bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of atherosclerosis and atherosclerotic risk factors in patients receiving hemodialysis and peritoneal dialysis
Authors: Cengiz K. , Dolu D.
Published: April 2007

BACKGROUND

Although some studies have found that myocardial infarction and cerebrovascular disease are more common in patients receiving continuous ambulatory peritoneal dialysis (CAPD) than in patients receiving hemodialysis (HD), the results of other studies have not supported these findings. Studies comparing patients receiving HD with patients receiving CAPD have had conflicting results.

OBJECTIVE

The aims of this study were to compare the atherosclerotic changes in CAPD and HD patients and to assess which factors might be responsible for atherosclerosis in dialysis patients.

METHODS

Enrolled in the study were 33 patients receiving HD, 32 patients receiving CAPD, and 33 controls for a total of 98 participants. Serum triglycerides (TG), total cholesterol (TC), high‐density lipoprotein (HDL), low‐density lipoprotein, lipoprotein (a) (Lp[a]), apolipoprotein A‐I, apolipoprotein B (Apo B), apolipoprotein E (Apo E), albumin, high‐sensitivity C‐reactive protein (hs‐CRP), fibrinogen, intact parathyroid hormone (iPTH), and ferritin levels were obtained from all patients. Carotid intima‐media thickness (CIMT) and plaque number were calculated using B‐mode ultrasonography.

RESULT

Serum TG, Lp(a), Apo B, hs‐CRP, fibrinogen, ferritin, and iPTH levels were significantly higher in the dialysis groups than in the control group; whereas HDL, Apo E, and albumin levels were decreased (p < .05); the others were same in the all groups. However, there was no difference between the HD and CAPD groups in the other lipid parameters except Lp(a) (p < .05). CIMT and plaque number of the patients treated with dialysis were higher than those of the control group (p < .01), but were not significantly different between the 2 dialysis groups (p > .05). CIMT and plaque number were positively correlated with age (r = 0.43; p < .05) and hs‐CRP level ( r = 0.40; p < .05) and negative correlated with serum albumin and hs‐CRP levels (r = −0.37, p < .05; and r = −0.25; p < .05, respectively).

CONCLUSIONS

Serum Apo B and Lp(a) levels were higher in the CAPD patients than in the HD patients. CIMT and plaque number were positively correlated with age and hs‐CRP level and negatively correlated with serum albumin and hs‐CRP levels.
Open operative management of dialysis‐dependent ischemic nephropathy
Authors: Piercy K. Todd , Mostafavi Kian , Craven Timothy E. , Craven Brandon L. , Edwards Matthew S. , Dean Richard H. , Hansen Kimberley J.
Published: April 2007

OBJECTIVE

This retrospective review examines open operative management of dialysis‐dependent ischemic nephropathy among consecutive hypertensive adults.

METHODS

From February 1987 through July 2005, 820 patients underwent open operative repair of 1220 kidneys at our center. A subgroup of 45 hypertensive patients (19 women, 26 men; mean age, 68 ± 9 years; mean BP, 205 ± 29/99 ± 20) considered permanently dialysis‐dependent prior to renal artery (RA) repair forms the basis of this report. Estimated glomerular filtration rate (EGFR) was determined from serial serum creatinine measures 14 weeks before and after RA repair. The mean rate of change of EGFR was estimated before and after RA repair using linear regression analysis. Analysis of kidney status and change in EGFR was performed. The relationship between renal function response after an operation and survival was determined by the product‐limit method.

RESULTS

Renal artery repairs to 73 kidneys included RA bypass (44 repairs: 22 saphenous vein repairs and 22 prosthetic grafts), RA endarterectomy (25 repairs; 13 transrenal and 12 transaortic), and RA reimplantation (4 repairs). Thirty‐five patients had bilateral procedures, including 4 procedures to solitary kidneys. Eighteen patients had combined aortic repair (13 AAA, 5 aortic occlusions). Of 28 RA occlusions, 25 were repaired. Three nephrectomies were performed for unreconstructable RA to a nonfunctioning kidney. After RA repair, 2 patients died (4.4%) within 30 days of operation or in‐hospital. Twenty‐nine of 43 (67%) surgical survivors stopped being dialysis dependent. Among patients removed from dialysis, postoperative EGFR ranged from 10.0 to 91.1 mL/min/1.73 m2(mean: 41.7 ± 18.6 mL/min/1.73 m2). Four patients initially removed from dialysis progressed to eventual dialysisdependence on follow‐up. Removal from dialysis was associated with a more rapid decline in preoperative EGFR (mean slope per week logeEGFR: −0.1489 ± 0.0180 off dialysis; −0.0748 ± 0.0236 on dialysis;p = .01); however, EGFR did not differ statistically after unilateral or bilateral RA procedures (mean: 25.8 ± 7.7 mL/min/1.73 m2unilateral versus 44.6 ± 3.8 mL/min/1.73 m2bilateral;p = .06). On follow‐up, improved survival was observed for patients removed from dialysis compared with patients who remained dialysis dependent (p = 0.003).

