evangelos , Brown Janet E. , Coleman Robert E.
Published: May 2008

BACKGROUND.

For patients with bone metastases, high N‐telopeptide of type I collagen (NTX) levels correlate with increased risks of skeletal‐related events and death. However, the relation between NTX decreases and clinical benefits is unclear.

METHODS.

Correlations between NTX normalization during treatment and clinical outcome were retrospectively analyzed in 3 large, phase 3 trials. Urinary NTX levels were measured at baseline and at Month 3 in patients with bone metastases from breast cancer (BC; n = 578), hormone‐refractory prostate cancer (HRPC; n = 472), or nonsmall‐cell lung cancer and other solid tumors (NSCLC/OST; n = 291) who received zoledronic acid or control (pamidronate for BC; placebo for HRPC and NSCLC/OST) for up to 24 months. NTX levels were characterized as normal (N; <64 nmol/mmol creatinine) or elevated (E; ≥64 nmol/mmol creatinine).

RESULTS.

After 3 months of zoledronic acid, most N‐group patients maintained normal levels; however, most E‐group patients normalized their NTX levels (BC, 81%; HRPC, 70%; NSCLC/OST, 81%). In contrast, NTX levels normalized with pamidronate in 65% of BC, with placebo in 8% of HRPC, and in 17% of NSCLC/OST E‐group patients. Normalized NTX correlated with improved overall survival versus persistently elevated NTX (significant for zoledronic acid‐treated patients; trend for placebo‐treated patients). Moreover, percentage reductions from baseline NTX levels correlated with benefits regardless of whether patients transitioned from E to N.

CONCLUSIONS.

Zoledronic acid normalizes or maintains normal NTX levels in most patients with bone metastases. Normalized NTX within 3 months of treatment, versus persistently elevated NTX, was associated with reduced risks of skeletal complications and death. Cancer 2008. © 2008 American Cancer Society.
Prognostic significance of ataxia‐telangiectasia mutated, DNA‐dependent protein kinase catalytic subunit, and Ku heterodimeric regulatory complex 86‐kD subunit expression in patients with nonsmall cell lung cancer
Authors: Xing Jinliang , Wu Xifeng , Vaporciyan Ara A. , Spitz Margaret R. , Gu Jian
Published: May 2008

BACKGROUND.

The double‐strand break (DSB) repair capacity has been implicated in the survival of patients in several cancer types. However, little is known about the prognostic importance of the key DSB repair genes—ataxia‐telangiectasia mutated (ATM), DNA‐dependent protein kinase catalytic subunit (DNA‐PKcs), and the Ku heterodimeric regulatory complex 86‐kD subunit (Ku80)—in nonsmall cell lung cancer (NSCLC). To address this issue, the authors determined the messenger RNA (mRNA) expression of these genes in patients NSCLC and assessed their prognostic relevance.

METHODS.

mRNA expression levels of ATM, DNA‐PKcs, and Ku80 were measured in tumor and adjacent normal tissues from 140 patients with NSCLC by using quantitative real‐time polymerase chain reaction analysis. Then, a Cox proportional hazards regression model and Kaplan‐Meier plots were used to evaluate the association between the tumor:normal (T/N) expression ratios of the 3 genes and the overall survival rate and duration in patients with NSCLC.

RESULTS.

mRNA expression of ATM and DNA‐PKcs, but not of Ku80, was significantly higher in tumor tissues than in adjacent normal tissues (P = .003 and P < .001, respectively). The high T/N expression ratios of ATM and DNA‐PKcs were associated significantly with a 1.82‐fold increased risk of death (95% confidence interval, 1.05–2.70) and a 2.13‐fold increased risk of death (95% confidence interval, 1.21–3.76), respectively. However, no significant association with risk was observed for Ku80. Kaplan‐Meier analyses revealed that patients with high T/N expression ratios of ATM or DNA‐PKcs had notably shorter median survival than patients with low ratios.

CONCLUSIONS.

