bluuebunny/crossref_metadata_2025 huggingface dataset:
Telbivudine versus lamivudine in Chinese patients with chronic hepatitis B: Results at 1 year of a randomized, double-blind trial
Authors: Hou Jinlin , Yin You-Kuan , Xu Daozhen , Tan Deming , Niu Junqi , Zhou Xiaqiu , Wang Yuming , Zhu Limin , He Yongwen , Ren Hong , Wan Mobin , Chen Chengwei , Wu Shanming , Chen Yagang , Xu Jiazhang , Wang Qinhuan , Wei Lai , Chao George , Constance Barbara Fielman , Harb George , Brown Nathaniel A. , Jia Jidong
Published: December 2007

Chronic hepatitis B and its life-threatening sequelae are highly prevalent in China. There is a need for effective new therapies to suppress hepatitis B virus (HBV) replication and ameliorate liver disease. In this study, we compared the efficacy of telbivudine, a nucleoside analogue, with lamivudine in Chinese patients. In this phase III, double-blind, multicenter trial conducted in China, 332 patients with compensated hepatitis B e antigen (HBeAg)–positive or HBeAg-negative chronic hepatitis B were randomly assigned to treatment with 600 mg of telbivudine or 100 mg of lamivudine daily for 104 weeks. The primary efficacy endpoint was reduction in serum HBV DNA levels at week 52 of treatment. Secondary endpoints included clearance of HBV DNA to undetectable levels, HBeAg loss and seroconversion, therapeutic response, and alanine aminotransferase (ALT) normalization. Viral resistance and safety were assessed. At week 52, among 290 HBeAg-positive patients, mean reductions of serum HBV DNA were significantly greater in telbivudine recipients than lamivudine recipients (6.3 log10 versus 5.5 log10,

P

< 0.001), and HBV DNA was polymerase chain reaction–negative in significantly more telbivudine recipients than lamivudine recipients (67% versus 38%,

P

< 0.001). ALT normalization (87% versus 75%,

P

= 0.007), therapeutic response (85% versus 62%,

P

= 0.001), and HBeAg loss (31% versus 20%,

P

= 0.047) were also significantly more common in the telbivudine group. Treatment effects showed similar patterns in the smaller HBeAg-negative group (n = 42). Viral resistance in telbivudine recipients was approximately half that observed with lamivudine; however, this difference was not statistically significant. Clinical adverse events were similar in the two treatment groups.

Conclusion:

In Chinese patients with chronic hepatitis B, telbivudine treatment for 52 weeks provided greater antiviral and clinical efficacy than lamivudine, with less resistance. (Hepatology 2007.)
The nucleotide binding motif of hepatitis C virus NS4B can mediate cellular transformation and tumor formation without Ha-ras co-transfection
Authors: Einav Shirit , Sklan Ella H. , Moon Hyang Mi , Gehrig Elizabeth , Liu Ping , Hao Ying , Lowe Anson W. , Glenn Jeffrey S.
Published: December 2007

Hepatitis C virus (HCV) is an important cause of chronic liver disease and is complicated by hepatocellular carcinoma (HCC). Mechanisms whereby the virus promotes cellular transformation are poorly understood. We hypothesized that the guanosine triphosphatase activity encoded in the HCV NS4B protein's nucleotide binding motif (NBM) might play a role in the transformation process. Here we report that NS4B can transform NIH-3T3 cells, leading to tumor formation

in vivo

. This transformation was independent of co-transfection with activated Ha-ras. Detailed analyses of NS4B mutants revealed that this transforming activity could be progressively inhibited and completely abrogated by increasing genetic impairment of the NS4B nucleotide binding motif.

Conclusion:

NS4B has

in vitro

and

in vivo

tumorigenic potential, and the NS4B transforming activity is indeed mediated by its NBM. Moreover, our results suggest that pharmacological inhibition of the latter might inhibit not only HCV replication but also the associated HCC.
NMR‐Solution Structures of Fluoro‐Substituted β‐Peptides: A 314‐Helix and a Hairpin Turn. The First Case of a 90° OCCF Dihedral Angle in an α‐Fluoro‐Amide Group
Authors: Mathad Raveendra I. , Jaun Bernhard , Flögel Oliver , Gardiner James , Löweneck Markus , Codée Jeroen D. C. , Seeberger Peter H. , Seebach Dieter , Edmonds Michael K. , Graichen Florian H. M. , Abell Andrew D.
Published: December 2007

To further study the preference of the antiperiplanar (ap) conformation in α‐fluoro‐amide groups, two β‐peptides, 1 and 2, containing a (2‐F)‐β3hAla and a (2‐F)‐β2hPhe residue, have been synthesized. Their NMR‐solution structures in CD3OH were determined and compared with those of non‐F‐substituted analogs, 3 and 4a. While we have found in a previous investigation (Helv. Chim. Acta 2005, 88, 266) that a stereospecifically introduced F‐substituent in the central position of a β‐heptapeptide is capable of ‘breaking’ the 314‐helical structure by enforcing the FCCO ap‐conformation, we could now demonstrate that the same procedure leads to a structure with the unfavorable ca. 90° FCCO dihedral angle, enforced by the 314‐helical folding in a β‐tridecapeptide (cf. 1; Fig. 4). This is interpreted as a consequence of cooperative folding in the longer β‐peptide. A F‐substituent placed in the turn section of a β‐peptidic hairpin turn was shown to be in an ap‐arrangement with respect to the neighboring CO bond (cf. 2; Fig. 7). Analysis of the non‐F‐substituted β‐tetrapeptides (with helix‐preventing configurations of the two central β2/β3‐amino acid residues) provides unusually tight hairpin structural clusters (cf. 3 and 4a; Figs. 8 and 9). The skeleton of the β‐tetrapeptide H‐(R)β3hVal‐(R)β2hVal‐(R)β3hAla‐(S)β3hPhe‐OH (4a) is proposed as a novel, very simple backbone structure for mimicking α‐peptidic hairpin turns.
Enantioselective Dehydrogenation of Alkan‐2‐ols by Gaseous (BINOLate)Ni+
Authors: Novara Francesca R. , Schwarz Helmut , Schröder Detlef
Published: December 2007