CONCLUSION

Open operative management of dialysis‐dependent ischemic nephropathy can remove selected patients from dialysis. Beneficial renal function response was associated with a rapid decline in preoperative renal function. Compared with that of patients who remained dialysis dependent, the survival of patients who could cease dialysis after the operation was was improved.
Work‐related stress, burnout, and job satisfaction of dialysis nurses in association with perceived relations with professional contacts
Authors: Arikan Fatma , Köksal Can Deniz , Gökçe Çig̀dem
Published: April 2007

OBJECTIVE

We set out to determine levels of job‐related stress, burnout, and job satisfaction in dialysis nurses and their association with nurses' perceptions regarding relations with co‐workers, and co‐worker opinions on the nursing profession. The subjects compared in this study were employed in the dialysis units, intensive care units (ICUs) and the most preferred (cardiology, general surgery and orthopedics wards) of three different hospitals.

METHODS

This descriptive and cross‐sectional study was conducted in April 2003, and included 180 nurses: 31 working in dialysis units, 100 in ICUs, and 49 in the most preferred wards of the same hospitals. The study candidates were assessed with the use of a questionnaire regarding their socio‐demographic characteristics, work places, and views concerning their relations with and the opinions of their professional contacts. Other means of data collection were the Work‐Related Strain Inventory (WRSI), the Maslach Burnout Inventory (MBI) and the Minnesota Work Satisfaction Questionnaire (MWSQ). Percentage estimations, the chi‐square test, and variance analysis were used for statistical evaluation of the data; p > 0.05 was accepted as significant.

RESULT

When compared with ICU and ward unit nurses, dialysis nurses had evidence of decreased job stress and burnout as well as increased job satisfaction, accompanied by decreased intention to leave the profession and higher levels of positive views concerning their relationships with physician co‐workers and the opinions of their professional contacts toward the nursing profession.

CONCLUSION

This study confirmed some established predictors of job satisfaction, work‐related stress, and burnout and provided data on an unexplored area. Dialysis nurses appear to be at a decreased risk for job stress, burnout and premature retirement from nursing, with higher levels of job satisfaction. Further. the quality of relationships with physician co‐workers and the opinions of professional contacts regarding the nursing profession as perceived by nurses may be related to job stress, burnout and work satisfaction.
Automatic selection of Web services based on attributes and ratings
Authors: Ata Shingo , Matsunaga Hisae , Oka Ikuo , Fujiwara Chikato
Published: April 2007

Web services are a unified framework that enables the exchange of information among distributed applications using existing World Wide Web communications technologies. Web services offer the benefit of simplifying the sharing of information among different applications that are operated via remote terminals. However, when multiple services exist that provide the same functionality, a mechanism for automatically selecting the most appropriate service from those on offer is necessary. Unfortunately, the majority of automatic selection mechanisms are designed to use a fixed set of indicators as the selection criteria and are therefore unable to adapt to the diverse demands of users. In this paper we propose a new mechanism for automatically performing such service selection that integrates a wide range of different indicators. Specifically, we assign attributes to each of the services that can be used as evaluation criteria; we then gather these attributes at the user's client. We can compute a rating for each service on the basis of the attributes that have been collected and select the service that is assigned the highest rating. In this paper we introduce the concept of an attribute database (an attribute repository) and define a new communications protocol to enable the registration and searching of attributes in order to deal with variation in the attributes used by different services. In addition, using a simulation of a distributed applications environment, we perform evaluations and demonstrate that the proposed selection mechanism is able to reduce execution times as compared to a random selection mechanism. We also implement the proposed mechanism in an experimental environment and show that it can be used in practice for automatically selecting services on the basis of attribute values. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(8): 40–49, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20284 Copyright © 2004 Wiley Periodicals, Inc.Copyright © 2007 Wiley Periodicals, Inc.
Packet forwarding along an explicit route using the unused address pool on a packet switching network
Authors: Imaizumi Hideaki , Nagami Ken‐Ichi , Nakamura Osamu , Murai Jun
Published: April 2007

This paper considers a connectionless (CL) packet switching network, such as IP, and proposes a method in which unused addresses are used as labels for packet flows with various granularities, which are transferred along explicitly specified routes. Generally, in CL packet‐switched networks, the next packet is selected and relayed to arrive at the destination host on the basis of the destination address attached to the packet. Consequently, it is impossible to transfer packets which have the same destination address but different requirements along separate routes. One technique for performing such a transfer is multi‐protocol label switching (MPLS) and is based on a different transfer paradigm. The cost of this method is high because the transfer schemes of each participating router must be modified. To address this problem, this paper proposes a method for flow‐based explicit route transfer. In the proposed method, a particular packet flow is allocated to an unused address so that an explicit route is composed from the unused address and the destination address of the packet is translated. In this method, the transfer scheme is kept essentially the same and explicit route transfer is realized only through a simple extension to the router. Depending on the mode of application, it is unnecessary to modify internal routers; the method can easily be applied to existing networks. In this paper, an application of the method to IP, as a typical CL packet switching network, is described, and the features of the proposed method are discussed. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(9): 78–89, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20308
Effective deflection control method in optical packet switching networks with shared buffers
Authors: Kawanabe Kazuki , Takahashi Tatsuro
Published: April 2007

