bluuebunny/crossref_metadata_2025 huggingface dataset:
Cutting Parameters for the Reduction in Material Degradation in the Laser Cutting of Advanced High-Strength Steels
Authors: Lamikiz A , López de Lacalle L N , Sánchez J A , del Pozo D , Etayo J M , López J M
Published: August 2006

This article presents the optimum cutting conditions for advanced high-strength steel (AHSS) laser cutting. Different series of AHSSs, used in the automotive industry at present, have been tested with different laser cutting parameters. The influence of laser cutting in the material and the changes in metallurgical characteristics have been studied. The results, as expected, demonstrate very different behaviours as a function of sheet thickness, while the variation in cutting parameters due to the influence of the material is less important. The results have been divided into two large groups with thicknesses of more than 1 mm and less than 1 mm. Parameter variation inside each group mainly depends on sheet material coating. The optimum cutting areas and the quality of the cut evaluated with different criteria are presented. Finally, the best position for the laser beam has been observed to be underneath the sheet.
Mechatronic Design of a Novel Wood Moulder
Authors: Taşcioğlu Y , Jackson M R
Published: August 2006

This paper introduces the novel concept for a profile-independent wood-moulding machine. The concept aims to eliminate tooling and set-up costs of conventional wood moulders in short production runs. The designed prototype and its expected performance in terms of production rate and product quality are outlined. The prototype is modelled and the contouring control algorithm is presented. It is shown through simulation that the target production rate and product quality can be achieved.
New Sliding Mode Controller for Robotic Manipulator Subjected to Disturbance and Uncertainty
Authors: Ham J H , Choi S B
Published: August 2006

This article presents a new sliding mode controller (SMC) for the position control of a robotic manipulator subjected to perturbations, such as parameter uncertainties and extraneous disturbances. The SMC is designed so that the sliding mode condition is satisfied and integrated with the perturbation estimator. The estimator is formulated by adopting a concept of the integrated average value of the imposed perturbation over a certain sampling period and realized using the Taylor series. In the formulation of the estimator, the relationship between control performance and sensor performance is established by adjusting the sampling ratio. Subsequently, in order to improve control performance, the actuating condition for the estimator is introduced: on-off switching condition (OSC). This condition is decided on the basis of the estimation error between actual and predicted values. By imposing the OSC, control accuracy can be enhanced when high frequency perturbations exist in the system. The benefits of the proposed methodology are demonstrated on a two-link planar manipulator. The position control performances of the manipulator are evaluated and compared between the proposed methodology and conventional control schemes.
Transient Response of Active Magnetic Bearing Rotor During Rotor Drop on Backup Bearings
Authors: Zeng S , Zhang J-Q , Wang H-N
Published: August 2006

Backup bearing is a key safety component of the rotating machinery with the active magnetic bearings (AMBs). Owing to many unexpected reasons, the AMB rotor running at the full speed may drop onto the backup bearings. Sometimes, the full clearance whirling motion is induced, which is harmful to the machine. Therefore, it is quite important to know the transient behaviour of the AMB rotor and the backup bearing. Till date, a lot of works have been performed on the AMB rotor drop and various mathematical models were established. However, most of them took into account only the interaction between the rotor journal and the backup bearing but neglected the interaction between the shaft and the stator component. As we know, for a real AMB machinery, there should be seal components, and the clearance of the seal component is very small to avoid the leakage. If an AMB failure occurs, the interaction between the shaft and the seal component is likely to happen. Thus, it is more reasonable to include this factor into the AMB rotor drop model. The problem is addressed in this work. The previous model is extended to include the shaft-stator contact. The numerical analysis based on two sets of AMB rotor data shows that the dynamic behaviour of the AMB changes greatly, if the shaft-stator contact is considered. There is no longer an optimum support damping to prevent the harmful full clearance whirling motion, and at this time, a well-balanced AMB rotor is preferred.
Elastic Properties of Carbon Nanotubes in the Radial Direction
Authors: Cao Guoxin , Tang Yuye , Chen Xi
Published: August 2006

A systematic numerical and theoretical analysis is carried out to study the radial elastic properties of single-walled, double-walled, and multi-walled carbon nanotubes (CNTs). The molecular dynamics simulations are used to study CNTs under radial pressure, and the deformation mechanisms of CNTs are explored by analysing the relationship between radial strain and strain energy. A parallel continuum model based on plane strain theory is verified by molecular dynamics (MD) simulation results in single-walled and double-walled CNTs, and extended into multi-walled CNTs that are computationally expensive for MD simulation. Good agreement is found between MD simulation results and continuum studies. The effective radial elastic moduli of CNTs are presented as a function of tube radii and the number of CNT layers. The results of this paper may be useful when analysing the mechanical integrity of CNT nanocomposites and nanofluidic components.
Test Bed for Mechanical Characterization of Nanowires
Authors: Desai A. V. , Haque M. A.
Published: August 2006

