bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterization of New Polyimides Containing Nitrile Groups
Authors: Li Li , Kikuchi Ryohei , Kakimoto Masa-Aki , Jikei Mitsutoshi , Takahashi Akio
Published: March 2005

Two new nitrile-containing diamine monomers, 4-[bis(4-aminophenyl)amino]benzonitrile and 4-[4-(1-cyanopropoxy)phenyl]2,6-bis(4-aminophenyl)pyridine were synthesized. The diamine monomers were reacted with various tetracarboxylic dianhydrides, followed by cyclodehydration (imidization) without isolation to produce a series of novel polyimides with pendant nitrile groups on the side chain. The polymers were obtained in quantitative yields with high molecular weight. Among them, polymers derived from ODPA and 6FDA showed good solubility, they could dissolve in polar solvents such as DMF, NMP, DMSO and even pyridine and m-cresol. These tough, transparent and flexible polyimide films had a tensile strength of 80–120 MPa, an elongation at break of 4–12% and a tensile modulus of 1.2–2.3 GPa. The polymers obtained exhibited high glass transition temperatures between 305 and 360 C. Moreover, they were fairly stable up to a temperature around or above 400 C and lost 10% weight in the range of 500–590 C and 470–580 C in nitrogen and air, respectively. Together the dielectric constants of the polyimides were measured to be 3.10–3.73 at 10 GHz. On the other hand, blank polyimides with no – CN groups were also prepared for comparison and the results revealed that the nitrile group affected the thermal property of polyimides as well as the electrical properties. Introduction of the –CN groups would increase the glass transition temperature and also the dielectric constant.
Preparation of Well-oriented Poly(p-phenylene pyromelliteimide) Fiber via Shear-induced Orientation of Poly(amic ethyl ester) Precursor during Polymerization
Authors: Zhuang Jin-Huang , Kimura Kunio , Xia Chu-E , Yamashita Yuhiko
Published: March 2005

The orientation of poly ( p-phenylene pyromelliteimide) (PPPI) molecules was examined by means of shearing during the gelation of poly(amic ethyl ester) (PAEE) precursor and thermal imidization. The polymerization of 1,4-phenylene diamine (PPDA) and 2,5-diethoxycarbonyl-1,4-benzenedicarbonyl chloride (DEBC), and that of N, N'-bis(trimethylsilyl)-1,4-phenylenediamine (N-silyl-PPDA) and DEBC yielded the PAEE gel during polymerization. With respect to the polymerization of PPDA and DEBC, 0.44 mol L-1 gave the highest DPn of PAEE at the gelation point, and the strong shear during gelation made the PAEE and ultimately PPPI molecular chains oriented in the planar mode. In contrast to this, the polymerization of N-silyl-PPDA and DEBC gave a higher DPn of PAEE at the gelation point than that of PPDA and DEBC. The strong shear stress applied to the PAEE gel, prepared at 0.50 mol L-1, induced the uni-axial orientation of the molecular chains, but the relaxation of the orientation occurred gradually with time. The addition of ethyl acetate to the gel prevented the relaxation of the chain orientation and accelerated the crystallization. As a result, uni-axial orientation of the PAEE molecular chains was induced along the shear direction in the gel rather than the planar mode, and ultimately the PPPI molecular chains were well-oriented.
Predictors of Violent Behavior in an Early Adolescent Cohort: Similarities and Differences Across Genders
Authors: Blitstein Jonathan L. , Murray David M. , Lytle Leslie A. , Birnbaum Amanda S. , Perry Cheryl L.
Published: March 2005

The authors assessed a cohort of 2,335 students from the Minneapolis, Minnesota, area to identify predictors of violent behavior and to determine whether the predictors varied by gender. The sample was 76% White; boys and girls were equally represented. The majority lived with two parents. A measure of violent behavior collected at the end of the eighth-grade year (2000) was entered into Poisson regression against baseline data collected at the beginning of the seventh-grade year (1998). Predictors of violent behavior influencing both boys and girls included depressive symptoms, perceived invulnerability to negative future events, paternal nonauthoritative behavior, and drinking alcohol. Additional predictors of violent behavior specific to girls included both risk and protective factors.
HIV Risk and Protection Among Gay Male Couples: The Role of Gay Community Integration
Authors: Fergus Stevenson , Lewis Megan A. , Darbes Lynae A. , Butterfield Rita M.
Published: March 2005

This study examined the association between different types of integration in the gay community and HIV risk among gay male couples. Previous research linking gay community integration and involvement among couples to HIV risk has been equivocal. Each partner in 59 gay couples completed a separate anonymous questionnaire that assessed two types of social involvement in the gay community, assimilation into the gay community, and sexual HIV risk behaviors. We used the actor-partner interdependence analysis approach, which maintains the couple as the unit of analysis while allowing for tests of within-couple, between-couple, actor, and partner effects. Analyses revealed that, controlling for symptoms of alcohol problems, going to gay bars and clubs independently predicted more HIV risk.
Development of Measures of Organizational Leadership for Health Promotion
Authors: Barrett Linda , Plotnikoff Ronald C. , Raine Kim , Anderson Donna
Published: March 2005

