bluuebunny/crossref_metadata_2025 huggingface dataset:
Griseofulvin Versus Terbinafine in the Treatment of Tinea Capitis: A Meta-analysis of Randomized, Clinical Trials
Authors: Fleece David , Gaughan John P. , Aronoff Stephen C.
Published: November 2004

Objective. Tinea capitis, a common pediatric infection in the United States, is caused mainly by Trichophyton species and affects many urban children. Although the current treatment of choice is oral griseofulvin, terbinafine has been shown to be variably effective in several comparative, randomized trials. The purpose of this study was to perform a meta-analysis of randomized, clinical trials comparing the efficacies of oral terbinafine and oral griseofulvin for the treatment of childhood tinea capitis.

Methods.The Medline database was searched for randomized, clinical studies comparing griseofulvin and terbinafine for the treatment of tinea capitis. Acceptance criteria included oral administration of griseofulvin for at least 6 weeks and the identification of a pathogenic dermatophyte from the scalp at the time of enrollment in the study. Scalp culture status at least 8 weeks after enrollment was used as the outcome. The common odds ratio (OR) with 95% confidence intervals (CIs), the Cochran-Mantel-Haenszel test for significance, and the Breslow-Day test for homogeneity were calculated.

Results.Six articles that satisfied all inclusion criteria were identified. These studies were combined by using outcomes at 12 to 16 weeks after enrollment. The common OR was 0.86 (95% CI: 0.57–1.27). When the 5 studies that identified Trichophyton species as the predominant pathogen were combined, using outcomes 12 weeks after enrollment, the results nearly favored terbinafine (OR: 0.65 [95% CI: 0.42–1.01]). For outcomes at 8 weeks after enrollment, no difference was found between the agents (OR: 0.84 [95% CI: 0.54–1.32]).

Consclusions.A 2- to 4-week course of terbinafine is at least as effective as a 6- to 8-week course of griseofulvin for the treatment of Trichophyton infections of the scalp. Griseofulvin is likely to be superior to terbinafine for the rare cases caused by Microsporum species.
Usefulness of the Serum Electrolyte Panel in the Management of Pediatric Dehydration Treated With Intravenously Administered Fluids
Authors: Wathen Joe E. , MacKenzie Todd , Bothner Joan P.
Published: November 2004

Background. The serum electrolyte panel (SEP) is a frequently ordered laboratory test, but it has unproven usefulness in the treatment of dehydrated pediatric patients. Our study purpose was to evaluate the usefulness of routinely ordering a SEP in the treatment of dehydrated pediatric patients receiving intravenous fluids (IVFs).

Methods. Children 2 months to 9 years of age who were receiving IVFs because of dehydration were prospectively studied in a pediatric emergency department (PED). Historical data, physical examination findings, degree of dehydration, and SEP results were recorded. After patient evaluation, attending physicians documented whether they would have ordered a SEP. Outcome measurements included changes in clinical management on the basis of SEP results, as well as correlations of dispositions and unscheduled return visits (URVs) with SEP results.

Results. A total of 182 patients were enrolled in the study. One hundred eleven patients had mild dehydration, 55 moderate dehydration, and 16 severe dehydration. Eighty-eight patients (48%; 95% confidence interval: 41–56%) had ≥1 abnormal SEP value. Clinically relevant findings included bicarbonate levels of <16 mmol/L for 28% of patients, hypoglycemia for 9.9%, hypokalemia for 6.0%, and hypernatremia for 3.0%. The attending physicians predicted that a SEP would be clinically important for 34% of all patients. There was a 58% sensitivity in detecting which children would have clinically significant SEP results. Overall, SEP results changed clinical management in 10.4% of cases. One hundred sixty-five (91%) of the patients were discharged from the PED (including 48 who were initially observed), of whom 7 (3.8%) had URVs to the PED within 72 hours and were given additional IVFs. Seventeen patients were admitted (median: 2.6 days), 2 of whom had URVs after hospital discharge for additional IVFs.

Conclusions. On the basis of initial presentation, attending physicians were poor at predicting which children would have clinically significant SEP results. Low bicarbonate values were correlated with observation unit use but not with hospitalization or URVs. The observation unit provided effective care for a subset of dehydrated patients, avoiding the need for hospitalization. Obtaining a SEP can provide useful information for the treatment of some children receiving IVFs because of dehydration.
Exception From Informed Consent for Pediatric Resuscitation Research: Community Consultation for a Trial of Brain Cooling After In-Hospital Cardiac Arrest
Authors: Morris Marilyn C. , Nadkarni Vinay M. , Ward Frances R. , Nelson Robert M.
Published: November 2004

Objectives. When prospective informed consent is not feasible, clinical research that presents more than minimal risk can proceed only after a community consultation and public disclosure process and the granting of exception from informed consent from the federal government. The applicability of exception from informed consent to pediatric resuscitation research has not been described. The objectives of this study were 1) to perform a community consultation and public disclosure process specific to a trial of induced hypothermia immediately after pediatric cardiac arrest and 2) to determine the applicability of exception from informed consent to randomized, controlled trials of emergency interventions after resuscitation from inpatient pediatric cardiac arrest.

Methods. Focus groups, information sheets with options for written responses, posted notices, e-mails, and telephone conversations with parents of critically ill children and hospital staff were conducted at a tertiary care children's hospital. Data were stored, organized, and retrieved using NVivo qualitative analysis software (QSR International).

