bluuebunny/crossref_metadata_2025 huggingface dataset:
Albinism andHermansky‐Pudlak Syndrome
Authors: King Richard A. , Summers C. Gail
Published: January 2005

The term albinism refers to a group of congenital genetic abnormalities resulting from an inability of the pigment cell (melanocyte) to synthesize normal amounts of melanin pigment and is produced by mutations in at least 12 genes. Reduced melanin synthesis in the melanocytes of the skin, hair, and eyes produces oculocutaneous albinism, while a reduction primarily involving the retinal pigment epithelium produces ocular albinism. Hermansky‐Pudlak syndrome includes the triad of oculocutaneous albinism, a mild bleeding diathesis, and a ceroid storage disease affecting primarily the lungs and the gut. Oculocutaneous albinism is the most common inherited disorder of generalized hypopigmentation, with an estimated frequency of 1 in 20,000 in most populations. It has been described in all ethnic groups and in all animal species making it one of the most widely distributed genetic abnormalities in the animal kingdom. Ocular albinism is less common with an estimated frequency of 1 in 50,000 to 1 in 60,000. It is X‐linked. Hermansky‐Pudlak syndrome is a rare condition in most populations. In the Puerto Rican population, however, two forms are found with type 1 having an estimated frequency of approximately 1 in 1800.
Arthrogryposis
Authors: Hall Judith G.
Published: January 2005

Arthrogryposis, or multiple congenital contractures, is relatively common, affecting one child in 3000. The challenge is to determine the specific diagnosis. Congenital contractures occur because of decreased fetal movement. The longer the reduction or lack of movement, the more severe the contractures. Decreased fetal movement occurs on the basis of abnormalities of brain, muscle, nerve, connective tissue, lack of space, maternal illness, environmental agents, or vascular compromise. Therapy may differ depending on the limb positioning and diagnosis.
ATR‐X
Authors: Gibbons Richard J.
Published: January 2005

In ATR‐X syndrome severe mental retardation is found in association with characteristic facial dysmorphism, genital abnormalities, and a variety of other congenital anomalies. Many affected individuals have α thalassemia, which arises because of a transcription defect in the synthesis of the α‐globin chains of adult hemoglobin (HbA, α2β2). ATR‐X results from mutation of a putative chromatin remodeling factor encoded by a gene,ATRX, on the X chromosome. The features of this syndrome indicate the importance of this gene product in the efficient transcription of an extensive repertoire of genes.
Fetal Alcohol Syndrome and Fetal Alcohol Spectrum Disorder
Authors: Chudley Albert E. , Longstaffe Sally E.
Published: January 2005

Fetal alcohol spectrum disorder is an “umbrella” term that describes the spectrum of ethanol teratogenesis in humans. At one end of the spectrum are the subset of individuals with fetal alcohol syndrome, and at the other end of the spectrum are those individuals with behavioral and cognitive deficits who exhibit minimal or no physical stigmata as a consequence of ethanol‐induced prenatal brain injury. It was not until the past 3 decades that the medical community was convinced of the devastating effects of excessive alcohol use in pregnancy on the children. Although the diagnosis of fetal alcohol syndrome and its spectrum is a medical diagnosis, its effects on society are far‐reaching. Fetal alcohol spectrum disorder is distinct from many genetic syndromes described in this book in that the disorder is potentially entirely preventable, and the diagnosis points toward two affected individuals: the drinking mother and the alcohol‐exposed child. Diagnosis, intervention, and prevention offer some of the greatest challenges to health care providers, families, and their communities. Multidisciplinary diagnostic teams are developing throughout North America and other parts of the world that provide accurate and comprehensive assessments and treatment options for affected individuals with this common disorder.
FragileXSyndrome
Authors: Hagerman Randi J.
Published: January 2005

Fragile X syndrome is the most common inherited cause of mental retardation. It is caused by a trinucleotide repeat expansion of three bases that occurs in the fragile X mental retardation 1 gene (FMR1) at Xq27.3. A small expansion, or premutation, has approximately 55–200 CGG repeats and is usually not associated with cognitive deficits. However, a larger expansion or full mutation, greater than 230 CGG repeats, is associated with fragile X syndrome and is associated with typical features such as a long face, prominent ears, macroorchidism, and intellectual deficit. When a full mutation is present, the gene becomes methylated and is not expressed. The overall prevalence in males and females may be as high as 1 in 2000 to 1 in 3000. The spectrum of clinical involvement of fragile X syndrome is quite broad. Classical physical features include large or prominent ears, a long face, high‐arched palate, prognathism in older individuals, hyperextensible finger joints, subluxable thumbs, mitral valve prolapse, large testicles, flat feet, and soft velvet‐like skin.
Holoprosencephaly
Authors: Gropman Andrea L. , Muenke Maximilian
Published: January 2005

Holoprosencephaly is the most common developmental defect of the brain and is characterized by failure of the forebrain to divide into two separate hemispheres and ventricles. It encompasses a spectrum of brain malformations along a continuum based on the degree of nonseparation of the hemispheres that includes alobar, semilobar, and lobar holoprosencephaly and syntelencephaly or middle interhemispheric variant. The distinction between these types is not absolute with gradations occurring. Midline craniofacial anomalies, developmental disability, neurologic problems, especially seizures and endocrine and feeding problems are common. Holoprosencephaly occurs as frequently as 1 in 250 in embryos and 1 in 10,000 to 1 in 20,000 live births. Holoprosencephaly is etiologically extremely heterogeneous. Multiple genes contribute to the phenotype. Of live‐born children with holoprosencephaly, up to one half have an associated cytogenetic abnormality, the most common of which is trisomy 13. Teratogens have been linked, particularly maternal diabetes. There are several lines of evidence linking defective cholesterol biosynthesis and holoprosencephaly.
Osteogenesis Imperfecta
Authors: Marini Joan C. , Letocha Anne D. , Chernoff Edith J.
Published: January 2005

