bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Polymer Nanocomposites as Electrolyte Membranes
Authors: Morozan Adina , Dumitru Anca , Nastase Claudia , Nastase Florin , Stamatin Ioan
Published: July 2008

Confidence in the potential of hydrogen as an energy vector and fuel bring the opportunities for enhancing electrolyzer performance. The aim of this paper is to develop new polymer nanocomposites as electrolyte membranes for PEM‐electrolyzer. A series of nanocomposite membranes, including GEFC/TiO2, GEFC/CNTs, and GEFC/TiO2CNTs have been developed and characterized by FT‐IR spectroscopy and AFM. The application of polymer nanocomposite membranes in electrochemical cells for water electrolysis was investigated. Experimental results obtained with respect to performance are reported and discussed related to GEFC membrane.
Technique for determining when plantar heel pain can be neural in origin
Authors: Dellon A. Lee
Published: July 2008

The surgeon doing microsurgery will encounter problems related to the heel not only in terms of how to reinnervate the transferred tissue, but also in patients presenting with heel pain. While most heel pain is thought to be related to the plantar fascia arising from the calcaneus, conceptually heel pain can be of neural origin. The technique for documenting sensibility in the heel is described using the Pressure‐Specified Sensory Device™. Knowledge of calcaneal nerve sensibility can determine whether there is sufficient sensation to prevent ulceration, whether there is a nerve entrapment that would benefit from neurolysis, or whether there is a neuroma that would benefit from resection. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Stereotactic image‐guided navigation in the preoperative imaging of perforators for DIEP flap breast reconstruction
Authors: Rozen W. M. , Ashton M. W. , Stella D. L. , Phillips T. J. , Taylor G. I.
Published: July 2008

Preoperative imaging is sought prior to DIEA (Deep Inferior Epigastric Artery) perforator flaps due to the potential for maximizing operative success and minimizing operative complications. Recent advances include the use of computed tomography (CT) angiography (CTA) and magnetic resonance angiography. Image‐guided stereotactic surgery is a recent technique that has been used with success in several fields of surgery. The variability of perforator anatomy makes DIEA perforator flap surgery a suitable candidate for such technology, but as yet this has not been described. A study was undertaken to determine the feasibility of CT‐guided stereotaxy technique in DIEA perforator flap surgery and to compare findings with both conventional CTA and operative findings. Five consecutive patients planned for an elective DIEA perforator flap were recruited. Each patient underwent preoperative imaging of the anterior abdominal wall vasculature with both conventional CTA and CT‐guided stereotactic imaging. Imaging findings were compared to operative findings. In all cases, all the major perforators were accurately localized with stereotactic imaging and with conventional CTA. Stereotactic navigation demonstrated a slightly better (nonsignificant) correlation with perforator location than conventional CTA. As such, CT‐guided stereotactic imaging is an accurate method for the preoperative planning of DIEA perforator flaps, providing additional and potentially more accurate data to conventional CTA. With no additional scanning required, the method described in this paper allows the combined use of both methods for preoperative planning. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
In vitro and in vivo evaluation of a biodegradable chitosan–PLA composite peripheral nerve guide conduit material
Authors: Xie Feng , Li Qing Feng , Gu Bin , Liu Kai , Shen Guo Xiong
Published: July 2008

Chitosan, a nature biodegradable material, has good biocompatibility but poor physical properties to serve as a nerve conduit. In this study, polylactic acid (PLA) was added to chitosan to form a composite material with improved intensity and elasticity, to be used as nerve conduits. The chitosan–PLA nerve conduits were fabricated with a mold casting/infrared dehydration technique. The constituent ratio of PLA and chitosan of 1:5 (v:v) was chosen to give the composite material both good mechanical properties and good biocompatibility. An in vitro cytotoxicity test showed that the chitosan–PLA material was not cytotoxic. The conduits were proved biodegradable and had many micropores to allow permeability. We evaluated chitosan–PLA nerve conduits as a guidance channel to repair 10 mm gaps in rat sciatic nerves. Nerve autograft and silicon conduits were used as the control. After 12 weeks, the regenerating nerves in three groups succeeded in passing through the nerve gap and reinnervating the muscle. Assessments, including ECG, histomorphometric evaluation, and weighing of triceps calf muscle, showed that the functional recovery of sciatic nerve was better in chitosan–PLA conduit group than in the silicon conduit group (P < 0.05), but the differences between the chitosan–PLA conduit group and the nerve autograft group were not significant (P > 0.05). Therefore, the chitosan–PLA guide proved to be a promising nerve conduit. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Secondary nerve reconstruction using vein conduit grafts for neglected digital nerve injuries
Authors: Lee Yen‐Hsun , Shieh Shyh‐Jou
Published: July 2008