Electrospray ionization of methanolic solutions of nickel(II) nitrate, 1,1′‐binaphthalene‐2,2′‐diol (BINOL), and secondary alcohols (ROH) inter alia affords monocationic complexes of the type [(BINOLate)Ni(ROH)]+, where BINOLate stands for singly deprotonated BINOL. Upon collision‐induced dissociation (CID), the mass‐selected ions undergo competing fragmentations involving loss of the alcohol ligand and expulsion of the corresponding carbonyl compound. The latter reaction leads to the hydride complex [(BINOL)Ni(H)]+ and can thus be regarded as the reversal of the reduction of ketones with metal hydrides. The possibility of the occurrence of enantioselective gas‐phase reactions is probed for combinations of chiral BINOLate ligands with chiral alkan‐2‐ols. Whereas aliphatic alkan‐2‐ols do not show pronounced chiral effects, enantioselective bond activation is observed for 1‐phenylethanol, indicating an interaction of the aromatic ring of the alkanol with the positively charged metal center.
Synthesis of Spiropyrimidodiazepines and Spirodiazepinopurines by Tandem Nitroso‐ene/Diels–Alder Reactions
Authors: Zhang Fang‐Li , Vasella Andrea
Published: December 2007

New spirocyclic heterocycles 8, 16, 19/20, 25, 27, and 30 derived from pyrimido[4,5‐b][1,4]diazepin]‐8′(9′H)‐one were synthesised by a tandem nitroso‐ene/Diels–Alder reaction of 4‐(alkenoylamino)‐5‐nitrosopyrimides. The crystal structure of 16 was established by X‐ray analysis. It is characterised by four pairs of intermolecular H‐bonds linking every two molecules in the unit cell. Sequential imine reduction and intramolecular condensation of the C(4′)‐(acylamino)‐pyrimido[4,5‐b][1,4]diazepines 27 and 30 led to the [1,4]diazepino[1,2,3‐gh]purines 28/29 and 31, respectively.
Thermolysis of Imidates: A New Method for the Generation of Carbonyl Ylides
Authors: Nikolaev Vsevolod V. , Linden Anthony , Heimgartner Heinz
Published: December 2007

Thermolysis of dimethyl 2‐[(3‐oxo‐3H‐isoindol‐1‐yl)oxy]malonate (8) promotes a [1,4]‐H shift in the imidic NCOCH fragment of the starting molecule, which leads to a reactive carbonyl ylide. This carbonyl ylide can be trapped by the CN bond of imidates and imines, as well as the CO bond of benzaldehyde. The corresponding cycloadducts 11, 14, and 16 are formed regioselectively in good yields (60–95%) and with high stereoselectivity. In the case of 11, the minor cycloadduct in solution undergoes an isomerization to give the more stable stereoisomer. The structures of two cycloadducts, i.e., 11a and 14a, have been established by X‐ray crystallography.
A Novel ‘Domino‐Click Approach’ to Unsymmetrical Bis‐1H‐1,2,3‐triazoles
Authors: Banday Abid H. , Arora Bhupinder S. , Alam Mohammed S. , Kumar Halmuthur M. Sampath
Published: December 2007

Aryl azides 1 were treated with allenylmagnesium bromide (2) to generate 1,5‐disubstituted butynyl‐1H‐1,2,3‐triazoles 3 in a domino fashion, which upon CuI‐catalyzed 1,3‐dipolar cycloaddition with aryl azides 4 afforded novel bis‐1H‐1,2,3‐triazoles 5 in quantitative yields (Scheme 1 and Table).
ent‐Kaurane Diterpenoids from Isodon japonicus
Authors: Yang Li‐Bin , Huang Sheng‐Xiong , Li Li‐Mei , Zhao Yong , Lei Chun , Xiao Wei‐Lie , Pu Jian‐Xin , Han Quan‐Bin , Sun Han‐Dong
Published: December 2007

Two new 6,7‐seco‐ent‐kaurane diterpenoids, isojaponins A (1) and B (2), together with 18 known ent‐kaurane diterpenoids were isolated from the aerial parts of Isodon japonicus. The structures of the two new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods in combination with MS experiments.
Nine New Sesquiterpenes from Dendrobium nobile
Authors: Zhang Xue , Liu Hong‐Wei , Gao Hao , Han Hui‐Ying , Wang Nai‐Li , Wu Hou‐Ming , Yao Xin‐Sheng , Wang Zhao
Published: December 2007

Nine new sesquiterpenes, i.e., dendronobilins A–I (1–9), with copacamphane‐type (1), picrotoxane‐type (2–6), muurolene‐type (7), alloaromadendrane‐type (8), and cyclocopacamphane‐type (9) skeletons, were isolated from the 60% EtOH extract of the stems of Dendrobium nobile. Their structures were established as (1R,2R,4S,5S,6S,8S,9R)‐2,8‐dihydroxycopacamphan‐15‐one (1), (2β,3β,4β,5β)‐2,4,11‐trihydroxypicrotoxano‐3(15)‐lactone (2), (2β,3β,5β,9α,11β)‐2,11‐epoxy‐9,11,13‐trihydroxypicrotoxano‐3(15)‐lactone (3), (2β,3β,5β,12R*)‐2,11,13‐trihydroxypicrotoxano‐3(15)‐lactone (4), (2β,3β,5β,12S*)‐2,11,13‐trihydroxypicrotoxano‐3(15)‐lactone (5), (2β,3β,5β,9α)‐9,10‐cyclo‐2,11,13‐trihydroxypicrotoxano‐3(15)‐lactone (6), (9β,10α)‐muurol‐4‐ene‐9,10,11‐triol (7), (10α)‐alloaromadendrane‐10,12,14‐triol (8), and (5β)‐cyclocopacamphane‐5,12,15‐triol (9) on the basis of spectroscopic analysis. The absolute configuration of compound 1 was tentatively assigned as (1R,2R,4S,5S,6S,8S,9R) according to its CD spectrum and the octant rule. Compounds 1 and 4–9 were inactive in our preliminary in vitro immunomodulatory bioassay.
Alkaloids from Fruits of Daphniphyllum oldhamii
Authors: Gan Li‐She , Wang Xiao‐Ning , Fan Cheng‐Qi , Wu Yan , Yue Jian‐Min
Published: December 2007