Nanowires are one-dimensional solids that are deemed to be the building-block materials for next-generation sensors and actuators. Owing to their unique length scale, they exhibit superior mechanical properties and other length-scale-dependent phenomena. Most of these are challenging to explore, owing to the difficulties in specimen preparation, manipulation, and the requirement of high-resolution force and displacement sensing. To address these issues, a micromechanical device for uniaxial mechanical testing of single nanowires and nanotubes is used here. The device has 10 nN force and 1 nm displacement resolution and its small size (2 ×1 mm) allows for in situ experimentation inside analytical chambers, such as the electron microscopes. A microscale pick-and-place technique is presented as a generic specimen preparation and manipulation method for testing single nanowires. Preliminary results on zinc oxide nanowires show the Young's modulus and fracture strain to be about 76 GPa and 8 per cent respectively.
Nanoparticle Detachment Using Shock Waves
Authors: Zhou D , Kadaksham A. T. J. , Murthy Peri M. D. , Varghese I , Cetinkaya C
Published: August 2006

The fundamentals of nanoparticle detachment at the sub-100nm level using pulsed laser-induced plasma (LIP) shock waves are investigated in the current study. Two detachment mechanisms based on rolling resistance moment and rolling by resonant frequency excitation are identified as possible detachment mechanisms for nanoparticles. The gas molecule-nanoparticle interactions are studied using the direct simulation Monte Carlo method to gain knowledge about the nature of the detachment forces and moments acting on a nanoparticle in the LIP shock wave field. The discrete nature of the gas molecules colliding with the particle on the sub-100 nm length scale is linked to the stochastic transient moment experienced by the particle. Both experimental and computational findings of the current study indicate that nanoparticle detachment at the sub-100 nm level is possible by LIP shock waves.
Photocatalysis of Perfluorinated Oligo(p-Phenylene)s
Authors: Maruo Katsuya , Wada Yuji , Yanagida Shozo
Published: August 2006

Perfluorination of oligo(p-phenylene)s (OPP-n), biphenyl(OPP-2) to p-quaterphenyl (OPP-4), induces various changes in the spectral and physical characteristics of OPP-n; a hypsochromic shift of their absorption spectra, a decrease in their fluorescence quantum yields, an increase in their fluorescence lifetimes, and a positive shift of their oxidation potentials. The resulting perfluorinated oligo(p-phenylene)s (F-OPP-n, n = 3 and 4) shows photocatalytic activities for the photoreduction of water and for the photooxidation of benzene to phenol. Irradiation of an aqueous methanol solution of F-OPP-3 with triethylamine as an electron donor, and noble metal colloid as an electron mediator at λ > 290 nm, leads to H2 evolution, although photodefluorination through F-OPP-3−• inevitably occurs to an appreciable extent. A similar irradiation of an aqueous acetonitrile solution with O2 and benzene induces the oxidation of benzene and water, yielding almost equal quantities of phenol and H2O2 without any accompanying degradation of F-OPP-3.
Effects of Chain Length of Chemically Modified Silica Gels on Adsorption of Acetylacetone and Its Copper Complex from Aqueous Phase
Authors: Kato Masanao , Hattori Toshiaki , Suzuki Tsuyoshi , Tsutsumi Kazuo
Published: August 2006

Distributions of acetylacetone and its copper complex between an aqueous phase and a chemically modified silica gel were measured. The modified silica gels were synthesized, and four different alkyl chains from butyl to octadecyl groups were introduced into the surface. The observed distributions were interpreted by a solubility parameter theory as in a liquid-liquid partition experiment. It is found that the solubility parameter theory can be used as a tool for interpretation of the distribution of acetylacetone and its complex between aqueous and gel phases.
Preparation of (R)-(2-Cyclopentenyl)methanol and the First Total Synthesis of (8R,11R)-Precapnelladiene
Authors: Maeda Koji , Inouye Yoshinobu
Published: August 2006

Enantiometrically pure (R)-(2-cyclopentenyl)methanol (2) was prepared from ethyl 2-oxocyclopentanecarboxylate. Coupling of 2 with 4,4-dimethyl-3-phenylthio-2-cyclohexenone gave an enol ether, which was converted into (8R,11R)-precapnelladiene, = −70.7°, in 6 steps.
Subsymmetry-Itemized Enumeration of Flexible Cyclohexane Derivatives
Authors: Fujita Shinsaku
Published: August 2006

The symmetry of a pair of two chair-forms of cyclohexane is represented by the pseudo-point group of order 24. Preparation of the mark table of the group shows the twelve substitution positions of the pair to be governed by the coset representation (/Cs). After the calculation of subduction of the (/Cs), cyclohexane derivatives are combinatorially enumerated by the USCI (unit-subduced-cycle-index) approach. A generating-function method and the elementary superposition theorem are used, giving values itemized with respect to molecular formulas and subsymmetries of . Since pseudo-point groups can be classified into iso- and anisoenergetic groups as well as into achiral and chiral groups, four categories (isoenergetic-achiral, isoenergetic-chiral (Type II), anisoenergetic-achiral (Type III), and anisoenergetic-chiral (Type IV)) are generated. The isoenergetic-achiral case is further subdivided into two cases (Type I and I′). Several pairs are illustrated and discussed in the light of this classification. The concept of chronality is also discussed.
The Total Synthesis of AB3217-A, a Novel Anti-mite Substance, via Intermolecular Etherification and Intramolecular Glycosylation
Authors: Nakata Masaya , Tamai Tetsuro , Kamio Tadashi , Kinoshita Mitsuhiro , Tatsuta Kuniaki
Published: August 2006

