bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacovigilance
Authors: Waller Patrick , Evans Stephen
Published: October 2006

Pharmacovigilance is considered here to include all safety‐related activity beyond the point at which humans are first exposed to a new medicinal drug. It is a process of clinical risk management involving the identification, investigation, and minimization of the adverse effects of medication, in particular those that have serious clinical consequences. This article considers the purposes of pharmacovigilance, methodologies, and systems and processes in place to prevent adverse drug reactions (ADRs), which includes the reporting to regulatory authorities of serious, unexpected, and suspected adverse reactions that occur in clinical trials. We also cover some historical aspects, consider the limitations of existing approaches, and provide pointers for the future development of this discipline.
Institution
Authors: Meinert Curtis L.
Published: October 2006

This article reviews the uses and definitions of the terms “institution,” “sponsor,” “study centers,” and “agency.”
Multicenter Trial
Authors: Meinert Curtis L.
Published: October 2006

This article defines and reviews the history of multicenter trials. Several key examples of multicenter trials are provided as well as same suggested readings.
The Belmont Report
Authors: Zucker Deborah
Published: October 2006

The Belmont Report summarizes the basic ethical principles and guidelines identified by the commission to assist in the protection of human subjects in research. The report focuses on three main areas, (
1
) the boundaries between research and practice, (
2
) the basic ethical principles that should underlie the conduct of research (autonomy, beneficence, justice) and the protection of human subjects, and (
3
) the application of these principles into practice. The report outlines general recommendations regarding obtaining informed consent, the assessment of risk and benefit, and the recruitment of participants. The Belmont Report lays out many of the ethical considerations that, to this day, are used in formulating regulations and in ensuring the protection of human study volunteers.
Clinical Significance
Authors: Kamath Celia C. , Sloan Jeffrey A. , Cappelleri Joseph C.
Published: October 2006

This article defines clinical significance, as opposed to statistical significance, as it relates to health‐related quality of life measures used in clinical trials. It provides a brief history of the concept and addresses the different perspectives from which it is perceived and interpreted. It describes the current methods used to assess clinical significance and provides several examples of the different ways of measuring, validating, and using clinical significance. Recent developments on the concept are discussed. Finally, directions for future research are highlighted.
Hypothesis
Authors: Rosenkranz Gerd
Published: October 2006

In the following article, the authors briefly review the role of hypotheses in science before statistical hypotheses and their relevance for clinical studies are investigated. The authors explain what statistical hypotheses have in common with scientific hypotheses and how they differ. In particular, testing statistical hypotheses is somewhat different from testing scientific hypotheses, although some general ideas apply to both. Eventually, the importance of formulating testable hypotheses for clinical studies are explored and some specific topics like superiority, equivalence, non‐inferiority, and multiple hypotheses are discussed.
Genetic counselors and research: Current practices and future directions
Authors: Clark Heather M. , Gamm Jennifer , Huether Carl A. , Buncher C. Ralph , Pfau Ruthann I. Blough , Warren Nancy Steinberg
Published: October 2006

Members of the genetic counseling community have debated the need for doctoral degree programs to further advance the profession. However, genetic counselors' interest in conducting independent research and attitudes toward obtaining a doctoral degree in genetic counseling has not been assessed in more than a decade. We designed a comprehensive web‐based survey to characterize the current research values and practices of genetic counselors. Respondents were asked to self‐report their current research involvement, their specific role in research activities, and their interest in performing research in the future. The study showed that a significant number of genetic counselors (84.5%) have conducted previous research, and 69.4% of respondents plan to perform research in the future. These results reflect the maturation of the genetic counseling field, in that a substantial number of genetic counselors consider active involvement in research to be a core role. The study also showed that 34.1% of respondents have high interest in a hypothetical PhD in Genetic Counseling, suggesting that the profession is primed for the development of doctoral degree training options. © 2006 Wiley‐Liss, Inc.
Uncertainty and perceived personal control among parents of children with rare chromosome conditions: The role of genetic counseling
Authors: Lipinski Shawn E. , Lipinski Michael J. , Biesecker Leslie G. , Biesecker Barbara B.
Published: October 2006

Little is known about the impact of genetic counseling on parental uncertainty or perceived control regarding the prognosis of a child with a chromosomal disorder. By exploring the parents' concerns and needs surrounding the child's diagnosis, a genetic provider can help to facilitate effective coping. This study tested the association of measures of parental uncertainty and perceived control with the perceived helpfulness of the genetic counselor. A survey was distributed to 875 members of the Chromosome Deletion Outreach (CDO) support group. We hypothesized that parents' perceptions about the helpfulness of the genetic counselor would modify the relationship between perceived uncertainty, perceived control, and coping. Among the 363 respondents, there was a significant negative correlation of the perceived helpfulness of seeing a genetic counselor with the levels of uncertainty (rs = −0.20,P‐value < 0.001). Lower perceived helpfulness of the genetic counselor, along with less perceived personal control, less benefit of a diagnosis, and lower parental age were significant predictors of the highest perceptions of uncertainty. The Transactional Model of Stress and Coping was used as a framework for interpreting the relationships between parental uncertainty, perceived control, and outcome variables. There was a significant positive correlation between parents' perceived personal control and their reports of helpfulness of the genetic counselor (rs = 0.20,P‐value <0.0006). Genetic counseling can be enhanced for parents faced with rare disorders by using interventions focused on reducing feelings of uncertainty and enhancing feelings of control. © 2006 Wiley‐Liss, Inc.
Referral to cancer genetic counseling: Are there stages of readiness?
Authors: O'Neill Suzanne M. , Peters June A. , Vogel Victor G. , Feingold Eleanor , Rubinstein Wendy S.
Published: October 2006