Digital nerve defects can result from neglected nerve injuries. The standard method of reconstruction is nerve grafting, but donor‐site morbidity encourages searching for alternative graft materials, including vein conduit grafts. From 1995–2005, three patients with neglected digital nerve injuries received vein conduit grafting for digital nerve reconstruction in our hospital. The interval between the injury and the reconstructive procedure ranged from 17 days to 2 years, and the length of the defects ranged from 0.8 to 2.5 cm. All the vein grafts were harvested from the distal forearm. Patient 1 had a moving and a static two‐point discrimination (M2PD and S2PD) of 3 and 4 mm, respectively, at a 12‐year follow‐up. Patient 2 had an M2PD of 5 mm and S2PD of 6 mm at an 11‐year follow‐up, and the patient 3 had both an M2PD and S2PD of 4 mm at a near 3‐year follow‐up. They all achieved useful sensory function (S3 and S3+) by modified Highet and Sander criteria. Although previous studies showed secondary repair using vein grafts yielded worse sensory recovery than that of primary repair, in our cases, secondary digital nerve reconstruction with vein conduit grafts gives excellent results at the long‐term sensory evaluation, two of them with more than 10 years' follow‐up. To the best of our knowledge, this might be the longest follow‐up after secondary digital nerve reconstruction using a vein conduit graft. It bears the advantages of readily accessible, no donor‐site morbidity, and compatible in size with digital nerves. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Isometric tetanic force measurement method of the tibialis anterior in the rat
Authors: Shin Richard H. , Vathana Torpon , Giessler Goetz A. , Friedrich Patricia F. , Bishop Allen T. , Shin Alexander Y.
Published: July 2008

Tetanic force measurements of rat tibialis anterior (TA) muscles have been described, but with a variety of stimulation parameters. This study presents a novel functional method of force measurement of the rat TA muscle and describes the optimization of stimulation parameters. Bilateral TA muscles in 10 male Lewis rats were attached to a force transducer after the corresponding hindlimb was fixed. Preload, stimulus intensity, duration, and frequency were optimized for each individual muscle and the isometric maximal tetanic muscle force was measured. The mean left side tetanic force as a percentage of the right was 100.0 ± 4.4% and was statistically equivalent. Large standard deviations between sides (35–50%) were observed in the optimized parameters (preload, stimulus intensity, duration, and frequency). Optimization of the variables affecting isometric tetanic force resulted in reproducible and reliable side‐to‐side measurements of the TA muscle in the rat model. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Neural cell transplantation effects on sciatic nerve regeneration after a standardized crush injury in the rat
Authors: Luís A. L. , Rodrigues J. M. , Geuna S. , Amado S. , Simões M. J. , Fregnan F. , Ferreira A. J. , Veloso A. P. , Armada‐Da‐Silva P. A. S. , Varejão A. S. P. , Maurício A. C.
Published: July 2008

The goal of the present study was to assess whether in vitro‐differentiated N1E‐115 cells supported by a collagen membrane would enhance rat sciatic nerve regeneration after a crush injury. To set up an appropriate experimental model for investigating the effects of neural cell transplantation, we have recently described the sequence of functional and morphologic changes occurring after a standardized sciatic nerve crush injury with a nonserrated clamp. Functional recovery was evaluated using the sciatic functional index, the static sciatic index, the extensor postural thrust, the withdrawal reflex latency, and ankle kinematics. In addition, histomorphometric analysis was carried out on regenerated nerve fibers by means of the 2D‐disector method. Based on the results of the EPT and of some of the ankle locomotor kinematic parameters analyzed, the hypothesis that N1E‐115 cells may enhance nerve regeneration is partially supported although histomorphometry disclosed no significant difference in nerve fiber regeneration between the different experimental groups. Therefore, results suggest that enrichment of equine type III collagen membrane with the N1E‐115 cellular system in the rat sciatic nerve crush model may support recovery, at least in terms of motor function. The discrepancy between functional and morphological results also suggests that the combined use of functional and morphological analysis should be recommended for an overall assessment of recovery in nerve regeneration studies. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Use of the venous flap for salvage of difficult ring avulsion injuries
Authors: Brooks Darrell , Buntic Rudolf F. , Taylor Chris
Published: July 2008

Ring avulsion can lead to soft tissue compromise resulting in eventual digit failure or restriction of motion. The authors present use of the venous flow through flap for simultaneous soft tissue and digital vessel reconstruction in severe ring avulsion injury. A retrospective review of ring avulsion injuries treated with transplantation of an arterialized (A‐V‐A) venous flap between 1999 and 2006 was conducted. Indications included digits which were debrided and required soft tissue and digital artery reconstruction. Eight venous flaps were transplanted for 3 Urbaniak class II and 5 Urbaniak class III ring avulsions. Average size of the venous flap was 6 cm2. All flaps and digits survived without partial necrosis. The soft tissue envelope was supple in all cases. Total active motion (TAM) ranged from 160 to 210°. The arterialized venous flow‐through flap is a reliable solution for the complex ring avulsion injury which requires simultaneous soft tissue and digital vessel reconstruction. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
An approximation to the solution of telegraph equation by variational iteration method
Authors: Biazar J. , Ebrahimi H. , Ayati Z.
Published: July 2008

The variational iteration method (VIM) has been applied to solve many functional equations. In this article, this method is applied to obtain an approximate solution for the Telegraph equation. Some examples are presented to show the ability of the proposed method. The results of applying VIM are exactly the same as those obtained by Adomian decomposition method. It seems less computation is needed in proposed method.© 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Die Bedeutung der Mutterkorn‐Alkaloide als Arzneistoffe. Weit mehr als nur α‐Blocker
Authors: Sinz Andrea
Published: July 2008