Osteogenesis imperfecta is an autosomal dominant disorder of connective tissue, commonly known as “brittle bone disease.” The frequency of osteogenesis imperfecta identifiable at birth is estimated to be between 1 in 20,000 and 1 in 30,000. Osteogenesis imperfecta is characterized by bone fragility; affected individuals sustain fractures after very mild trauma. Because osteogenesis imperfecta is a generalized connective tissue disorder, other typical features include blue sclerae, dentinogenesis imperfecta, hearing loss, cardiopulmonary abnormalities, easy bruisability, excessive sweating, and loose joints. Current therapeutic management is discussed.
Proteus Syndrome
Authors: Biesecker Leslie G.
Published: January 2005

Proteus syndrome is a disorder of segmental or mosaic overgrowth that can affect any tissue. The most common complications include overgrowth that can lead to orthopedic complications, soft tissue overgrowth of the feet, linear nevi, vascular malformations, and tumor predisposition. All confirmed cases are sporadic, and it has been hypothesized that the disorder is caused by a postzygotic mutation in a growth‐promoting gene. Proteus syndrome is rare and overdiagnosed. There are fewer than 100 documented cases in the literature, and many people who carry the diagnosis cannot be confirmed as affected when published diagnostic criteria are rigorously applied.
Rett Syndrome
Authors: Smeets Eric E. , Schrander‐Stumpel Connie T. R. M.
Published: January 2005

Rett syndrome is a neurodevelopmental disorder related to a defective protein involved in the transcription of methylated deoxyribonucleic acid (DNA). It affects almost exclusively girls. The causative gene has been identified (MECP2). The diagnosis is made clinically, based on internationally accepted criteria that were recently revised. More than 95% of theMECP2mutations occurde novo.An 80% mutation detection rate occurs in individuals with classical Rett syndrome when standard techniques are used to analyze the coding region. In variant Rett syndrome the likelihood of finding a mutation is lower. Early intervention and comprehensive life‐long management of Rett syndrome can significantly improve the health and longevity of affected individuals. Management is optimized by involvement of a multidisciplinary team consisting of many different medical and paramedical specialists and an individualized approach. Parents are an integral part of the team, as they become the greatest experts concerning their affected child's history, behavior, and needs.
Velo‐Cardio‐Facial Syndrome
Authors: Shprintzen Robert J.
Published: January 2005

Velo‐cardio‐facial syndrome is the most common contiguous gene syndrome in humans. It has very variable phenotypes but involves the heart, face, palate, and vasculature in the large majority of affected individuals. Behavioral abnormalities, including learning disabilities and psychiatric symptoms, are common. Velo‐cardio‐facial syndrome is caused by a microdeletion of chromosome 22q11.2.
W
agr Syndrome
Authors: Clericuzio Carol L.
Published: January 2005

The WAGR syndrome is a multiple congenital anomaly–mental retardation syndrome caused by interstitial deletion of the distal portion of chromosome 11p13. It is a contiguous gene deletion syndrome, and WAGR is an acronym for the primary features: W for
W
ilms tumor, A for
a
niridia, G for
g
enital anomalies, and R for mental
r
etardation. Wilms tumor and male genital anomalies are caused by deletion of the
WT1
tumor‐suppressor gene, and aniridia is caused by deletion of
PAX6
ocular developmental gene. Mental retardation is presumed to be a consequence of deletion of multiple as yet unidentified genes in the region. Most cases are identified by chromosome studies of children with sporadic aniridia and are due to
de novo
deletions of 11p13, although a few familial translocations are reported. Individuals with the WAGR syndrome have a high risk for developing Wilms tumor and late‐onset renal failure, and should be monitored for these complications.
Williams Syndrome
Authors: Morris Colleen A.
Published: January 2005

Williams syndrome has been variably been termed Williams‐Beuren syndrome, idiopathic hypercalcemia, and supravalvar aortic stenosis syndrome. It is estimated to occur in 1 in 10,000 births. The diagnosis of Williams syndrome is based upon recognition of the characteristic pattern of dysmorphic facial features, developmental delay, short stature relative to the family background, connective tissue abnormality, unique cognitive profile, and typical personality that includes empathy, overfriendliness, attention problems, and anxiety. This disorder is caused by a submicroscopic deletion of chromosome 7q11.23, which arises by unequal crossing over in a chromosome region where there are a large number of repetitive deoxyribonucleic acid (DNA) sequences. The commonly deleted region is approximately 1.5 megabases (Mb), and 21 genes have thus far been mapped within it. Many of the manifestations of Williams syndrome are caused by deletion of the elastin gene.
Wolf‐Hirschhorn (4p‐) Syndrome
Authors: Battaglia Agatino
Published: January 2005