As genetic awareness spreads among healthcare providers and the general public, and evidence mounts to show the efficacy of cancer control methods, referrals to cancer genetic counseling services for risk assessment are becoming more common. However, few studies have examined referral patterns to genetics and even less is known about referral uptake to clinical cancer genetic counseling. We investigated outcome of genetics referral in 43 affected women attending a breast cancer treatment program who were referred based on having BRCA mutation carrier risks ≥10%. Within 6 months, of the 36 women we were able to recontact, 13 (36%) came to an appointment at the cancer genetic counseling clinic (Acceptors), 10 (27%) said they intended to come in the future (Intenders), and 13 (36%) said they would not consider genetic counseling (Decliners). Referral uptake was framed by elements of the Transtheoretical model (TTM) to determine if decisional balance scores (DBSs), a summary of an individual's “Pro” and “Con” opinions related to genetic testing, correlated with their decision to follow through. Mean DBS's were strongly negative for the Decliner group (−7.4), weakly negative for the Intender group (−1.1), and positive for the Acceptor group (5.4). The difference in the DBS along the continuum was due more to the mean “Con” score decreasing, rather than the mean “Pro” score increasing. Theoretical frameworks are needed to study adherence to referral for cancer genetic counseling. Stage‐based theories may have a role to play. © 2006 Wiley‐Liss, Inc.
Ethical and clinical practice considerations for genetic counselors related to direct‐to‐consumer marketing of genetic tests
Authors: Wade Christopher H. , Wilfond Benjamin S.
Published: October 2006

Several companies utilize direct‐to‐consumer (DTC) advertising for genetic tests and some, but not all, bypass clinician involvement by offering DTC purchase of the tests. This article examines how DTC marketing strategies may affect genetic counselors, using available cardiovascular disease susceptibility tests as an illustration. The interpretation of these tests is complex and includes consideration of clinical validity and utility, and the further complications of gene–environment interactions and pleiotropy. Although it is unclear to what extent genetic counselors will encounter clients who have been exposed to DTC marketing strategies, these strategies may influence genetic counseling interactions if they produce directed interest in specific tests and unrealistic expectations for the tests' capacity to predict disease. Often, a client's concern about risk for cardiovascular diseases is best addressed by established clinical tests and a family history assessment. Ethical dilemmas may arise for genetic counselors who consider whether to accept clients who request test interpretation or to order DTC‐advertised tests that require a clinician's authorization. Genetic counselors' obligations to care for clients extend to interpreting DTC tests, although this obligation may be fulfilled by referral or consultation with specialists. Genetic counselors do not have an obligation to order DTC‐advertised tests that have minimal clinical validity and utility at a client's request. This can be a justified restriction on autonomy based on consideration of risks to the client, the costs, and the implications for society. Published 2006 Wiley‐Liss, Inc.
Through the viewfinder: Positive Exposure a year later
Authors: Sutton Erica J. , Rosapep Lauren , Ball Karen , Truitt Megan , Biesecker Barbara , Guidotti Rick , McLean Diane
Published: October 2006

Positive Exposure, a non‐profit organization founded and directed by former fashion photographer Rick Guidotti and co‐directed by psychiatrist Dr. Diane McLean, uses photography and video interviews to explore the lived experiences of people affected with genetic conditions. Positive Exposure challenges pervasive social biases and stereotypes about genetic variation and strives to broaden and enrich societal perceptions of human beauty and spirit. Presented here are the open‐ended personal reflections completed by four individuals with craniofacial differences recruited from a support group, Inner Faces. These four case studies aim to relay the professional photo‐shoot experiences of people who may be challenged by the stigma associated with craniofacial differences. Questions addressed issues of perceived self‐esteem, stigma, hopefulness, and photography experiences. These personal reflections were gathered 1 year following participation in a Positive Exposure photo‐shoot. Participants described the ways in which the photo‐shoot has been a lasting and life‐promoting experience. In addition, these individuals emphasize the integral and enduring role the photographer, Rick Guidotti, played in their personal awakening. Positive Exposure provided these individuals with renewed identification of both inner and outer sources of beauty. These four case studies suggest that Positive Exposure may serve as a sustainable intervention to bolster self‐esteem and self‐image. Published 2006 Wiley‐Liss, Inc.
Response of NIPAAm‐Ch gel to temperature changes and its effectiveness on nitrification as medium for immobilization
Authors: Yuan Linjiang , Kusuda Tetsuya , Satoh Hisashi
Published: October 2006

Increase in mass transport resistance is one of the major difficulties in immobilization by the use of gels. Functional gels can change their volume and inner structure depending on ambient conditions as stimuli and may reduce the difficulty as a novel immobilization matrix. The response of poly N‐isopropylacrylamide‐co‐chlorophyllin (NIPAAm‐Ch) gel to temperature changes and its performance on nitrification with nitrifiers immobilized by the gel were investigated in a continuous‐flow stirred‐tank reactor (CFSTR) with cyclic temperature changes. The gel with an immobilized nitrifier swelled and shrank alternately with 1.2–1.6‐fold volume change under a cyclic temperature change of 32–36°C with a period of 2 or 4 h in the reactor. Volume changes of the gel brought periodic changes of its structure that accelerated dissolved oxygen transfer and concentrated ammonium into, and as a result, promoted nitrification compared with that at constant temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 681–686, 2007
Enhanced properties of innovative laponite‐filled waterborne acrylic resin dispersions
Authors: Nobel M. L. , Mendes E. , Picken S. J.
Published: October 2006