Mutterkorn‐Alkaloide und ihre an der Δ9,10‐Doppelbindung hydrierten Derivate besitzen als α‐Blocker nur noch geringe therapeutische Bedeutung, da sie partielle Antagonisten und partielle Agonisten an α‐Adrenozeptoren darstellen. Daher finden sie in den aktuellen Leitlinien zur Behandlung der arteriellen Hypertonie der Deutschen Hochdruckliga e. V. (Deutsche Hypertonie Gesellschaft) keine Erwähnung. Da Mutterkorn‐Alkaloide zusätzlich zu α‐Adrenozeptoren auch an 5‐HT‐Rezeptoren und Dopaminrezeptoren angreifen, finden sie Anwendung als Migränetherapeutika, bei Morbus Parkinson und in der Therapie der Altersdemenz. Allerdings werden die Mutterkorn‐Alkaloide auch im Bereich der Migränetherapie zunehmend von den Triptanen in den Hintergrund gedrängt. Es bleibt abzuwarten, wie sich die Anwendung der Mutterkorn‐Alkaloide in den nächsten Jahren entwickeln wird und ob sie sich als so genannte “dirty drugs” auf dem Markt werden behaupten können.
Viel Körperfett erhöht das Risiko für Krebserkrankungen
Authors: Winckler Thomas
Published: July 2008

Eine neue britische Studie unterstreicht ein erhöhtes Risiko übergewichtiger oder adipöser Menschen, an Krebs zu erkranken.
Current practice perspectives on the management of thrombosis in children with renal insufficiency: The results of a survey of pediatric hematologists in North America
Authors: Sharathkumar Anjali Alatkar
Published: July 2008

Background

No guidelines exist for the management of venous thromboembolic events (VTE) in children with renal insufficiency (RI).

Objective

To define current practice patterns of VTE management in children with RI.

Methods

An online multiple choice survey encompassing general questions/clinical scenarios related to thrombosis in RI. Study participants: Pediatric hematologists who were members of Hemophilia and Thrombosis Research Society (HTRS) of North America.

Results

Response rate was 54% (39/75). VTE was perceived as the major hemostatic problem in children with RI by half (20/39) of respondents. All respondents used anticoagulation for treatment of VTE while 56% used it for prophylaxis of VTE in this population. Management practices varied with respect to choice of anticoagulants employed, consideration of prophylactic anticoagulation, and evaluation for hereditary thrombophilia. Low molecular weight heparin was perceived as a safe anticoagulation for VTE treatment by 77% of respondents given that anti‐factor Xa monitoring was performed to assess bioaccumulation in RI. Thromboprophylaxis was considered for preventing thrombosis at central venous catheter, renal allo‐graft and arterio‐venous fistula in the context of previous history of thrombosis and congenital/acquired thrombophilia. The majority (>70%) would treat life‐threatening emergencies such as superior vena cava syndrome with fibrinolytics despite RI.

Conclusions

This pediatric study documents that substantial variability existed among pediatric hemologists with respect to VTE management in children with RI. Larger studies are required to better define the epidemiology and management of VTE in children with RI including the value of screening for underlying hereditary thrombophilia. Pediatr Blood Cancer 2008;51:657–661. © 2008 Wiley‐Liss, Inc.
JAK2 V617F positive polycythemia Vera in a child with neurofibromatosis type I
Authors: Berman Jason N. , Greer Wenda L. , Archambeault Sophie , Loh Mignon L. , Riddell Christie , Morash Barbara , Dumas Nadine , Fernandez Conrad V. , Ludman Mark D.
Published: July 2008

We report a child with polycythemia vera (PV). This patient demonstrates the acquired somatic JAK2 V617F mutation and also has neurofibromatosis type I (NF1). NF1, while not previously associated with PV, is associated with another childhood MPD, juvenile myelomonocytic leukemia (JMML). Thus we examined a number of genetic abnormalities identified in JMML patients, but found no association in this case. Neurofibromin sequencing failed to identify a causative mutation. An unknown genetic abnormality resulting in NF1 may have predisposed this young child to acquiring the common JAK2 mutation. Pediatr Blood Cancer 2008;51:689–691. © 2008 Wiley‐Liss, Inc.
Increased serum monocyte chemoattractant protein‐1, macrophage inflammatory protein‐1β, and interleukin‐8 concentrations in hemophagocytic lymphohistiocytosis
Authors: Tamura Kazushi , Kanazawa Takashi , Tsukada Shota , Kobayashi Tohru , Kawamura Machiko , Morikawa Akihiro
Published: July 2008

Background

Hemophagocytic lymphohistiocytosis (HLH) is characterized by hypercytokinemia caused by macrophage and T cell activation. We analyzed the serum concentrations of monocyte chemoattractant protein (MCP)‐1, macrophage inflammatory protein (MIP)‐1β, and interleukin (IL)‐8 to investigate the roles of these chemokines in the pathophysiology of HLH.

Methods

Seven patients clinically diagnosed with HLH were examined. Serum cytokines and chemokines were measured. The differences in the serum concentrations between the patients with HLH and the controls were investigated.

Results

In patients with an active phase of HLH, the serum MCP‐1, MIP‐1β, and IL‐8 levels all were significantly higher than in healthy controls. The chemokine elevations decreased rapidly after initiation of chemotherapy. During increases in disease activity, elevation of MCP‐1 and MIP‐1β preceded elevation of the serum ferritin level, which is a clinical indicator of HLH disease activity.