Deflection routing is considered as a method to avoid packet collisions in an optical packet switching system. Deflection routing is a method of avoiding collision by link substitution, in which the colliding packet is sent to an idle link. Thus, the load on the congested part of the network is distributed and the bandwidth can be utilized effectively. When excessively frequent deflections are performed, however, the load on the whole network is increased, which produces an adverse effect. Another problem is that sequence errors can occur in the same flow due to differences of transmission delay, since packets are sent to different routes. From these points of view, this paper proposes a deflection control method which can remedy the above problems, and applies the proposed method to an optical packet switching system. In the proposed control method, class separation is performed with respect to sequence error, and deflection is permitted to packets of nonpriority class. This improves performance by large‐scale grouping. In order to alleviate the increase in load on the whole network, a control algorithm which can deal with changes of the link utilization and the number of traversed hops is devised. The effectiveness of the approach is shown by computer simulation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(9): 67– 77, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20312
Content protection in adaptive content delivery
Authors: Fujimoto Hiroshi , Suzuki Takashi , Nakayama Takehiro , Takeshita Atushi , Ramzan Zulfikar , Gentry Craig , Jain Ravi
Published: April 2007

This paper considers environment‐adaptive content delivery in which an intermediary modifies the content between the content provider and the content user, and proposes a system in which the provider can securely control content modification by the intermediary in accordance with usage rules defined in the content. In order to have the intermediary follow the usage rules strictly, it is indispensable to provide a content protection technique in which tampering with content or usage rules by a third party is prevented while permitting content modification by intermediaries approved by the provider within the scope of the usage rules. The authors consider the hash‐tree signature method in which data deletion by the intermediary is permitted, and propose a signature system with a place holder extension permitting data addition. A highly efficient realization of the proposed signature system based on the hash‐sign‐switch (HSS) method is presented. The effectiveness of the approach is shown by a quantitative evaluation using the implemented system. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(9): 54–66, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20341
Design of rotational dielectric dome with linear array feed for wide‐angle multibeam antenna applications
Authors: Kawahara Hiroyuki , Deguchi Hiroyuki , Tsuji Mikio , Shigesawa Hiroshi
Published: April 2007

This paper proposes a method for design of the shape and thickness of a dielectric dome by optimization, aiming at achieving multibeam emission with a uniform high gain for a wide range of angles. The dielectric dome has the features that it does not require a tremendous number of elements, as in the constrained lens, and that excellent multibeam characteristics can be realized over a wider range of angles than in the conventional dielectric lens. These features are demonstrated through an example of the design of a dielectric dome in which a decrease in gain is avoided over a wide range of angles up to 70°. The validity of the proposed method is verified by numerical analysis, and also by measurement and evaluation of the radiation pattern of the constructed dielectric dome antenna in the Ka band. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(5): 49– 57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20254
All polarization‐maintaining type Yb mode‐locked fiber laser with photonic crystal fiber
Authors: Sumimura Kazuhiko , Yoshida Hidetsugu , Tanaka Kazuhiro , Okada Hajime , Fujita Hisanori , Nakatsuka Masahiro , Sawada Hisashi , Yoshida Minoru
Published: April 2007

We have demonstrated a polarization‐maintaining (PM) Yb mode‐lock highly stable fiber laser with high beam quality. The characteristics of side‐hole type PM Yb‐doped fiber (YDF) were examined. The splicing connection between PM‐YDF and PANDA fiber was optimized. We optimized the laser oscillation output and improved the efficiency of the fiber length in the Fabry‐Perot cavity. We demonstrated an all PM single‐mode fiber ring cavity. Mode‐locking was produced by inserting a semiconductor saturable absorption mirror (SESAM). A PM photonic crystal fiber (PCF) was used for dispersion compensation in the cavity. Stable mode‐lock operation with 500‐ps pulses at 7.2 MHz was observed. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(5): 27–32, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20326
Approximate analytical solutions for nonlinear photonic crystal fibers
Authors: Kirihara Takahito , Fujisawa Takeshi , Saitoh Kunimasa , Koshiba Masanori
Published: April 2007

This paper proposes an analytical approximation theory for evaluation of the transmission characteristics of a nonlinear photonic crystal fiber. A photonic crystal fiber with a complex cross‐sectional structure is replaced equivalently with a conventional step‐index fiber so that an analytical approximation theory developed for the conventional nonlinear optical fiber can be applied directly to the nonlinear photonic crystal fiber. In order to derive an effective index of refraction of the clad region of the photonic crystal fiber with holes, an empirical formula for the normalized frequency of the photonic crystal fiber proposed recently is introduced. Hence, the fundamental quantities describing the transmission characteristics of the nonlinear photonic crystal fiber, specifically the effective index of refraction and the effective core cross section, can easily be derived without numerical calculations. By using the proposed method, the optical power dependence of the transmission characteristics of the nonlinear photonic crystal fiber is analyzed. Validity of the proposed method is verified by comparison of the results with those by calculations based on the full‐vectorial finite element method. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(5): 19– 26, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20327
Synthesis and Secondary Structure of Alternate α,β‐Hybrid Peptides Containing Oxazolidin‐2‐one Moieties
Authors: Angelici Gaetano , Luppi Gianlugi , Kaptein Bernard , Broxterman Quirinus B. , Hofmann Hans‐Jörg , Tomasini Claudia
Published: April 2007