The first total synthesis of AB3217-A has been achieved. The deacetylanisomycin unit, (3S,4S,5R)-3-benzyloxy-1-(benzyloxycarbonyl)-5-[(1R)-1-hydroxy-1-(4-methoxyphenyl)methyl]-4-(2-tetrahydropyranyloxy)pyrrolidine (18), was prepared from dimethyl l-tartrate by a stereoselective pyrrolidine-ring formation and a stereoselective reduction of phenyl ketone as the key steps. The lithium alkoxide of 18 was coupled with the d-xylofuranose unit, phenyl 2,3-di-O-benzyl-5-O-trifluoromethanesulfonyl-1-thio-α-d-xylofuranoside which was prepared from 1,2 : 5,6-di-O-isopropylidene-α-d-glucofuranose, via an intermolecular etherificaiton. The resulting coupling product was subjected to de-O-tetrahydropyranylation and an intramolecular glycosylation to afford 4,12,13-tribenzyl-6-(benzyloxycarbonyl)AB3217-A (30). Final deprotection of 30 furnished AB3217-A.
Novel Imidazoles and Hydantoins Moderately Strained by Incorporation with 2-Azabicyclo[2.2.1]heptene Skeleton
Authors: Kobayashi Tomoshige , Fujieda Hiroki , Murakami Yoriko , Nakamura Takehiro , Ono Katsuhiko , Yamamoto Shin-ya , Kato Hiroshi
Published: August 2006

The reactions of 3-acyl-2-azabicyclo[2.2.1]hept-5-enes with phenyl isocyanate, phenyl isothiocyanate, and ethoxycarbonyl isothiocyanate followed by cyclization reactions under basic conditions respectively provided a hydantoin, a thiohydantoin, and a 1,3-dihydro-2H-imidazole-2-thione incorporated with the azabicyclic skeleton. Treatment of the imidazolethione with Raney nickel gave a phenyl-substituted imidazole fused with 2-azabicyclo[2.2.1]hept-2-ene. The effect of annulation on the 13C NMR of the imidazole ring is discussed.
Remarkable Effect of C-Methyl Substitutions on the Ligand Field Strength of a Cobalt(III) Complex Containing a Cyclic Tetraamine with a Folded cis-Type Configuration
Authors: Yashiro Morio , Komiyama Makoto , Kuroda Kana , Miura Shuji , Yoshikawa Sadao , Yano Shigenobu
Published: August 2006

Cobalt(III) complexes containing an optically active 14-membered cyclic tetraamine (R,R-Me6[14]aneN4, 7(R), 14(R)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) and a bidentate ligand (glycinato, S-alaninato, or oxalato), in which the tetraamine takes the folded cis-type configuration, were prepared and characterized by elementary analyses, 1H and 13C NMR spectroscopy, and circular dichroism spectroscopy. Electronic absorption and 59Co NMR spectroscopies indicate that stereochemical modification of the 14-membered cyclic ligand with C-methyl groups causes an unusual decrease in the ligand field strength of the complex. Rapid dissociation of the chelated alaninato ligand from the cobalt(III) complex, which is generally inert, was observed for the [Co(S-alaninato)(R,R-Me6[14]aneN4)]2+ complex system. The dependence of the dissociation of the alaninato chelate on the ligand field strength is strongly suggested.
Co-agglutination test for cysticercus antigen detection in the serum for the diagnosis of cysticercosis
Authors: Parija S C , Rajesh Reddy S
Published: August 2006

The objective of the study was to develop the co-agglutination (Co-A) test, a rapid slide agglutination test for the diagnosis of cysticercosis. The present study included 21 cases of cysticercosis, which comprised seven cases of clinico-radiologically definite cases of neurocysticercosis (NCC) proven with either computed tomography (CT) scan or magnetic resonance imaging (MRI), eight cases of clinically strong NCC, six cases of extraneural cysticercosis in muscle and eye; 40 non-cysticercal parasitic infection controls; and 20 healthy controls. Hyperimmune cysticercus antiserum was raised in rabbits and was used to coat Staphylococcus aureus (Cowan strain-I) bearing protein A (SAPA) cells, and the Co-A was standardized to detect cysticercal antigen in the serum. Serum samples from 12 out of 21 (57%) cases of cysticercosis were positive for cysticercal antigen by the Co-A test. Of the 12 positive samples, eight were from cases of neurocysticercosis and four from cases of extra-neural cysticercosis. Serum samples from seven out of 40 non-cysticercal parasitic infection controls and serum samples from one out of 20 (5%) healthy controls showed a false-positive reaction for the antigen by the Co-A test. There was a statistically significant difference between the antigen detection rates among cysticercosis patients on one hand, and the patients with other parasitic diseases ( P=0.0014), and healthy controls ( P=0.0003) on the other. The Co-A test appears to be a moderately sensitive and specific test for the diagnosis of cysticercosis.
Knowledge and practice of help-seeking for treatment of mental disorders in Pemba Island, Zanzibar
Authors: Mirza Ilyas , Okitapoy Michel On'okoko , Jenkins Rachel
Published: August 2006