The current findings suggested that the T/N expression ratios of ATM and DNA‐PKcs may be useful for identifying NSCLC patients with a poor prognosis who may benefit from more aggressive therapy. Cancer 2008. ©2008 American Cancer Society.
Effect of exercise on upper extremity pain and dysfunction in head and neck cancer survivors
Authors: McNeely Margaret L. , Parliament Matthew B. , Seikaly Hadi , Jha Naresh , Magee David J. , Haykowsky Mark J. , Courneya Kerry S.
Published: May 2008

BACKGROUND.

Shoulder pain and disability are well recognized complications associated with surgery for head and neck cancer. This study was designed to examine the effects of progressive resistance exercise training (PRET) on upper extremity pain and dysfunction in postsurgical head and neck cancer survivors.

METHODS.

Fifty‐two head and neck cancer survivors were assigned randomly to PRET (n = 27) or a standardized therapeutic exercise protocol (TP) (n = 25) for 12 weeks. The primary endpoint was change in patient‐rated shoulder pain and disability from baseline to postintervention. Secondary endpoints were upper extremity strength and endurance, range of motion, fatigue, and quality of life.

RESULTS.

Follow‐up assessment for the primary outcome was 92%, and adherence to the supervised PRET and TP programs were 95% and 87%, respectively. On the basis of intention‐to‐treat analyses, PRET was superior to TP for improving shoulder pain and disability (−9.6; 95% confidence interval [95% CI], −16.4 to −4.5; P = .001), upper extremity strength (+10.8 kg; 95% CI, 5.4–16.2 kg; P < .001), and upper extremity endurance (+194 repetitions × kg; 95% CI, 10–378 repetitions × kg; P = .039). Changes in neck dissection impairment, fatigue, and quality of life favored the PRET group but did not reach statistical significance.

CONCLUSIONS.

The PRET program significantly reduced shoulder pain and disability and improved upper extremity muscular strength and endurance in head and neck cancer survivors who had shoulder dysfunction because of spinal accessory nerve damage. Clinicians should consider the addition of PRET in the rehabilitation of postsurgical head and neck cancer survivors. Cancer 2008. © 2008 American Cancer Society.
Retropharyngeal lymph node metastasis in nasopharyngeal carcinoma detected by magnetic resonance imaging
Authors: Tang Linglong , Li Li , Mao Yanping , Liu Lizhi , Liang Shaobo , Chen Yong , Sun Ying , Liao Xinbiao , Tian Li , Lin Aihua , Liu Mengzhong , Ma Jun
Published: May 2008

BACKGROUND.

Retropharyngeal lymph node (RLN) metastasis was not included in the current American Joint Committee on Cancer (AJCC) staging system (6th edition) for nasopharyngeal carcinoma (NPC).The object of the current study was to investigate the prognostic value and staging categories of RLN metastasis in NPC detected by magnetic resonance imaging (MRI).

METHODS.

All 924 consecutive patients with newly diagnosed NPC were examined with MRI before treatment with definitive intent radiotherapy.

RESULTS.

The incidence of RLN metastasis was 73.5%. On multivariate analysis, RLN metastasis was found to be an independent prognostic factor for distant metastasis‐free survival (DMFS) in all patients (P= .040). In patients with N0 disease, significant differences were observed between patients with and those without RLN metastasis after adjusting for T classification (P= .046). With regard to laterality, no significant differences were observed in DMFS between patients with unilateral and bilateral RLN metastasis in N0 disease (P= .734). No significant difference in the hazards ratios for either DMFS or disease‐free survival (DFS) was found between patients with N0 disease with RLN metastasis and patients with N1 disease (P= .092 andP= .149, respectively). When RLN was classified as N1 disease, there was a better segregation of different N classifications in terms of DFS and DMFS curves, whereas the difference in hazards ratios for N0 and N1 disease was more obvious in DMFS (from 0.461 vs 0.785 to 0.317 vs 0.690).

CONCLUSIONS.