Results. In focus groups (n = 8), parents (n = 23) and hospital staff (n = 33) concluded that prospective informed consent is not feasible for a trial of induced hypothermia after inpatient pediatric cardiac arrest. Focus group participants endorsed exception from informed consent for a trial of induced hypothermia but only if study information is easily available prospectively and if all parents have an explicit opportunity to decline participation in a verbal conversation before study enrollment. Separate from and without knowledge of the focus group results, 7 (100%) of 7 parents of past or current patients and 21 (50%) of 42 hospital staff who provided written opinions endorsed exception from informed consent for this study. Five (12%) of 42 hospital staff opposed, and 16 (38%) of 42 were neutral. In telephone conversations, 14 (70%) of 20 parents of children who were previously resuscitated from cardiac arrest endorsed exception from informed consent for this study, 3 (15%) of 20 opposed, and 3 (15%) of 20 were unsure.

Conclusions. Community consultation for inpatient resuscitation research can be conducted in a children's hospital, with hospital staff and parents of patients as the relevant community. Exception from informed consent is necessary and appropriate for a randomized trial of induced hypothermia begun within 30 minutes after pediatric cardiac arrest. A process in which families are informed prospectively and have a pre-enrollment option to decline participation will likely be acceptable to families, health care providers, and the institution.
Daytime Sleepiness and Hyperactivity in Children With Suspected Sleep-Disordered Breathing
Authors: Melendres Cecilia S. , Lutz Janita M. , Rubin Eric D. , Marcus Carole L.
Published: November 2004

Objectives. Excessive daytime sleepiness (EDS) is seen less frequently as a presenting complaint in children with sleep-disordered breathing than in adults. Instead, symptoms of hyperactivity are often described. We hypothesized that children with suspected sleep-disordered breathing (S-SDB) were both sleepier and more hyperactive than control subjects. Furthermore, we hypothesized that overnight polysomnographic parameters correlated with sleepiness and hyperactivity.

Methods. A cross-sectional study was conducted at a university-affiliated hospital and a community-based pediatric clinic. A total of 108 patients with S-SDB (mean [standard deviation] age: 7 ± 4 years) and 72 control subjects (8 ± 4 years) were recruited. A modified Epworth Sleepiness Scale (ESS) and the Conners Abbreviated Symptom Questionnaire were administered. Polysomnography was performed in patients with S-SDB.

Results. Patients with S-SDB had a higher ESS (8.1 ± 4.9 vs 5.3 ± 3.9) and a higher Conners score (12.8 ± 7.6 vs 9.0 ± 6.2) than control subjects. On the basis of adult criteria, 28% of patients had EDS. There was no difference in the ESS and Conners scores of patients with primary snoring and patients with obstructive sleep apnea. The ESS had weak correlations with polysomnographic parameters.

Conclusions. Although the ESS score of children with S-SDB was within the normal range for adults, these children were sleepier and more hyperactive than control subjects. However, these data should be confirmed by a population-based study.
Providing Life-Saving Health Care to Undocumented Children: Controversies and Ethical Issues
Authors: Young Janine , Flores Glenn , Berman Stephen
Published: November 2004

Pediatricians and hospitals with special pediatric expertise are facing the dilemma of rationing care to uninsured, undocumented children, especially for expensive life-saving care such as transplants, chemotherapy, and dialysis. This article reviews a relevant case history and provides a review and discussion of the ethical and policy issues associated with this problem.
Nontherapeutic Use of Antimicrobial Agents in Animal Agriculture: Implications for Pediatrics
Authors: Shea Katherine M. ,   Committee on Environmental Health,   Committee on Infectious Diseases
Published: November 2004

Antimicrobial resistance is widespread. Overuse or misuse of antimicrobial agents in veterinary and human medicine is responsible for increasing the crisis of resistance to antimicrobial agents. The American Academy of Pediatrics, in conjunction with the US Public Health Service, has begun to address this problem by disseminating policies on the judicious use of antimicrobial agents in humans. Between 40% and 80% of the antimicrobial agents used in the United States each year are used in food animals; many are identical or very similar to drugs used in humans. Most of this use involves the addition of low doses of antimicrobial agents to the feed of healthy animals over prolonged periods to promote growth and increase feed efficiency or at a range of doses to prevent disease. These nontherapeutic uses contribute to resistance and create health dangers for humans. This report will describe how antimicrobial agents are used in animal agriculture and review the mechanisms by which such uses contribute to resistance in human pathogens. Although therapeutic use of antimicrobial agents in agriculture clearly contributes to the development of resistance, this report will concentrate on nontherapeutic uses in healthy animals.
Dealing With the Parent Whose Judgment Is Impaired by Alcohol or Drugs: Legal and Ethical Considerations
Authors: Fraser John J. , McAbee Gary N. ,   Committee on Medical Liability
Published: November 2004