This study describes the development and psychometric evaluation of four scales measuring leadership for health promotion at an organizational level in the baseline survey ( n = 144) of the Alberta Heart Health Project. Content validity was established through a series of focus groups and expert opinion appraisals, pilot testing of a draft based on capacity assessment instruments developed by other provinces involved in the Canadian Heart Health Initiative, and the literature. Psychometric analyses provided empirical evidence of the construct validity and reliability of the organizational leadership scales. Principal component analysis verified the unidimensionality of the leadership scales of (a) Practices for Organizational Learning, (b) Wellness Planning, (c) Workplace Climate, and (d) Organization Member Development. Scale alpha coefficients ranged between .79 and .91 thus establishing good to high scale internal consistencies. These measures can be used by both researchers and practitioners for the assessment of organizational leadership for health promotion and heart health promotion.
Intention or Experience? Predictors of Continued Breastfeeding
Authors: DiGirolamo Ann , Thompson Nancy , Martorell Reynaldo , Fein Sara , Grummer-Strawn Laurence
Published: March 2005

Despite the known benefits of breastfeeding, many women do not breastfeed their infants or stop breastfeeding early. This study examines the effects of prenatal intention and initial breastfeeding experiences on breast-feeding initiation and duration among 1,665 U.S. women completing questionnaires on infant feeding practices. Outcomes included no initiation of breastfeeding at birth and termination at < 10 weeks, 10 to < 20 weeks, or 20 to < 30 weeks. Predictor variables included intended breast feeding duration and early breast feeding experiences with analyses controlling for demographic characteristics, previous breastfeeding experience, and prenatal intentions to work after delivery. Prenatal intentions to never initiate or to stop breastfeeding early were significant risk factors for all breastfeeding outcomes. Initial breastfeeding experiences were significant risk factors for early termination. This study supports using the intention construct from the theory of reasoned action to predict initiation of behavior but suggests the need to include initial experience when predicting maintenance of behavior.
Impact Analysis and Mediation of Outcomes: The Going Places Program
Authors: Simons-Morton Bruce , Haynie Denise , Saylor Keith , Crump Aria Davis , Chen Rusan
Published: March 2005

The purpose of the study was to evaluate the impact of the Going Places Program and mediation of treatment effects. Seven middle schools were randomized to intervention or comparison conditions and students ( n = 1,320) in two successive cohorts provided five waves of data from sixth through eighth grade. The Going Places Program included classroom curriculum, parent education, and school environment components. Latent growth curve analyses demonstrated significant treatment group effects on outcome expectancies, friends who smoke, and smoking. Friends who smoke mediated the program effect on adolescents’ smoking progression. The protective effect of the Going Places Program on smoking progression was due in part to the prevention of increases in friends who smoke.
Organ Donor Registration Preferences Among Hispanic Populations: Which Modes of Registration Have the Greatest Promise?
Authors: Siegel Jason T. , Alvaro Eusebio M. , Jones Sara Pace
Published: March 2005

There is little debate over Hispanics’ need for viable organs. Although organ donor registries can potentially assist in alleviating this need, the U.S. Department of Health and Human Services (DHHS) has called on researchers to investigate methods to maximize such potential. This research effort answers the aforementioned call by surveying Hispanics, both those who prefer to use Spanish (SP, n = 239) and those who prefer not to use Spanish (NSP, n = 364) about the methods of donor registration that they would most likely utilize. When provided with different options for organ donor registration, signing up by applying for a driver’s license, through a place of worship, or through a doctor’s office were among the most popular methods; over the telephone, tax forms, or through the use of home computer were among the least popular. Furthermore, the DHHS-suggested idea of registering via organ donor kiosks was very well received.
Healthy Eating and Exercise: Strategies for Weight Management in the Rural Midwest
Authors: Nothwehr Faryle , Peterson N. Andrew
Published: March 2005

Obesity prevalence has increased dramatically in the United States. Rural areas have been especially affected, yet few weight management studies have been conducted in these populations. This study was designed to assess weight management attitudes and strategies used when rural adults in particular attempt to lose weight, employing measures that are more specific than those reported in similar studies. The survey was completed by 123 adults aged 19 to 71, with a 29% response rate. Scales demonstrated good to excellent internal consistency, and test-retest reliability. Persons currently trying to lose weight were more likely to report self-monitoring behaviors and goal setting but no more likely to report use of specific behavioral strategies compared to persons not trying to lose weight. The results suggest considerable interest in weight management among rural adults and provide a starting point for planning future weight management interventions in this and similar populations.
Modeling Psychological Empowerment Among Youth Involved in Local Tobacco Control Efforts
Authors: Holden Debra J. , Evans W. Douglas , Hinnant Laurie W. , Messeri Peter
Published: March 2005

The American Legacy Foundation funded 13 state health departments for their Statewide Youth Movement Against Tobacco Use in September 2000. Its goal was to create statewide tobacco control initiatives implemented with youth leadership. The underlying theory behind these initiatives was that tobacco control efforts can best be accomplished by empowering youth. To evaluate these initiatives, the authors developed a conceptual framework for youth empowerment that was used as a guide in developing standardized cross-site measures. This article describes the domains and attributes used to operationalize psychological empowerment as an outcome of youth involvement in these initiatives and presents results of our two-stage structural equation modeling. We conclude with a summary of lessons learned to date and recommendations for applying these findings to work in the field.
Rapamycin selectively expands CD4+CD25+FoxP3+ regulatory T cells
Authors: Battaglia Manuela , Stabilini Angela , Roncarolo Maria-Grazia
Published: March 2005