Conclusions

These results suggest that MCP‐1, MIP‐1β, and IL‐8 play important roles in the pathophysiology of HLH. In addition, the serum concentrations of these chemokines may be sensitive markers for assessing disease activity in patients with HLH. Pediatr Blood Cancer 2008;51:662–668. © 2008 Wiley‐Liss, Inc.
Pancytopenia with myelodysplasia due to copper deficiency
Authors: Angotti Lauren B. , Post Ginell R. , Robinson Nancy S. , Lewis Jocelyn A. , Hudspeth Michelle P. , Lazarchick John
Published: July 2008

We present a case of pancytopenia in a 9‐month‐old infant with total parenteral nutrition (TPN) dependence due to short bowel syndrome. Bone marrow examination revealed left‐shifted myeloid maturation, erythroid and myeloid dysplasia with normal iron stores. Serum copper level was 2 µm/dl (normal range 90–190 mcg/dl). After supplementation, copper levels normalized at 143 mcg/dl, and the macrocytic anemia, neutropenia, and thrombocytopenia resolved. Copper deficiency should be considered in the differential diagnosis of cytopenias and myelodsyplasia, particularly in the growing number of pediatric patients with TPN dependency or malabsorption. Pediatr Blood Cancer 2008;51:693–695. © 2008 Wiley‐Liss, Inc.
Clofarabine in refractory Langerhans cell histiocytosis
Authors: Rodriguez‐Galindo Carlos , Jeng Michael , Khuu Phuong , McCarville M. Beth , Jeha Sima
Published: July 2008

Patients with multi‐system Langerhans cell histiocytosis (LCH) who progress on frontline therapy have a dismal outcome. Responses to cladribine have been reported in relapsed LCH, but there are no well defined salvage regimens for LCH is refractory to therapy. The next generation deoxyadenosine analog, clofarabine, has demonstrated activity in patients with leukemia that is refractory to salvage regimens, including other nucleotide congeners; however, no experience exist on the use of clofarabine in LCH. In this report we describe significant single agent activity of clofarabine in disseminated LCH refractory to salvage regimens, including cladribine. Pediatr Blood Cancer 2008;51:703–706. © 2008 Wiley‐Liss, Inc.
Late effects in survivors of tandem peripheral blood stem cell transplant for high‐risk neuroblastoma
Authors: Hobbie Wendy L. , Moshang Thomas , Carlson Claire A. , Goldmuntz Elizabeth , Sacks Nancy , Goldfarb Samuel B. , Grupp Stephan A. , Ginsberg Jill P.
Published: July 2008

Background

Increasing numbers of children with advanced neuroblastoma are achieving cure. We describe the clinical late effects specific to survivors of stage IV neuroblastoma all similarly treated using tandem autologous peripheral blood stem cell rescue with TBI.

Method

The medical records of 35 neuroblastoma patients treated at CHOP between 1997 and 2001 were examined. Eighteen of the 35 patients died of progressive disease, and 4 were lost to follow‐up. Thirteen patients continue to follow‐up in our Multidisciplinary Cancer Survivorship Clinic where they are evaluated and monitored by a consistent group of subspecialists that evaluate long‐term sequelae. Data on treatment exposures including TBI and treatment related sequelae identified by clinician assessment and/or diagnostic testing were collected.

Results

Results indicate late effects were present in all 13 subjects, 12 of whom suffered from multiple negative sequelae, including issues with growth hormone deficiency, dental problems, osteochondromas and hearing deficiencies, among others, most at higher rates than reported previously.

Conclusions

The findings in this small cohort indicate the need for future prospective studies of this intensive pediatric cancer treatment, and underscore the importance of medical intervention and long‐term monitoring of these at‐risk subjects to increase overall quality‐of‐life. Pediatr Blood Cancer 2008;51:679–683. © 2008 Wiley‐Liss, Inc.
New evidence for the molecular–chemical diversity of potato plant rhizodeposits obtained by pyrolysis–field Ionisation mass spectrometry
Authors: Schlichting André , Leinweber Peter
Published: July 2008

Introduction – Detailed descriptions of the molecular–chemical diversity in plant rhizodeposits are scarce. The vast majority of our knowledge is derived from a priori methods of analysis, such as GC‐MS and HPLC.

Objective – To analyse the composition of rhizodeposits from the potato cultivar Solanum tuberosum L. cv. Albatros by pyrolysis –field ionisation mass spectrometry (Py–FIMS) and to explain differences in relation to plant growth stage and photoperiod.

Methodology – Potato (Solanum tuberosum L.) plants were grown in non‐sterile, native soil under controlled environmental conditions (plant chamber). Rhizodeposit samples were collected by leaching during two different growth stages and after the physiological day‐ and night‐cycle. All leachate samples were investigated by Py–FIMS. Mass spectrometric data were evaluated by multivariate statistics.

Results – Screening of the rhizodeposits by Py–FIMS revealed a broad range of m/z signals. Low‐molecular‐weight substances of m/z 15–56 (8.1–18.6%), alkylaromatics (12.0–15.9%), phenols and lignin monomers (8.8–13.1%) and carbohydrates (6.0–11.2%) comprised the largest proportions of total ion intensity (TII). Mass signals with significantly different abundance at the various sampling dates were assigned to compound classes of carbohydrates, phenols and lignin monomers, lignin dimers, lipids, N‐containing compounds, sterols, peptides and free fatty acids; these were supplemented by marker signals for N‐acetylmuramic acid from bacterial cell walls and signal molecules for the regulation of secondary pathways such as 4‐hydroxycinnamic acid and linolenic acid.

Conclusion – Py–FIMS was well suited to detect the molecular‐chemical diversity of potato plant rhizodeposits and, compared with traditional a priori analytical methods, provided detailed evidence for significant differences in the composition of rhizodeposits depending on growth stage and diurnal period. Copyright © 2008 John Wiley & Sons, Ltd.
Assessment of different sample processing procedures applied to the determination of melatonin in plants
Authors: Arnao Marino B. , Hernández‐Ruiz Josefa
Published: July 2008

Introduction – Melatonin, an indoleamine well known in vertebrates and structurally related to other important substances such as tryptophan or indole‐3‐acetic acid, is also present in the plant kingdom although its specific function(s) remain to be established. The emerging field of melatonin studies in plants has progressed very slowly, mainly due to the problems associated with melatonin quantification in plants.