The objective of this study was to describe how people explain mental disorders and its treatment in Pemba Island, Zanzibar. Eight hundred and twenty-one participants (users, carers, health professionals, traditional healers, community members and leaders) were interviewed as part of a cross-sectional survey. Most people viewed mental disorder as arising within their internal or supernatural world. Although they thought that they could be helped both by primary health care and alternative healing, the majority described going to the traditional healers when things went wrong. This provides evidence that there is considerable reliance on traditional care for the treatment of mental disorders. It is therefore important for the health services to be in dialogue with the traditional healers.
Emerging co-infection of HIV and hepatitis B virus in far western Nepal
Authors: Poudel Krishna C , Jimba Masamine , Okumura Junko , Wakai Susumu
Published: August 2006

We detected a prevalence (11%) of hepatitis B virus (HBV) infection among male adult villagers ( n = 149) in far western Nepal where migration to India is common. Although only one migrant-returnee was infected with both HBV and HIV, co-infection may occur more frequently in future as the HIV prevalence is high (8%).
Clinico-pathological patterns of squamous cell carcinoma in Nigeria
Authors: Adigun I A , Buhari M O , Ayorinde R O
Published: August 2006

Squamous cell carcinoma (SCC) is the second most common form of skin cancer and frequently arises in the sun-exposed skin of middle-aged and elderly individuals. We retrospectively reviewed 443 patients managed for SCC (cutaneous and non-cutaneous) in our hospital from January 1979 to December 2002. The age distribution showed peak incidence between fourth and sixth decades of life. The duration of symptoms ranged from 6 months to 552 months (standard deviation [SD] = 54.29), while the head and neck region was the most common site of cutaneous SCC.

SCC is not rare in our environment. Patients with skin lesions are advised to present early to their physician for early diagnosis and appropriate treatment.
Feasibility and acceptance of telemedicine for wound care in patients with chronic leg ulcers
Authors: Hofmann-Wellenhof R , Salmhofer W , Binder B , Okcu A , Kerl H , Soyer H P
Published: August 2006

We examined the feasibility and acceptance of teledermatology for wound management of patients with chronic leg ulcers by home-care nurses. Forty-one chronic leg ulcers of different origin in 14 patients were included. After an initial in-person visit in which leg ulcers were assessed and classified, and underlying diseases noted, follow-up visits were done by home-care nurses. Once a week 1–4 digital images of the wound and surrounding skin and relevant clinical information were transmitted via a secure Website to an expert at the wound care centre. The experts provided an assessment of wound status and therapeutic recommendations. In 89% of the 492 teleconsultations, the quality of images was sufficient or excellent and the experts were confident giving therapeutic recommendations. Treatment modalities were changed or adapted in one-third of the consultations. There was a significant decrease in visits to a general physician or the wound care centre. The acceptance of teledermatology was high in patients, home-care nurses and wound experts. Teledermatology offers great potential for chronic wound care and seems to be accepted both by patients and health-care persons.
Evaluation of a mobile health system for supporting postoperative patients following day surgery
Authors: Pérez F , Montón E , Nodal M J , Viñoles J , Guillen S , Traver V
Published: August 2006

A system based on mobile phones with built-in cameras has been developed for the postoperative management of patients sent home after day surgery. The system allows patients to send pictures and pulse oximetry measurements to a hospital server in a few seconds. Health professionals can then see what patients are describing and make a more objective estimate of the patients’ status. Over a five-month period, a total of 49 patients used the system. A total of 222 images were sent, the average image delivery time being 29 s (SD 11). In nine cases (18%), the availability of images modified the treatment, and a visit to an emergency unit was avoided in eight of them who had blood-stained dressings and normal haematomas. The patients who had their treatment modified sent more images (an average of 5.4/patient) than those for whom images confirmed the correct treatment (3.1/patient). Each telephone call lasted for a mean duration of 18 min (range 8–34). The patient satisfaction data showed that all the aspects studied were evaluated in a very positive way, with 96% of the patients completely satisfied with the attention received by the mobile health application.
Organizational decentralization in radiology
Authors: Aas I H Monrad
Published: August 2006

At present, most hospitals have a department of radiology where images are captured and interpreted. Decentralization is the opposite of centralization and means ‘away from the centre’. With a Picture Archiving and Communication System (PACS) and broadband communications, transmitting radiology images between sites will be far easier than before. Qualitative interviews of 26 resource persons were performed in Norway. There was a response rate of 90%. Decentralization of radiology interpretations seems less relevant than centralization, but several forms of decentralization have a role to play. The respondents mentioned several advantages, including exploitation of capacity and competence. They also mentioned several disadvantages, including splitting professional communities and reduced contact between radiologists and clinicians. With the new technology decentralization and centralization of image interpretation are important possibilities in organizational change. This will be important for the future of teleradiology.
An assessment of parental satisfaction with mode of delivery of specialist advice for paediatric cardiology: Face-to-face versus videoconference
Authors: Weatherburn Gwyn , Dowie Robin , Mistry Hema , Young Tracey
Published: August 2006