Rapamycin is an immunosuppressive compound that is currently used to prevent acute graft rejection in humans. In addition, rapamycin has been shown to allow operational tolerance in murine models. However, a direct effect of rapamycin on T regulatory (Tr) cells, which play a key role in induction and maintenance of peripheral tolerance, has not been demonstrated so far. Here, we provide new evidence that rapamycin selectively expands the murine naturally occurring CD4+CD25+FoxP3+ Tr cells in vitro. These expanded Tr cells suppress proliferation of syngeneic T cells in vitro and prevent allograft rejection in vivo. Interestingly, rapamycin does not block activation-induced cell death and proliferation of CD4+ T cells in vitro. Based on this new mode of action, rapamycin can be used to expand CD4+CD25+FoxP3+ Tr cells for ex vivo cellular therapy in T-cell-mediated diseases. (Blood. 2005;105:4743-4748)
Telomere length as a prognostic parameter in chronic lymphocytic leukemia with special reference to VH gene mutation status
Authors: Grabowski Pawel , Hultdin Magnus , Karlsson Karin , Tobin Gerard , Åleskog Anna , Thunberg Ulf , Laurell Anna , Sundström Christer , Rosenquist Richard , Roos Göran
Published: March 2005

B-cell chronic lymphocytic leukemia (CLL) consists of 2 prognostic entities where cases with mutated immunoglobulin VH genes have better outcome than unmutated cases. VH-mutated CLLs display longer telomeres compared with unmutated cases and telomere length has been indicated to predict outcome, although the prognostic value of telomere length has not been fully established in CLL. We analyzed telomere length, VH gene mutation status, and clinical parameters in a large series of CLL. Telomere length was assessed by quantitative polymerase chain reaction (PCR), giving a very good correlation to telomere length estimated by Southern blotting (P < .001). The prognostic information given by mutation status (n = 282) and telomere length (n = 246) was significant (P < .001, respectively). Telomere length was a prognostic factor for stage A (P = .021) and stage B/C (P = .018) patients, whereas mutation status predicted outcome only in stage A patients (P < .001). Furthermore, mutated CLLs were subdivided by telomere length into 2 groups with different prognoses (P = .003), a subdivision not seen for unmutated cases (P = .232). Interestingly, the VH-mutated group with short telomeres had an overall survival close to that of the unmutated cases. Thus, by combining VH mutation status and telomere length, an improved subclassification of CLL was achieved identifying previously unrecognized patient groups with different outcomes. (Blood. 2005;105:4807-4812)
T-cell generation by lymph node resident progenitor cells
Authors: Terra Rafik , Louis Isabelle , Le Blanc Richard , Ouellet Sophie , Zúñiga-Pflücker Juan Carlos , Perreault Claude
Published: March 2005

In the thymus, 2 types of Lin–Sca-1+ (lineage-negative stem cell antigen-1–positive) progenitors can generate T-lineage cells: c-Kithi interleukin-7 receptor α–negative (c-KithiIL-7Rα–) and c-KitloIL-7Rα+. While c-KithiIL-7Rα– progenitors are absent, c-KitloIL-7Rα+ progenitors are abundant in the lymph nodes (LNs). c-KitloIL-7Rα+ progenitors undergo abortive T-cell commitment in the LNs and become arrested in the G1 phase of the cell cycle because they fail both to up-regulate c-myb, c-myc, and cyclin D2 and to repress junB, p16INK4a, and p21Cip1/WAF. As a result, development of LN c-KitloIL-7Rα+ progenitors is blocked at an intermediate CD44+CD25lo development stage in vivo, and LN-derived progenitors fail to generate mature T cells when cultured with OP9-DL1 stromal cells. LN stroma can provide key signals for T-cell development including IL-7, Kit ligand, and Delta-like–1 but lacks Wnt4 and Wnt7b transcripts. LN c-KitloIL-7Rα+ progenitors are able to generate mature T cells when cultured with stromal cells producing wingless-related MMTV integration site 4 (Wnt4) or upon in vivo exposure to oncostatin M whose signaling pathway intersects with Wnt. Thus, supplying Wnt signals to c-KitloIL-7Rα+ progenitors may be sufficient to transform the LN into a primary T-lymphoid organ. These data provide unique insights into the essence of a primary T-lymphoid organ and into how a cryptic extrathymic T-cell development pathway can be amplified.
Bacillus subtilis actin-like protein MreB influences the positioning of the replication machinery and requires membrane proteins MreC/D and other actin-like proteins for proper localization
Authors: Defeu Soufo Hervé Joël , Graumann Peter L
Published: March 2005

Background

Bacterial actin-like proteins have been shown to perform essential functions in several aspects of cellular physiology. They affect cell growth, cell shape, chromosome segregation and polar localization of proteins, and localize as helical filaments underneath the cell membrane. Bacillus subtilis MreB and Mbl have been shown to perform dynamic motor like movements within cells, extending along helical tracks in a time scale of few seconds.

Results

In this work, we show that Bacillus subtilis MreB has a dual role, both in the formation of rod cell shape, and in chromosome segregation, however, its function in cell shape is distinct from that of MreC. Additionally, MreB is important for the localization of the replication machinery to the cell centre, which becomes aberrant soon after depletion of MreB. 3D image reconstructions suggest that frequently, MreB filaments consist of several discontinuous helical filaments with varying length. The localization of MreB was abnormal in cells with decondensed chromosomes, as well as during depletion of Mbl, MreBH and of the MreC/MreD proteins, which we show localize to the cell membrane. Thus, proper positioning of MreB filaments depends on and is affected by a variety of factors in the cell.