Objective – Two commonly used procedures for plant samples are compared. The analytical characteristics of both procedures are quantitatively presented using different solvents and small amounts of fresh biological material, and the respective recovery rates and quantitative limits are presented. Some improvements are suggested.

Methodology – Two different sample extraction procedures were compared: a direct‐sample extraction (DSE) and a homogenised‐ sample extraction (HSE). Melatonin was then determined in the respective plant samples by HPLC with fluorescence detection.

Results – Using the DSE procedure, more than 94% melatonin was recovered from standard solutions, whereas levels higher than 93% were recovered from the spiked plant samples, with little difference between ethyl acetate and chloroform extractions. In the case of HSE, the recoveries of melatonin were approximately half and never higher than 55%. The ultrasonic treatment proposed in the DSE procedure showed different levels of efficiency (2–20%), depending on the sample.

Conclusion – This study has established that, with the direct sample extraction procedure, higher recovery rates are obtained both in standard solutions and in plant samples. The straightforwardness and reproducibility of the extraction procedure is accompanied by the high sensitivity obtained with fluorescence detection. Copyright © 2008 John Wiley & Sons, Ltd.
Molekularpudding
Authors: Vilgis Thomas
Published: July 2008

Der Begriff Pudding weckt sicher viele Kindheitserinnerungen und ist vor allem mit einem besonders cremig‐elastischen Mundgefühl verbunden. Pudding kochen war aber auch stets eine zeitraubende Angelegenheit, zumindest ohne Puddingpulver. Moderne Hydrokolloide, Polyelektrolyte und andere essbare Polymere erlauben ein weites Experimentierfeld für Puddings und Cremes, die nur noch gerührt und nicht mehr erwärmt werden müssen.
Mechanism of nucleophilic substitutions at phenacyl bromides with pyridines. A computational study of intermediate and transition state
Authors: Fábián Attila , Ruff Ferenc , Farkas Ödön
Published: July 2008

DFT computations have been performed on nucleophilic substitutions of phenacyl bromides with pyridines to investigate the mechanism of the reaction. In contrast with earlier suppositions, tetrahedral intermediate is not formed by the addition of pyridine on the CO group of phenacyl bromide, because the total energy of the reacting species increases continuously, when the distance between the N and C(O) atoms of reactants is shorter than 2.7 Å. At a greater distance, however, a bridged complex of the reactants is observed, in which the N atom of pyridine is slightly closer to the C atom of the CO, than to the C atom of the CH2Br group of phenacyl bromide, the distances are 2.87 and 3.05 Å, respectively. The attractive forces between the oppositely polarized N and C(O) atoms in the complex decrease the free energy of activation of the SN2 attack of pyridine at the CH2Br group. The calculated structural parameters of the SN2 transition states (TS) indicate, that earlier TSs are formed when the pyridine nucleophile bears electron‐donating (e‐d) groups, while electron‐withdrawing (e‐w) groups on phenacyl bromide substrate increase the tightness of the TS. Free energies of activation computed for the SN2 substitution agree well with the data calculated from the results of kinetic experiments and correlate with the σPy substituent constants, derived for pyridines, and with the Hammett σ constants, when the substituents (4‐MeO‐4‐NO2) are varied on the pyridine or on the phenacyl bromide reactants. Copyright © 2008 John Wiley & Sons, Ltd.
Exploring the reaction of iodine with α‐diazo esters
Authors: Verardo Giancarlo , Geatti Paola , Gambi Alberto
Published: July 2008

In this paper we describe the unprecedented reaction between α‐diazo esters 1 and iodine. The reaction, carried out in the presence of aqueous NaHCO3, afforded the Z‐isomer of the corresponding unsaturated‐2‐iodo ester 8. The configuration of compounds 8 was determined using the 3JCH coupling between carbonyl carbon atom and alkene proton. Mechanistic considerations accounting for the observed phenomena and including quantum chemical calculations are proposed. Copyright © 2008 John Wiley & Sons, Ltd.
Plasma Process. Polym. 5/2008
Authors: Walton Scott G. , Lock Evgeniya H. , Fernsler Richard F.
Published: July 2008

Cover: The cover shows images of electron beam produced plasmas used in processing applications at the US Naval Research Laboratory. The images shown are of plasmas produced by (clockwise from the top): a magnetized sheet‐beam, an un‐magnetized cylindrical beam, and parallel magnetized sheet beams. Further details can be found in the article by S. G. Walton,* E. H. Lock, and R. F. Fernsler on page 453.
Knowledge, attitude and willingness of Nigerian physiotherapists to provide care for patients living with Acquired Immunodeficiency Syndrome
Authors: Oyeyemi Adetoyeje , Oyeyemi Adewale , Abegunde Alfred
Published: July 2008