Comparisons of parental satisfaction were made after specialist paediatric cardiology consultations were conducted either by conventional face-to-face delivery or telemedicine. Satisfaction statements were rated by 100 parents: 20 who experienced telemedicine; 56 with new children seen in the outreach clinics; 24 with children on review whose next appointment was at the specialist centre. There was general satisfaction with both types of consultations, but significant differences were noted. Those who had videoconferences felt that they had received an explanation about how the specialist advice would be obtained, and that they could see the pictures being discussed clearly. Those who had experienced telemedicine believed that teleconsultations could save them travelling time and money and they found the technical aspects of sound and picture quality acceptable. They were not discomforted by the technology and felt reassured by the consultation with the specialist. However, there was some ambivalence towards the statements suggesting that teleconsultations could take the place of conventional face-to-face consultations.
An economic evaluation of Japanese telemedicine, focusing on teleradiology and telepathology
Authors: Miyahara Shoichi , Tsuji Masatsugu , Lizuka Chikako , Hasegawa Takasi , Taoka Fumio , Teshima Masaaki
Published: August 2006

We collected information by postal survey from 622 medical institutions reported to be using telemedicine in Japan. The questionnaire asked about willingness to pay (WTP) for telemedicine and willingness to undertake (WTU) it. The Kernel Estimation Method was used to obtain WTP for teleradiology (4379 yen), telepathology (9526 yen), teleconferencing (2084 yen) and teleconsultation (633 yen). The estimated WTU were teleradiology (3875 yen), telepathology (17,918 yen), teleconferencing (3230 yen) and teleconsultation (3643 yen). These values are larger than the current charges that customers actually pay or providers receive. Multiplying these values by the number of medical institutions that had implemented telemedicine allows the total annual benefits of telemedicine to be estimated, e.g. for teleradiology, the annual benefit in terms of WTP and WTU (millions of yen per year) were 140.20 and 1101.75, respectively. Based on the results of the survey, specific policy measures to promote telemedicine further include improvement of quality and reimbursement.
Adefovir Dipivoxyl for the Treatment of Delta-Related Liver Cirrhosis
Authors: Grattagliano Ignazio , Palmieri Vincenzo O , Portincasa Piero , Palasciano Giuseppe
Published: August 2006

Objective:

To report a case suggesting the beneficial effect of adefovir dipivoxyl in patients with delta-related decompensated liver cirrhosis ineffectively treated with lamivudine.

Case Summary:

A 55-year-old woman with chronic hepatitis B virus (HBV), antihepatitis Be positive, and hepatitis delta virus (HDV)–related decompensated liver cirrhosis (Child–Pugh score B9) was awaiting liver transplantation. During this time, she was treated with lamivudine 100 mg/day; however, the drug was stopped after 8 months because it did not produce viral clearance or return serum aminotransferase levels to within normal limits. The patient was not a candidate for interferon alfa therapy but was prescribed adefovir dipivoxyl 10 mg/day. Five months later, serum aminotransferase levels had normalized and, after 7 months of treatment with adefovir, the patient became negative for serum HBV-DNA and immunoglobulin M (IgM) antidelta. At the time of writing (20 mo of therapy), the HBV-DNA and IgM antidelta remained negative, whereas hepatitis B surface antigen and circulating HDV-RNA were positive. No adverse effects associated with adefovir were reported, and the Child–Pugh score (A6) had improved.

Discussion:

This is the first reported case of some beneficial biochemical and serologic effects of adefovir dipivoxyl in the treatment of delta cirrhosis. The virologic pattern of the patient after adefovir is indicative of poor liver disease activity and prospectively enhances liver transplantation outcome, indicating that adefovir might also be useful in the phase prior to liver transplantation.

Conclusions:

Although we have no plausible explanation for our patient's favorable response to adefovir treatment, this case contributes to the knowledge regarding treatment of this very difficult condition as well as adefovir efficacy. Given the positive outcome, this report suggests that adefovir might be beneficial in patients with delta-related liver cirrhosis not responsive to previous lamivudine therapy. Based on the high tolerability of this therapy, this case encourages clinical trials.
Rare Case of Metformin-Induced Leukocytoclastic Vasculitis
Authors: Salem Chaker Ben , Hmouda Houssem , Slim Raoudha , Denguezli Mohamed , Belajouza Colandane , Bouraoui Kamel
Published: August 2006

Objective:

To report a case of leukocytoclastic vasculitis (LV) related to metformin.

Case Summary:

A 33-year-old woman developed palpable purpura on her lower limbs after starting self-medication with metformin 850 mg/day for weight loss. Drug-induced vasculitis was suspected, metformin was stopped, and the rash improved significantly. One month later, the woman again took metformin. Similar cutaneous lesions recurred, and skin biopsy showed LV, which was managed by discontinuing metformin and applying topical antiseptics. The patient had no further episodes of skin rash over a follow-up period of 3 months.

Discussion:

Metformin has widespread use throughout the world. It has a variety of metabolic and vascular effects. Our patient developed a rash within a few days of metformin administration. Resolution of skin manifestations within several days after withdrawal of the drug and their recurrence when the drug was reintroduced were consistent with a pathogenic role of metformin. Other known causes of vasculitis were excluded in a reasonable way. According to the Naranjo probability scale, the vasculitis experienced by our patient was probably due to metformin.