In view of the possible future applications of waterborne automotive coatings, acrylic‐based nanocomposite dispersions were investigated by the simple mixing of aqueous laponite nanoparticle dispersions with acrylic resin dispersions. The mechanical, flow, and leveling properties of waterborne nanocomposite dispersion formulations containing increasing concentrations of silicate and nonvolatile components (nvc) in the acrylic dispersions were investigated. The results obtained were related to the morphological information obtained from transmission electron microscopy and wide‐angle X‐ray scattering measurements in liquid suspension or on the cured films. At low synthetic silicate loading when flow, leveling, and appearance properties were still acceptable for processing and application, a large increase in the modulus of the cured coating films was observed, which was a result of the special morphology of the laponite‐rich regions of the cured film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 687–697, 2007
Influence of core–shell rubber particles synthesized with different initiation systems on the impact toughness of modified polystyrene
Authors: Gao Guanghui , Zhou Chao , Yang Haidong , Zhang Huixuan
Published: October 2006

Core–shell poly(butadiene‐graft‐styrene) (PB‐g‐PS) rubber particles were synthesized with different initiation systems by emulsion grafting polymerization. These initiation systems included the redox initiators and an oil‐soluble initiator, 1,2‐azobisisobutyronitrile (AIBN). Then the PB‐g‐PS impact modifiers were blended with polystyrene (PS) to prepare the PS/PB‐g‐PS blends. In the condition of the same tensile yield strength on both samples, the Izod test showed that the notched impact strength of PS/PB‐g‐PS(AIBN) was 237.8 J/m, almost 7 times than that of the PS/PB‐g‐PS(redox) blend, 37.2 J/m. From transmission electron microscope (TEM) photographs, using the redox initiators, some microphase PS zones existed in the core of PB rubber particles, which is called “internal‐grafting.” This grafting way was inefficient on toughening. However, using AIBN as initiator, a great scale of PS subinclusion was seen within the PB particle core, and this microstructure increased the effective volume fraction of the rubber phase with a result of improving the toughness of modified polystyrene. The dynamic mechanical analysis (DMA) on both samples showed that the glass transition temperature (Tg) of rubber phase of PS/PB‐g‐PS(AIBN) was lower than that of PS/PB‐g‐PS(redox). As a result, the PB‐g‐PS(AIBN) had better toughening efficiency on modified polystyrene than the PB‐g‐PS(redox), which accorded with the Kerner approximate equation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 738–744, 2007
Mixture printing pastes from high substitued guar gum and alginates on reactive printing of viscose
Authors: Perrin Akçakoca Kumbasar E.
Published: October 2006

The rheology of binary mixtures of two alginates and one carboxymethyl guar has been measured. Two reactive dyes were printed from pastes based on mixtures. The printing and the final print (color yield, levelness, and fabric stiffness) were assessed. Most of the mixtures reacted in accordance with the dye, and interacted especially with one of the dyes for which CMG was used. However, it is seen that mixture of CMG with alginates can be used in reactive printing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 745–751, 2007
Effects of material parameters on the diffusion and sorption properties of wood‐flour/polypropylene composites
Authors: Steckel Vera , Clemons Craig M. , Thoemen Heiko
Published: October 2006

Composites of wood in a thermoplastic matrix (wood–plastic composites) are considered a low maintenance solution to using wood in outdoor applications. Knowledge of moisture uptake and transport properties would be useful in estimating moisture‐related effects such as fungal attack and loss of mechanical strength. Our objectives were to determine how material parameters and their interactions affect the moisture uptake and transport properties of injection‐molded composites of wood‐flour and polypropylene and to compare two different methods of measuring moisture uptake and transport. A two‐level, full‐factorial design was used to investigate the effects and interactions of wood‐flour content, wood‐flour particle size, coupling agent, and surface removal on moisture uptake and transport of the composites. Sorption and diffusion experiments were performed at 20°C and 65 or 85% relative humidity as well as in water, and diffusion coefficients were determined. The wood‐flour content had the largest influence of all parameters on moisture uptake and transport properties. Many significant interactions between the variables were also found. The interaction between wood‐flour content and surface treatment was often the largest. The diffusion coefficients derived from the diffusion experiments were different from those derived from the sorption experiments, suggesting that different mechanisms occur. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 752–763, 2007
Synthesis, characterization, and flocculation characteristics of polyacrylamide‐grafted glycogen
Authors: Adhikary P. , Tiwari K. N. , Singh R. P.
Published: October 2006

The synthesis of glycogen‐g‐polyacrylamide (Gly‐g‐PAM) was carried out by a ceric ion‐induced solution polymerization technique. Six grades of graft copolymers were synthesized by the variation of catalyst and monomer concentrations. These graft copolymers were characterized by intrinsic viscosity measurements, FTIR spectroscopy, and X‐ray diffraction techniques. Flocculation performance of these graft copolymers were done in kaolin suspension. Of the above grades, the graft copolymer Gly‐g‐PAM 5, which has longer PAM chains, showed best flocculation performance. The flocculation performance of the graft copolymer was compared with commercial flocculants and other PAM‐grafted flocculants developed so far in the authors' laboratory. In all the cases, it was found that the graft copolymer performed the best. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 773–778, 2007
Effect of compatibilizer distribution on the blends of starch/biodegradable polyesters
Authors: Yu Long , Dean Katherine , Yuan Qiang , Chen Ling , Zhang Ximei
Published: October 2006