Wolf‐Hirschhorn syndrome is a multiple congenital anomalies/mental retardation disorder due to deletion of the short arm of chromosome 4. A more complete delineation of the phenotype and better definition of this condition has only been possible in the last two decades. Until recently, it was commonly stated that development is severely compromised in affected individuals, and only recent large studies have allowed recognition of a much wider clinical spectrum.
Guanidinoacetate methyltransferase deficiency identified in adults and a child with mental retardation
Authors: Araújo H. Caldeira , Smit W. , Verhoeven N.M. , Salomons G.S. , Silva S. , Vasconcelos R. , Tomás H. , Almeida I. Tavares de , Jakobs C. , Duran M.
Published: January 2005

Our study describes the adult clinical and biochemical spectrum of guanidinoacetate methyltransferase (GAMT) deficiency, a recently discovered inborn error of metabolism. The majority of the previous reports dealt with pediatric patients, in contrast to the present study. A total of 180 institutionalized patients with a severe mental handicap were investigated for urine and plasma uric acid and creatinine. Patients with an increased urinary uric acid/creatinine ratio and/or decreased creatinine were subjected to the analysis of guanidinoacetate (GAA). Four patients (three related and one from an unrelated family) were identified with GAMT‐deficiency. A fifth patient had died before a biochemical diagnosis could be made. They all had shown a normal psychomotor development for the first year of life, after which they developed a profound mental retardation. Three out of four had convulsions and all four totally lacked the development of speech. Their GAMT activity in lymphoblasts was impaired and two novel mutations were identified: the 59 G > C and 506 G > A missense mutations. Urinary GAA was increased, but highly variable 347–1,624 mmol/mol creat (Controls <150 mmol/mol creat). In plasma and CSF the GAA levels were fairly constant at 17.3–27.0 μmol/L (Controls 1.33–3.33) and 11.0–12.4 μmol/L, respectively (Controls 0.068–0.114). GAMT deficiency in adults is associated with severe mental retardation and absence or limited speech development. Convulsions may be prominent. The nonspecific nature of the clinical findings as well as the limited availability of GAA assays and/or in vivo magnetic resonance spectroscopy of the brain may mean that many more patients remain undiagnosed in institutions for persons with mental handicaps. © 2005 Wiley‐Liss, Inc.
Recent developments in the radiation grafting of N‐vinyl‐2‐pyrrolidone onto low‐density polyethylene with cinnamonitrile derivatives
Authors: Elassar Abdel‐Zaher A. , El‐Sawy Naeem M.
Published: January 2005

The radiation‐induced graft polymerization of N‐vinyl‐2‐pyrrolidone onto low‐density polyethylene films was conducted with γ radiation by a simultaneous technique. The grafted copolymer was modified with cinnamonitrile or benzylidene malononitrile. The modified and grafted films were amidoximated with hydroxylamine hydrochloride in a basic medium. However, during amidoximation, the benzylidene malononitrile was cyclized to yield isoxazole ring through an addition to the nitrile group in its structure, whereas the nitrile groups of cinnamonitrile were converted into amidoxime groups. The swelling behavior of the grafted copolymers and copolymers grafted and modified either with cinnamonitrile or benzylidene malononitrile was studied. Amidoximated and grafted films and copolymer–metal complexes of Cu(II) were prepared and characterized. The effect of the isoxazole ring on polymeric materials was also investigated. These films were characterized with different analysis techniques, such as infrared, ultraviolet (UV), elemental analysis, energy‐dispersive spectroscopy, and electron spin resonance (ESR). The UV and ESR analyses revealed that the geometric structure of Cu(II) was square‐planar. Scanning electron microscopy was used to examine the grafted and modified films to determine the changes in the surface morphology. Morphological changes clearly appeared for both complexed and isoxazole films because of the increase in their crystallinity. The thermal stability of different films was investigated with thermogravimetric analysis. The improvement of the copolymer by modification with cinnamonitrile derivatives showed great promise for some practical applications, such as metal recovery by complexation or the use of isoxazole in medicine. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1189–1197, 2005
The performances of BMI nanocomposites filled with nanometer SiC
Authors: Yan Hongxia , Ning Rongchang , Liang Guozheng , Ma Xiaoyan
Published: January 2005

Nanocomposites of bismaleimide (BMI) with different proportions of nanometer SiC were prepared by a high shear dispersion process and casting method at elevated temperature. The mechanical and tribological properties of the nanocomposites were investigated. The bending strength and impact strength of the nanocomposite specimens were determined, and the sliding wear performance of the nanocomposites was investigated on an M‐200 friction and wear tester. The dispersion of nanometre SiC was observed with a transmission electron microscope (TEM), while those of the worn surfaces and transfer films on the counterpart steel ring were observed with a scanning electron microscope (SEM). The experimental results indicate that the nanocomposites exhibited lower friction coefficient and wear loss as well as higher bending and impact strength than BMI resin under the same testing conditions. The lowest wear rate was obtained with the nanocomposite containing 6.0 wt % SiC, while the highest mechanical properties were obtained with the nanocomposite containing 2.0 wt % SiC. The wear mechanism of the nanocomposite is mainly adhesion wear, while that of pure BMI resin is mainly fatigue cracking with plastic deformation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1246–1250, 2005
Rigid nonproteinogenic cyclic amino acids as ligands for glutamate receptors: trans‐Tris(homoglutamic) acids
Authors: Meyer Udo , Bisel Philippe , Bräuner‐Osborne Hans , Madsen Ulf , Höfner Georg , Wanner Klaus Th. , Frahm August Wilhelm
Published: January 2005