Seventeen Daphniphyllum alkaloids, including two new pentacyclic alkaloids, yuzuric acid (1) and daphnezomic acid (2), and 15 known ones, were isolated from the fruits of Daphniphyllum oldhamii. The structures and configuration of the two new alkaloids were determined on the basis of spectroscopic methods, especially 2D NMR techniques.
A Novel Method for the Synthesis of Substituted Benzochromenes by Ethylenediamine Diacetate‐Catalyzed Cyclizations of Naphthalenols to α,β‐Unsaturated Aldehydes. Concise Synthesis of the Natural Products Lapachenole, Dihydrolapachenole, and Mollugin
Authors: Lee Yong Rok , Kim Yun Mi
Published: December 2007

A new synthetic route for biologically interesting benzochromenes was developed starting from naphthalenols and α,β‐unsaturated aldehydes in the presence of ethylenediamine diacetate. This methodology was applied for the total synthesis of the biologically important natural products lapachenole, dihydrolapachenole, and mollugin with a benzochromene moiety.
One‐Pot Synthesis of 4‐(Alkylamino)‐1‐(arylsulfonyl)‐3‐benzoyl‐1,5‐ dihydro‐5‐hydroxy‐5‐phenyl‐2H‐pyrrol‐2‐ones via a Multicomponent Reaction
Authors: Alizadeh Abdolali , Rezvanian Atieh , Zhu Long‐Guan
Published: December 2007

An effective route to novel 4‐(alkylamino)‐1‐(arylsulfonyl)‐3‐benzoyl‐1,5‐dihydro‐5‐hydroxy‐5‐phenyl‐2H‐pyrrol‐2‐ones 10 is described (Scheme 2). This involves the reaction of an enamine, derived from the addition of a primary amine 5 to 1,4‐diphenylbut‐2‐yne‐1,4‐dione, with an arenesulfonyl isocyanate 7. Some of these pyrrolones 10 exhibit a dynamic NMR behavior in solution because of restricted rotation around the CN bond resulting from conjugation of the side‐chain N‐atom with the adjacent α,β‐unsaturated ketone group, and two rotamers are in equilibrium with each other in solution (10 ⇌ 11; Scheme 3). The structures of the highly functionalized compounds 10 were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS), by elemental analyses, and, in the case of 10a, by X‐ray crystallography. A plausible mechanism for the reaction is proposed (Scheme 4).
A Guaianolide Sesquiterpene, a Chromenone, and a Flavanone from Ligularia macrophylla
Authors: Wang Qi , Chen Daofeng
Published: December 2007

Three new compounds, (5β,9β)‐guaia‐6,10(14)‐dien‐9‐ol (=rel‐(1R,3aS,5R,8aR)‐1,2,3,3a,4,5,6,8a‐octahydro‐1‐methyl‐4‐methylene‐7‐(1‐methylethyl)azulen‐5‐ol; 1), 6‐acetyl‐8‐methoxy‐2,3‐dimethylchromen‐4‐one (=6‐acetyl‐8‐methoxy‐2,3‐dimethyl‐4H‐1‐benzopyran‐4‐one; 2), and (2S)‐3′‐hydroxy‐5′,7‐dimethoxyflavanone (=(2S)‐2,3‐dihydro‐2‐(3‐hydroxy‐5‐methoxyphenyl)‐7‐methoxy‐4H‐1‐benzopyran‐4‐one; 3) were isolated from the roots and rhizomes of Ligularia macrophylla, together with seven known compounds. Their structures and configurations were elucidated by spectroscopic methods, including 2D‐NMR techniques.
Association of catechol‐O‐methyltransferase variants with loudness dependence of auditory evoked potentials
Authors: Juckel Georg , Kawohl Wolfram , Giegling Ina , Mavrogiorgou Paraskevi , Winter Christine , Pogarell Oliver , Mulert Christoph , Hegerl Ulrich , Rujescu Dan
Published: December 2007

Objective

The loudness dependence of auditory evoked potentials (LDAEP) provides a measure of the central serotonergic activity. As dopamine transporter availabilities also correlate with LDAEP, a dopaminergic influence is probable. The enzyme catechol‐O‐methyltransferase (COMT) is involved in the inactivation of synaptic dopamine. The aim of this study was to investigate the relationship between genetic variants of the COMT gene influencing synaptic dopamine levels and the LDAEP.

Methods

Rs737865 in intron 1, rs4680 coding for a Val158Met substitution and rs165599 in the 3′ region were investigated in 95 carefully selected healthy subjects of German descent (41 males, 54 females). The LDAEP was calculated as a linear regression slope with stimulus intensity as independent and N1/P2‐amplitude as dependent variables.

Results

Single marker analysis showed weak associations for two single nucleotide polymorphisms (SNPs) (rs737865: CC vs. T allele carrier; rs4680: G‐allele carrier vs. AA homozygotes). A‐G (rs4680–rs165599) was associated with lower LDAEP scores. Accordingly, haplotype analysis with all SNPs (rs737865–rs4680–rs165599) showed that the T‐A‐G haplotype was associated with lower scores.