Various blends of gelatinized cornstarch and two biodegradable polyesters, PCL or PBSA, were prepared via melt processing using a twin‐screw extruder. Distribution of a compatibilizer MDI (methylenediphenyl diisocyanate) was controlled through the processing conditions employed and its effect on the resultant microstructure and mechanical properties of the blends were studied by SEM, DSC, TGA, and mechanical testing. When the MDI was distributed in the starch phase, the highly reactive isocyanate groups in MDI were most probably consumed by water that resulted in an overall weakening of its compatibilizing effect. Modulus, yield strength, and impact strength were increased by more than 35, 40, and 300%, respectively, when MDI was distributed in the polyester phase first rather than in the starch phase prior to blending. SEM observation showed that the interface between starch and the polyesters was improved significantly while DSC and TGA investigation also confirmed the microstructural difference. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 812–818, 2007
Incorporation of azobenzene chromophore into poly(amide‐imide)
Authors: Balogh D. T. , Carvalho A. J. F.
Published: October 2006

Poly(amide‐imide)s (PAI) bearing azobenzene chromophore groups were prepared by allowing a hydroxyl‐containing azobenzene dye (Disperse Red 1) to react with and reactive‐terminated PAI with weight–average molecular weights ranging from ∼ 1.2 to 2.0 × 104 g/mol. Such PAI were prepared by the condensation of trimellitic anhydride (TMA) and 4,4′‐methylene diphenyl diisocyanate (MDI). The final polymers presented a deep red color, with an absorption maxima in N,N‐dimethylformamide (DMF) solution at 490 nm, close to the azobenzene reactant used (Disperse Red 1) and molecular weights slightly higher than the pristine polymer, showing that the azo chromophore incorporation reaction does not lead to side reactions. The azofunctionalized polymer presented a high Tg value (170°C) that could be increased by a thermal curing process to 240°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 841–847, 2007
Solid‐state grafting of succinic anhydride onto poly(vinyl alcohol)
Authors: Zhou Zheng‐Fa , Xu Wei‐bing , He Dian , Fan Ji‐xian , Yu Feng , Ren Feng‐Mei
Published: October 2006

The graft reaction of succinic anhydride onto poly(vinyl alcohol) (PVA) was catalyzed by p‐toluenesulfonic acid monohydrate in solid state. The infrared spectra and 1H‐NMR spectra confirmed that succinic anhydride was successfully grafted onto PVA backbone. The influences of reaction temperature, reaction time, the amount of succinic anhydride, and the amount of catalyst on the graft reaction were studied. Uncrosslinked PVA graft copolymer with grafting degree up to about 6.5% could be obtained under low reaction temperature, short reaction time, and low amount of catalyst, whereas crosslinked PVA with high gel content could be obtained under high reaction temperature, long reaction time, and high amount of catalyst. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 848–852, 2007
Metabolic flux analysis of the two astaxanthin‐producing microorganisms Haematococcus pluvialis and Phaffia rhodozyma in the pure and mixed cultures
Authors: Dong Qing‐Lin , Zhao Xue‐Ming , Ma Hong‐Wu , Xing Xiang‐Ying , Sun Nai‐Xia
Published: October 2006

The two major astaxanthin‐producing microorganisms Phaffia rhodozyma and Haematococcus pluvialis exhibited elevated astaxanthin yields under the mixed culture regime, and the changes in flux distribution were investigated by means of metabolic flux analysis (MFA). In the mixed culture of the two strains, the carbon flux towards astaxanthin formation in P. rhodozyma increased by 20%, which may be due to the enriched oxygen evolved through the photosynthesis of H. pluvialis. On the other hand, the uptake of pyruvate and CO2 excreted by P. rhodozyma also facilitated astaxanthin synthesis in H. pluvialis, which reduced 33% of the carbon flux exported from Calvin cycle to the catabolic pathway, and in turn raised the carbon flux to glyceraldehyde‐3‐phosphate by 25%. As a result, the carbon flux diverted to astaxanthin synthesis increased 2.8‐fold in comparison with that in the pure culture.
The development of China's medical biotech industry needs to be driven by innovation
Authors: Yu Zailin , Dai Yuehan
Published: October 2006

The Chinese biotech industry is going through a period of fast growth, and with its huge population, China is predicted to be the biggest single‐country market in the world. However, the Chinese biotech industry has to tackle the critical issue of innovation, which should be the driving force for China's development into an advanced and responsible country. Here, in this article, the authors review the history of the Chinese biotech industry, exemplified by the development of genetically engineered drugs during the last 20 years, and also point out its the future.
A complete protein pattern of cellulase and hemicellulase genes in the filamentous fungus Trichoderma reesei
Authors: Ouyang Jia , Yan Ming , Kong Dechong , Xu Lin
Published: October 2006

The complete protein pattern of cellulase and hemicellulase genes was studied through the Genome‐wide analysis in Trichoderma reesei. The genome database revealed the presence of 39 ORFs encoding related proteins, including 32 enzymes with a catalysis domain related to cellulases and hemicellulases and 7 related proteins with a cellulose‐binding module (CBM). Ten of these encoded yet undescribed enzymes, including six novel β‐glucosidases or xylosidases, two putative xylanases and two undescribed mannases. To better illustrate the relation of these 39 related proteins, four groups were created and analyzed by phylogenetic analysis: group A corresponding to xylanases, group B belonging to mannases and acting to degrade mannan; group C containing all known and putative cellulose‐degrading proteins that have highly conserved CBMs; and group D containing β‐glucosidase and β‐xylosidase. Group D was the largest group, in which 8 β‐glucosidases appeared to be non‐secreted proteins.
Recent advances of microfluidics in Mainland China
Authors: Lin Bingcheng , Long Zhicheng , Liu Xin , Qin Jianhua
Published: October 2006