The second‐generation asymmetric synthesis of the trans‐tris(homoglutamic) acids reported herein proceeds via Strecker reaction of chiral ketimines, obtained from condensation of racemic 2‐ethoxycarbonylmethylcyclopentanone and commercially available (S)‐ and (R)‐1‐phenylethylamine, respectively. In the key stereodifferentiating step, the cyanide addition leads to mixtures of diastereomeric α‐amino nitrile‐esters, the composition of which is independent of the reaction temperature and the type of the solvent, respectively. Hydrolysis of the α‐amino nitrile‐esters with concentrated H2SO4 yielded diastereomeric mixtures of secondary α‐amino amido‐esters, which after separation were hydrogenolyzed and hydrolyzed each to the enantiomeric trans‐1‐amino‐2‐carboxymethylcyclopentanecarboxylic acids. Their configuration was completely established by NMR methods, CD spectra, and X‐ray analysis of the trans‐1S,2R‐configured secondary α‐amino amido‐ester. In receptor binding assays and functional tests, trans‐1S,2R‐1‐amino‐2‐carboxymethylcyclopentanecarboxylic acid hydrochloride was found to behave as a selective mGluR2‐antagonist without relevant binding properties at iGluRs. Chirality 17:99–107, 2005. © 2005 Wiley‐Liss, Inc.
Skin‐sparing mastectomy and immediate reconstruction is an acceptable treatment option for patients with high‐risk breast carcinoma
Authors: Downes Kevin J. , Glatt Brian S. , Kanchwala Suhail K. , Mick Rosemarie , Fraker Douglas L. , Fox Kevin R. , Solin Lawrence J. , Bucky Louis P. , Czerniecki Brian J.
Published: January 2005

BACKGROUND

Skin‐sparing mastectomy (SSM) followed by immediate reconstruction is an effective treatment option for patients with early‐stage breast carcinoma, but its use in patients with more advanced disease is controversial.

METHODS

A retrospective review was performed that included 38 consecutive patients with high‐risk breast carcinoma who underwent SSM and immediate reconstruction (between July 1996 and January 2002). Tumor characteristics, type of reconstruction, margin status, timing of adjuvant therapy, postoperative complications, and incidence of recurrence were evaluated.

RESULTS

High‐risk patients (Stage IIA [n = 4 patients] Stage IIB [n = 23 patients] Stage IIIA [n = 8 patients] and Stage IIIB [n = 3 patients]) underwent immediate reconstruction after SSM with the use of a transverse rectus abdominis myocutaneous flap (n = 31 patients), a latissimus dorsi myocutaneous flap plus an implant (n = 3 patients), or tissue expanders with subsequent implant placement (n = 4 patients). The median follow‐up was 52.9 months (range, 27.5–92.0 months), and the median time to recurrence has not yet been reached at the time of last follow‐up. The median interval from surgery to the initiation of postoperative adjuvant therapy was 38 days (range, 25–238 days). Local recurrence was seen in 1 patient (2.6%), systemic recurrence in was seen in 10 patients (26.3%), and both local and distant metastases in were seen in 2 other patients (5.3%).

CONCLUSIONS

SSM with immediate reconstruction appeared to be an oncologically safe treatment option for high‐risk patients with advanced stages of breast carcinoma. In addition to the aesthetic and psychological benefits of performing SSM with immediate reconstruction, local recurrence rates and disease‐free survival were favorable when combined with the use of radiation therapy and adjuvant chemotherapy, as indicated. Cancer 2005. © 2005 American Cancer Society.
Survival in prostate carcinoma—Outcomes from a prospective, population‐based cohort of 8887 men with up to 15 years of follow‐up
Authors: Aus Gunnar , Robinson David , Rosell Johan , Sandblom Gabriel , Varenhorst Eberhard
Published: January 2005

BACKGROUND

To decide on screening strategies and curative treatments for prostate carcinoma, it is necessary to determine the incidence and survival in a population that is not screened.

METHODS

The 15‐year projected survival data were analyzed from a prospective, complete, population‐based registry of 8887 patients with newly diagnosed prostate carcinoma from 1987 to 1999.

RESULTS

The median patient age at diagnosis was 75 years (range, 40–96 years), and 12% of patients were diagnosed before the age 65 years. The median follow‐up was 80 months for patients who remained alive. In total, 5873 of 8887 patients (66.1%) had died, and 2595 of those patients (44.2%) died directly due to prostate carcinoma. The overall median age at death was 80 years (range, 41–100 years). The projected 15‐year disease‐specific survival rate was 44% for the whole population. In total, 18% of patients had metastases at diagnosis (M1), and their median survival was 2.5 years. Patients with nonmetastatic T1–T3 prostate carcinoma (age < 75 years at diagnosis; n = 2098 patients) had a 15‐year projected disease‐specific survival rate of 66%. Patients who underwent radical prostatectomy had a significantly lower risk of dying from prostate carcinoma (relative risk, 0.40) compared with patients who were treated with noncurative therapies or radiotherapy.

CONCLUSIONS

The disease‐specific mortality was comparatively high, but it took 15 years to reach a disease‐specific mortality rate of 56%. These data form a truly population‐based baseline on how prostate carcinoma will affect a population when screening is not applied and can be used for comparison with other health care strategies. Cancer 2005. © 2005 American Cancer Society.
Incidence of noncutaneous melanomas in the U.S.
Authors: McLaughlin Colleen C. , Wu Xiao‐Cheng , Jemal Ahmedin , Martin Howard J. , Roche Lisa M. , Chen Vivien W.
Published: January 2005

BACKGROUND

Description of the epidemiology of noncutaneous melanoma has been hampered by its rarity. The current report was the largest in‐depth descriptive analysis of incidence of noncutaneous melanoma in the United States, using data from the North American Association of Central Cancer Registries.