The synthesis and conformational analysis of a novel class of foldamers containing (S)‐β3‐homophenylglycine [(S)‐β3‐hPhg] and D‐4‐carboxy‐oxazolidin‐2‐one (D‐Oxd) residues in alternate order is reported. The experimental conformational analysis performed in solution by IR, 1H NMR, and CD spectroscopy unambiguously proved that these oligomers fold into ordered structures with increasing sequence length. Theoretical calculations employing ab initio MO theory suggest a helix with 11‐membered hydrogen‐bonded rings as the preferred secondary structure type. The few formal helix alternatives can be excluded in particular by steric effects of the oxazolidin‐2‐one rings. The novel structures enrich the field of peptidic foldamers and might be useful in the mimicry of native peptides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
CEC and EKC of natural compounds
Authors: Scherz Heimo , Huck Christian W. , Bonn Günther K.
Published: April 2007

In this review, an overview of CEC and EKC methods with their developments are summarized for different natural compounds. It is divided into three main parts. The first part elaborates the separation of lipophilic compounds without any charged groups. The second part constitutes CEC and EKC of lipophilic compounds containing ionizable functional groups whereas the third part contains hydrophilic compounds. Packed, monolithic, coated, or raw fused‐silica (FS) capillaries are among the choice for stationary phases. Applications of these phases on the above‐mentioned three classes of compounds, coupled with different detection methods, e.g. MS or LIF, are explored and their advantages and disadvantages are discussed.
Tris interference in IEF and 2‐DE
Authors: Smejkal Gary B. , Robinson Myra H.
Published: April 2007

When dried IPGs are hydrated with protein solutions, the concentration of protein and other ionic constituents is constant throughout the strip. Tris, initially present at a very low concentration, focuses during IEF and accumulates in the gradient at a pH corresponding to its pKa at the operative temperature of electrophoresis. Tris focuses more rapidly than many basic proteins, and concentrates into a localized zone of increased conductivity which coincides with a precipitous voltage drop in that vicinity. Basic proteins, already near their pI, are frequently observed to align at the periphery of this zone. Acidic proteins imbibed at the basic end of the gradient must traverse this region before this ionic boundary is formed, or otherwise may fail to migrate to their proper positions in the pH gradient.
Determination of neurotransmitters in PC 12 cells by microchip electrophoresis with fluorescence detection
Authors: Shi Baoxian , Huang Weihua , Cheng Jieke
Published: April 2007

A sensitive fluorescence detection system with an Hg‐lamp as the excitation source and a photon counter as the detector for microchip CE (MCE) has been developed. O‐Phthaldialdehyde (OPA, λex = 340 nm) was employed to label the catecholamine neurotransmitters such as dopamine (DA), norepinephrine (NE), and amino acid neurotransmitters including alanine (Ala), taurine (Tau), glycine (Gly), glutamic acid (Glu), and aspartic acid (Asp). The separation of seven derivatized neurotransmitters was successfully performed in MCE and the detection limits (S/N = 3) for DA, NE, Ala, Tau, Gly, Glu, and Asp were 0.85, 0.49, 0.23, 0.15, 0.13, 0.18, and 0.29 fmol, respectively. The system was then successfully applied for separation and determination of neurotransmitters in rat pheochromocytoma (PC 12) cells, and the average amounts of analyte per cell from a cell population were 2.5 fmol for DA, 3.3 fmol for Ala, 8.2 fmol for Tau, 4.0 fmol for Gly, and 1.9 fmol for Glu, respectively. By single‐cell injection mode, electrophoresis separation and quantitative measurement of Glu in individual PC 12 cells was obtained. The average value of Glu per cell from single PC 12 cells analysis was found to be 3.5 ± 3.1 fmol.
Access to Paullone Analogues by Intramolecular Heck Reaction
Authors: Joucla Lionel , Popowycz Florence , Lozach Olivier , Meijer Laurent , Joseph Benoît
Published: April 2007

The syntheses of paullone (1a) and three paullone derivatives, including a sulfur analogue (2a), a tricyclic derivative (2b), and a ring‐enlarged variant (2c), are described, Pd‐catalyzed intramolecular Heck reaction being the key step. The kinase‐inhibitory properties of the novel paullone analogues were investigated.
Internal gravity wave resonance of thermal convection fields in rectangular cavities with heat‐flux vibration (effects of aspect ratio on the fields)
Authors: Matsumura Shota , Ishida Hideshi , Momose Kazunari , Kawahara Genta
Published: April 2007

In this paper the thermal convection field and its resonance phenomena in a rectangular cavity with heat‐flux vibration are numerically examined and the results are compared with those of a square cavity. As in the case of α=1, the critical angular velocity at which the relative amplitude of the midplane Nusselt number αm has a local maximum agrees very well with the resonance angular velocity of the internal gravity wave ωr, estimated by the theoretical equation proposed by Thorpe, even when the aspect ratio is α=5 and the Prandtl number is Pr=0.71 for a range of the Rayleigh number Ra. However, αm has two local maxima for a larger Ra, which is peculiar to the case of larger α. The time variation of sub‐components of the fluctuating component of the midplane Nusselt number shows that the phase at the maximum value of αm agrees well with that of the sub‐component of velocity for the first resonance angular velocity ωr. For the other angular velocity ωr2, the phase of αm agrees with that of the sub‐component of temperature. Moreover, we found that the boundary angular velocity ω0 between the first two of the five ω regions, which classify the thermal convection fields against ω, can be expressed by a function of α, Ra, and Pr and that αm is independent of α and Ra for a relatively wide range of ω/ω0. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(3): 158– 171, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20149
Long‐term population‐based marriage rates among adult survivors of childhood cancer in Britain
Authors: Frobisher Clare , Lancashire Emma R. , Winter David L. , Jenkinson Helen C. , Hawkins Michael M.
Published: April 2007