Background and Purpose. Adequate knowledge, positive attitude, and willingness to provide services are important factors in rendering competent and compassionate care to patients living with Acquired Immunodeficiency Syndrome (AIDS). Inadequate knowledge and poor attitude could exclude the application of the principles of logic and scientific methods to the practice of physiotherapy, and could result in fragmented care, with a potentially negative impact on treatment outcome and patient satisfaction. The purpose of this study was (1) to investigate the Nigerian physiotherapists' global knowledge, attitude and willingness to provide care for patients living with AIDS (PLWA), and to (2) determine the relationship between socio‐demographic variables and previous encounter with PLWA, and physiotherapists' knowledge, attitude and willingness to care for AIDS survivors. Methods. Using a 90‐item two‐part questionnaire that elicited sociodemographic and previous AIDS encounter information, and also assessed knowledge, attitude and willingness to provide care to PLWA, physiotherapists (N = 131) practicing in Nigeria were surveyed. Results. Overall, the physiotherapists showed unsatisfactory knowledge about AIDS, harbored negative attitude towards PLWA, and some were unwilling to provide care for PLWA. Previous experience caring for PLWA influenced their attitude, and modest but positive relationships were found between knowledge and attitude and between attitude and willingness. Conclusion. The study underscores the need to address Nigerian physiotherapists' working knowledge deficits and negative attitudes to PLWA. A comprehensive AIDS education that would assist clinicians in exploring their attitude, stereotype and bias against PLWA is warranted. Copyright © 2008 John Wiley & Sons, Ltd.
Discovery of sarcosine dimethylglycine methyltransferase from Galdieria sulphuraria
Authors: McCoy Jason G. , Bailey Lucas J. , Ng Yi Han , Bingman Craig A. , Wrobel Russell , Weber Andreas P. M. , Fox Brian G. , Phillips George N.
Published: July 2008

An enzyme with sarcosine dimethylglycine methyltransferase (SDMT) activity has been identified in the thermophilic eukaryote, Galdieria sulphuraria. The crystal structure of the enzyme, solved to a resolution of 1.95 Å, revealed a fold highly similar to that of mycolic acid synthases. The kcat and apparent KM values were 64.3 min−1 and 2.0 mM for sarcosine and 85.6 min−1 and 2.8 mM for dimethylglycine, respectively. Apparent KM values of S‐adenosylmethionine were 144 and 150 μM for sarcosine and dimethylglycine, respectively, and the enzyme melting temperature was 61.1°C. Modeling of cofactor binding in the active site based on the structure of methoxy mycolic acid synthase 2 revealed a number of conserved interactions within the active site. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Identification and characterization of folding inhibitors of hen egg lysozyme: An example of a new paradigm of drug design
Authors: Caldarini M. , Vasile F. , Provasi D. , Longhi R. , Tiana G. , Broglia R. A.
Published: July 2008

Studies of protein folding indicate the presence of native contacts in the denatured state, giving rise to folding elements which contribute to the accomplishment of the native state. The possibility of finding molecules which can interact with specific folding elements of a target protein preventing it from reaching its native state, and hence from becoming biologically active, is particularly attractive. The notion that folding elements not only provide molecular recognition directing the folding process, but also have conserved sequence, implies that targeting such elements will make protein folding inhibitors less susceptible to mutations which, in many cases, abrogate drug effects. The folding‐inhibition strategy can lead to a truly novel and rational approach to drug design, aside from providing new insight into folding. This is illustrated in the case of hen egg lysozyme. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Using distances between α‐carbons to predict protein structure
Authors: Crecca Christina R. , Roitberg Adrian E.
Published: July 2008

Knowledge of a protein's structure is important in understanding its function. The usual experimental structure determination methods can be costly and time‐consuming. We present an idea for a fast and inexpensive protein structure prediction method that combines modeling with less expensive experimental data. Our method involves three steps: (1) building a decoy set, (2) measuring inter‐residue distances in a target protein, and (3) comparing the measured distances with those calculated in each decoy. We postulate that structures with a small number of similar inter‐residue distances will also have similar three‐dimensional structure. We further hypothesize that the minimum number of distances needed to determine structure is much less than the total number of inter‐residue distances in the protein. To develop our protocol, we apply our method to target proteins whose structures have been solved experimentally but have not been included in the set. We simulate experimental data by calculating α‐carbon distances from the experimentally determined structures of our target proteins. We have created a large, generalized decoy set using most of the structures in the Protein Data Bank. It can be used to study any protein composed of 100 residues or less. Using this decoy set, we searched for four proteins; our predicted structures ranged in RMSD from 3.6 to 7.7 Å. We have also analyzed the RMSD distributions of the decoys using the search proteins as references and found the distributions to be similar for each protein. Of the nearly 5,000 CαCα distances in a 100 residue protein, knowledge of only twenty‐five distances will usually result in predicting a reliable model. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
The thermal set point of water vapor and life in the condensed state
Authors: Chun Paul W.
Published: July 2008

Application of the Planck–Benzinger thermal work function to biological systems has demonstrated a basic pattern for life processes, in that there is a lower cutoff point, Th, where entropy is favorable but enthalpy is unfavorable, i.e. ΔH0(Th)(+) = TΔS0(Th)(+), and upper cutoff, Tm, above which enthalpy is favorable but entropy unfavorable, i.e. ΔH0(Tm)(−) = TΔS0(Tm)(−). Only between these two limits, where ΔG0(T) = 0, is the net chemical driving force favorable for interacting biological processes. In the case of water vapor condensation, the compensatory temperatures, Th and Tm, are 30 K and 380 K. As water is a part of every living system, this suggests that the single point at which the system is its most stable, defined as the thermal set point, TS, must fall between the limits defined by the compensatory temperatures, 30 K and 380 K. We find that each interacting biological system will exhibit a negative minimum of Gibbs free energy change at a single well‐defined temperature, TS, where the bound unavailable energy TΔS0 = 0. At this point, ΔH0(TS)(−) = ΔG0(TS)(−)minimum, the maximum work can be accomplished. For water vapor condensation, the thermal set point falls at 260 K and TCp at ΔCp0(T) = 0 is 130 K. In examining interacting protein systems, it would appear that the heat capacity change of reaction of water within the system determines the behavior of the other thermodynamic functions. It is clear that the requirements for the existence of a condensed state of water and the existence of life are essentially the same, and are uniquely linked to a characteristic thermal set point. Without the existence of a condensed state, life would not exist. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Ab initio modeling of noncontact atomic force microscopy imaging of benzene on Cu(110) surface
Authors: Atodiresei N. , Caciuc V. , Hölscher H. , Blügel S.
Published: July 2008