METHODS

Pooled data from 27 states and one metropolitan area were used to examine the incidence of noncutaneous melanoma by anatomic subsite, gender, age, race, and geography (northern/southern and coastal/noncoastal) for cases diagnosed between 1996 and 2000. Percent distribution by stage of disease at diagnosis and histology were also examined.

RESULTS

Between 1996 and 2000, 6691 cases of noncutaneous melanoma (4885 ocular and 1806 mucosal) were diagnosed among 851 million person‐years at risk. Ocular melanoma was more common among men compared with women (6.8 cases per million men compared with 5.3 cases per million women, age‐adjusted to the 2000 U.S. population standard), whereas mucosal melanoma was more common among women (2.8 cases per million women compared with 1.5 cases per million men). Rates of ocular melanoma among whites were greater than eight times higher than among blacks. Rates of mucosal melanoma were approximately two times higher among whites compared with blacks.

CONCLUSIONS

In contrast to cutaneous melanoma, there was no apparent pattern of increased noncutaneous melanoma among residents of southern or coastal states, with the exception of melanoma of the ciliary body and iris. Despite their shared cellular origins, both ocular and mucosal melanomas differ from cutaneous melanoma in terms of incidence by gender, race, and geographic area. Cancer 2005. © 2005 American Cancer Society.
A low‐loss snubber for reducing motor terminal surge voltage
Authors: Kon Hironobu
Published: January 2005

The development of an advanced Insulated Gate Bipolar Transistor (IGBT) has enabled high‐frequency switching operation and has improved the performance of PWM inverters for motor drive. However, the IGBT's high rate ofdv/dthas adverse effects on motor insulation stress. In many motor drive applications, the inverter and motor are separated, requiring long motor feeds. The long cable contributes high‐frequency ringing at the motor terminal and results in high surge voltage which stresses the motor insulation. The inverter output filter and RDC snubber are the conventional method for reducing the surge voltage.

In this paper, we propose a new low‐loss snubber to reduce the motor terminal surge voltage. The snubber consists of the series connection of chraging/discharging capacitor and the voltage‐clamped capacitor. At IGBT turn‐off, the snubber starts to operate when the IGBT voltage reaches the voltage‐clamped level. Sincedv/dtis decreased by snubber operating, the peak level of the surge voltage can be reduced. Also the snubber operates at the IGBT voltage above the voltage‐clamped level, and the snubber loss is largely reduced compared with the RDC snubber. The proposed snubber enables reduction of the motor terminal surge voltage with low loss. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 64–72, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10378
Analysis of biological motors via multidimensional fractionation: A strategy
Authors: Serwer Philip
Published: January 2005

Past strategies for the analysis of ATP‐fueled motors include single‐motor analysis. Single‐motor analysis bypasses limitations caused by motor asynchrony during the traditional ensemble averaging analysis. The present communication describes revised ensemble averaging analysis that also can bypass asynchrony‐derived limitations. This revised analysis makes measurements of one motor variable dependent on the others. One example is nondenaturing gel electrophoresis with more than one dimension. Each dimension measures one of the motor variables. This multidimensional procedure is used to obtain the values of “conformational” motor variables as a function of a “clock” motor variable. In theory, the cycle of the motor can be analyzed from a single multidimensional analysis of a collection of asynchronous motors sampled at only one time. That is to say, motor asynchrony becomes an asset, rather than a liability.
The efficiency of electrokinetic pumping at a condition of maximum work
Authors: Griffiths Stewart K. , Nilson Robert H.
Published: January 2005

Numerical methods are employed to examine the work, electric power input, and efficiency of electrokinetic pumps at a condition corresponding to maximum pump work. These analyses employ the full Poisson‐Boltzmann equations and account for both convective and conductive electric currents, including surface conductance. We find that efficiencies at this condition of maximum work depend on three dimensionless parameters, the normalized zeta potential, normalized Debye layer thickness, and a fluid property termed the Levine number indicating the nominal ratio of convective to conductive electric currents. Efficiencies at maximum work exhibit a maximum for an optimum Debye layer thickness when the zeta potential and Levine number are fixed. This maximum efficiency increases with the square of the zeta potential when the zeta potential is small, but reaches a plateau as the zeta potential becomes large. The maximum efficiency in this latter regime is thus independent of the zeta potential and depends only on the Levine number. Simple analytical expressions describing this maximum efficiency in terms of the Levine number are provided. Geometries of a circular tube and planar channel are examined.
A triple‐injection method for microchip electrophoresis
Authors: Tabuchi Mari , Baba Yoshinobu
Published: January 2005