The objectives of this study were to assess the number of adult survivors of childhood cancer who ever married and the factors influencing marriage, compare observed marriages to those expected from the general population, and assess age at marriage and influencing factors. The data is based on the British Childhood Cancer Survivor Study (BCCSS), which is a population‐based cohort of 18,119 individuals who were diagnosed with childhood cancer between 1940 and 91 and survived at least 5 years. Fourteen thousand five hundred thirty‐nine were alive, aged at least 16 years and eligible to receive a postal questionnaire, which ascertained marriage status. Thirty‐four percent of 9,954 survivors had married. Survivors with the following characteristics: males, CNS neoplasm, received radiotherapy, diagnosed with mental retardation, registered blind, low social functioning score (calculated from SF‐36 health status measure), and achieved the highest level of educational attainment, were less likely to have married than the complementary survivor groups. The deficits in the proportion ever married compared to the general population were mostly between 9 and 18% among males and 7–10% among females. The largest ever married deficits were among male CNS neoplasm survivors aged 30 years or over (29–38%). Age at first marriage among survivors was related to: sex, childhood cancer type, age at diagnosis, chemotherapy, radiotherapy, mental retardation, and level of educational attainment. Regular follow‐up for these survivors should address not just physical late‐effects of the childhood cancer and treatment, but also psychosocial needs throughout the lifespan of the survivors to help them achieve life events as they occur in the general population. © 2007 Wiley‐Liss, Inc.
The interrelated dynamics of unemployment and low‐wage employment
Authors: Stewart Mark B.
Published: April 2007

This paper examines the extent of state dependence in unemployment and the role played in this by intervening low‐wage employment. A range of dynamic random and fixed‐effects estimators are compared. Low‐wage employment is found to have almost as large an adverse effect as unemployment on future prospects and the difference in their effects is found to be insignificant. Evidence is presented that low‐wage jobs act as the main conduit for repeat unemployment and considerably increases its probability. Obtaining a higher‐wage job reduces the increased risk of repeat unemployment to insignificance. Copyright © 2007 John Wiley & Sons, Ltd.
Mineralization of radiation‐crosslinked polyvinyl alcohol/polyvinyl pyrrolidone hydrogels
Authors: Zainuddin  , Hill David J.T. , Whittaker Andrew K.
Published: April 2007

A study of the calcification of the polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) hydrogels during their exposure to a calcium chloride solution or a simulated body fluid has been carried out. On the basis of the experiments, using a two‐compartment permeation cell, the diffusion of calcium ions and their subsequent deposition in the hydrogels were elucidated. Steady‐batch experiments were also performed to further elaborate the deposition pattern and the types of calcium deposits. It was demonstrated that Fick's second law of diffusion can describe the diffusion of calcium ions through PVA/PVP hydrogels at 310 K. The diffusion coefficient was determined to be (4.4 ± 0.1) × 10−10 m2/s and the partition coefficient for the hydrogels was 0.06. Formation of calcium deposits was noticed taking place both on the surface and inside the hydrogels. The deposits formed on the surface have flake morphology, while the deposits inside the hydrogels are more like globular aggregates. Both types of deposits have been characterized as being comprised calcium and hydroxyl ion deficient apatites with chloride ions the most likely substituting species at the hydroxyl sites. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Substance P augments PGE2 and IL‐6 production in titanium particles‐stimulated fibroblasts from hip periprosthetic membrane
Authors: Qian Yebin , Zeng Bing‐Fang , Zhang Xian‐long , Jiang Yao
Published: April 2007

Aseptic loosening remains the primary cause of failure in total joint arthroplasty. Implant‐derived particles are thought to be a main cause of osteolysis that leads to failure of total joint arthroplasty. The nervous system has been implicated in the etiology and pathogenesis of joint diseases. Substance P (SP) immunoreactive nerve fibers have been detected in the pseudomembrane and pseudocapsular tissues of aseptic loose hip prostheses, suggesting that SP might be involved in the process of aseptic loosening. Fibroblasts are abundant in periprosthetic membrane. Neuropeptides are able to modulate cytokine production by fibroblasts. In this study, we isolated fibroblasts from periprosthetic membrane at the time of revision hip arthroplasty performed because of aseptic loosening. Fibroblasts were stimulated with titanium (Ti) particles or SP. Prostaglandin (PG) E2 and interleukin‐6 (IL‐6) assays were performed using enzyme‐linked immunosorbent assay kit. PGE2 and IL‐6 secretion by fibroblasts have been significantly increased in the presence of Ti particles or SP. Moreover SP caused significant increase in PGE2 and IL‐6 production by Ti particles‐stimulated fibroblasts. Thus, SP and Ti particles acted synergistically to increase PGE2 and IL‐6 secretion in fibroblasts from periprosthetic membrane. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Theoretical study of the interaction between sodium ion and a cyclopeptidic tubular structure
Authors: Ferrante Francesco , Manna Gianfranco La
Published: April 2007