Conclusions

These findings support the hypothesis that the LDAEP is also influenced by dopaminergic transmission. However, replications of these very preliminary but potentially important findings in independent samples are needed. Copyright © 2007 John Wiley & Sons, Ltd.
Magnetic resonance imaging‐based detection of glial brain tumors in mice after antiangiogenic treatment
Authors: Claes An , Gambarota Giulio , Hamans Bob , van Tellingen Olaf , Wesseling Pieter , Maass Cathy , Heerschap Arend , Leenders William
Published: December 2007

Proper delineation of gliomas using contrast‐enhanced magnetic resonance imaging (CE‐MRI) poses a problem in neuro‐oncology. The blood brain barrier (BBB) in areas of diffuse‐infiltrative growth may be intact, precluding extravasation and subsequent MR‐based detection of the contrast agent gadolinium diethylenetriaminepenta‐acetic acid (Gd‐DTPA). Treatment with antiangiogenic compounds may further complicate tumor detection as such compounds can restore the BBB in angiogenic regions. The increasing number of clinical trials with antiangiogenic compounds for treatment of gliomas calls for the development of alternative imaging modalities. Here we investigated whether CE‐MRI using ultrasmall particles of iron oxide (USPIO, Sinerem®) as blood pool contrast agent has additional value for detection of glioma in the brain of nude mice. We compared conventional T1‐weighted Gd‐DTPA‐enhanced MRI to T2*‐weighted USPIO‐enhanced MRI in mice carrying orthotopic U87 glioma, which were either or not treated with the antiangiogenic compound vandetanib (ZD6474, ZACTIMA™). In untreated animals, vessel leakage within the tumor and a relatively high tumor blood volume resulted in good MRI visibility with Gd‐DTPA‐ and USPIO‐enhanced MRI, respectively. Consistent with previous findings, vandetanib treatment restored the BBB in the tumor vasculature, resulting in loss of tumor detectability in Gd‐DTPA MRI. However, due to decreased blood volume, treated tumors could be readily detected in USPIO‐enhanced MRI scans. Our findings suggest that Gd‐DTPA MRI results in overestimation of the effect of antiangiogenic therapy of glioma and that USPIO‐MRI provides an important complementary diagnostic tool to evaluate response to antiangiogenic therapy of these tumors. © 2007 Wiley‐Liss, Inc.
Past, present and future of atomic force microscopy in life sciences and medicine
Authors: Parot Pierre , Dufrêne Yves F. , Hinterdorfer Peter , Le Grimellec Christian , Navajas Daniel , Pellequer Jean‐Luc , Scheuring Simon
Published: December 2007

To introduce this special issue of the Journal of Molecular Recognition dedicated to the applications of atomic force microscopy (AFM) in life sciences, this paper presents a short summary of the history of AFM in biology. Based on contributions from the first international conference of AFM in biological sciences and medicine (AFM BioMed Barcelona, 19–21 April 2007), we present and discuss recent progress made using AFM for studying cells and cellular interactions, probing single molecules, imaging biosurfaces at high resolution and investigating model membranes and their interactions. Future prospects in these different fields are also highlighted. Copyright © 2007 John Wiley & Sons, Ltd.
Structural characterization of pulsed laser deposited poly(methylmethacrylate) thin films
Authors: Fazio B. , Trusso S. , Fazio E. , Neri F.
Published: December 2007

Cross‐linking content and polymerization degree of poly(methylmethacrylate) PMMA thin films have been investigated by means of Fourier transform infrared and micro‐Raman spectroscopic techniques. The samples were deposited by means of pulsed laser ablation of a PMMA target at room temperature. The laser fluence was varied from 0.5 J/cm2 up to 4 J/cm2. Experimental results show that it is possible to deposit PMMA thin films with a very low monomer content (smaller than 3%) and to modulate the cross‐linking occurrence upon tuning the laser fluence. Moreover, the effect of the post‐deposition thermal treatment on the polymerization degree has been exploited. Then, we estimated the value of the polymerization enthalpy, which is comparable to the value at which the complete conversion of monomers in polymer is reached. Copyright © 2007 John Wiley & Sons, Ltd.
TEM/local excision: Indications, techniques, outcomes, and the future
Authors: Saclarides Theodore J.
Published: December 2007

Transanal endoscopic microsurgery (TEM) has emerged as a safe method for excising virtually any rectal adenoma and carefully selected cancers. Extended applications include treatment of extra‐ and supra‐sphincteric fistulae, rectovaginal fistulae, anastomotic strictures, and sinus tracts. The procedure utilizes an air‐tight system, long shafted instruments, high‐quality magnifying optics, and constant carbon dioxide insufflation, all of which facilitate a precise excision and closure with clear margins. Complications are few, most patients can be treated as an outpatient. J. Surg. Oncol. 2007;96:644–650. © 2007 Wiley‐Liss, Inc.
KTP laser and nitinol alloy stents: Are they compatible?
Authors: Young Orla , Kirrane F. , Hughes J.P. , Fenton J.E.
Published: December 2007

Background/Objective

Nitinol alloy stents are in frequent use in recanalizing malignant airway stenoses. Potassium titanyl phosphate (KTP) is one of the lasers of choice in removal of obstructing airway lesions. There is a paucity of research regarding the safety of these advances working together.

Study Design/Materials and Methods

In vitro study involving direct contact application of KTP laser with nitinol alloy stents under microscope guidance in varying gaseous environments.

Results

Stent damage can occur once power settings exceed one watt. Complete stent destruction occurs regardless of gaseous environment at a mere three watts of power.