We report here a novel triple injection method for microchip electrophoresis (µ‐CE) that results in a higher intensity of DNA peaks. This new method includes a triple‐repeated process of a combination of a sample loading voltage and a separation voltage in each interval, namely (loading time) + (separation time) + (loading time) + (separation time) + (loading time), prior to electrophoretic separation. All these injections were electrokinetically controlled by a software. Although the usual sample injection, which included the process of one 60 s electrokinetically application, was limited by the amount of sample, peaks of 40% higher intensity were obtained using the new method within half of the conventional injection time compared to the conventional method. Maximum peak intensity was successfully achieved with integration of the intensities of the triple‐repeated peaks by adjusting the application period of the separation voltage. Repetition of the sample loading voltage for an adjusted period with a further adjusted period of separation voltage in each interval may be an effective method for injection of samples that results in peaks with higher intensity.
System zones in capillary zone electrophoresis: Moving boundaries caused by freely migrating hydrogen ions
Authors: Beckers Jozef L. , Boček Petr
Published: January 2005

We demonstrate that system zones (SZs) can be expected in background electrolytes (BGEs) with a low buffer capacity. The mobilities of this type of SZ (mSZ) could be determined by calculations both based on a mathematical model and by a simulation program. The values of mSZ are increasing for decreasing buffer capacities and lower concentrations of the BGEs. For completely unbuffered BGEs with a pH below 7, the mSZ reached values up to 350×10−9 m2V−1s−1. This value indicates that the existence of this type of SZ originates from migrating hydrogen ions. Although both the mathematical model and simulation program do not consider the influence of the pH of the sample solution, experiments have shown that the pH of the sample solution is also very important. The lower the pH of the sample solution, the larger the mSZ in a specific BGE for cationic SZs. Using completely unbuffered BGEs the hydrogen ions present in the original sample start to migrate freely through the capillary tube with the mobility of a single hydrogen ion and cause stepwise disturbances in the base line of the detector trace. It is remarkable that this type of SZ appears not to affect the electromigration dispersion (EMD) in a strong way and so far only dips could be obtained experimentally.
Large‐volume stacking in capillary electrophoresis using pH hysteresis of the electroosmotic flow in a bare fused‐silica capillary
Authors: Han Ji Hye , Chun Man‐Seog , Riaz Asif , Chung Doo Soo
Published: January 2005

For large‐volume stacking with the electroosmotic flow pump (LVSEP) in capillary electrophoresis of anionic analytes it is required that the electroosmotic mobility (EOM) should be smaller than the magnitudes of the effective mobilities of the analytes. When a fused‐silica capillary is treated with an acidic solution, the silanoate group on the silica surface is neutralized to silanol and the EOM is suppressed. Due to the slow deprotonation equilibrium of the silanol group at an intermediate pH, this reduced EOM can be retained during a number of electrophoresis runs. Using a bare fused‐silica capillary preconditioned with 0.01  M HCl, successful LVSEP at pH 6.0 was achieved for weakly acidic compounds with two orders of magnitude enhancements in the concentration sensitivity. The repeatability in migration times of ten analytes stacked by LVSEP in a single day was excellent with the relative standard deviation (RSD) less than 1% (n = 6). The day‐to‐day repeatability was also excellent with RSD less than 3% (n = 3×6) when the capillary was preconditioned each day.
Performance evaluation of shear links and orthotropic bridge deck panels for the new San Francisco–Oakland Bay Bridge
Authors: Uang Chia‐Ming , Seible Frieder , McDaniel Cole , Chou Chung‐Che
Published: January 2005

This paper presents results from testing and the associated analytical studies of steel shear links and orthotropic bridge decks to support the design of the new East Span for the San Francisco–Oakland Bay Bridge. Cyclic testing of full‐scale built‐up links showed that the specimens were able to reach an inelastic rotation more than twice that which would be produced from a 1500‐year Safety Evaluation Earthquake event. Nevertheless, brittle fracture occurred before the inelastic design rotation capacity, as specified in the AISC Seismic Provisions, was developed. Based on a parametric study, a modification to the welding details was proposed, which proved to be effective in preventing this type of fracture in a subsequent testing program. Monotonic testing of two reduced‐scale orthotropic bridge deck panels, one stiffened with closed ribs and another one with open ribs, also showed that these specimens could develop a compression capacity greater than that which would be produced by the design earthquake. The post‐buckling behavior was associated with the buckling direction and the type of ribs. Copyright © 2005 John Wiley & Sons, Ltd.
The origin and development of the african evaluation guidelines
Authors: Rouge Jean‐Charles
Published: January 2005

A description of the complex geographical and cultural context of the African Evaluation Guidelines, with special emphasis on the role of the African Evaluation Association, is followed by a discussion of the development of the guidelines, their implementation,
and use.
Vibrational computations beyond the harmonic approximation: Performances of the B3LYP density functional for semirigid molecules
Authors: Carbonniere Philippe , Lucca Tecla , Pouchan Claude , Rega Nadia , Barone Vincenzo
Published: January 2005

The performances of the B3LYP density functional in the computation of harmonic and anharmonic frequencies were tested using 14 standard basis sets of double and triple zeta quality for a set of semirigid molecules containing from 4 to 12 atoms. The quality of the results is assessed by comparison with the most reliable computations available in the literature. The study reveals that the relatively cheap 6‐31+G(d,p) basis set performs a very good job for harmonic frequency calculations and that B3LYP anharmonicities are in close agreement with the reference values irrespective of the basis set used. On these grounds “hybrid force fields” are proposed to achieve the best compromise between computer time and quality of the results. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 384–388, 2005
The Influence of the Rubber Carboxyl Functionality on the Processability and Properties of Solid Rubber Modified Epoxy Mixtures
Authors: Dispenza Clelia , Spadaro Giuseppe , McGrail Patrick T.
Published: January 2005