An estimated 11 to 17.5 million children are being raised by a substance-abusing parent or guardian. The importance of this statistic is undeniable, particularly when a patient is brought to a pediatric office by a parent or guardian exhibiting symptoms of judgment impairment. Although the physician-patient relationship exists between the pediatrician and the minor patient, other obligations (some perceived and some real) should be considered as well. In managing encounters with impaired parents who may become disruptive or dangerous, pediatricians should be aware of their responsibilities before acting. In addition to fulfilling the duty involved with an established physician-patient relationship, the pediatrician should take reasonable care to safeguard patient confidentiality; protect the safety of the patient and other patients, visitors, and employees; and comply with reporting mandates. This clinical report identifies and discusses the legal and ethical concepts related to these circumstances. The report offers implementation suggestions when establishing anticipatory office procedures and training programs for staff on what to do (and not do) in such situations to maximize the patient's well-being and safety and minimize the liability of the pediatrician.
Overcrowding Crisis in Our Nation's Emergency Departments: Is Our Safety Net Unraveling?
Authors:   Committee on Pediatric Emergency Medicine
Published: November 2004

Emergency departments (EDs) are a vital component in our health care safety net, available 24 hours a day, 7 days a week, for all who require care. There has been a steady increase in the volume and acuity of patient visits to EDs, now with well over 100 million Americans (30 million children) receiving emergency care annually. This rise in ED utilization has effectively saturated the capacity of EDs and emergency medical services in many communities. The resulting phenomenon, commonly referred to as ED overcrowding, now threatens access to emergency services for those who need them the most. As managers of the pediatric medical home and advocates for children and optimal pediatric health care, there is a very important role for pediatricians and the American Academy of Pediatrics in guiding health policy decision-makers toward effective solutions that promote the medical home and timely access to emergency care.
Levels of Neonatal Care
Authors:   Committee on Fetus and Newborn
Published: November 2004

This Policy Statement was revised. See https://doi.org/10.1542/peds.2012-1999.

The concept of designations for hospital facilities that care for newborn infants according to the level of complexity of care provided was first proposed in 1976. Subsequent diversity in the definitions and application of levels of care has complicated facility-based evaluation of clinical outcomes, resource allocation and utilization, and service delivery. We review data supporting the need for uniform nationally applicable definitions and the clinical basis for a proposed classification based on complexity of care. Facilities that provide hospital care for newborn infants should be classified on the basis of functional capabilities, and these facilities should be organized within a regionalized system of perinatal care.
Injury Risk of Nonpowder Guns
Authors: Laraque Danielle ,   and Committee on Injury, Violence, and Poison Prevention
Published: November 2004

Nonpowder guns (ball-bearing [BB] guns, pellet guns, air rifles, paintball guns) continue to cause serious injuries to children and adolescents. The muzzle velocity of these guns can range from approximately 150 ft/second to 1200 ft/second (the muzzle velocities of traditional firearm pistols are 750 ft/second to 1450 ft/second). Both low- and high-velocity nonpowder guns are associated with serious injuries, and fatalities can result from high-velocity guns. A persisting problem is the lack of medical recognition of the severity of injuries that can result from these guns, including penetration of the eye, skin, internal organs, and bone. Nationally, in 2000, there were an estimated 21840 (coefficient of variation: 0.0821) injuries related to nonpowder guns, with approximately 4% resulting in hospitalization. Between 1990 and 2000, the US Consumer Product Safety Commission reported 39 nonpowder gun–related deaths, of which 32 were children younger than 15 years. The introduction of high-powered air rifles in the 1970s has been associated with approximately 4 deaths per year. The advent of war games and the use of paintball guns have resulted in a number of reports of injuries, especially to the eye. Injuries associated with nonpowder guns should receive prompt medical management similar to the management of firearm-related injuries, and nonpowder guns should never be characterized as toys.
Mixing characteristics of an internal mixer: Uniformity of mixed rubber
Authors: Toh Michiharu , Gondoh Toyohiko , Mori Tetsuo , Mishima Mamoru
Published: November 2004

Uniformity of mixed rubber in an internal mixer equipped with three long‐type rotor sets was investigated. After mixing butadiene rubber with ZnO powder for a certain period of time, a small amount of the mixed rubber was taken out from two points in the mixer: the center point of the reservoir and the side point of the sickle‐shaped zone on the rotors. The concentration of ZnO in the sampled rubber was measured by the atomic absorption analyzer to know the dispersion of ZnO into the rubber. The twist direction and helix angle of rotors, and the position of ZnO powder incorporation, affected the uniformity of mixed rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 166–172, 2005
Magnetic resonances of ions in biological systems
Authors: Engström Stefan , Bowman Joseph D.
Published: November 2004

A magnetic field transduction mechanism based on an ion oscillator model is derived from an explicit quantum mechanical description. The governing equation prescribes how the electric dipole moment of an ion oscillating in a symmetric potential well evolves under the influence of an arbitrary magnetic field. The resulting equation is an analog of the Bloch equation, a well‐studied model for magnetic resonances in atomic and molecular spectroscopy. The differential equation for this ion oscillator model is solved numerically for a few illustrative magnetic field exposures, showing when those resonances occur with single frequency, linearly polarized fields. Our formulation makes explicit the conditions that must be present for magnetic fields to produce observable biological effects under the ion oscillator model. The ion's potential well must have symmetry sufficient to produce a degenerate excited state, e.g., octahedral or trigonal bipyramid potentials. The impulse that excites the ion must be spatially correlated with the orientation of the detector that reads off the final state of the oscillator. The orientation between the static and oscillating magnetic fields that produces resonance is a complicated function of the field magnitudes and frequency. We suggest several classes of experiments that could critically test the validity of the model presented here. Bioelectromagnetics 25:620–630, 2004. © 2004 Wiley‐Liss, Inc.
Effects of weak $16{2\over3}$ Hz magnetic fields on growth parameters of young sunflower and wheat seedlings
Authors: Fischer G. , Tausz M. , Köck M. , Grill Dieter
Published: November 2004