The results of the current MRI‐based study demonstrate that RLN metastasis affects the DMFS rates of NPC. The authors propose that RLN metastasis be classified as N1 disease, regardless of its laterality. Cancer 2008. ©2008 American Cancer Society.
Prophylactic antibiotics reduce morbidity due to septicemia during intensive treatment for pediatric acute myeloid leukemia
Authors: Kurt Beth , Flynn Patricia , Shenep Jerry L. , Pounds Stanley , Lensing Shelly , Ribeiro Raul C. , Pui Ching‐Hon , Razzouk Bassem I. , Rubnitz Jeffrey E.
Published: May 2008

BACKGROUND.

The aim of this study was to determine whether antibiotic prophylaxis during periods of neutropenia reduced streptococcal (S. viridans) sepsis and overall bacterial sepsis.

METHODS.

The authors reviewed outcomes of 78 evaluable patients who were consecutively treated for acute myeloid leukemia (AML) from October 2002 through January 2007. Several successive prophylactic antibiotic regimens were used. All patients received antifungal prophylaxis with oral voriconazole.

RESULTS.

Oral cephalosporins did not significantly reduce the odds of bacterial sepsis (P = .81) or streptococcal (S. viridans) sepsis (P = .90) relative to no prophylaxis. Intravenous (iv) cefepime completely prevented streptococcal (S. viridans) sepsis and reduced the odds of bacterial sepsis 91% (P < .0001) relative to no prophylaxis, but resistant gram‐negative bacteria emerged in 2 patients. Vancomycin with oral ciprofloxacin or a cephalosporin reduced the odds of bacterial sepsis by 93% (P < .0001) and streptococcal (S. viridans) sepsis by 99% (P < .0001). The fungal infection rate did not differ significantly between patients who did and did not receive antibiotic prophylaxis (1.0 per 1000 patient‐days for both groups). The observed reduction in average hospital days per chemotherapy course for patients given vancomycin regimens or cefepime was 5.7 (P < .0001) and 4.1 (P = .0039) days, respectively. No reduction was observed with oral cephalosporins (P = .10). Furthermore, vancomycin regimens or cefepime were associated with a 20% reduction in healthcare charges (P = .0015) relative to using no antibiotics. One patient, who was on oral cefuroxime alone, died of septicemia.

CONCLUSIONS.

Prophylaxis with intravenous cefepime or a vancomycin regimen, and voriconazole, reduced morbidity in children with AML, and resulted indramatic decreases in the incidence of septicemia and hospitalization days. Cancer 2008. © 2008 American Cancer Society.
A pathway for predation in the brain of the barn owl (Tyto alba): Projections of the gracile nucleus to the “claw area” of the rostral wulst via the dorsal thalamus
Authors: Wild J.M. , Kubke M.F. , Peña J.L.
Published: May 2008

The Wulst of birds, which is generally considered homologous with the isocortex of mammals, is an elevation on the dorsum of the telencephalon that is particularly prominent in predatory species, especially those with large, frontally placed eyes, such as owls. The Wulst, therefore, is largely visual, but a relatively small rostral portion is somatosensory in nature. In barn owls, this rostral somatosensory part of the Wulst forms a unique physical protuberance dedicated to the representation of the contralateral claw. Here we investigate whether the input to this “claw area” arises from dorsal thalamic neurons that, in turn, receive their somatosensory input from the gracile nucleus. After injections of biotinylated dextran amine into the gracile nucleus and cholera toxin B chain into the claw area, terminations from the former and retrogradely labeled neurons from the latter overlapped substantially in the thalamic nucleus dorsalis intermedius ventralis anterior. These results indicate the existence in this species of a “classical” trisynaptic somatosensory pathway from the body periphery to the telencephalic Wulst, via the dorsal thalamus, one that is likely involved in the barn owl's predatory behavior. The results are discussed in the context of somatosensory projections, primarily in this and other avian species. J. Comp. Neurol. 509:156–166, 2008. © 2008 Wiley‐Liss, Inc.