Summary: A high molecular weight, carboxyl functionalised solid rubber was added to an epoxy resin‐aromatic amino system developed for autoclave curing of honeycomb core composite structures. The achievement of an optimal balance of viscous flow and viscoelasticity of the resin, by controlling the nature and extent of cross‐linking of the functionalised rubber, was proposed as a route to void‐free honeycomb skins. The aim of the present investigation is to understand how the concentration of carboxylic groups of the rubber, prereacted with one of the epoxy monomers, affects the matrix resin flow properties. The concentration of carboxyl groups was changed by reacting them with a monofunctional epoxy resin. Dynamic shear viscosity profiles varying frequency, temperature and as function of time during isothermal cure have been determined for blends with differently functionalised rubbers. Carbon fibre wettability and laminate consolidation quality have been evaluated, making composite samples according to conventional prepregging and autoclave curing processes, through electron microscopy of fracture surfaces from transverse flexural strength tests.

Loss factor and storage modulus from dynamic‐mechanical torsion analysis for PWE0 blend. Loss factor and storage modulus for Nipol 1072 are reported for comparison.

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Loss factor and storage modulus from dynamic‐mechanical torsion analysis for PWE0 blend. Loss factor and storage modulus for Nipol 1072 are reported for comparison.
Expandable Graphite Systems for Phosphorus‐Containing Unsaturated Polyester, 2
Authors: Shih Yeng‐Fong
Published: January 2005

Summary: A series of flame‐retardant‐containing unsaturated polyesters have been developed. The flame retardants include expandable graphite (EG) and phosphorous‐containing materials (ammonium polyphosphate (APP) and triphenyl phosphate (TPP)). The flame‐retardant properties of these samples were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), and UL‐94 tests. Moreover, the kinetic parameters of these flame‐retardant‐containing unsaturated polyesters were calculated by the Coats and Redfern method, the Ozawa method, and temperature modulated thermogravimetric analysis (MTGA). The differences and relationship among different analytical methodologies were investigated. Pyrolysis gas chromatography mass spectrometry (Py/GC/MS) was also used to investigate the pyrolysis products of the samples.

Activation energy vs. conversion curves for various samples (Ozawa method).

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Activation energy vs. conversion curves for various samples (Ozawa method).
Re‐Plasticization by Confinement During Annealing Induced Phase Separation in Polycarbonate/Phthalate Plasticized Films
Authors: Tuteja Bindu , Khan Ferdous , Sundararajan Pudupadi
Published: January 2005

Summary: It is common practice during the analysis using optical microscopy to place the sample on a microscope slide and cover it with a cover slide or another microscope slide. The sample is thus sandwiched or “confined” between two glass surfaces. Such a set up is used in all disciplines of science to study the changes in the structure and morphology of materials caused by annealing and other processes in situ. We describe a case of annealing induced phase separation in polycarbonate plasticized with diphenyl terephthalate and diphenyl isophthalate, which unexpectedly showed a significant difference between the confined configuration as defined above and the “unconfined” state. This was traced to the large depression of the melting point of the plasticizer in the polymer. When annealing was performed with the composite film confined between two glass slides, with the temperatures used here, the phase‐separated small molecule melts and re‐plasticizes the polymer. As a result, there was no increase (recovery) of the Tg of the polymer with annealing temperature. Such a confinement (or overcoating) could be a route to maintaining the Tg of the composite in multi‐layer devices, even if phase separation occurs during the operation of the device. However, when the covering glass slide was not used, sublimation of the plasticizer occurred, and the normal Tg recovery was seen. This is also the first reported case of re‐plasticization of the polymer upon annealing in such a confined state. We also note significant differences in the phase separation behaviour of the terephthalate and isophthalate configurations.

Optical micrographs of films annealed at 130 °C for 2 h: left: DPTP/BPAPC: 10/90, confined; right: DPTP/BPAPC: 10/90, unconfined.

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Optical micrographs of films annealed at 130 °C for 2 h: left: DPTP/BPAPC: 10/90, confined; right: DPTP/BPAPC: 10/90, unconfined.
Directly Fabricating Monolayer Nanoparticles on a Polymer Surface by UV‐Induced MMA/DVB Microemulsion Graft Polymerization
Authors: Wang Yongxin , Zhong Wenbin , Jiang Nan , Yang Wantai
Published: January 2005

Summary: A sequential two‐step method was successfully used for the photografting of methyl methacrylate/1,2‐divinylbenzene (MMA/DVB) microemulsion onto the surface of a poly(propylene) (PP) film. Atomic force microscopy (AFM) images showed that nanoparticles with a cross‐section diameter of 60 nm were directly grafted onto the substrate's surface. Environment scanning electron microscope (ESEM) images proved that the particles formed just a single layer on the surface. The dormant groups on the nanoparticles' surface were a potential factor in the evolution of single layer into multilayer nanoparticles.

The surface morphology of a PP film after being grafted with a MMA/DVB microemulsion. Nanoparticles (about 60 nm in size) are clearly tethered onto the substrate's surface with just one layer.