Previous studies on effects of magnetic fields on plants focussed on the power frequencies (50–60 Hz), but in Austria and Germany electric railways are powered by a frequency of 16⅔ Hz. In the present study, sunflower and wheat seedlings were exposed to 16⅔ Hz sinusoidal 20 μT (rms) vertical magnetic fields. Seeds were germinated in a germination roll and grown for 12 days under continued exposure. Seven series with sunflower and six series with wheat were done over 2 years. Sunflower seedlings exposed to experimental magnetic field showed small, but significant increases in total fresh weights, shoot fresh weights, and root fresh weights, whereas dry weights and germination rates remained unaffected. Experimentally treated wheat exhibited marginally (but significantly) higher root fresh and dry weights, total fresh weights, and higher germination rates. Bioelectromagnetics 25:638–641, 2004. © 2004 Wiley‐Liss, Inc.
Comment: A biological guide for electromagnetic safety: the stress response
Authors: Blank Martin , Goodman Reba
Published: November 2004

Questions of safety of electromagnetic (EM) fields should be based on relevant biological properties, i.e., specific cellular reactions to potentially harmful stimuli. The stress response is a well documented protective reaction of plant and animal cells to a variety of environmental threats, and it is stimulated by both extremely low frequency (ELF) and radio frequency (RF) EM fields. It involves activation of DNA to initiate synthesis of stress proteins. Thermal and non‐thermal stimuli affect different segments of DNA and utilize different biochemical pathways. However, both ELF and RF stimulate the same non‐thermal pathway. Since the same biochemical reactions are stimulated in different frequency ranges with very different specific absorption rates (SARs), SAR level is not a valid basis for safety standards. Studies of EM field interactions with DNA and with model systems provide insight into a plausible mechanism that can be effective in ELF and RF ranges. Bioelectromagnetics 25:642–646, 2004. © 2004 Wiley‐Liss, Inc.
Compensating bends in a 16‐base‐pair DNA oligomer containing a T3A3 segment: A NMR study of global DNA curvature
Authors: McAteer Kathleen , Aceves‐Gaona Alejandro , Michalczyk Ryszard , Buchko Garry W. , Isern Nancy G. , Silks Louis A. “Pete” , Miller John H. , Kennedy Michael A.
Published: November 2004

In‐phase ligated DNA containing TnAn segments fail to exhibit the retarded polyacrylamide gel electrophoresis (PAGE) migration observed for in‐phase ligated AnTn segments, a behavior thought to be correlated with macroscopic DNA curvature. The lack of macroscopic curvature in ligated TnAn segments is thought to be due to cancellation of bending in regions flanking the TpA steps. To address this issue, solution‐state NMR, including residual dipolar coupling (RDC) restraints, was used to determine a high‐resolution structure of [d(CGAGGTTTAAACCTCG)2], a DNA oligomer containing a T3A3 tract. The overall magnitude and direction of bending, including the regions flanking the central TpA step, was measured using a radius of curvature, Rc, analysis. The Rc for the overall molecule indicated a small magnitude of global bending (Rc = 138 ± 23 nm) towards the major groove, whereas the Rc for the two halves (72 ± 33 nm and 69 ± 14 nm) indicated greater localized bending into the minor groove. The direction of bending in the regions flanking the TpA step is in partial opposition (109°), contributing to cancellation of bending. The cancellation of bending did not correlate with a pattern of roll values at the TpA step, or at the 5′ and 3′ junctions, of the T3A3 segment, suggesting a simple junction/roll model is insufficient to predict cancellation of DNA bending in all TnAn junction sequence contexts. Importantly, Rc analysis of structures refined without RDC restraints lacked the precision and accuracy needed to reliably measure bending. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Occurrence of circadian rhythms in hairy root cultures grown under controlled conditions
Authors: Lanoue Arnaud , Shakourzadeh Khalil , Marison Ian , Laberche Jean‐Claude , Christen Philippe , Sangwan‐Norreel Brigitte , Boitel‐Conti Michèle
Published: November 2004

Hairy roots obtained by transformation via Agrobacterium rhizogenes provide an artificial plant material devoid of aerial parts with high growth on hormone‐free media. Fundamental knowledge of hairy root physiology is essential to develop and control its culture. In contrast to shake‐flask cultures, a bioreactor set‐up combined with on‐line data logging provides an efficient tool to study rapid physiological variations in hairy root cultures. Datura innoxia hairy roots were grown in a bioreactor equipped with on‐line data analyses of pH, dissolved oxygen (pO2), conductivity, oxygen, and carbon dioxide. The experiments were done at a constant temperature and in the absence of light cues. The results obtained showed that the carbon dioxide evolution rate (CER) presented regular oscillations during the culture. Similar oscillations were also observed for the oxygen uptake rate (OUR). These signals were treated mathematically to look for the existence of a rhythm. An autocorrelation function was used to detect any periodic components. The results demonstrate that hairy root respiration exhibited peaks of 1 day. These oscillations, having a period of about 24 h, were also observed in pH and conductivity signals, although not for the pO2 signal. The data acquired in the absence of hairy roots showed that the observed periodic behavior was not an artifact. No effect on rhythms was observed by the imposition of an external “day/night” cycle. The fact that oscillations persisted in the absence of external stimuli, with a free‐running period of 24 h, suggests that a circadian rhythm exists in hairy roots of D. innoxia. © 2004 Wiley Periodicals, Inc.
Fluorescence and CD spectroscopic analysis of the α‐chymotrypsin stabilization by the ionic liquid, 1‐ethyl‐3‐methylimidazolium bis[(trifluoromethyl)sulfonyl]amide
Authors: De Diego Teresa , Lozano Pedro , Gmouh Said , Vaultier Michel , Iborra José L.
Published: November 2004