The history and current status of research on microfluidics in China is summarized in this review. The recent representative contributions in this field by Chinese scientists are cited. A perspective on some trends in future development of this field in China is presented.
Investigating pH and Cu (II) effects on lipase activity and enantioselectivity via kinetic and spectroscopic methods
Authors: Xu Tian‐Wen , Xu Jian‐He , Yu Wei , Zhong Ju‐Hua
Published: October 2006

For Candida rugosa lipase (CRL) catalyzed hydrolysis of racemic 1‐phenethyl acetate, both the weakly acidic pH (pH 6.0) and the addition of 1 mM copper (II) ion enhanced the enzyme activity and enantioselectivity (E value) about twofold, as compared with that under neutral pH and noadditive conditions. The decrease of activation free energy (ΔG) and increase of kcat(R)/kcat(S) at weakly acidic pH and/or in the presence of copper (II) characterized the kinetic behavior of CRL. On the other hand, for providing reasonable insights into the catalytic mechanism and the structural basis for enantioselectivity alteration, spectroscopic techniques were employed to probe conformational changes of the enzyme in each medium assayed. The fluorescence emission spectra revealed that pH and copper (II) might exert different effects on the microenvironment of Trp residue and thereby on the protein conformation, which could be further verified by UV‐visible and Raman spectra. The conformational modulation of CRL associated with either pH or copper (II) concentration in the reaction medium could be attributed to the flexible and sensitive conformation of the enzyme, which is responsible for the significant variation of apparent activity and enantioselectivity with the tuning of biocatalyst microenvironment.
Effects of PKC ζ on early genome transcription activation in mouse 1‐cell stage fertilized eggs
Authors: Yu Bing‐zhi , Fu Wei , Su Wen‐hui , Yu Da‐hai , Zhang Zhe , Feng Chen
Published: October 2006

Effects of PKC ζ on the activation of embryonic transcription in 1‐cell stage fertilized mouse eggs were explored. The effects of PKC antagonist calphostin C and PKC ζ specific inhibitor on the activation of embryonic early transcription were observed by Western blotting and cell immunofluorescence. PKC activity increased gradually from G1 phase to late G2 phase in mouse 1‐cell stage fertilized eggs, and reached a maximum in G2 stage. Calphostin C inhibited PKC activity by about 47% in 1‐cell stage fertilized eggs. Calphostin C inhibited early transcription in 1‐cell stage fertilized eggs (p < 0.01). PKC ζ‐Thr410 in G2 were about 27% and 110% higher than those in G1 phase of 1‐cell stage fertilized eggs and MII oocytes, respectively. PKC ζ specific inhibitor can also inhibit early transcription in 1‐cell stage fertilized eggs (p < 0.05). The results suggest that PKC ζ participates in early transcription activation in mouse 1‐cell stage fertilized eggs. Copyright © 2006 John Wiley & Sons, Ltd.
Upconversion Between 4f–5d Excited States in Tm2+‐Doped CsCaCl3, CsCaBr3, and CsCaI3
Authors: Grimm J. , Beurer E. , Gerner P. , Güdel H. U.
Published: October 2006

Near‐infrared to visible upconversion luminescence in CsCaCl3:Tm2+, CsCaBr3:Tm2+ and CsCaI3:Tm2+ is presented and analysed. The upconversion process involves exclusively the 4f–5d excited states of Tm2+, which is a novelty among upconversion materials. The presence of more than one long‐lived 4f–5d excited state is the prerequisite for this. Multiple emissions from Tm2+ are observed in the title compounds. This is made possible by the favourable energy structure within the 4f–5d states and the low phonon energies of the materials. The energy positions of the relevant 4f–5d states, and thus the photophysical and light emission properties, are affected by the chemical variation along the series. The upconversion efficiency increases from chloride to iodide and the mechanism is found to be a combination of absorption and energy‐transfer steps.
Atoms‐in‐Molecules Analysis of Extended Hypervalent Five‐Center, Six‐Electron (5c–6e) C2Z2O Interactions at the 1,8,9‐Positions of Anthraquinone and 9‐Methoxyanthracene Systems
Authors: Nakanishi Waro , Nakamoto Takashi , Hayashi Satoko , Sasamori Takahiro , Tokitoh Norihiro
Published: October 2006