DFT calculations have been carried out to describe the pathway of a sodium ion along the stacking direction of a tubular structure set up by five cyclopeptidic units, which can be considered a suitable model of a hollow tubular structure of indefinite length. A lattice of points inside the tubular structure is defined and the DFT interaction energy values with a sodium ion are obtained. The data allow predicting a zigzag path of the ion inside the hosting structure. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Common system setup for the entire catalytic cycle of cytochrome P450cam in quantum mechanical/molecular mechanical studies
Authors: Zheng Jingjing , Altun Ahmet , Thiel Walter
Published: April 2007

We describe a system setup that is applicable to all species in the catalytic cycle of cytochrome P450cam. The chosen procedure starts from the X‐ray coordinates of the ferrous dioxygen complex and follows a protocol that includes the careful assignment of protonation states, comparison between different conceivable hydration schemes, and system preparation through a series of classical minimizations and molecular dynamics (MD) simulations. The resulting setup was validated by quantum mechanical/molecular mechanical (QM/MM) calculations on the resting state, the pentacoordinated ferric and ferrous complexes, Compound I, the transition state and hydroxo intermediate of the CH hydroxylation reaction, and the product complex. The present QM/MM results are generally consistent with those obtained previously with individual setups. Concerning hydration, we find that saturating the protein interior with water is detrimental and leads to higher structural flexibility and catalytically inefficient active‐site geometries. The MD simulations favor a low water density around Asp251 that facilitates side chain rotation of protonated Asp251 during the conversion of Compound 0 to Compound I. The QM/MM results for the two preferred hydration schemes (labeled SE‐1 and SE‐4) are similar, indicating that slight differences in the solvation close to the active site are not critical as long as camphor and the crystallographic water molecules preserve their positions in the experimental X‐ray structures. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Coarse‐graining: A procedure to generate equilibrated and relaxed models of amorphous polymers
Authors: Curcó David , Alemán Carlos
Published: April 2007

We present a coarse‐graining procedure to construct models of amorphous polymers. The method, which was applied to polyethylene, is based on a generation–relaxation strategy previously developed to provide independent atomistic microstructures. The coarse‐graining was performed by assigning positions to mesoscopic particles denoted blobs, which represent groups of atoms, through distance, angle and dihedral distribution functions. The interaction energy between pairs of blobs was evaluated through a soft potential, whose parameters were derived from atomistic models. Three levels of coarse‐graining that differ in the number of atoms included in the blob have been considered. The structural and energy‐related properties calculated using the coarse‐grained models developed in this study are in good agreement with those obtained using atomistic simulations. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
New parallel algorithm for MP2 energy gradient calculations
Authors: Ishimura Kazuya , Pulay Peter , Nagase Shigeru
Published: April 2007

A new parallel algorithm has been developed for calculating the analytic energy derivatives of full accuracy second order Møller‐Plesset perturbation theory (MP2). Its main projected application is the optimization of geometries of large molecules, in which noncovalent interactions play a significant role. The algorithm is based on the two‐step MP2 energy calculation algorithm developed recently and implemented into the quantum chemistry program, GAMESS. Timings are presented for test calculations on taxol (C47H51NO14) with the 6‐31G and 6‐31G(d) basis sets (660 and 1032 basis functions, 328 correlated electrons) and luciferin (C11H8N2O3S2) with aug‐cc‐pVDZ and aug‐cc‐pVTZ (530 and 1198 basis functions, 92 correlated electrons). The taxol 6‐31G(d) calculations are also performed with up to 80 CPU cores. The results demonstrate the high parallel efficiency of the program. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Electronic structures and chemical bonding in 4d transition metal monohalides
Authors: Cheng L. , Wang M. Y. , Wu Z. J. , Su Z. M.
Published: April 2007

Bond distances, vibrational frequencies, dipole moments, dissociation energies, electron affinities, and ionization potentials of MX (XM = Y‐Cd, X = F, Cl, Br, I) molecules in neutral, positively, and negatively charged ions were studied by density functional method, B3LYP. The bonding patterns were analyzed and compared with both the available data and across the series. It was found that besides ionic component, covalent bonds are formed between the 4d transition metal s, d orbitals, and the p orbital of halogen. For both neutral and charged molecules, the fluorides have the shortest bond distance, iodides the longest. Although the opposite situation is observed for vibrational frequency, that is, fluorides have the largest value, iodides the smallest. For neutral and anionic species, the dissociation energy tends to decrease with the increasing atomic number from Y to Cd, suggesting the decreasing or weakening of the bond strength. For cationic species, the trend is observed from Y to Ag. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Geometry optimization using generalized, chemically meaningful constraints
Authors: Budzelaar Peter H. M.
Published: April 2007

An external geometry optimizer (BOptimize) is described that can be used together with a number of existing quantum‐chemical codes (Gaussian, Gamess‐UK, Turbomole, ADF, Orca, Priroda, Spartan‐PM3, Mopac) and allows flexible and general constrained optimizations. Some details of the implementation are discussed, and examples are provided of constrained optimizations that would be difficult or impossible to perform with existing optimizers. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Inhibitor docking screened by the modified SAFE_p scoring function: Application to cyclic urea HIV‐1 PR inhibitors
Authors: Vilar Santiago , Villaverde M. Carmen , Sussman Fredy
Published: April 2007