The stability of α‐chymotrypsin in the ionic liquid, 1‐ethyl‐3‐methyl‐imidizolium bis[(trifluoromethyl)sulfonyl]amide ([emim][NTf2]), was studied at 30 and 50°C and compared with the stability in other liquid media, such as water, 3
M sorbitol, and 1‐propanol. The kinetic analysis of the enzyme stability pointed to the clear denaturative effect of 1‐propanol, while both 3M sorbitol and [emim][NTf2] displayed a strong stabilizing power. For the first time, it is shown that enzyme stabilization by ionic liquids seems to be related to the associated structural changes of the protein that can be observed by differential scanning calorimetry (DSC) and fluorescence and circular dichroism (CD). The [emim][NTf2] enhanced both the melting temperature and heat capacity of the enzyme compared to the other media assayed. The fluorescence spectra clearly showed the ability of [emim][NTf2] to compact the native structural conformation of α‐chymotrypsin, preventing the usual thermal unfolding which occurs in other media. Changes in the secondary structure of this β/β protein, as quantified by the CD spectra, pointed to the great enhancement (up 40% with respect to that in water) of β‐strands in the presence of the ionic liquid, which reflects its stabilization power. © 2004 Wiley Periodicals, Inc.
Hoechst 33258 Selectively Inhibits Group I Intron Self‐Splicing by Affecting RNA Folding
Authors: Disney Matthew D. , Childs Jessica L. , Turner Douglas H.
Published: November 2004

Fungal pathogens are increasing in prevalence due to an increase in resistant strains and the number of immunocompromised humans. Candida albicans is one of these pathogens, and ∼40 % of strains contain a group I self‐splicing intron, which is a potential RNA drug target, in their large subunit rRNA precursor. Here, we report that Hoechst 33258 and derivatives thereof are selective inhibitors of C. albicans group I intron self‐splicing with an IC50 of 17 μM in 2 mM Mg2+. Chemical probing of the intron in the presence of Hoechst 33258 reveals that the folding of several nucleotides in the P4/P6 region of the intron is affected. A nucleotide near the J4/5 region is protected from chemical modification in the presence of Hoechst 33258 and several nearby are more reactive; this suggests that this region is the molecule's binding site. These results expand the available information on small‐molecule targeting of RNA and suggest that the RNAtargeting scaffold provided by Hoechst may prove valuable in designing compounds that inhibit the functions of RNA.
A Kinetically Stabilized Ferrocenyl Diphosphene: Synthesis, Structure, Properties, and Redox Behavior
Authors: Nagahora Noriyoshi , Sasamori Takahiro , Takeda Nobuhiro , Tokitoh Norihiro
Published: November 2004

A new, stable ferrocenyl diphosphene [Tbt‐PP‐Fc] (1) (Tbt=2,4,6‐tris[bis(trimethylsilyl)methyl]phenyl, Fc = ferrocenyl) was synthesized by the dehydrochlorination reaction of the corresponding diphosphane, [Tbt‐P(H)‐P(Cl)‐Fc] (8), with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in good yield. Diphosphene 1 is very stable in the solid state and also in solution. In the 31P NMR spectrum (C6D6), diphosphene 1 showed a low‐fielded AB quartet at δ 501.7 and 479.5 ppm with the coupling constant 1JPP=546 Hz, which is characteristic of an unsymmetrically substituted trans‐diphosphene. The molecular structure of 1 was established by X‐ray crystallographic analysis, which showed a trans‐diphosphene with a C‐P‐P‐C torsion angle of 177.86(17)°. The phosphorusphosphorus bond length of 1 [2.0285(15) Å] which is considerably shorter than the typical PP single‐bond lengths (ca. 2.22–2.24 Å) and within the range of reported PP double‐bond lengths (1.985–2.051 Å) for diaryl diphosphenes, evidenced the PP double‐bond character of 1 in the solid state. In addition, the cyclic voltammograms of 1 showed reversible reduction and oxidation couples at −1.95 and +0.34 V versus SCE, respectively. The electrochemical results for 1 were reasonably supported by the DFT calculations, which suggested that the LUMO and HOMO orbitals should be mainly π* orbital of the diphosphene moiety and d orbitals of the iron(II) atom, respectively.
A Modular Approach to DNA‐Programmed Self‐Assembly of Macromolecular Nanostructures
Authors: Gothelf Kurt V. , Brown Raymond S.
Published: November 2004

DNA‐programmed organic reactions are new and powerful tools for assembling chemical compounds into predetermined complex structures and a brief review of their use is given. This approach is particular efficient for the selection and covalent coupling of multiple components. DNA‐templated synthesis is used for polymerization of PNA tetramers and for copying of the connectivity information in DNA. Direct DNA‐programmed multicomponent coupling of custom designed organic modules is described. The macromolecular structures obtained are highly conjugated potentially conducting nanoscaffolds. Some future developments in this area are discussed.
A Practical Synthesis of (+)‐Biotin from L‐Cysteine
Authors: Seki Masahiko , Hatsuda Masanori , Mori Yoshikazu , Yoshida Shin‐ichi , Yamada Shin‐ichi , Shimizu Toshiaki
Published: November 2004