Conclusions:

Clinicians should be aware of the ability of metformin to induce cutaneous LV.
Effects of a long-distance run on cardiac markers in healthy athletes
Authors: Leers Mathie P.G. , Schepers Raymond , Baumgarten Ruben
Published: August 2006

Clin Chem Lab Med 2006;44:999–1003.
Inverted-U Profile of Dopamine–NMDA-Mediated Spontaneous Avalanche Recurrence in Superficial Layers of Rat Prefrontal Cortex
Authors: V. Stewart Craig , Plenz Dietmar
Published: August 2006

Prefrontal cortex (PFC) functions, such as working memory, attention selection, and memory retrieval, depend critically on dopamine and NMDA receptor activation by way of an inverted-U-shaped pharmacological profile. Although single neuron responses in the PFC have shown some aspects of this profile, a network dynamic that follows the dopamine–NMDA dependence has not been identified.

We studied neuronal network activity in acute medial PFC slices of adult rats by recording local field potentials (LFPs) with microelectrode arrays. Bath application of dopamine or the dopamine D1agonistSKF38393[(+/−)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol hydrochloride] in combination with NMDA induced spontaneous LFPs predominantly in superficial cortex layers. The LFPs at single electrodes were characterized by sharp negative peaks that were clustered in time across electrodes revealing diverse spatiotemporal patterns on the array. The pattern formation required fast GABAergic transmission, coactivation of the dopamine D1and NMDA receptor, and depended in an inverted-U profile on dopamine. At moderate concentrations of dopamine or the dopamine D1agonist, the pattern size distribution formed a power law with exponent α = −1.5, indicating that patterns are organized in the form of neuronal avalanches, thereby maximizing spatial correlations in the network. At lower or higher concentrations, α was more negative than −1.5, indicating reduced spatial correlations. Likewise, at moderate dopamine concentrations, the avalanche rate and recurrence of specific avalanches was maximal with recurrence frequencies after a “power law”-like heavy-tail distribution with a slope of −2.4.

We suggest that the dopamine–NMDA-dependent spontaneous recurrence of specific avalanches in superficial cortical layers might facilitate integrative and associative aspects of PFC functions.
The Role of Protein Interaction Motifs in Regulating the Polarity and Clustering of the Metabotropic Glutamate Receptor mGluR1a
Authors: Das Sonal S. , Banker Gary A.
Published: August 2006

When expressed in cultured hippocampal neurons, the metabotropic glutamate receptor mGluR1a is polarized to dendrites and concentrated at postsynaptic sites. We used a mutational analysis to determine how previously identified protein interaction motifs in the C terminus of mGluR1a contribute to its localization. Our results show that the polyproline motif that mediates interaction with Homer family proteins is critical for the synaptic clustering of mGluR1a. A single point mutation in this motif, which prevents the binding of Homer with mGluR1a, reduced its colocalization with a postsynaptic marker to near-chance levels but did not affect its dendritic polarity. In contrast, deleting the PDZ (postsynaptic density-95/Discs large/zona occludens-1) binding domain, which interacts with Tamalin and Shank, had no effect on synaptic localization. Neither of these protein interaction motifs is important for trafficking to the plasma membrane or for polarization to dendrites. Although deleting the entire C terminus of mGluR1a only modestly reduced its dendritic polarity, this domain was sufficient to redirect an unpolarized reporter protein to dendrites. These observations suggest that mGluR1a contains redundant dendritic targeting signals. Together, our results indicate that the localization of mGluR1a involves two distinct steps, one that targets the protein to dendrites and a second that sequesters it at postsynaptic sites; different protein interactions motifs mediate each step.
Dysfunctional Long-Range Coordination of Neural Activity during Gestalt Perception in Schizophrenia
Authors: Uhlhaas Peter J. , Linden David E. J. , Singer Wolf , Haenschel Corinna , Lindner Michael , Maurer Konrad , Rodriguez Eugenio
Published: August 2006

Recent theoretical and empirical research on schizophrenia converges on the notion that core aspects of the pathophysiology of the disorder may arise from a dysfunction in the coordination of distributed neural activity. Synchronization of neural responses in the β-band (15–30 Hz) and γ-band range (30–80 Hz) has been implicated as a possible neural substrate for dysfunctional coordination in schizophrenia. To test this hypothesis, we examined the electroencephalography (EEG) activity in 19 patients with aDiagnostic and Statistical Manual of Mental Disorder, edition IV criteria, diagnosis of schizophrenia and 19 healthy control subjects during a Gestalt perception task. EEG data were analyzed for phase synchrony and induced spectral power as an index of neural synchronization. Schizophrenia patients were impaired significantly in the detection of images that required the grouping of stimulus elements into coherent object representations. This deficit was accompanied by longer reaction times in schizophrenia patients. Deficits in Gestalt perception in schizophrenia patients were associated with reduced phase synchrony in the β-band (20–30 Hz), whereas induced spectral power in the γ-band (40–70 Hz) was mainly intact. Our findings suggest that schizophrenia patients are impaired in the long-range synchronization of neural responses, which may reflect a core deficit in the coordination of neural activity and underlie the specific cognitive dysfunctions associated with the disorder.
Prefibrillar Amyloid Aggregates Could Be Generic Toxins in Higher Organisms
Authors: Baglioni Serena , Casamenti Fiorella , Bucciantini Monica , Luheshi Leila M. , Taddei Niccolò , Chiti Fabrizio , Dobson Christopher M. , Stefani Massimo
Published: August 2006