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The surface morphology of a PP film after being grafted with a MMA/DVB microemulsion. Nanoparticles (about 60 nm in size) are clearly tethered onto the substrate's surface with just one layer.
Myocytes positive for in situ markers for DNA breaks in human hearts which are hypertrophic, but neither failed nor dilated: a manifestation of cardiac hypertrophy rather than failure
Authors: Koda Masahiko , Takemura Genzou , Kanoh Motoo , Hayakawa Kenji , Kawase Yukinori , Maruyama Rumi , Li Yiwen , Minatoguchi Shinya , Fujiwara Takako , Fujiwara Hisayoshi
Published: January 2005

The significance of DNA breaks reported in failing hearts is controversial, although they may suggest myocyte apoptosis and may thus be responsible for the progression of heart failure. This study attempted to check the validity of the in situ markers for DNA breaks for detecting myocyte death and to evaluate separately two factors, failure or hypertrophy, crucial for DNA breaks in pathological human hearts. In the autopsy study, myocytes showed positivity for in situ nick end‐labelling (TUNEL) and of Taq and Pfu polymerase‐based in situ ligation assays not only in dilated cardiomyopathy (DCM, n = 9) with failure, but also in hypertrophic cardiomyopathy (HCM, n = 8) and hypertensive heart disease (HHD, n = 4) without failure. There was a significant correlation between each in situ marker and heart weight. The incidence of TUNEL‐positive myocytes always exceeded that seen in in situ ligation assays. In addition, there were significant correlations between the in situ markers and the expression of the proliferating cell nuclear antigen (PCNA) and of the spliceosome component of 35 kD (SC‐35). Similarly, in the left ventricular biopsy study using 23 DCM, 21 HCM, 11 HHD, and 13 non‐hypertrophic hearts, the incidence of the in situ markers showed significant correlations with the left ventricular mass index and myocyte size, but not with cardiac function and dilatation. Positivity of myocytes for in situ markers for DNA breaks, such as TUNEL and in situ ligation assays, may be an epiphenomenon accompanying cardiac hypertrophy, but not myocyte death in pathological human hearts. Copyright © 2003 John Wiley & Sons, Ltd.
Risk and protective factors for poor school adjustment in lesbian, gay, and bisexual (LGB) high school youth: Variable and person‐centered analyses
Authors: Murdock Tamera B. , Bolch Megan B.
Published: January 2005

This study examined the relations between school climate and school adjustment among 101 lesbian, gay, and bisexual (LGB) high school students and the moderating influence of social support on those relations. Students completed surveys to assess three aspects of the school climate (the school's exclusion/inclusion of LGB people, personal victimization in school for being LGB, and social support from teachers) as well as social support from family and close friends. Criterion variables were GPA, school belonging, and discipline problems. School climate variables explained significant amounts of variance in all criterion variables, after controlling for prior GPA, and there were no moderating effects of parent or friend support. Cluster analyses revealed one small group (n= 14) of highly vulnerable youth who were the least adjusted, most victimized, and least supported. Implications for teachers, counselors, and future research are discussed. © 2005 Wiley Periodicals, Inc. Psychol Schs 42: 159–172, 2005.
Synthesis and photochromic reaction of 1,2‐diphenylperfluorocyclopentenes
Authors: Takeshita Michinori , Ogawa Miwa , Miyata Keisuke , Yamato Takehiko
Published: January 2005

The synthesis and photochromic reaction of 1,2‐diphenylperfluorocyclopentenes are reported. Upon UV irradiation, hexane solutions of 1,2‐diphenylperfluorocyclopentenes afforded red solution of dihydrophenanthrenes, which gradually give the initial 1,2‐diphenylperfluorocyclopentenes at room temperature thermally or under irradiation with visible light. The activation energies for the thermal isomerization of the dihydrophenanthrenes are estimated. Copyright © 2003 John Wiley & Sons, Ltd.
Efficient room temperature continuous‐wave operation of an Yb3+:Sc2O3crystal laser at 1041.6 and 1094.6 nm
Authors: Liu J. , Rico M. , Griebner U. , Petrov V. , Peters V. , Petermann K. , Huber G.
Published: January 2005

An Yb‐doped Sc2O3crystal grown by the heat exchanger method provided extremely high pump (62.2%) and slope (72.7%) efficiencies in a continuous‐wave (cw) laser operating either at 1041.6 or 1094.6 nm depending on the output coupling. Maximum powers of 1.55 and 1.35 W, respectively, were achieved by Ti:sapphire laser pumping without special cooling. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local characteristics of the electronic structure of MgO: LCAO and plane‐wave calculations
Authors: Evarestov R. A. , Smirnov V. P. , Tupitsyn I. I. , Usvyat D. E.
Published: January 2005

Linear combinations of atomic orbitals and plane‐wave calculations of the electronic structure of the ionic crystal MgO were performed. Local characteristics of the electronic structure of this crystal are obtained using the traditional approaches and the method based on Wannier‐type atomic orbitals (WTAOs). It is demonstrated that the results of the conventional methods for chemical bonding analysis in MgO are contradictory and unreasonable. On the contrary, the results of the WTAO method for both types of the basis correctly exhibit the ionic nature of chemical bonding in this crystal. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
The Stark effect in atomic Rydberg states through a quantum defect approach
Authors: Menéndez J. M. , Martín I. , Velasco A. M.
Published: January 2005

A basis set of quantum defect orbitals (QDOs) has been adopted for the diagonalization of the Hamiltonian matrix of nonhydrogenic atoms in the presence of an external electric field, so that the Stark structure of the Rydberg states has been possible to determine. The presently obtained Stark maps are in excellent agreement with those resulting from theory and experiment, as reported in the literature for a few representative atoms. The adequacy of the Stark quantum defect orbital (SQDO) procedure for accurately dealing with properties related to the Stark effect in atoms is suggested. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005