α‐Amino aldehyde 4, which is readily derived from L‐cysteine through cyclization and elaboration of the carboxy group, was subjected to the Strecker reaction, which, via sodium bisulfite adduct 16, afforded α‐amino nitrile 5 with high diastereoselectivity (syn/anti=11:1) and in high yield. Amide 6, derived from 5, was converted to thiolactone 8, a key intermediate in the synthesis of (+)‐biotin (1), by a novel S,N‐carbonyl migration and cyclization reaction. The Fukuyama coupling reaction of 8 with the zinc reagent 21, which has an ester group, in the presence of a heterogeneous Pd/C catalyst allowed the efficient installation of the 4‐carboxybutyl chain to provide 9. Compound 9 was hydrogenated and the protecting groups removed to furnish 1 in 10 steps and in 34 % overall yield from L‐cysteine.
Risk factors associated with earlier age of onset in familial pancreatic carcinoma
Authors: James Ted A. , Sheldon David G. , Rajput Ashwani , Kuvshinoff Boris W. , Javle Milind M. , Nava Hector R. , Smith Judy L. , Gibbs John F.
Published: November 2004

BACKGROUND

An estimated 5–10% of all pancreatic adenocarcinomas have a hereditary association. The objective of the current study was to characterize the clinical and pathologic features of familial pancreatic carcinoma and to determine potential differences in demographics, risk factors, and outcomes between familial and sporadic pancreatic carcinoma populations.

METHODS

A retrospective review was performed to identify patients diagnosed with pancreatic carcinoma who had an associated familial disposition. Demographic analyses and assessment of clinical features and treatment outcomes were performed for the familial subgroup, and the results were compared with observations made in the nonfamilial, or ‘sporadic’, population.

RESULTS

Thirty of 826 patients (3.6%) had familial pancreatic carcinoma. Baseline demographics, resectability, and metastases were similar in both the familial cohort and the sporadic cohort. The mean age of onset was slightly lower in the familial cohort (57.6 years, compared with 61 years in the sporadic cohort). However, the familial population had a significantly greater proportion of patients who were diagnosed at age < 50 years compared with the sporadic population (36.7% vs. 18.3%; P = 0.017). A positive smoking history was more commonly associated with familial pancreatic carcinoma (87% vs. 66%; P = 0.06). The overall median survival durations were 7 months and 6 months for the familial group and the sporadic group, respectively.

CONCLUSIONS

Patients with familial pancreatic carcinoma present at an earlier age compared with their counterparts who have nonfamilial disease. Smoking may play a significant role in the risk or promotion of pancreatic carcinoma in patients with an inherited predisposition. Cancer 2004. © 2004 American Cancer Society.
Cellular and subcellular distribution of spinophilin, a PP1 regulatory protein that bundles F‐actin in dendritic spines
Authors: Ouimet Charles C. , Katona István , Allen Patrick , Freund Tamás F. , Greengard Paul
Published: November 2004

Spinophilin is an actin binding protein that positions protein phosphatase 1 next to its substrates in dendritic spines. It contains a single PDZ domain and has the biochemical characteristics of a cytoskeletal scaffolding protein. Previous studies suggest that spinophilin is present in most spines, but the concentration of spinophilin varies from brain region to region in a manner that does not simply reflect differences in spine density. Here, we show that spinophilin is enriched in the great majority of dendritic spines in cerebral cortex, caudatoputamen, hippocampal formation, and cerebellum, irrespective of regional differences in spinophilin concentration. In addition, spinophilin is present postsynaptic to asymmetrical contacts on interneuronal dendritic shafts. We further show that, in hippocampus and ventral pallidum, spinophilin is occasionally present in dendritic shafts adjacent to γ‐aminobutyric acid‐containing contacts. Thus, the functional role of spinophilin may not be exclusively restricted to excitatory synapses and may be significant at a small fraction of inhibitory contacts. These data also suggest that the concentration of spinophilin per spine is variable and is likely regulated by local physiological factors and/or regional influences. J. Comp. Neurol. 479:374–388, 2004. © 2004 Wiley‐Liss, Inc.
Multiple Aromaticity and Antiaromaticity in Silicon Clusters
Authors: Zhai Hua‐Jin , Kuznetsov Aleksey E. , Boldyrev Alexander I. , Wang Lai‐Sheng
Published: November 2004

A series of silicon clusters containing four atoms but with different charge states (Si42+, Si4, Si42−, and NaSi4−) were studied by photoelectron spectroscopy and ab initio calculations. Structure evolution and chemical bonding in this series were interpreted in terms of aromaticity and antiaromaticity, which allowed the prediction of how structures of the four‐atom silicon clusters change upon addition or removal of two electrons. It is shown that Si42+ is square‐planar, analogous to the recently discovered aromatic Al42− cluster. Upon addition of two electrons, neutral Si4 becomes σ‐antiaromatic and exhibits a rhombus distortion. Adding two more electrons to Si4 leads to two energetically close structures of Si42−: either a double antiaromatic parallelogram structure or an aromatic system with a butterfly distortion. Because of the electronic instability of doubly charged Si42−, a stabilizing cation (Na+) was used to produce Si42− in the gas phase in the form of Na+[Si42−], which was characterized experimentally by photoelectron spectroscopy. Multiple antiaromaticity in the parallelogram Na+[Si42−] species is highly unusual.
Spectroscopic Properties of Trapped Electrons on the Surface of MgO Nanoparticles
Authors: Sterrer Martin , Berger Thomas , Stankic Slavica , Diwald Oliver , Knözinger Erich
Published: November 2004