More than 40 human diseases are associated with fibrillar deposits of specific peptides or proteins in tissue. Amyloid fibrils, or their precursors, can be highly toxic to cells, suggesting their key role in disease pathogenesis. Proteins not associated with any disease are able to form oligomers and amyloid assembliesin vitrodisplaying structures and cytotoxicity comparable with those of aggregates of disease-related polypeptides. In isolated cells, such toxicity has been shown to result from increased membrane permeability with disruption of ion homeostasis and oxidative stress. Here we microinjected into the nucleus basalis magnocellularis of rat brains aggregates of an Src homology 3 domain and the N-terminal domain of the prokaryotic HypF, neither of which is associated with amyloid disease. Prefibrillar aggregates of both proteins, but not their mature fibrils or soluble monomers, impaired cholinergic neuron viability in a dose-dependent manner similar to that seen in cell cultures. Contrary to the situation with cultured cells, however, under our experimental conditions, cell stress in tissue is not followed by a comparable level of cell death, a result that is very likely to reflect the presence of protective mechanisms reducing aggregate toxicity. These findings support the hypothesis that neurodegenerative disorders result primarily from a generic cell dysfunction caused by early misfolded species in the aggregation process.
Chemical free energies and the third law of thermodynamics
Authors: COFFEY PATRICK
Published: August 2006

At the close of the 19th century, it had become clear that determination of the free energy of chemical reactions was the key to understanding chemical affinity. Yet the available methods for obtaining free energies were unreliable and of limited applicability, and there was no known method for determination of free energies from thermal measurements. Walther Nernst's 1906 heat theorem, which later became known as the third law of thermodynamics, would prove to be the key to thermometric determinations of free energies. The paper examines the chemical significance of the third law; earlier attempts by le Chatelier, Lewis, Richards, Haber, and van't Hoff at the problem; and some later clarifications of the third law. The paper then covers the human side of the discovery of the third law, including disputes among Nernst, Lewis, and Richards.
A Mother's Feelings for Her Infant Are Strengthened by Excellent Breastfeeding Counseling and Continuity of Care
Authors: Ekström Anette , Nissen Eva
Published: August 2006

OBJECTIVE. Continuous support during the childbirth process ultimately may strengthen the mother's self-esteem and her capacity to interact with and nurture her infant and also may improve paternal involvement in general. In the present study, we investigated whether mothers, who were attended by midwives and nurses who had had a process-oriented training program in breastfeeding counseling, perceived stronger maternal feelings for their infant than mothers who had received only routine care.

METHODS. In a previous study, an intervention that included a process-oriented program on breastfeeding counseling for health professionals and continuity in family classes through childbirth was conducted. The 10 largest municipalities were classified in pairs that were similar in size and had similar figures of breastfeeding duration. The municipalities were randomized pairwise to either an intervention or a control group. The present study is a follow-up study on women's feelings for their infants in relation to the kind of care that they had had and was undertaken between April 2000 and January 2003. The sampling frame was based on women who were cared for at either the intervention clinic or control clinics. The mothers at the control clinics had received standard routine care and had attended family classes through the point of birth. Data collection for control group A started before effects of the intervention could be studied. Data for control group B were collected simultaneously with data collection for the intervention group (n = 540). The mothers responded to 3 questionnaires at 3 days and at 3 and 9 months postpartum. Background data of the mothers were collected. The perception of support that was provided by the health professionals and the perception of mother–infant relationship and feelings for the infant were rated on Likert scales.

RESULTS. At 3 days postpartum, both the intervention group and control group B versus the control group A thought that their understanding of the infant was better, they perceived more strongly that the infant as their own, and they enjoyed more breastfeeding and resting with the infant. Although there was no significant difference between the intervention group and control group B at 3 days and 3 months observation, mothers in the intervention group talked more to their infant, perceived their infant to be more beautiful than other infants, and perceived more strongly that the infant was their own than did the mothers in control group B at 9 months observation. In addition, the mothers in the intervention group felt significantly more confident with the infant and felt the infant to be closer than did the mothers in control group B.

CONCLUSION. A process-oriented breastfeeding training program for antenatal midwives and postnatal nurses that included an intervention that guaranteed continuity of care strengthened the maternal relationship with the infant and the feelings for the infant.
Extremely Growth-Retarded Infants: Is There a Viability Centile?
Authors: Kamoji Vishwanath M. , Dorling Jon S. , Manktelow Bradley N. , Draper Elizabeth S. , Field David J.
Published: August 2006

BACKGROUND. It is known that extremely premature infants do less well than more mature infants, and this fact has led some countries to adopt a “cutoff for viability” using birth weight or gestation. Infants affected by intrauterine growth retardation are at additional risk of poor outcome. There are few data to inform decisions about viability and (dis)continuation of intensive care when both extreme prematurity and severe growth retardation are present.

OBJECTIVE. We focused on (1) premature infants affected by marked intrauterine growth retardation to determine if there was a cutoff weight centile below which the mortality sharply increased and (2) the short-term outcome of extremely premature and growth-retarded infants to determine a cutoff for viability.

METHODS. We evaluated preterm infants of 22–32 weeks' gestation if they were alive at the onset of labor and born to European mothers resident in the Trent (United Kingdom) health region between 1994 and 2003. Infants were categorized into 6 weight centiles, and infants in each category were assessed for survival to discharge from the neonatal unit, duration of respiratory support, length of stay in the neonatal unit, and the age at death in nonsurvivors.