Conclusion

Our data provide genetic and cytological links between MreB and the membrane, as well as with other actin like proteins, and further supports the connection of MreB with the chromosome. The functional dependence on MreB of the localization of the replication machinery suggests that the replisome is not anchored at the cell centre, but is positioned in a dynamic manner.
Non-invasive Fetal RHD and RHCE Genotyping Using Real-time PCR Testing of Maternal Plasma in RhD-negative Pregnancies
Authors: Hromadnikova Ilona , Vechetova Lenka , Vesela Klara , Benesova Blanka , Doucha Jindrich , Vlk Radovan
Published: March 2005

We assessed the feasibility of fetal RHD and RHCE genotyping by analysis of DNA extracted from plasma samples of RhD-negative pregnant women using real-time PCR and primers and probes targeted toward RHD and RHCE genes. We analyzed 45 pregnant women in the 11th to 40th weeks of pregnancy and correlated the results with serological analysis of cord blood after delivery. Non-invasive prenatal fetal RHD exon 7, RHD exon 10, RHCE exon 2 (C allele), and RHCE exon 5 (E allele) genotyping analysis of maternal plasma samples was correctly performed in 45 out of 45 RhD-negative pregnant women delivering 24 RhD-, 17 RhC-, and 7 RhE-positive newborns. Detection of fetal RHD and the C and E alleles of RHCE gene from maternal plasma is highly accurate and enables implementation into clinical routine. We recommend performing fetal RHD and RHCE genotyping together with fetal sex determination in alloimmunized D-negative pregnancies at risk of hemolytic disease of the newborn. In case of D-negative fetus, amplification of another paternally inherited allele (SRY and/or RhC and/or RhE positivity) proves the presence of fetal DNA in maternal circulation.
The Fetal Erythroblast Is Not the Optimal Target for Non-invasive Prenatal Diagnosis: Preliminary Results
Authors: Kølvraa Steen , Christensen Britta , Lykke-Hansen Lene , Philip John
Published: March 2005

Fetal cells, present in the blood of pregnant women, are potential targets for non-invasive prenatal diagnosis. The fetal erythroblast has been the favorite target cell type. We investigated four methods of enrichment for fetal erythroblasts, identifying only three fetal erythroblasts in 573 ml of maternal blood. This is much less than the expected two to six fetal cells per ml of maternal blood. Hamada and Krabchi used a cell type-independent marker, i.e., the Y chromosome in maternal blood from male pregnancies after Carnoy fixation, leaving the nuclei for hybridization with X-and Y-chromosome-specific probes. We found with a similar technique 28 fetal cells in 15 ml of maternal blood. The fetal origin of cells was confirmed by hybridizing the nuclei with X- and Y-chromosome-specific probes, using two consecutive hybridizations with the two probes in opposite colors (reverse FISH). Candidate fetal cells were inspected after each hybridization. Only cells that were found to change the color of both probe signals from first to second hybridization were diagnosed as fetal. To reduce the labor-intensive slide screening load, we used semi-automated scanning microscopy to search for candidate cells. We conclude that erythroblasts form only a small fraction of fetal cells present in maternal blood.
First-trimester NRBC Count in Maternal Circulation: Correlation with Doppler Ultrasound Studies
Authors: Mavrou Ariadni , Kolialexi Aggeliki , Souka Athena , Pilalis Athanasios , Kavalakis Yannis , Antsaklis Panagiotis , Kanavakis Emmanuel , Antsaklis Aristidis
Published: March 2005

This study aimed to determine whether the number of nucleated red blood cells (NRBCs) in maternal circulation during the first trimester of pregnancy could identify pregnancies that will have an anomalous Doppler in the second trimester. A total of 85 blood samples were obtained at 11–14 weeks of gestation with mean uterine arterial perfusion index >1.6, as noted by Doppler ultrasonography. NRBCs were enriched by magnetic automated cell sorting using anti-CD71 and were stained with May/Grunwald/Giemsa. A total of 4.8 NRBCs (range 1–75) were identified in 68 cases. Follow-up scans at 22–24 weeks were available in 46 cases. In 39 women, blood flow in the uterine arteries normalized, whereas in seven, high resistance was noted. One woman in the high-resistance group developed preeclampsia (PET; four NRBCs) and another delivered an intrauterine growth restriction (IUGR) baby (75 NRBCs). The number of NRBCs in women whose Doppler indices later normalized and in those who continued to have increased impedance was similar. The study indicates that NRBC number in maternal circulation during the first trimester cannot be used to screen pregnancies at high risk for developing preeclampsia (PET)/IUGR. High-impedance blood flow in the uterine arteries in the first trimester may be due to an unfinished process of trophoblastic invasion, most likely to be completed successfully by 22–24 weeks.
An Approach for Quantitative Assessment of Fluorescence In Situ Hybridization (FISH) Signals for Applied Human Molecular Cytogenetics
Authors: Iourov Ivan Y. , Soloviev Ilia V. , Vorsanova Svetlana G. , Monakhov Viktor V. , Yurov Yuri B.
Published: March 2005