Conclusions

Our results suggest that KTP laser is unsafe to use in the presence of a nitinol alloy stent, regardless of the gaseous environment. Lasers Surg. Med. 39:803–807, 2007. © 2007 Wiley‐Liss, Inc.
Diode laser hair removal around ileo‐colo ostomys is safe, effective and beneficial: A pilot study
Authors: van der Ploeg‐Westerveld Jos , Wagter Jacqueline , van Gemert Martin J.C. , Neumann H.A.M. , Bour H. , Zwart A.
Published: December 2007

Background and Objective

Hair removal around an ileo‐colo ostomy can cause a number of problems. We compared laser hair removal with mechanical shaving around the ostomy.

Method

Eleven patients were selected with hairy skin around the ostomy for therapy with an AlGaAs diode laser at 800 nm. Three to four treatments were given with an interval of 6 weeks.

Results

Ten patients completed laser therapy. The average hair reduction was 60% based on visual inspection. Shaving frequency reduced from once a week to once every 6 weeks.

Conclusions

Laser hair removal likely becomes the preferred method in ostomy patients. Lasers Surg. Med. 39:773–775, 2007. © 2007 Wiley‐Liss, Inc.
Dynamic skin cooling with an environmentally compatible alternative cryogen during laser surgery
Authors: Jia Wangcun , Svaasand Lars O. , Nguyen Thang B. , Nelson J. Stuart
Published: December 2007

Background and Objectives

Cryogen spray cooling with tetrafluoroethane (R134a) has been used to enhance epidermal protection during dermatologic laser surgery. However, R134a has a very high global warming potential (GWP = 1300). Our objective was to evaluate the cooling effectiveness of an alternative cryogen with a much lower GWP, namely liquid carbon dioxide (CO2, GWP = 1).

Study Design/Materials and Methods

A thin‐film thermocouple deposited on an epoxy skin phantom was used to measure surface temperature (Ts) variations induced by R134a or CO2 sprays. The temperature distribution in the skin phantom was estimated using Ts and Duhamel's method. Impact pressure and noise level of both cryogen sprays were measured with a dynamic sensor and sound meter, respectively. Consumption of both cryogens was also evaluated.

Results

For R134a sprays, Ts was kept almost constant after 15 milliseconds. For CO2 sprays, Ts decreased continuously during the entire spurt of 50 milliseconds. The minimum Ts induced by the CO2 sprays was lower than that induced by R134a when the spurt duration was longer than 35 milliseconds. Numerical simulation shows that CO2 sprays were able to induce very similar temperature reductions in the skin phantom as compared to R134a sprays when the spurt duration and delay time were selected appropriately. R134a sprays induced an impact pressure of 3.6 kPa, as compared to 43.1 kPa for CO2 sprays. The maximum noise level for R134a sprays was 109 dBA as compared to 135 dBA for the CO2 sprays. The R134a consumption for a 50 milliseconds spurt is 67 mg as compared to 225 mg for a CO2 spurt of the same duration.

Conclusions

CO2 sprays are expected to have similar skin cooling efficacy as R134a sprays. Although the CO2 consumption is higher than R134a, its contribution to global warming is still much less than R134a. The effects of varying spurt durations on in vivo human skin and the impact on cutaneous blood flow require further investigation. Lasers Surg. Med. 39:776–781, 2007. © 2007 Wiley‐Liss, Inc.
Effect of low‐level laser therapy on bone repair: Histological study in rats
Authors: Pretel Hermes , Lizarelli Rosane F.Z. , Ramalho Lizeti T.O.
Published: December 2007

Background and Objectives

Bone remodeling is characterized as a cyclic and lengthy process. It is currently accepted that not only this dynamics is triggered by a biological process, but also biochemical, electrical, and mechanical stimuli are key factors for the maintenance of bone tissue. The hypothesis that low‐level laser therapy (LLLT) may favor bone repair has been suggested. The purpose of this study was to evaluate the bone repair in defects created in rat lower jaws after stimulation with infrared LLLT directly on the injured tissue.

Study Design/Materials and Methods

Bone defects were prepared on the mandibles of 30 Holtzman rats allocated in two groups (n = 15), which were divided in three evaluation period (15, 45, and 60 days), with five animals each. control group—no treatment of the defect; laser group—single laser irradiation with a GaAlAs semiconductor diode laser device (λ = 780 nm; P = 35 mW; t = 40 s; Θ = 1.0 mm; D = 178 J/cm2; E = 1.4 J) directly on the defect area. The rats were sacrificed at the pre‐established periods and the mandibles were removed and processed for staining with hematoxylin and eosin, Masson's Trichrome and picrosirius techniques.

Results

The histological results showed bone formation in both groups. However, the laser group exhibited an advanced tissue response compared to the control group, abbreviating the initial inflammatory reaction and promoting rapid new bone matrix formation at 15 and 45 days (P<0.05). On the other hand, there were no significant differences between the groups at 60 days.

Conclusion

The use of infrared LLLT directly to the injured tissue showed a biostimulating effect on bone remodeling by stimulating the modulation of the initial inflammatory response and anticipating the resolution to normal conditions at the earlier periods. However, there were no differences between the groups at 60 days. Lasers Surg. Med. 39:788–796, 2007. © 2007 Wiley‐Liss, Inc.
Erratum: Reciprocity of exposure time and irradiance on energy density during photoradiation on wound healing in a murine pressure ulcer model
Authors: Lanzafame Raymond J. , Stadler Istvan , Kurtz Andrew F. , Connelly Roger , Timothy Peter A. , Brondon Philip , Olson Donald
Published: December 2007

In this original published article, Dr. Peter, Sr's name was misprinted. It should be Timothy A. Peter, Sr.
Progression of cortical and spinal dysfunctions over time in amyotrophic lateral sclerosis
Authors: Attarian Shahram , Vedel Jean‐Pierre , Pouget Jean , Schmied Annie
Published: December 2007