RESULTS. We identified a total of 8228 infants who met the study criteria. Of these, 4448 infants were male, 6194 were from singleton pregnancies, and 2887 were born at ≤28 completed weeks of gestation. Survival to discharge was markedly reduced in the infants born at ≤28 weeks of gestation with a birth weight less than the 2nd centile. Stillbirth was inversely related to birth weight centile in infants born before 29 weeks of gestation.

CONCLUSIONS. The survival for infants born at ≤28 weeks' gestation and having a birth weight in less than the 2nd centile is poor, and consideration should be given to modifying their management.
Barriers to Following the Supine Sleep Recommendation Among Mothers at Four Centers for the Women, Infants, and Children Program
Authors: Colson Eve R. , Levenson Suzette , Rybin Denis , Calianos Catharine , Margolis Amy , Colton Theodore , Lister George , Corwin Michael J.
Published: August 2006

OBJECTIVES. The risk for sudden infant death syndrome in black infants is twice that of white infants, and their parents are less likely to place them in the supine position for sleep. We previously identified barriers for parents to follow recommendations for sleep position. Our objective with this study was to quantify these barriers, particularly among low-income, primarily black mothers.

DESIGN/METHODS. We conducted face-to-face interviews with 671 mothers, 64% of whom were black, who attended Women, Infants, and Children Program centers in Boston, Massachusetts, Dallas, Texas, Los Angeles, California, and New Haven, Connecticut. We used univariate analyses to quantify factors that were associated with choice of sleeping position and multivariate logistic regression to calculate adjusted odds ratios for the 2 outcome variables: “ever” (meaning usually, sometimes, or last night) put infant in the prone position for sleep and “usually” put infant in the supine position to sleep.

RESULTS. Fifty-nine percent of mothers reported supine, 25% side, 15% prone, and 1% other as the usual position. Thirty-four percent reported that they ever placed infants in the prone position. Seventy-two percent said that a nurse, 53% a doctor, and 38% a female friend or relative provided source of advice. Only 42% reported that a nurse, only 36% a doctor, and only 15% a female friend or relative recommended the supine position for sleep. When a female friend or relative recommended the prone position, mothers were more likely ever to place their infants in the prone position and less likely usually to choose supine compared with those who received no advice from friends or relatives. When a doctor or a nurse recommended a nonsupine position, the mothers were less likely to choose supine compared with those who received no advice from a doctor or a nurse. Mothers who trusted the opinion of a doctor or a nurse about infant sleeping position were more likely to place their infants in the supine position. Half of the mothers believed that infants were more likely to choke when supine, and they were less likely to place their infants supine. Mothers who believed that infants are more comfortable in the prone position (36%) were more likely to place their infants prone. Twenty-nine percent believed that having their infants sleep with an adult helps prevent sudden infant death syndrome, and only 43% believed that sudden infant death syndrome is related to sleeping position.

CONCLUSIONS. We identified specific barriers to placing infants in the supine position for sleep (lack of or wrong advice, lack of trust in providers, knowledge and concerns about safety and comfort) in low-income, primarily black mothers that should be considered when designing interventions to get more infants onto their back for sleep.
Mimics of Childhood Stroke: Characteristics of a Prospective Cohort
Authors: Shellhaas Renée A. , Smith Sabrina E. , O'Tool Erin , Licht Daniel J. , Ichord Rebecca N.
Published: August 2006

BACKGROUND. Little is known about the clinical features and spectrum of diagnoses in children with “stroke mimics,” those with acute neurologic deficits but without cerebrovascular diseases.

OBJECTIVES. Our goal was to describe patients with stroke mimics and to determine if clinical features predict benign diagnoses.

METHODS. Our stroke consult team registered a prospective consecutive cohort of 143 patients with acute presentations suspicious for cerebrovascular disease from November 2003 to November 2004. Cases in which stroke was ruled out (stroke mimics) were reviewed for clinical features and diagnostic test results and were classified “benign” if there was no structural brain lesion and there was an expectation of complete recovery.

RESULTS. Of the 143 cases evaluated for suspected stroke, 30 (21%) had stroke mimics. Presenting signs included seizure (n = 11), headache (n = 9), mental status change (n = 6), focal weakness (n = 14), and focal sensory change (n = 7). Eleven patients had “benign” diagnoses (3 migraine, 3 psychogenic diagnoses, 3 musculoskeletal abnormalities, 1 delirium, and 1 episodic vital sign changes). Nineteen patients had “not-benign” diagnoses (3 reversible posterior leukoencephalopathy syndrome, 3 neonatal seizures, 2 vascular anomalies, 2 inflammatory disease, 2 intracranial infection, 2 epilepsy, 2 metabolic stroke, 1 tumor, 1 drug toxicity, and 1 idiopathic intracranial hypertension). Except for the presence of seizures, there were no significant differences in presentation or risk factors between benign and not-benign cases.

CONCLUSIONS. Many disorders mimic childhood stroke. History and clinical presentation often do not distinguish the one third of patients with benign disorders from the two thirds with more serious problems, necessitating timely comprehensive investigations, especially brain MRI.