To clarify the nature of five‐center, six‐electron (5c–6e) C2Z2O interactions, atoms‐in‐molecules (AIM) analysis has been applied to an anthraquinone, 1,8‐(MeZ)2ATQ (1(Z=Se),2(Z=S), and3(Z=O)), and a 9‐methoxyanthracene system, 9‐MeO‐1,8‐(MeZ)2ATC (4(Z=Se),5(Z=S), and6(Z=O)), as well as 1‐(MeZ)ATQ (7(Z=Se),8(Z=S), and9(Z=O)) and 9‐MeO‐1‐(MeZ)ATC (10(Z=Se),11(Z=S), and12(Z=O)). The total electronic energy density (Hb(rc)) at the bond critical points (BCPs), an appropriate index for weak interactions, has been examined for 5c–6e C2Z2O and 3c–4e CZO interactions of the np(O)⋅⋅⋅σ*(ZC) type in1–12. Some hydrogen‐bonded adducts were also re‐examined for convenience of comparison. The total electronic energy densities varied in the following order: O⋅⋅⋅O (3:Hb(rc)=0.0028 au)=O⋅⋅⋅O (6: 0.0028 au)>O⋅⋅⋅O (9: 0.0025 au)≥NN⋅⋅⋅HF (0.0024 au)≥O⋅⋅⋅O (12: 0.0023 au)≫H2O⋅⋅⋅HOH (0.0015 au)>S⋅⋅⋅O (8: 0.0013 au)=S⋅⋅⋅O (2: 0.0013 au)≥S⋅⋅⋅O (11: 0.0012 au)=S⋅⋅⋅O (5: 0.0012 au)>HF⋅⋅⋅HF (0.0008 au)=Se⋅⋅⋅O (10: 0.0008 au)=Se⋅⋅⋅O (4: 0.0008 au)≥Se⋅⋅⋅O (1: 0.0007 au)≥Se⋅⋅⋅O (7: 0.0006 au)≫HCN⋅⋅⋅HF (−0.0013 au).Hb(rc) values for S⋅⋅⋅O were predicted to be smaller than the hydrogen bond of H2O⋅⋅⋅HOH andHb(rc) values for Se⋅⋅⋅O are very close to or slightly smaller than that for HF⋅⋅⋅HF in both the ATQ and 9‐MeOATC systems. In the case of Z=Se and S,Hb(rc) values for 5c–6e C2Z2O interactions are essentially equal to those for 3c–4e CZO if Z is the same. The results demonstrate that two np(O)⋅⋅⋅σ*(ZC) 3c–4e interactions effectively connect through the central np(O) orbital to form the extended hypervalent 5c–6e system of the σ*(CZ)⋅⋅⋅np(O)⋅⋅⋅σ*(ZC) type for Z=Se and S in both systems. Natural bond orbital (NBO) analysis revealed that ns(O) also contributes to some extent. The electron charge densities at the BCPs, NBO analysis, and the total energies calculated for1–12, together with the structural changes in the PhSe derivatives, support the above discussion.
Methyl Vinyl Ketone+OH and Methacrolein+OH Oxidation Reactions: A Master Equation Analysis of the Pressure‐ and Temperature‐Dependent Rate Constants
Authors: Ochando‐Pardo Montserrat , Nebot‐Gil Ignacio , González‐Lafont Àngels , Lluch José M.
Published: October 2006

High‐level electronic structure calculations and master equation analyses were carried out to obtain the pressure‐ and temperature‐dependent rate constants of the methyl vinyl ketone+OH and methacrolein+OH reactions. The balance between the OH addition reactions at the high‐pressure limit, the OH addition reactions in the fall‐off region, and the pressure‐independent hydrogen abstractions involved in these multiwell and multichannel systems, has been shown to be crucial to understand the pressure and temperature dependence of each global reaction. In particular, the fall‐off region of the OH addition reactions contributes to the inverse temperature dependence of the rate constants in the Arrhenius plots, leading to pressure‐dependent negative activation energies. The pressure dependence of the methyl vinyl ketone+OH reaction is clearly more important than in the case of the methacrolein+OH reaction owing to the weight of the hydrogen abstraction process in this second system. Comparison of the theoretical rate constants and the experimental measurements shows quite good agreement.
MTO Schiff‐Base Complexes: Synthesis, Structures and Catalytic Applications in Olefin Epoxidation
Authors: Zhou Ming‐Dong , Zhao Jin , Li Jun , Yue Shuang , Bao Chang‐Nian , Mink Janos , Zang Shu‐Liang , Kühn Fritz E.
Published: October 2006

Several Schiff‐base ligands readily form complexes with methyltrioxorhenium(VII) (MTO) by undergoing a hydrogen transfer from a ligand‐bound OH group to a ligand N atom. The resulting complexes are stable at room temperature and can be handled and stored in air without problems. Due to the steric demands of the ligands they display distorted trigonal‐bipyramidal structures in the solid state, as shown by X‐ray crystallography, with the O− moiety binding to the Lewis acidic Re atom and the Re‐bound methyl group being located either in cis or trans position to the Schiff base. In solution, however, the steric differences seem not to be maintained, as can be deduced from 17O NMR spectroscopy. Furthermore, the Schiff‐base ligands exchange with donor ligands. Nevertheless, the catalytic behaviour is influenced significantly by the Schiff bases coordinated to the MTO moiety, which lead either to high selectivities and good activities or to catalyst decomposition. A large excess of ligand, in contrast to the observations with aromatic N‐donor ligands, is detrimental to the catalytic performance as it leads to catalyst decomposition.
Improved translation efficiency of injected mRNA during early embryonic development
Authors: Fink Maria , Flekna Gabriele , Ludwig Alfred , Heimbucher Thomas , Czerny Thomas
Published: October 2006

Injection techniques are a powerful approach to study gene function in fish and frog model systems. In particular, in vitro transcribed mRNA is broadly used for such misexpression experiments. Sequence elements flanking the coding region, such as untranslated repeats and polyadenylation sequences, are known to affect the stability and the translation efficiency of mRNA. Here we show that in early embryos, poly(A) signals strongly contribute to the activity of the injected mRNA. Of interest, they only marginally affect mRNA stability, whereas the translation efficiency is dramatically enhanced. Combination of a poly(A) tail and an SV40 late poly(A) signal leads to highly synergistic effects of the two elements for injected mRNA. Compared with established vector systems, we detected a 20‐fold improvement for mRNA derived from the novel transcription vector pMC. Developmental Dynamics 235:3370–3378, 2006. © 2006 Wiley‐Liss, Inc.
Steric effects on the dialkyl substituted X2C2Si silylenes: A theoretical study
Authors: Kassaee M. Z. , Musavi S. M. , Soleimani‐Amiri S. , Ghambarian M.
Published: October 2006