To characterise electron‐trapping sites on the surface of MgO nanoparticles, surface colour centres were generated using UV light in conjunction with selected hydrogen‐based electron sources. Four different colour‐centre species, including the characteristic (e−)(H+) or F${{{+\hfill \atop S\hfill}}}$(H) centre, were identified due to the distinct shape of the respective electron paramagnetic resonance (EPR) signals. The analysis of the EPR saturation behaviour down to microwave powers of 5×10−3 mW reveals an enhanced spin‐relaxation probability of the (e−)(H+) centre compared to all other F${{{+\hfill \atop S\hfill}}}$ centres that do not exhibit significant magnetic interactions with hydroxylic protons. Beside the dipolar magnetic interaction in the (e−)(H+) centre observed by EPR, the electronic interaction between the unpaired electron and the proton of a closely spaced OH group produces a redshift of the OH stretching band by about 70 to 170 cm−1, as observed by infrared spectroscopy. EPR and IR spectroscopic data obtained after the selective address of individual reaction channels for surface colour‐centre formation point to the fact that (e−)(H+) centres are formed by trapping electrons from H atoms. Consequently, the underlying surface defect does not belong to the sites of the MgO surface, which chemisorb hydrogen via a heterolytic splitting process.
Perceptual interactions between fruity and woody notes of wine
Authors: Atanasova Boriana , Thomas‐Danguin Thierry , Langlois Dominique , Nicklaus Sophie , Etievant Patrick
Published: November 2004

The quantitative olfactory interactions in three binary mixtures of wine aroma compounds were studied. For the ﬁrst two mixtures, whisky lactone (woody note) was mixed separately with two esters (fruity note), ethyl butyrate and isoamyl acetate. For the third mixture, guaiacol (woody note) was mixed with ethyl butyrate (fruity note). Perceived odour intensity of 24 stimuli (four supra‐threshold concentration levels of two compounds and the respective 16 mixtures) were evaluated in ﬁve replications, by a trained panel of 13 subjects. The results showed that for the three binary mixtures studied, quantitative perceptual interactions were non‐level independent, non‐symmetrical, and reached the compromise level of hypo‐addition. The experimental data highlighted that generally mixtures with high whisky lactone levels led to the compromise level of mixture intensity perception, whereas mixtures with high fruity note intensity proportions did not. A tendency to hyper‐addition was observed in iso‐intense mixtures only at the lowest intensity level. Copyright © 2004 John Wiley & Sons, Ltd.
Measurements of thermal conductivity and thermal diffusivity of alternative refrigerants in liquid phase with a transient short‐hot‐wire method
Authors: Tomimura Toshio , Maki Syou , Zhang Xing , Fujii Motoo
Published: November 2004

A transient short‐hot‐wire method has been proposed to simultaneously measure the thermal conductivity and thermal diffusivity of liquids. The method has been applied to the refrigerant HCFC‐22, alternative refrigerants HFC‐32, HFC‐125, HFC‐134a and refrigerant mixtures HFC‐32/125 [35/65, 50/50 (HFC‐410A), 68/32 wt%], HFC‐32/125/134a [23/25/52 (HFC‐407C) wt%]. From the present study, it is shown that the measured results agree well with the literature values on thermal conductivity and those on thermal diffusivity obtained from NIST's thermophysical property database, REFPROP Ver. 6.0. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(8): 540–552, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20032
Analysis of the parameters of the sintered loop heat pipe
Authors: Zan K.J. , Zan C.J. , Chen Y.M. , Wu S.J.
Published: November 2004

The purpose of this paper is to establish an experimental formula for sintered dendritic nickel powder. For this reason, wick structures with different porosity ranging from 65 to 80% were fabricated by cold pressing sintering process at fixed porosity and their parameters that included porosity, pore radius, and permeability were also measured. According to both the capillary limitation and the present experimental formula of the sintered dendritic nickel powder, the wick structure parameters that would affect the heat transfer capacity of the loop heat pipe (LHP) were analyzed theoretically and then investigated experimentally. The results showed that there exists an optimal combination of wick structure parameters by which the performance of the LHP would achieve optimization. The maximum heat transfer capacity was up to 500 W and the thermal resistance was 0.12°C/W at the allowable working temperature 80°C. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(8): 515–526, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20034
Control of turbulent channel flow over a backward‐facing step by suction or injection
Authors: Sakuraba Kenichiro , Fukazawa Kazuharu , Sano Masatoshi
Published: November 2004

Experiments have been performed for turbulent channel flow over a backward‐facing step. The backward‐facing step is controlled by equipping a slit at the bottom corner of the step. Low momentum fluids in the recirculation region are sucked or high momentum fluids are injected from the slit. The width of the slit is changed between 2, 3, and 5 mm, and the flow ratio is varied from 0.00 to 0.15. The wall static pressure and local heat transfer coefficient are measured behind the backward‐facing step. The wall shear stress is measured using a micro flow sensor. In addition, the velocity profiles and turbulent intensities are measured by a split hot film probe. It is found that the heat transfer and pressure drop characteristics are controlled by the flow ratio. When the suction flow ratio is 0.06, the highest performance is obtained. Enhancement of the heat transfer is related to the increase of turbulence intensity. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(8): 490–504, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20036
Conducting polymers grown in hydrogel scaffolds coated on neural prosthetic devices
Authors: Kim Dong‐Hwan , Abidian Mohammad , Martin David C.
Published: November 2004