A number of applied molecular cytogenetic studies require the quantitative assessment of fluorescence in situ hybridization (FISH) signals (for example, interphase FISH analysis of aneuploidy by chromosome enumeration DNA probes; analysis of somatic pairing of homologous chromosomes in interphase nuclei; identification of chromosomal heteromorphism after FISH with satellite DNA probes for differentiation of parental origin of homologous chromosome, etc.). We have performed a pilot study to develop a simple technique for quantitative assessment of FISH signals by means of the digital capturing of microscopic images and the intensity measuring of hybridization signals using Scion Image software, commonly used for quantification of electrophoresis gels. We have tested this approach by quantitative analysis of FISH signals after application of chromosome-specific DNA probes for aneuploidy scoring in interphase nuclei in cells of different human tissues. This approach allowed us to exclude or confirm a low-level mosaic form of aneuploidy by quantification of FISH signals (for example, discrimination of pseudo-monosomy and artifact signals due to over-position of hybridization signals). Quantification of FISH signals was also used for analysis of somatic pairing of homologous chromosomes in nuclei of postmortem brain tissues after FISH with “classical” satellite DNA probes for chromosomes 1, 9, and 16. This approach has shown a relatively high efficiency for the quantitative registration of chromosomal heteromorphism due to variations of centromeric alphoid DNA in homologous parental chromosomes. We propose this approach to be efficient and to be considered as a useful tool in addition to visual FISH signal analysis for applied molecular cytogenetic studies.
Dup(13)(q14.2-q14.3): Yet Another New Differential Diagnostic Aspect for Short Stature–like Phenotype
Authors: Schreyer Isolde , Neumann Annett , Beensen Volkmar , Eichhorn Karl-Heinz , Heller Anita , Claussen Uwe , Liehr Thomas
Published: March 2005

We report on the case of a pregnant woman with hyposomia who was previously suspected of having Turner syndrome. Prenatal cytogenetic diagnostics showed a fetal karyotype of 46,XX,dup(13)(q14.2q21.1) ish.13q14(RB1 × 3). Parental and grandparental chromosome analyses were performed and the dup(13) was found to be of maternal origin (de novo). The pregnancy was continued and a healthy female child was born with normal development apart from growth retardation. The reported chromosomal aberration is, together with two other cases reported in the literature, the first hint of a short stature–like phenotype due to dup(13)(q14.2q14.3).
Rapid Prenatal Diagnostics in the Interphase Nucleus: Procedure and Cut-off Rates
Authors: Liehr Thomas , Ziegler Monika
Published: March 2005

Results of a rapid prenatal aneuploidy screening in uncultured amniocytes using FISH are available within 24 hr. However, care has to be taken of possible pitfalls in connection with the commercially available probe sets and in the interpretation of results in general. Here we present our cut-off rates for and the way in which we handle the Aneu Vysion kit (ABBOTT/Vysis), based on the experience of 1200 studied cases. In summary, the method is reliable, and the risk for misdiagnosis is low (~0.4%). Nonetheless, the test should be used exclusively as a preamble to full chromosome analysis by microscopy.
Preimplantation Genetic Diagnosis—An Overview
Authors: Ogilvie Caroline Mackie , Braude Peter R. , Scriven Paul N.
Published: March 2005

Since the early 1990s, preimplantation genetic diagnosis (PGD) has been expanding in scope and applications. Selection of female embryos to avoid X-linked disease was carried out first by polymerase chain reaction, then by fluorescence in situ hybridization (FISH), and an ever-increasing number of tests for monogenic diseases have been developed. Couples with chromosome rearrangements such as Robertsonian and reciprocal translocations form a large referral group for most PGD centers and present a special challenge, due to the large number of genetically unbalanced embryos generated by meiotic segregation. Early protocols used blastomeres biopsied from cleavage-stage embryos; testing of first and second polar bodies is now a routine alternative, and blastocyst biopsy can also be used. More recently, the technology has been harnessed to provide PGD-AS, or aneuploidy screening. FISH probes specific for chromosomes commonly found to be aneuploid in early pregnancy loss are used to test blastomeres for aneuploidy, with the aim of replacing euploid embryos and increasing pregnancy rates in groups of women who have poor IVF success rates. More recent application of PGD to areas such as HLA typing and social sex selection have stoked public controversy and concern, while provoking interesting ethical debates and keeping PGD firmly in the public eye.
Evaluation of a Soybean Lectin–based Method for the Enrichment of Erythroblasts
Authors: Babochkina Tatiana , Mergenthaler Susanne , Lapaire Olaf , Kiefer Vivian , Yura Hirofumi , Koike Kimie , Holzgreve Wolfgang , Hahn Sinuhe
Published: March 2005

We performed a comparative study of the enrichment of erythroblasts by a soybean agglutinin galactose-specific lectin method and a standardized magnetic cell-sorting (MACS) protocol. Blood samples, obtained from 11 pregnant women at between 11 and 40 weeks of gestation, were split and examined by each method in parallel. The number of erythroblasts recovered by the lectin method was approximately eightfold higher than the number obtained by MACS. Our data suggest that the lectin-based method may provide a better approach for the enrichment of rare fetal erythroblasts from maternal blood.
Prenatal Diagnosis and Molecular Cytogenetic Characterization of an Unusual Complex Structural Rearrangement in a Pregnancy Following Intracytoplasmic Sperm Injection (ICSI)
Authors: Trimborn M. , Liehr T. , Belitz B. , Pfeiffer L. , Varon R. , Neitzel H. , Tönnies H.
Published: March 2005