In view of the conflicting results about the links between lower and upper motor neuron (LMN, UMN) dysfunction in amyotrophic lateral sclerosis (ALS), we undertook this study to correlate their changes over time. Single motor units (MUs) were characterized by their macro‐MU potentials, twitch amplitude, and excitatory responses to transcranial magnetic stimulation (TMS). Ten ALS patients were studied 2 to 4 times and their data were subdivided into epochs corresponding to mean disease duration of 12 (58 MUs), 20 (60 MUs), 32 (50 MUs), 43 (40 MUs), and 168 months (55 MUs). The MU size increased and the contractile effectiveness and the excitatory response rates decreased significantly with time. The contractile effectiveness of MUs producing normal excitatory responses decreased with time, whereas a gradual loss of excitatory responses was observed among MUs with normal electromechanical properties. Since no correlation was found between UMN and LMN dysfunction, we conclude that UMN and LMN probably degenerate independently in ALS. Muscle Nerve, 2008
Using forward calculations of the magnetic field perturbation due to a realistic vascular model to explore the BOLD effect
Authors: Marques José P. , Bowtell R. W.
Published: December 2007

This paper assesses the reliability of the infinite cylinder model used previously in the literature to simulate blood oxygenation level dependent (BOLD) signal changes. A three‐dimensional finite element method was applied to a realistic model of the cortical vasculature, and the results compared with those generated from a simple model of the vasculature as a set of independent, randomly oriented, infinite cylinders. The realistic model is based on scanning electron microscopy measurements of the terminal vascular bed in the superficial cortex of the rat. Good agreement is found between the two models with regard to the extravascular R2* and R2 dependence on the cerebral blood volume and blood oxygenation fraction. Using the realistic model, it is also possible to gain further understanding of the relative importance of intravascular and extravascular BOLD contrast. A simple parameterisation of the dependence of the relaxation rates on relative cerebral blood volume and blood–tissue susceptibility difference was carried out, allowing discussion of the variation in the form of the haemodynamic response with field strength. Copyright © 2007 John Wiley & Sons, Ltd.
A new MRI method, tested in vitro for the assessment of thermal coagulation and demonstrated in vivo on focused ultrasound ablation
Authors: Carasso Dina , Hanannel Arik , Navon Gil
Published: December 2007

A new MRI method is described. It is implemented for the assessment of thermal coagulation after thermal treatment. The method does not require injection of a contrast agent. The image is based on the amount of magnetization exchange between macromolecules and water in the tissue. Coagulated tissue has a faster magnetization exchange rate, forming the new contrast. In this study, the new imaging method is shown to have good contrast between coagulated and untreated excised tissues of porcine liver and muscle. The method is also successfully demonstrated in vivo in rat thigh muscle thermally treated with focused ultrasound. Copyright © 2007 John Wiley & Sons, Ltd.
Some edge‐fault‐tolerant properties of the folded hypercube
Authors: Hsieh Sun‐Yuan
Published: December 2007

In this article, we analyze some edge‐fault‐tolerant properties of the folded hypercube, a variant of the regular hypercube that is obtained by adding an edge to every pair of nodes with complementary addresses. We show that ann‐dimensional folded hypercube is (n− 2)‐edge‐fault‐tolerant Hamiltonian‐connected whenn(≥ 2) is even, (n− 1)‐edge‐fault‐tolerant strongly Hamiltonian‐laceable whenn(≥ 1) is odd, and (n− 2)‐edge‐fault‐tolerant hyper Hamiltonian‐laceable whenn(≥ 3) is odd. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
The maximum congested cut problem and its robust counterpart: Exact and approximation algorithms for the single and the multicommodity case
Authors: Scutellà Maria G.
Published: December 2007

We study an optimization problem which can be interesting in several network applications, especially in telecommunication. Given a capacitated directed network G in which a flow, related to a certain commodity, has to be sent from a given set of origins to a given set of destinations, we want to compute a maximum congested cut, i.e., a cut (S,T) of G which maximizes the ratio between the net demand of T and the capacity of the cut. We will show that a maximum congested cut can be computed in polynomial time by formulating the problem as a special maximum mean‐weight cut problem, and solving it by Newton's method for linear fractional combinatorial optimization (Radzik, Complexity in Numerical Optimization, World Scientific, Singapore, 1993). The introduced formulation will be extended to the case in which the flow demands vary in a polyhedron D, and a cut has to be determined which maximizes the congestion with respect to the flow demands in D, addressing a robust version of the problem. We will prove that the robust maximum congested cut problem is coNP‐Hard. Special cases solvable in polynomial time as well as approximation algorithms for some relevant hard cases will be proposed. The specialization of the proposed approaches to the well‐studied class of Hose models (Duffield et al., Proc., Conf Appl Technol Architect Protocol Comp Comm 29 (1999), 95–108) will be discussed. Then, in the second part of the paper, we will investigate the case in which k commodities are given, and a maximum congested cut has to be computed in such a multicommodity flow context. This problem is NP‐Hard. Some algorithmic considerations will be formulated in order to approximate the maximum congested cut in multicommodity networks, also addressing the robust version of the problem. A consequence of the stated results is a polynomial time algorithm for the sparsest cut problem in undirected graphs, for the special case in which k is O(log n), and an O(${{k}\over{\log n}}$)‐approximationalgorithm for the general case, where n denotes the cardinality of the node set. Furthermore, a new heuristic approach for the directed sparsest cut problem will be suggested. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
Transversals of subtree hypergraphs and the source location problem in digraphs
Authors: van den Heuvel Jan , Johnson Matthew
Published: December 2007