With the aim of recognizing the steric effects on the silylenic H2C2Si structures, ab initio and DFT calculations are carried out on 24 structures of X2C2Si (where X is hydrogen (H), methyl (Me), isopropyl (i‐pro), and tert‐butyl (tert‐Bu)). These species are at either triplet (t) or singlet (s) states. They are confined to the following three sets of structures (1X, 2X and 3X). Structures 1X include silacyclopropenylidenes (1s‐H and 1t‐H) and their 2,3‐disubstituted derivatives (1t‐Me, 1s‐Me; 1t‐i‐pro, 1s‐i‐pro; 1t‐tert‐Bu, 1s‐tert‐Bu). Structures 2X include vinylidenesilylenes (2s‐H and 2t‐H) and their 3,3‐disubstituted derivatives (2t‐Me, 2s‐Me; 2t‐i‐pro, 2s‐i‐pro; 2t‐tert‐Bu, 2s‐tert‐Bu). Structures 3X include ethynylsilylenes (3s‐H and 3t‐H) and their 1,3‐disubstituted derivatives (3t‐Me, 3s‐Me; 3t‐i‐pro, 3s‐i‐pro; 3t‐tert‐Bu, 3s‐tert‐Bu). Singlet–triplet energy separations (Δ Es‐t, X) and relative energies for the above structures are acquired at HF/6‐31G*, B1LYP/6‐31G*, B3LYP/6‐31G*, MP2/6‐31G*, HF/6‐31G**, B1LYP/6‐31G**, B3LYP/6‐31G**, and MP2/6‐31G** levels of theory. The highest Δ Es‐t, X is encountered for 1X. All singlet states of X2C2Si, are more stable than their corresponding triplet states. Linear correlations are found between the LUMO–HOMO energy gaps of the singlet 1s‐X and 2s‐X with their corresponding singlet–triplet energy separations calculated at B3LYP/6‐31G**. The seven structures 2s‐Me, 2t‐Me, 3s‐Me, 1t‐Me, 1s‐Me, 1s‐tert‐Bu, and 3t‐tert‐Bu do not appear to be real isomers. Different stability orders are obtained as a function of the substituents (X). The order of stability for six isomers of H2C2Si is 1s‐H > 2s‐H > 3s‐H > 2t‐H > 3t‐H > 1t‐H. Replacing hydrogen atoms by methyl group (X = Me) presents a new stability order: 1s‐Me > 3s‐Me > 2s‐Me > 3t‐Me > 2t‐Me > 1t‐Me; and for (i‐pro)2C2Si is 1s‐i‐pro > 2s‐i‐pro ≈ 3s‐i‐pro > 3t‐i‐pro ≈ 2t‐i‐pro > 1t‐i‐pro. Using the larger tert‐butyl group as a substituent (X), yet it offers a more different stability order for six structures of (tert‐Bu)2C2Si: 1s‐tert‐Bu > 3s‐tert‐Bu > 2s‐tert‐Bu > 3t‐tert‐Bu > 1t‐tert‐Bu > 2t‐tert‐Bu. Among eight levels employed, B3LYP/6‐31G** appears as the method of choice. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:619–633, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20204
Synthesis and thermal stability of S‐trimethylsilyl esters of tetracoordinated phosphorus amidothioacids
Authors: Nizamov Il'yas S. , Bolshakova Olga V. , Al'metkina Lyubov A. , Nizamov Il'nar D. , Sergeenko Gulnur G. , Frolova Liliya V. , Krivolapov Dmitry B. , Batyeva Elvira S. , Litvinov Igor A.
Published: October 2006

S‐(Diethylamino)dimethylsilyl bis(diethylamido)dithiophosphate 3 was obtained by the reaction of tetraphosphorus decasulfide 1 with bis(diethylamino)dimethylsilane 2a. The reactions of Lawesson's reagent 5 with 2a and the alkyl homologues of Davy's reagent 8a,b with trimethyl(diethylamino)silane 6 were studied. On the basis of these reactions, methods of synthesizing S‐(diethylamino)dimethylsilyl or S‐(diethylamino)diphenylsilyl 4‐methoxyphenyl (diethylamido)dithiophosphonates 7a and 7b and S‐trimethylsilyl S‐alkyl(diethylamido)trithiophosphates 9a,b are described. The optimal reaction conditions and thermal stability of S‐trimethylsilyl S‐ethyl(diethylamido)trithiophosphate 9a were defined by differential thermal analyses. Compound 9a have been decomposed to form 2,4‐bis(diethylamido)‐1,3,2,4‐dithiadiphosphetane‐2,4‐disulfide 10 which structure was established by X‐ray single crystal diffraction. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:670–675, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20231
Microwave‐assisted solid‐phase synthesis of 2,4,5‐triaryl imidazoles in solventless system: An improved protocol
Authors: Oskooie Hossein A. , Alimohammadi Zahra , Heravi Majid M.
Published: October 2006

The solventless microwave‐assisted synthesis of 2,4,5‐triaryl imidazoles from 1,2‐diphenylethandione or 2‐hydroxy‐1,2‐diphenylethanone in the presence of NH4OAc/NaHSO4 supported onto silica gel under microwave irradiation is reported. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:699–702, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20237
Syntheses of symmetric and unsymmetric 2,6‐bis(phosphino)phenols
Authors: Beganskiene Aldona , Nikishkin Nicolai I. , Luck Rudy L. , Urnezius Eugenijus
Published: October 2006