Our laboratory has in the past developed a method for the prediction of ligand binding free energies to proteins, referred to as SAFE_p (Solvent free energy predictor). Previously, we have applied this protocol for the prediction of the binding free energy of peptidic and cyclic urea HIV‐1 PR inhibitors, whose X‐ray structures bound to enzyme are known. In this work, we present the first account of a docking simulation, where the ligand conformations were screened and inhibitor ranking was predicted on the basis of a modified SAFE_p approach, for a set of cyclic urea‐HIV‐1 PR complexes whose structures are not known. We show that the optimal dielectric constant for docking is rather high, in line with the values needed to reproduce some protein residue properties, like pKa's. Our protocol is able to reproduce most of the observed binding ranking, even in the case that the components of the equation are not fitted to experimental data. Partition of the binding free energy into pocket and residue contributions sheds light into the importance of the inhibitor's fragments and on the prediction of “hot spots” for resistance mutations. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Preparation and characterization of a novel activated carbon‐supported N‐doped visible light response photocatalyst (TiO2−xNy/AC)
Authors: Liu Shouxin , Chen Xiaoyun
Published: April 2007

A photocatalyst, TiO2−xNy/AC (activated carbon (AC) supported N‐doped TiO2), highly active in both the Vis and UV range, was prepared by calcination of the TiO2 precursor prepared by acid‐catalyzed hydrolysis in an ammonia atmosphere. The powders were characterized by diffuse reflectance spectroscopy, scanning electron microscopy, X‐ray diffraction, N2 adsorption, Fourier transform infrared spectroscopy and phenol degradation. The doped N in the TiO2 crystal lattice creates an electron‐occupied intra‐band gap allowing electron‐hole pair generation under Vis irradiation (500–560 nm). The TiO2−xNy/AC exhibited high levels of activity and the same activity trends for phenol degradation under both Vis and UV irradiation: TiO2−xNy/AC calcined at 500 °C for 4 h exhibited the highest activity. The band‐gap level newly formed by doped N can act as a center for the photo‐generated holes and is beneficial for the UV activity enhancement. The performance of the prepared TiO2−xNy/AC photocatalyst revealed its practical potential in the field of solar photocatalytic degradation of aqueous contaminants. Copyright © 2007 Society of Chemical Industry
Decolorization, mineralization, and toxicity reduction of acid orange 6 by iron‐sacrificed plates in the electrocoagulation process
Authors: Chang E‐E , Hsing Hao‐Jan , Ko Chi‐Sean , Chiang Pen‐Chi
Published: April 2007

In this study, electrocoagulation (EC) was used to investigate the decolorization and mineralization of an azo dye solution, as well as biodegradation enhancement and toxicity reduction. Initial pH, flow rate, and acid orange 6 concentration were investigated, and the optimum operational parameters were found to be pH = 4, flow rate (Q) = 0.3 to 0.5 L min−1, and current density = 68.3 A dm−2. With these optimal parameters, total organic carbon and color removal efficiencies of 40% and 98% were achieved, respectively. Biodegradation was evaluated using the ratio of the 5‐day biological oxygen demand (BOD5) and the chemical oxygen demand (COD), which was 0.19 to 0.25 initially and increased to the range 0.25 to 0.4 after EC treatment, indicating that biodegradability was significantly enhanced. The mean effective concentration (EC50) was measured to represent the toxicity of the solution. Initial EC50 values ranged from 25 to 6.6%, which represent extremely toxic to very toxic solutions. After EC treatment, the toxicity levels were reduced significantly, suggesting that the EC process could be a promising method for reducing the toxicity of textile wastewater. Copyright © 2007 Society of Chemical Industry
Natural volatile treatments increase free‐radical scavenging capacity of strawberries and blackberries
Authors: Chanjirakul Korakot , Wang Shiow Y , Wang Chien Y , Siriphanich Jingtair
Published: April 2007