The conducting polymer polypyrrole (PPy) was electrochemically grown on hydrogel scaffolds deposited on the surface of microfabricated neural prosthetic devices. It is shown that the pyrrole monomer can be grown vertically through the hydrogel layer up to the surface without affecting the adjacent sites on the probes. The electrochemical properties of the conducting polymer‐modified hydrogels were studied by impedance spectroscopy and cyclic voltammetry. It is also found that the conducting polymers could still be readily grown through the hydrogel after the microstructure is disrupted by freeze drying. Impedance measurements at the biologically important frequency of 1 kHz showed that the minimum impedance of this polymer‐modified hydrogel was 7 kΩ. This is much lower than the minimum impedance of polypyrrole film (∼100 kΩ). © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 577–585, 2004
Formation of hydroxyapatite/biopolymer biomaterials. I. Microporous composites from solidified emulsions
Authors: Ritzoulis C. , Scoutaris N. , Demetriou E. , Papademetriou K. , Kokkou S. , Stavroulias S. , Panayiotou C.
Published: November 2004

Microporous materials of controlled pore size were prepared by means of a three‐step process involving in situ hydrochemical preparation of a hydroxyapatite–sodium caseinate (HAp–Cas) composite material into a Cas‐stabilized oil‐in‐water emulsion, subsequent concentration and drying of the composite–emulsion, and removal of the oil by means of supercritical carbon dioxide extraction. The resulting composite materials were found to contain micron‐sized pores in the space previously occupied by the oil droplets. In order to elucidate the structure of the resulting porous product, its Cas–HAp composition was studied in the corresponding nonporous composite material. In nonporous samples, a protein assay by means of visible spectroscopy suggested equilibrium between the Cas that was trapped in the composite structure and the Cas that remained in solution after precipitation. This observation was confirmed by separate thermogravimetric analysis and Fourier transform IR spectroscopy measurements. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 675–684, 2004
Lysosomal and mitochondrial pathways in H2O2‐induced apoptosis of alveolar type II cells
Authors: Yin Lei , Stearns Rebecca , González‐Flecha Beatriz
Published: November 2004

Increasing evidence suggests a role for apoptosis in the maintenance of the alveolar epithelium under normal and pathological conditions. However, the signaling pathways modulating alveolar type II (AT II) cell apoptosis remain poorly defined. Here we investigated the role of lysosomes as modulators of oxidant‐mediated AT II cell apoptosis using an in vitro model of H2O2‐stress. H2O2 stress led to time‐dependent increases in intracellular oxidants, mitochondrial membrane polarization, cytochrome c release, lysosomal rupture, and AT II cells apoptosis. Increased apoptosis was prevented by specific inhibition of the caspase cascade using the broad‐spectrum caspase inhibitor z‐VAD‐fmk or a caspase 3 inhibitor, or by using functional inhibitors for cathepsin D (pepstatin A) or cathepsin B. Inhibition of cathepsin D also prevented mitochondrial permeabilization and cythocrome c release suggesting that lysosomal rupture precedes and is necessary for the activation of the mitochondrial pathway of cell death. © 2004 Wiley‐Liss, Inc.
Quintessential PBDs and PBDs with prime power block sizes ≥ 8
Authors: Abel R. J. R. , Bennett F. E.
Published: November 2004

In this paper, we look at the existence of (v K) pairwise balanced designs (PBDs) for a few sets K of prime powers ≥ 8 and also for a number of subsets K of {5, 6, 7, 8, 9}, which contain {5}. For K = {5, 7}, {5, 8}, {5, 7, 9}, we reduce the largest v for which a (v, K)‐PBD is unknown to 639, 812, and 179, respectively. When K is Q≥8, the set of all prime powers ≥ 8, we find several new designs for 1,180 ≤ v ≤ 1,270, and reduce the largest unsolved case to 1,802. For K =Q0,1,5(8), the set of prime powers ≥ 8 and ≡ 0, 1, or 5 (mod 8) we reduce the largest unknown case from 8,108 to 2,612. We also obtain slight improvements when K is one of {8, 9} or Q0,1(8), the set of prime powers ≡ 0 or 1 (mod 8). © 2004 Wiley Periodicals, Inc.
Fair trade coffee: building producer capacity via global networks
Authors: Raynolds Laura T. , Murray Douglas , Leigh Taylor Peter
Published: November 2004

This article examines the ongoing rapid expansion in Fair Trade coffee networks linking Northern consumers with producers in the global South. We provide a comparative analysis of the experiences of seven coffee producer co‐operatives in Latin America, identifying the characteristics which facilitate successful integration into Fair Trade networks. Our analysis finds that coffee organizations, communities and producers derive important material and non‐material benefits from Fair Trade. We conclude that while the financial benefits of Fair Trade appear the most important in the short run, it is the capacity building nature of Fair Trade that will prove the most important in fueling sustainable development in the long run. Copyright © 2004 John Wiley & Sons, Ltd.