Compounds bearing the structural motif of 2,6‐bis(phosphino)phenol have been synthesized via two general methods. Double lithium‐halogen exchange occurred in low‐temperature reactions of O‐protected (by methyl‐ or tetrahydropyranyl groups) 2,6‐dibromo‐4‐methylphenol derivatives with BuLi (2 equivalents); quenching the reaction mixtures with chlorophosphines ClPR2 (R = Ph, iPr) and corresponding O‐deprotection yielded symmetrically substituted 2,6‐bis(phosphino)phenols. Sequential incorporation of PR2 functionalities was accomplished via single lithium‐halogen exchange (1 eq. of BuLi) of tetrahydropyranyl‐protected 2,6‐dibromo‐4‐methylphenol followed by ClPR2 quenches, thus enabling the syntheses of unsymmetric 2,6‐bis(phosphino)phenols. Such compounds were also obtained via sequential ortho‐lithiations of tetrahydropyranyl‐protected 4‐tert‐but ylphenol, followed by ClPR2 quenches. All of the new compounds have been characterized by spectrometric methods (1H and 31P NMR, and mass spectrometry). In addition, two of the compounds, 1‐(diphenylphosphino)‐3‐(diphenylphosphoryl)‐2‐methoxy‐5‐methylbenzene (3a‐ox) and 1,3‐bis(diphenylphosphino)‐2‐methoxy‐5‐methylbenzene (6a) have also been characterized via single crystal X‐ray diffraction experiments. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:656–663, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20251
Soluble poly(ethylene glycol) supported efficient synthesis of 2,5‐disubstituted 1,3,4‐oxadiazoles and 1,3,4‐thiadiazoles
Authors: Li Zheng , Yang Jingya , Wang Junke , Wang Xicun
Published: October 2006

An efficient soluble poly(ethylene glycol) (PEG) supported liquid‐phase parallel synthetic method for 2,5‐disubstituted 1,3,4‐oxadiazoles and 1,3,4‐thiadiazoles is described. 2‐Aryl‐5‐(4′‐methoxycarbonylphenoxymethyl)‐1,3,4‐oxadiazoles and 2‐aryloxymethyl‐5‐(4′‐methoxycarbonylphenoxyacetamido)‐1,3,4‐thiadiazoles are synthesized in high yield and high purity using this polymer supported strategy. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:664–669, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20253
Lawesson's reagent for direct thionation of hydroxamic acids: Substituent effects on LR reactivity
Authors: Przychodzeń Witold
Published: October 2006

To explore the generality and scope of direct thionation of hydroxamic acids (HAs), the reaction of various structurally diverse HAs with Lawesson's reagent was investigated. The yield of thiohydroxamic acid (THAs) is poor when HAs possess bulky acyl and/or N‐substituents, acidic α‐hydrogen atoms, or an N‐phenyl ring. THAs yields were correlated with Brown sigma parameter. The relative rates of two subsequent processes k and k were also measured. Correlation was also found for methine proton chemical shifts of N‐isopropyl benzothiohydroxamic acids. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:676–684, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20259
One‐pot synthesis of aryl and heteroaroyl‐substituted hydroxypyrazolines from the reactions of β‐alkoxyvinyl trichloromethyl ketones with heteroarylhydrazides
Authors: Bonacorso Helio G. , Oliveira Marli R. , Costa Michelle B. , Drekener Roberta L. , Silva Letícia B. da , Zanatta Nilo , Martins Marcos A. P.
Published: October 2006

The one‐step regiospecific synthesis of a novel series of 10 trichloromethyl‐, aryl‐, and heteroaroyl‐substituted 5‐hydroxy‐2‐pyrazolines affords 1‐(2‐thenoyl)‐, 1‐(2‐furoyl)‐, and 1‐(isonicotinoyl)‐3‐aryl‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐pyrazoles in 63–92% yields from the cyclocondensation reactions of 1,1,1‐trichloro‐4‐methoxy‐4‐aryl‐3‐buten‐2‐ones (where aryl substituents are –C6H5, 4‐CH3C6H4, 4‐OCH3C6H4, 4‐FC6H4, 4‐ClC6H4, 4‐BrC6H4) with 2‐thiophenecarboxylic hydrazide, furoic hydrazide, and isonicotinic acid hydrazide, respectively. Dehydration reaction of two 2‐pyrazolines with P2O5 furnished the corresponding 1H‐pyrazoles in low yields (21–29%). © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:685–691, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20261
Restoring theta‐like rhythmicity in rats restores initial learning in the Morris water maze
Authors: McNaughton Neil , Ruan Ming , Woodnorth Mary‐Anne
Published: October 2006

Neural activity often becomes rhythmic during mental processing. But there has been no direct proof that rhythmicity, per se, is important for mental function. We assessed this issue in relation to the contribution of hippocampal theta‐frequency rhythmicity to learning in the Morris water maze by blocking theta (and other septal inputs to the hippocampus) and then using electrical stimulation to restore rhythmicity. We injected tetracaine into the medial septal area, and so blocked septal input to the hippocampus in rats throughout 16 consecutive trials in a Morris water maze. Rats with no hippocampal theta also showed no initial learning in the maze. Theta rhythmicity in the supramammillary area remained after septal blockade, and we used this to trigger electrical stimulation of the fornix superior. This substantially restored hippocampal theta‐like rhythmicity throughout training at a normal frequency but with abnormal wave forms. This treatment applied throughout training substantially restored initial learning. Fixed frequency (7.7 Hz) stimulation produced rhythmic activity and a brief improvement in learning. Irregular stimulation with an average frequency of 7.7 Hz produced little rhythmicity and little improvement in learning. These results demonstrate that brain rhythmicity, per se, can be important for mental processing even when the detailed information originally carried by neurons is lost and when the reinstated pattern of population firing is not normal. The results suggest that the precise frequency of rhythmicity may be important for hippocampal function. Functional rhythmicity needs, therefore, to be included in neural models of cognitive processing. The success of our procedure also suggests that simple alterations of rhythmicity could be used to ameliorate deficits in learning and memory. © 2006 Wiley‐Liss, Inc.