A hypergraph H = (V,E) is a subtree hypergraph if there is a tree T on V such that each hyperedge of E induces a subtree of T. Since the number of edges of a subtree hypergraph can be exponential in n = |V|, one can not always expect to be able to find a minimum size transversal in time polynomial in n. In this paper, we show that if it is possible to decide if a set of vertices W ⊆ V is a transversal in time S(n) (where n = |V|), then it is possible to find a minimum size transversal in O(n3S(n)). This result provides a polynomial algorithm for the Source Location Problem: a set of (k,l)‐sources for a digraph D = (V,A) is a subset S of V such that for any v ∈ V there are k arc‐disjoint paths that each join a vertex of S to v and l arc‐disjoint paths that each join v to S. The Source Location Problem is to find a minimum size set of (k,l)‐sources. We show that this is a case of finding a transversal of a subtree hypergraph, and that in this case S(n) is polynomial. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
New facets for the planar subgraph polytope
Authors: Hicks Illya V.
Published: December 2007

This study describes certain facet classes for the planar subgraph polytope. These facets are extensions of Kuratowski facets and are of the form 2x(U) + x(E(G)\U) ≤ 2|U| + |E(G)\U| − 2 where the edge set U varies and can be empty. Two of the new types of facets complete the class of extended subdivision facets, explored by Jünger and Mutzel. In addition, the other types of facets consist of a new class of facets for the polytope called 3‐star subdivisions. It is also shown that the extended and 3‐star subdivision facets are also equivalent to members of the class of facets with coefficients in {0, 1, 2} for the set covering polytope. Computational results displaying the effectiveness of the facets in a branch‐and‐cut scheme for the maximum planar subgraph problem are presented. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
Cycle‐based algorithms for multicommodity network flow problems with separable piecewise convex costs
Authors: de Souza Mauricio C. , Mahey Philippe , Gendron Bernard
Published: December 2007

We present cycle‐based algorithmic approaches to find local minima of a nonconvex and nonsmooth model for capacity expansion of a network supporting multicommodity flows. By exploiting complete optimality conditions for local minima, we give the convergence analysis of the negative‐cost cycle canceling method. The cycle canceling method is embedded in a tabu search strategy to explore the solution space beyond the first local optimum. Reaching a local optimum, the idea is to accept a cost‐increasing solution by pushing flow around a positive‐cost cycle, and then to make use of the cycle cancelling method incorporating tabu search memory structures to find high quality local optima. Computational experiments on instances of the literature show that the tabu search algorithm can significantly improve feasible solutions obtained by the local optimization procedure, and it outperforms the capacity and flow assignment heuristic in terms of solution quality. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
A graph theory approach for designing conservation reserve networks with minimal fragmentation
Authors: Önal Hayri , Wang Yicheng
Published: December 2007

Habitat fragmentation is often cited as one of the most important factors that adversely affect species persistence and survival ability. Contiguity of habitat sites is usually desirable when designing a conservation reserve. If a contiguous reserve is not feasible, due to landscape characteristics or economic constraints, designing a reserve network with minimal fragmentation may be a viable strategy. This article presents a linear integer programming formulation of the problem using graph theory concepts. A graph is constructed where nodes correspond to individual sites and directed arcs are defined for pairs of nodes corresponding to adjacent sites. The model determines a minimal representative tree as a subgraph where each node in the tree corresponds to either a selected reserve site or a gap site. Reserve fragmentation is defined as the sum of gap sites, which is to be minimized. An important computational problem is the formation of cycles when determining the minimal representative tree. This problem is resolved using an iterative procedure that utilizes Dantzig‐cuts when a cycle occurs in the solution. Arbitrarily generated data sets are used to explore the computational efficiency of this approach. Finally an empirical application of the model to a real data set involving 744 sites and 32 endangered/threatened bird species is presented. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
New dynamic programming algorithms for the resource constrained elementary shortest path problem
Authors: Righini Giovanni , Salani Matteo
Published: December 2007

The resource constrained elementary shortest path problem (RCESPP) arises as a pricing subproblem in branch‐and‐price algorithms for vehicle‐routing problems with additional constraints. We address the optimization of the RCESPP and we present and compare three methods. The first method is a well‐known exact dynamic‐programming algorithm improved by new ideas, such as bidirectional search with resource‐based bounding. The second method consists in a branch‐and‐bound algorithm, where lower bounds are computed by dynamic‐programming with state‐space relaxation; we show how bounded bidirectional search can be adapted to state‐space relaxation and we present different branching strategies and their hybridization. The third method, called decremental state‐space relaxation, is a new one; exact dynamic‐programming and state‐space relaxation are two special cases of this new method. The experimental comparison of the three methods is definitely favorable to decrement state‐space relaxation. Computational results are given for different kinds of resources, arising from the capacitated vehicle‐routing problem, the vehicle‐routing problem with distribution and collection, and the vehicle‐routing problem with capacities and time windows. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
Techniques for analyzing dynamic random graph models of web‐like networks: An overview
Authors: Cami Aurel , Deo Narsingh
Published: December 2007

Various random graph models have recently been proposed to replicate and explain the topology of large, complex, real‐life networks such as the World Wide Web and the Internet. These models are surveyed in this article. Our focus has primarily been on dynamic random graph models that attempt to account for the observed statistical properties of web‐like networks through certain dynamic processes guided by simple stochastic rules. Particular attention is paid to the equivalence between mathematical definitions of dynamic random graphs in terms of inductively defined probability spaces and algorithmic definitions of such models in terms of recursive procedures. Several techniques that have been employed for studying dynamic random graphs—both heuristic and analytic—are expounded. Each technique is illustrated through its application in analyzing various graph parameters, such as degree distribution, degree‐correlation between adjacent nodes, clustering coefficient, distribution of node‐pair distances, and connected‐component size. A discussion of the most recent salient work and a comprehensive list of references in this rapidly‐expanding area are included. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
The fractional congestion bound for efficient edge disjoint routing
Authors: Baveja Alok
Published: December 2007