We report on a balanced complex chromosomal aberration detected in a fetus after amniocentesis. The pregnancy was achieved after intracytoplasmic sperm injection. GTG-banding revealed a complex structurally rearranged karyotype with a translocation between chromosomes 5 and 15 and an additional paracentric inversion in the der(15) between bands 5q11.2 and 5q15. Ag-NOR staining showed an interstitial active nuclear organizer region in the der(15). Molecular cytogenetic analyses using whole-chromosome–painting probes, comparative genomic hybridization, and multicolor banding did not point to further structural aberrations or imbalances. Therefore, a complex rearrangement with three breakpoints has occurred, and the karyotype can be described as 46,XX,der(5)t(5;15)(q11.2;p12),der(15)t(5;15)(q11.2;p12)inv(5)(q11.2q15).
Another Small Supernumerary Marker Chromosome (sSMC) Derived from Chromosome 2: Towards a Genotype/Phenotype Correlation
Authors: Mrasek Kristin , Starke Heike , Liehr Thomas
Published: March 2005

Here we report a prenatally detected small supernumerary marker chromosome (sSMC) derived from chromosome 2 as demonstrated by cenM-FISH (centromere-specific multicolor fluorescence in situ hybridization). By application of a recently described subcentromere-specific probe set (subcenM-FISH) for chromosome 2, the presence of a small partial trisomy due to a karyotype 47,XX, + r(2)(::p11.1->q11.2::) was demonstrated. Including this case, a total of 11 patients with sSMC(2) are described throughout the literature. Based on that data, a first genotype/phenotype correlation according to the size and structure of the marker is suggested.
First-trimester Screening: An Overview
Authors: Eiben Bernd , Glaubitz Ralf
Published: March 2005

An improvement in prenatal screening for chromosomal defects has been achieved by combining sonography and biochemical markers. Analyzing markers taken from maternal blood such as pregnancy-associated plasma protein A and free β-human chorionic gonadotropin in combination with the ultrasound marker nuchal translucency provides detection rates of 90% for the most important chromosomal anomalies. In addition, nuchal translucency is a marker for severe heart defects. This report discusses the potential of new markers such as the nasal bone.
Sperm and Blastomere Aneuploidy Detection in Reproductive Genetics and Medicine
Authors: Gianaroli Luca , Magli M. Cristina , Ferraretti Anna P.
Published: March 2005

The use of multiple probes in fluorescence in situ hybridization (FISH) permits the simultaneous analysis of several chromosomes in both blastomeres and spermatozoa. Preimplantation genetic diagnosis (PGD) for aneuploidy provides information on embryonic chromosomal status, enabling the selection of embryos carrying aneuploid condition. This strategy directly affects implantation, as documented for patients with a poor prognosis for pregnancy, who have the tendency to generate high proportions of chromosomally abnormal embryos. PGD for aneuploidy also has contributed information on early phases in human embryology by clarifying the molecular basis in some cases of irregular development. Multicolor FISH has also been used to study chromosomes on spermatozoa. Experimental strategies and modifications enabled the analysis of samples with a very low number of sperm cells, including samples retrieved from the genital tract or directly from the testicular tissue. The results confirmed that the incidence of aneuploidy increases proportionally with the severity of the male-factor condition. This observation suggests that, in selected cases, the paternal contribution to aneuploidy in the developing conceptus could be more relevant than expected from general data from aborted fetuses and live births.
Topology of Chromosomes 18 and X in Human Blastomeres from 3- to 4-Day-old Embryos
Authors: Diblík Jan , Macek Milan , Magli Maria-Cristina , Krejčí Roman , Gianaroli Luca
Published: March 2005

The positions of chromosomes 18 and X fluorescence in situ hybridization signals were analyzed in blastomeres generated from human in vitro fertilization 3- to 4-day-old embryos after preimplantation screening of aneuploidy of chromosomes 13, 16, 18, 21, 22, X, and Y. Fluorescent signal localization compared with a three-dimensional sphere model of random signal distribution revealed significant differences, providing evidence of peripheral localization of chromosome 18 in aneuploid ( p=0.0013) and aneuploid/euploid blastomeres ( p=0.0011). No differences were found in localization of chromosome 18 in euploid and in chromosome X in euploid and aneuploid blastomeres.
The Metabolic Syndrome: Requiescat in Pace
Authors: Reaven Gerald M
Published: March 2005

Values for insulin-mediated glucose disposal vary continuously throughout a population of apparently healthy individuals, with at least a sixfold variation between the most insulin sensitive and most insulin resistant of these individuals. The more insulin resistant a person, the more insulin must be secreted to prevent decompensation of glucose tolerance. Insulin resistance is not a disease, but a description of a physiologic state, and approximately one third of an apparently healthy population is sufficiently insulin resistant to be at increased risk to develop a cluster of abnormalities and related clinical syndromes. The primary value of the concept of insulin resistance is that it provides a conceptual framework with which to place a substantial number of apparently unrelated biological events into a pathophysiological construct. In contrast, the metabolic syndrome was introduced as a diagnostic category to identify individuals that satisfy three of five relatively arbitrarily chosen criteria to initiate lifestyle changes with the goal of decreasing risk of cardiovascular disease. Consequently, the value of the notion of the metabolic syndrome must be considered not in pathophysiologic terms, but as a pragmatic approach to obtain a better clinical outcome. In this review, an effort is made to critically evaluate the concept of the metabolic syndrome, the criteria chosen to identify individuals with the syndrome, and the clinical utility of making, or not making, a diagnosis of the metabolic syndrome.
Inhibition of phosphatidylinositol 3-kinase modifies boar sperm motion parameters
Authors: Aparicio I M , Gil M C , Garcia-Herreros M , Peña F J , Garcia-Marin L J
Published: March 2005