The imaging of the detailed atomic structure of single organic molecules adsorbed on a surface is still a challenge for noncontact atomic force microscopy (NC‐AFM). To investigate such a NC‐AFM imaging process, we performed ab initio calculations to simulate the interaction of clean silicon tips with a benzene molecule adsorbed on a Cu(110) surface. The apex structure of the AFM tip was modeled by Si4H3 and Si4H9 clusters. These two nanotips were approached on top of three different molecular sites. The forces acting on the Si4H3 nanotip are always repulsive and lead to a displacement of the benzene molecule on the Cu(110) surface. On the contrary, the forces acting on the Si4H9 nanotip can be attractive or repulsive depending on the approaching molecular site. In this case, the benzene molecule can bind to the tip and is retracted from the surface. The different behavior of the two nanotips considered in our study is analyzed in the framework of the frontier orbital theory. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Electric quadrupole oscillator strengths of helium
Authors: Alexander S. A. , Coldwell R. L.
Published: July 2008

Using a set of explicitly correlated trial wave functions that describe the three lowest singlet and triplet states of the helium atom with symmetry S, P, and D, we calculate the electric quadrupole oscillator strengths for all possible 1S‐1D, 1P‐1P, 1D‐1D, 3S‐3D, 3P‐3P, and 3D‐3D transitions and compare their accuracy to our earlier calculations of the electric dipole oscillator strengths. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Carbon‐donated hydrogen bonding: Electrostatics, frequency shifts, directionality, and bifurcation
Authors: Compaan Katherine , Vergenz Robert , Von Rague Schleyer Paul , Arreguin Isis
Published: July 2008

Structure, energies, electrostatics, and vibrational modes were calculated ab initio for dimethyl sulfoxide (DMSO) and its 1:1 hydrogen bonded complex with chloride ion at the MP2/6‐311+G** level. The interaction energy is −71.476 kJ/mole. On average, the CH stretching frequencies decreased by 35 cm−1, whereas their intensities increased by a factor of 19. Methyl torsion frequencies increased by 50–80 cm−1. We review the past and present understanding of hydrogen bonding, and apply these perspectives to analyze properties of the complex. The stretching shifts conform to the established spectral criteria for hydrogen bonding. The bifurcated geometry of the complex and its electrostatic character are fully consistent with trends observed in classically defined hydrogen bonds. All of the established definitions and criteria for identifying hydrogen bonding have been challenged. By any of the most well‐established criteria, the DMSO/Cl− complex is hydrogen bonded. We propose a generally applicable working definition of hydrogen bonding to clarify and unify understanding of this interaction. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Virtual space reduction in quasi‐particle electron propagator calculations: Applications to polycyclic aromatic hydrocarbons
Authors: Dolgounitcheva O. , Flores‐Moreno R. , Zakrzewski V. G. , Ortiz J. V.
Published: July 2008

Recently developed techniques of virtual space reduction in quasi‐particle electron propagator calculations are applied to naphthalene, anthracene, phenanthrene, naphthacene, pentacene, and hexacene. Electron density difference matrices corresponding to second‐order transition energies are used to reduce the rank of the virtual orbital space for further electron propagator calculations in the partial third‐order approximation. Within this approach, only minor deviations from ionization energies obtained with the full virtual orbital space are introduced. Comparison is made with a conventional, energy‐based virtual orbital space contraction. No more than 0.14 eV of the calculated ionization energy is lost when the virtual space's dimension is reduced by 50%. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Correlation studies in weakly confining quantum dot potentials
Authors: Kimani Peter , Jones Preston , Winkler Peter
Published: July 2008

We investigate the electron correlation in few‐electron closed‐shell atomic systems and similarly in few‐electron quantum dots under weak confinement. As usual we start with restricted Hartree–Fock (HF) calculations and add electron correlation in steps in a series of approximations based on the single particle Green's function approach: (i) second‐order Green function (GF); (ii) 2ph‐Tamm‐Dancoff approximation (TDA); and (iii) an extended version thereof which introduces ground‐state correlation into the TDA. Our studies exhibit similarities and differences between weakly confined quantum dots and standard atomic systems. The calculations support the application of HF, GF, and TDA techniques in the modeling of three‐dimensional quantum dot systems. The observed differences emphasize the significance of confinement and electronic features unique to quantum dots, such as the increased binding of electrons with higher angular momentum and thus—compared to atomic systems—modified shell‐filling sequences. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Micropipette tips – the unsung heroes of mass spectrometry
Authors: Rakhmankulova Malika , Stavrou Steven W. , Yuen Alvis P. , Zhou Raymond , Kessler Paul , Pevsner Paul H.
Published: July 2008