This article investigates the following problem: Given the fractional relaxation of the edge disjoint routing problem, how small a fractional congestion is sufficient to guarantee efficient edge disjoint routing? That is, what is the largest possible valuevsuch that a fractional flow with congestion at mostv, can be efficiently converted into an edge disjoint routing? Leighton, Lu, Rao, and Srinivasan (SIAM J Comput 2001) have established that fractional congestion of at most the order ofO(1/(dlogk)) is sufficient, wheredis the maximum path length in the fractional relaxation, andkis the number of pairs to be routed. It is also known thatΘ(1/d) is the correct bound, if we are only interested in an existence result (Leighton, Rao, and Srinivasan, Hawaii International Conference on System Sciences, 1998). Motivated by the fact thatdis small for many types of routing problems, specifically, polylogarithmic for expander graphs, this article improves upon the former result by showingO(1/(dlogd)) fractional congestion to suffice. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
Sufficient conditions for a graph to be super restricted edge‐connected
Authors: Wang Shiying , Lin Shangwei
Published: December 2007

Restricted edge connectivity is a more refined network reliability index than edge connectivity. A restricted edge cut F of a connected graph G is an edge cut such that G‐F has no isolated vertex. The restricted edge connectivity λ′ is the minimum cardinality over all restricted edge cuts. We call G λ′‐optimal if λ′ = ξ, where ξ is the minimum edge degree in G. Moreover, a λ′‐optimal graph G is called a super restricted edge‐connected graph if every minimum restricted edge cut separates exactly one edge. Let D and g denote the diameter and girth of G, respectively. In this paper, we first present a necessary condition for non‐super restricted edge‐connected graphs with minimum degree δ ≥ 3 and D ≤ g − 2. Next, we prove that a connected graph with minimum degree δ ≥ 3 and D ≤ g − 3 is super restricted edge‐connected. Finally, we give some sufficient conditions on the conditional diameter and the girth for super restricted edge‐connected graphs. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
On a graph coloring problem arising from discrete tomography
Authors: Bentz C. , Costa M.C. , de Werra D. , Picouleau C. , Ries B.
Published: December 2007

An extension of the basic image reconstruction problem in discrete tomography is considered: given a graph G = (V,E) and a family $\cal {P}$ of chains Pi together with vectors h(Pi) = (h,…,h), one wants to find a partition V1,…,Vk of V such that for each Pi and each color j, |Vj ∩ Pi| = h. An interpretation in terms of scheduling is presented. We consider special cases of graphs and identify polynomially solvable cases; general complexity results are established in this case and also in the case where V1,…,Vk is required to be a proper vertex k‐coloring of G. Finally, we examine also the case of (proper) edge k‐colorings and determine its complexity status. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
A Reach and Bound algorithm for acyclic dynamic‐programming networks
Authors: Bailey Matthew D. , Smith Robert L. , Alden Jeffrey M.
Published: December 2007

Node pruning is a commonly used technique for solution acceleration in a dynamic‐programming network. In pruning, nodes are adaptively removed from the dynamic programming network when they are determined not to lie on an optimal path. We introduce an ε‐pruning condition that extends pruning to include a possible error in the pruning step. This results in a greater reduction of the computation time; however, as a result of the inclusion of this error, the solution can be suboptimal or possibly infeasible. This condition requires the ability to compare the costs of an optimal path from a node to a terminal node. Therefore, we focus on the class of acyclic dynamic programming networks with monotonically decreasing optimal costs‐to‐go. We provide an easily implementable algorithm, Reach and Bound, which maintains feasibility and bounds the solution's error. We conclude by illustrating the applicability of Reach and Bound on a problem of single location capacity expansion. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
Spectral bounds for the maximum cut problem
Authors: Ben‐Ameur Walid , Neto José
Published: December 2007

The maximum cut problem is a classical combinatorial optimization problem that is known to be NP‐hard in general. In the present article, we provide some new lower and upper bounds that are based on the eigenvalues of the weight matrix with modified diagonal entries. Namely, we show that some upper bounds presented here are generally better than the SDP bound introduced by Goemans and Williamson, JACM 42 (1995), 1115–1145. We also discuss the complexity of computing these bounds and provide some preliminary computational results. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008
Polynomial preserving recovery for meshes from Delaunay triangulation or with high aspect ratio
Authors: Zhang Zhimin
Published: December 2007

A newly developed polynomial preserving gradient recovery technique is further studied. The results are twofold. First, error bounds for the recovered gradient are established on the Delaunay type mesh when the major part of the triangulation is made of near parallelogram triangle pairs with ε‐perturbation. It is found that the recovered gradient improves the leading term of the error by a factor ε. Secondly, the analysis is performed for a highly anisotropic mesh where the aspect ratio of element sides is unbounded. When the mesh is adapted to the solution that has significant changes in one direction but very little, if any, in another direction, the recovered gradient can be superconvergent. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Finite element study of time‐dependent Maxwell's equations in dispersive media
Authors: Li Jichun , Chen Yitung
Published: December 2007

In this article, we consider the time‐dependent Maxwell's equations in a bounded domain when dispersive media are involved. The Crank‐Nicolson scheme is developed to approximate the electric field equation by Nedelec edge elements and is proved to be optimal convergent in energy norm. The analysis is carried out for Debye medium, but the same results hold true for other dispersive media such as plasma and Lorentz medium. Furthermore, our analysis extends straightforward to cases when a dispersive medium and a simple medium (such as air) are coupled. Mathematics Subject Classification (2000): 65N30, 35L15, 78‐08. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Equilibrated error estimators for discontinuous Galerkin methods
Authors: Cochez‐Dhondt Sarah , Nicaise Serge
Published: December 2007

We consider some diffusion problems in domains of ℝd, d = 2 or 3 approximated by a discontinuous Galerkin method with polynomials of any degree. We propose a new a posteriori error estimator based on H(div)‐conforming elements. It is shown that this estimator gives rise to an upper bound where the constant is one up to higher order terms. The lower bound is also established with a constant depending on the aspect ratio of the mesh, the dependence with respect to the coefficients being also traced. The reliability and efficiency of the proposed estimator is confirmed by some numerical tests. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008