Motility is the most widely used indicator of sperm quality. Besides modulation by the cAMP pathway little is known regarding the intracellular pathways that regulate boar sperm motility. Recently the role of phosphatidylinositol 3-kinase (PI3-K) in the regulation of human sperm motility has been described. Therefore, the aim of this study was to investigate the role of PI3-K in boar sperm kinematics by using the specific PI3-K inhibitor, LY294002. Boar sperm was incubated up to 1 h in non-capacitating medium in the presence or absence of the cAMP analog, 8Br-cAMP or the PI3-K inhibitor, LY294002 or both. Boar sperm incubated in capacitating medium was treated in the presence or absence of LY294002. First, we have clearly identified that PI3-K is present in whole lysates of boar spermatozoa. Inhibition of PI3-K significantly increased boar sperm straight-line velocity, circular velocity and average velocity without an effect on the percentage of progressively motile spermatozoa in both media. Inhibition of PI3-K induced the same effects on boar sperm velocities as activation of the cAMP/protein kinase A (PKA) pathway and treatment with the PI3-K inhibitor, LY294002 had neither summatory nor synergic effects on boar sperm motion parameters when treated simultaneously with the cAMP analog 8Br-cAMP. Our data suggest that PI3-K plays a negative role, regulating boar sperm motion parameters through a possible inhibition of the cAMP/PKA activating pathway, and since some Computer Aided Sperm Analysis (CASA)-derived parameters have been related to field fertility our results point to the possibility of modulating sperm motile quality by modifying the PI3-K cellular pathway.
Molecular physiology and pathology of Ca2+-conducting channels in the plasma membrane of mammalian sperm
Authors: Felix Ricardo
Published: March 2005

Current evidence indicates that mechanisms controlling the intracellular Ca2+concentration play pivotal roles in determining sperm fertilizing ability. Multiple Ca2+-permeable channels have been identified and characterized in the plasma membrane and in the acrosome membrane of mammalian sperm. This review summarizes the recent findings and assesses the evidence suggesting that these channels play roles in controlling a host of sperm functions ranging from motility to the acrosome reaction, and describes recent advances in the identification of the underlying gene defects of inherited sperm Ca2+channelopathies.
La2Hf2O7:Ti4+ ceramic scintillator for x-ray imaging
Authors: Ji Yaming , Jiang Danyu , Shi Jianlin
Published: March 2005

Transparent ceramic scintillators of La2Hf2O7:Ti4+ were developed by a novel combustion synthesis method. The optical transmittance for a 1.0-mm-thick specimen is about 60% of the incident light, and the x-ray stopping power is also quiet high. The broad emission band centered at 475 nm originates from the oxide-Ti4+ charge-transfer transitions, which renders fast decay time on the order of 10 μs. The highest relative light output has reached about 1.5 times that of Bi4Ge3O12 (BGO) single crystal when excited by 120 kV x-rays.
Early dissolution behavior of copper in a molten Sn–Zn–Ag solder
Authors: Yu Chang-Ho , Lin Kwang-Lung
Published: March 2005

The early dissolution behavior of Cu in a molten Sn–Zn–Ag solder was studied at 250 °C by fast quenching the dissolving specimen in liquid nitrogen. The atomic level dissolution behavior of Cu in the molten solder was revealed by high-resolution transmission electron microscopy. The dissolution of Cu occurs through channel dissolution and thermal vibrational dissolution. The dissolution channel has a dimension of less than 0.5 nm. The formation of channels, and thus the channel zone, is initiated by preferential removal of Cu atoms from the surface vacant site of Cu lattice. Relict strips of lattice between channels subsequently dissolve into the molten solder with the aid of thermal vibration and the interaction with liquid Zn atoms. The dissolved atoms form an atomic cluster zone. These clusters are the intermediate state of the dissolution of Cu from the channel zone into the molten Sn–Zn–Ag solder. The clusters convert into an amorphous structure prior to further formation of compound.
Quantum chemical study of adsorption and dissociation of HfCl4 and H2O on Ge/Si(100) − (2×1): Initial stage of atomic layer deposition of HfO2 on SiGe surface
Authors: Chen Wei , Zhang David Wei , Ren Jie , Lu Hong-Liang , Zhang Jian-Yun , Xu Min , Wang Ji-Tao , Wang Li-Kong
Published: March 2005

We investigated adsorption and dissociation of water and HfCl4 on a Ge/Si(100) −(2 × 1) surface with a density-functional theory. The Si–Ge and Ge–Ge homodimers are used to represent the Si1−xGex surface. (i) Water first adsorbs on the bare Ge/Si(100) − (2 × 1) surface and then dissociates into OH and H. The activation energy for adsorption of water on the Ge–Ge homodimer is much higher than that on the Si–Ge heterodimer. (ii) HfCl4 dissociates upon adsorption on the Ge/Si(100) − (2 × 1) surface into HfCl3 and Cl. No net activation barrier exists during the adsorption of HfCl4 on both SiGe surface dimers. The molecular adsorption state is found to be metastable according to the calculation, which implies that the reaction tends to move toward to the product rather than trapping in HfCl4 adsorbed state. The difference in the potential energy surface between reactions on Si–Ge and Ge–Ge dimers is due to different bond strengths.
Deformation-induced nanocrystallization: A comparison of two amorphous Al-based alloys
Authors: Jiang W.H. , Pinkerton F.E. , Atzmon M.
Published: March 2005