Free‐radical scavenging capacities of strawberries and blackberries treated with methyl jasmonate (MJ), allyl isothiocyanate (AITC), essential oil of Melaleuca alternifolia (tea‐tree oil or TTO), and ethanol (EtOH) were investigated. All of these natural volatiles tested reduced the severity of decay in both strawberries and blackberries during storage at 10 °C as compared to the control. Most of these compounds enhanced antioxidant capacity and free‐radical scavenging capacity, except the AITC treatment. The MJ treatment for strawberries and blackberries had the highest antioxidant capacity, expressed as oxygen radical absorbance capacity (ORAC) values, after 7 days of storage. Moreover, the MJ treatment promoted the antioxidant capacity in strawberries and blackberries as measured by the radical 2,2‐di (4‐tert‐octylphenyl) ‐1‐picrylhydrazyl (DPPH) and the radical cation 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS•+) scavenging activity in both 7 and 14 days after storage. The MJ treatment also increased scavenging capacities on the superoxide radical (O2•−), hydrogen peroxide (H2O2), hydroxyl radical (•OH), and singlet oxygen (1O2) in strawberries and blackberries. Treatment with TTO or EtOH enhanced most of these free‐radical scavenging capacities, except for H2O2 in strawberries, and for O2•− and 1O2 in blackberries. These results indicated that all of the natural volatile compounds tested in this study, except AITC, promoted the antioxidant capacity and scavenging capacity of most major free radicals and, thus, helped to improve the physiology of berry fruits and enhanced their resistance to decay. While AITC was also very effective in reducing decay, its effect on free‐radical scavenging capacity was inconsistent, suggesting that additional mechanisms may be involved in its inhibition of fungal growth. Copyright © 2007 Society of Chemical Industry
Correlation between tumor blood flow assessed by perfusion CT and effect of neoadjuvant therapy in advanced esophageal cancers
Authors: Makari Yoichi , Yasuda Takushi , Doki Yuichiro , Miyata Hiroshi , Fujiwara Yoshiyuki , Takiguchi Shuji , Matsuyama Jin , Yamasaki Makoto , Hirao Takafumi , Koyama Mitsuhiro Koyama , Nakamuara Hironobu , Monden Morito
Published: April 2007

Background

Redundant blood supply by angiogenesis is a great advantage for the continuous growth of solid tumors. However, with chemotherapy (ChT), it can be disadvantageous due to increased drug delivery. An objective, reproducible, and non‐invasive method for evaluating tumor blood supply is offered by perfusion CT.

Methods

Fifty‐five advanced esophageal cancers (95% squamous cell carcinomas) were evaluated for hemodynamic parameters, including blood flow (BF), blood volume (BV), and mean transit time (MTT) of primary tumor by perfusion CT scan. Forty‐six underwent neoadjuvant therapy (36 ChT and 10 chemoradiotherapy (CRT)) as primary treatment of the cancer and 36 underwent esophagectomy.

Results

Clinicopathological parameters were not significantly associated with hemodynamic parameters, except for hematogenic metastasis, which was not frequent (seven patients), but significantly associated with high BF (P = 0.0165). High BF and low MTT correlated significantly with a good response by neoadjuvant therapies (P = 0.0004 and P = 0.0124), while BV did not. The patients with high BF more frequently underwent esophagectomy and displayed better prognosis than those with lower values, while neither BV nor MTT was associated with patient survival.

Conclusions

Tumor BF by perfusion CT can partly predict the effect of ChT and CRT and survival. Further large cohort studies in homogeneous patient groups will reveal its clinical usefulness. J. Surg. Oncol. 2007;96: 220–229. © 2007 Wiley‐Liss, Inc.
Quantitative determination of BMS‐378806 in human plasma and urine by high‐performance liquid chromatography/tandem mass spectrometry
Authors: Xue Y.‐J. , Yan Jing‐He , Arnold Mark , Grasela Dennis , Unger Steve
Published: April 2007

BMS‐378806 is a human immunodeficiency virus (HIV) entry inhibitor that is being developed for the oral treatment of HIV infection. Human plasma and urine LC/MS/MS methods have been developed and validated for the quantitation of BMS‐378806. For human plasma method, methyl t‐butyl ether was used to extract BMS‐378806 from plasma in a 96‐well format, and the organic layers were dried down and then reconstituted for the injection, while a dilute‐and‐shoot approach was used for human urine method in a 96‐well format. Chromatographic separation was achieved isocratically on a Phenomenex C18 (2) Luna column (2×50 mm2, 5 μm). The mobile phase contained 60:40 v/v of 0.1% formic acid in water and ACN. Detection was by positive ion electrospray MS/MS. The standard curves ranged from 1.25 to 1000 ng/mL for the plasma assay and from 10 to 5000 ng/mL for the urine assay. The curves were fitted to a 1/x2 weighted quadratic regression model for both methods. The validation results demonstrated that both methods had satisfactory precision and accuracy across the calibration ranges. The methods were applied to the analysis of human plasma and urine samples from a single ascending dose clinical study to assess the pharmacokinetics of the drug. The pharmacokinetic analysis results indicated the absorption and disposition of the drug was rapid. The systemic exposure of BMS‐378806 was generally dose proportional among the doses from 100 to 1200 mg, but not dose proportional to 1600 mg. There were modest increases in the systemic exposure when the drug was given with food or given as a solution formulation. Renal excretion was not a substantial elimination pathway of the drug. BMS‐378806 was safe and well tolerated over a dose range of 100–1600 mg administered as a single oral dose.
Temperature effects on solute retention for hydride‐based stationary phases
Authors: Pesek Joseph J. , Matyska Maria T. , Hearn Milton T. W. , Boysen Reinhard
Published: April 2007

The effect of solute retention is investigated for two hydride‐based stationary phases: bidentate C18 and cholesterol. Several small molecules and peptides are used as solutes. In the reversed‐phase mode, most compounds have the expected temperature behavior, i. e. decreasing retention with increasing temperature. Two analogs of the drug lisinopril do exhibit the opposite behavior on the cholesterol column; increasing retention with increasing temperature. In the aqueous normal phase (ANP) mode, more compounds, particularly certain peptides, have this unusual retention behavior with respect to temperature. These preliminary studies indicate that as ANP retention becomes stronger, there is a greater possibility of observing increasing retention with increasing temperature.