Micropipette tip (tip) pipetting accuracy and precision are functions of tip manufacture consistency, morphological variation, and retained inner tip wall particulate matter. Irregular tip inner wall surfaces and retained particulate matter cause pipetting inaccuracy. Washed and unwashed tips from seven manufacturers were compared using weight by difference (six), microscopic Luxol Fast Blue staining (seven), and matrix‐assisted laser desorption/onization time‐of‐flight (MALDI‐TOF) mass spectrometry (six). Photomicrographs revealed tip irregularity and inner wall retained particulate matter. Computer model analysis was used to identify tip irregularity and retained matter. These tests established the utility of a pipette solvent wash to increase the performance and the accuracy of tips and, thus, improve the MALDI mass spectra obtained. Copyright © 2008 John Wiley & Sons, Ltd.
Application of probe electrospray to direct ambient analysis of biological samples
Authors: Chen Lee Chuin , Nishidate Kentaro , Saito Yuta , Mori Kunihiko , Asakawa Daiki , Takeda Sen , Kubota Takeo , Terada Nobuo , Hashimoto Yutaka , Hori Hirokazu , Hiraoka Kenzo
Published: July 2008

Recently, we have developed probe electrospray ionization (PESI) that uses a solid needle. In this system, the probe needle moves up and down along the vertical axis by a motor‐driven system. At the highest position of the probe needle, electrospray is generated by applying a high voltage. In this study, we applied PESI directly to biological samples such as urine, mouse brain, mouse liver, salmon egg, and fruits (orange, banana, etc.). Strong ion signals for almost all the samples were obtained. The amount of liquid sample picked up by the needle is as small as pL or less, making PESI a promising non‐invasive technique for detecting biomolecules in living systems such as cells. Therefore, PESI may be useful as a versatile and ready‐to‐use semi‐online analytical tool in the fields of medicine, pharmaceuticals, agriculture, food science, etc. Copyright © 2008 John Wiley & Sons, Ltd.
Psychological consequences of life‐saving cardiac surgery in patients and partners: measurement of emotional stress by the Impact of Event Scale
Authors: Bunzel Brigitta , Roethy Wilfried , Znoj Hansjoerg , Laederach‐Hofmann Kurt
Published: July 2008

The objective of this study is to investigate the long‐term psychological aftermaths of the implantation of a ventricular assist device as bridge to successful heart transplantation. Cross‐sectional, retrospective assessment of 30 patients (aged 48.1 ± 11.5 years, m/f = 28/2, 64.8 ± 32.2 months, range 12–134 months after transplantation) and 21 partners (m/f = 1/20) by standardized instruments [Impact of Event Scale (IES‐R), Hospital Anxiety and Depression Scale] and a questionnaire about specific problems regarding the time on the device (Artificial Heart Questionnaire) at Vienna Transplant Center (Austria) were used. Twenty patients suffered from dilatative cardiomyopathy and 10 of ischemic cardiomyopathy. The assist remained implanted for 158 ± 130 days (range 28–711). After transplantation, patients had to stay in Coronary care unit for 8.5 ± 7.3 days (range1–40) and remained in hospital for 29.8 ± 7.9 days (range 21–51) before they were transferred to a rehabilitation unit. None of the patients but 23 per cent of the partners (n = 6) met the criteria for post‐traumatic stress disorder (Maercker cut‐off > 0). Thereby, the IES‐R sum scales differed significantly between the two groups [21.2 ± 15.1 (mean ± standard deviation) for patients versus 38.1 ± 27.8 for partners, respectively, p = 0.001]. Two per cent of the patients and 19 per cent (p = 0.055) of the partners showed mild to moderate depression, and 4 per cent of patients and 23 per cent (p = 0.007) of their partners reported mild to moderate anxiety. None of the results were significantly influenced by the time elapsed since transplantation, the patients' age, diagnoses or indication for heart transplantation. However, the type of assist device had significant effects on hyperarousal (p = 0.040), avoidance (p = 0.030), sum scale (p = 0.050) and IES‐R‐cut‐offs (p = 0.039) of the spouses. Concerning the specific heart support related questions, patients rated all the items lower than did their respective spouses. These values significantly were lower for pain (p = 0.034) and stroke (p = 0.008) in spouses than patients. Despite of patients being much closer to a life threat, it is their partners who experience significantly more psychological distress even in the long run. Our findings highlight the need to support the supporting persons. Copyright © 2008 John Wiley & Sons, Ltd.
Is a Highly Ionic Material Still Ionic as a Nanoparticle?
Authors: Masenelli B. , Nicolas D. , Mélinon P.
Published: July 2008

The evolution of ionicity with size in highly ionic nanoparticles is investigated in small sesquioxide clusters. Representative clusters (Y2O3)N (N < 50) are theoretically analyzed by first‐principle calculations within the density functional theory within the local‐density approximation (DFT‐LDA) framework and compared to experimental results obtained in an ultrahigh vacuum environment. By studying the structural relaxation and the electronic density of states as a function of size, the respective roles of ionicity and covalency are elucidated. For compounds as ionic as rare earth sesquioxides, the highly ionic bond essentially governs and preserves the crystalline structure. Particular attention is paid to the mechanism responsible for the surface relaxation. The role of the ions at the corners and edges appears prominent, especially in reducing the dipole carried by the particles. Eventually, contrary to the observations and computations concerning ionic surfaces, the mean ionicity remains constant as the size is reduced. It emphasizes that the description of highly ionic nanoparticles cannot be directly inferred from knowledge regarding the ionic surface reconstruction.