Using conventional and high-resolution transmission electron microscopy (HRTEM), the effects of rolling at room temperature on the microstructures of amorphous Al90Fe5Gd5and Al86.8Ni3.7Y9.5were compared. In rolled Al90Fe5Gd5, nanocrystallites were observed at shear bands, whereas none were observed in rolled Al86.8Ni3.7Y9.5. When HRTEM was combined with with Fourier transform filtering, nanoscale, low-density defects were imaged. In Al90Fe5Gd5, the shear bands contain few defects, which are concentrated at the boundary zone between the shear bands and undeformed region, whereas in Al86.8Ni3.7Y9.5, the shear bands contain a uniform distribution of defects with a density higher than the undeformed region. The preferential precipitation of nanocrystallites in rolled Al90Fe5Gd5is attributed to a kinetic effect due to uniformly-distributed excess free volume in the shear bands.
In situ deposition/positioning of magnetic nanoparticles with ferroelectric nanolithography
Authors: Lei Xiaojun , Li Dongbo , Shao Rui , Bonnell Dawn A.
Published: March 2005

Ferroelectric nanolithography is a new approach to processing nanostructures, which can position multiple components made of various materials into predefined configurations. Local polarization in ferroelectric compounds is manipulated to control the surface electronic structure and direct attachment of molecules and particles. Here, the presence of optically excited electron-hole pairs on ferroelectric domains is confirmed, and reaction paths for photo reduction of several reactive metal particles are determined. Subsequent and simultaneous deposition of multiple metals is demonstrated, and the magnetic properties of Co based particles are confirmed.
Correction factor for contact area in nanoindentation measurements
Authors: Troyon Michel , Huang Liye
Published: March 2005

In the relationship between unloading contact stiffness, elastic modulus, and contact area, which is the fundamental basic equation for nanoindentation analysis, a multiplicative correction factor is generally needed. Sometimes this correction factor is called γ to take into account the elastic radial inward displacements, and sometimes it is called β to correct for the fact that the indenter shape is not a perfect cone. In reality, these two effects simultaneously coexist and thus it is proposed that this correction factor is α = βγ. From nanoindentation data measured on three materials of different elastic moduli with a sharp Berkovich indenter and a worn one, the tip of which was blunt, it is demonstrated that the correction factor α does not have a constant value for a given material and indenter type but depends on the indenter tip rounding and also on the deformation of the indenter during indentation. It seems that α increases with the tip radius and also with the elastic modulus of the measured materials.
Oxidation of carbon on nickel-based metallic substrates: Implications for high-temperature superconductor coated conductors
Authors: List F.A. , Heatherly L. , Lee D.F. , Leonard K.J. , Goyal A.
Published: March 2005

Adhesion of thin films of epitaxial oxides to nickel-based metallic substrates is important for the successful development of high-temperature superconductor coated conductors. Detachment of epitaxial oxide buffer layers at the oxide/metal interface during either oxide growth or subsequent processing renders the conductor useless. In this study, thermal desorption spectroscopy (TDS) has been used to identify and understand one of the causes of buffer layer detachment, oxidation of carbon at the oxide–metal interface to form carbon monoxide. Results of TDS indicate that on the surface of a bare nickel-based alloy substrate, the rate of carbon oxidation depends on both the supply of carbon from the substrate and the supply of oxygen from the vapor. Sulfur at the surface of the alloy substrate reduces the rate of carbon oxidation. The effectiveness of various treatments of the bare substrate to eliminate CO formation and epitaxial oxide detachment has been demonstrated. TDS provides both a means to evaluate the kinetics of the oxidation reaction and a tool to assess the need and effectiveness of a substrate oxidation treatment.
Characteristics of Spawning Lake Sturgeon in the Upper Black River, Michigan
Authors: Smith Kregg M. , Baker Edward A.
Published: March 2005

The population of lake sturgeon Acipenser fulvescens in Black Lake, Michigan, is confined to a smaller spatial habitat than was historically available, which has led to concern over the future viability of the population. Biological data were collected from spawning lake sturgeons in the Upper Black River in 2001 and 2002 to assess the size of the spawning run and the condition of spawning fish relative to other populations. A 1.6-km section of the total 11 km of available habitat in the Upper Black River was an important spawning location for lake sturgeon. Spawning fish were captured and data were collected at the spawning sites from 115 adults in 2001 and 104 adults in 2002. Fish gender was determined by the presence of ripe gametes. The male : female sex ratio was 1.55:1 in 2001 and 2.06:1 in 2002. Weight at length for spawning lake sturgeons was comparable to that of other studied populations, and the average size at age of spawning lake sturgeons was slightly higher than for spawning fish from the Sturgeon River, Michigan, an open tributary to Lake Superior with a self-sustaining population. Consecutive-year spawning was documented for 10 male lake sturgeons, which showed an average increase in total length and weight of 1.6 cm and 1.15 kg, respectively. Age estimates predicted by a von Bertalanffy model for the spawning adults predicted males representing 25 different age-classes ranging from age 12 to age 63 and females representing 29 different age-classes ranging from age 20 to age 70. On the basis of our observations of ripe gametes, growth of the annual spawners, and overall condition of the spawning fish, we conclude that the spatially restricted habitat in Black Lake was sufficient to support adult lake sturgeon growth and gamete production.