bluuebunny/crossref_metadata_2025_split huggingface dataset:
New developments in natural products‐based anti‐AIDS research
Authors: Yu Donglei , Morris‐Natschke Susan L. , Lee Kuo‐Hsiung 
Published: August 2006

AbstractThis review discusses anti‐HIV natural products from several compound classes, including terpenoids, coumarins, alkaloids, polyphenols, tannins, and flavonoids. Natural products can provide novel anti‐AIDS chemotherapeutic leads that are structurally unique or have new mechanisms of action. The drug discovery and development process proceeds from bioactivity‐directed isolation and identification of a promising lead natural product, followed by rational design‐based structural modification and structure–activity relationship analyses to optimize the lead compound as a drug candidate. This process is notably exemplified by the discovery of the modified betulinic acid derivative, DSB [PA‐457], which is currently in Phase II clinical trial and is the first‐in‐class HIV maturation inhibitor (MI). © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 1, 108–132, 2007
MRI detects myocardial iron in the human heart
Authors: Ghugre Nilesh R. , Enriquez Cathleen M. , Gonzalez Ignacio , Nelson Marvin D. , Coates Thomas D. , Wood John C. 
Published: August 2006

AbstractIron‐induced cardiac dysfunction is a leading cause of death in transfusion‐dependent anemia. MRI relaxation rates R2(1/T2) and R(1/T) accurately predict liver iron concentration, but their ability to predict cardiac iron has been challenged by some investigators. Studies in animal models support similar R2 and R behavior with heart and liver iron, but human studies are lacking. To determine the relationship between MRI relaxivities and cardiac iron, regional variations in R2 and R were compared with iron distribution in one freshly deceased, unfixed, iron‐loaded heart. R2 and R were proportionally related to regional iron concentrations and highly concordant with one another within the interventricular septum. A comparison of postmortem and in vitro measurements supports the notion that cardiac R should be assessed in the septum rather than the whole heart. These data, along with measurements from controls, provide bounds on MRI‐iron calibration curves in human heart and further support the clinical use of cardiac MRI in iron‐overload syndromes. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
The significance of diabetes and disability: referrals made to a disability service
Authors: Singh R , Hunter J , Fulton C 
Published: August 2006

AbstractDiabetes mellitus is an important cause of disability even after correction for complications. It has been suggested that diabetes may be underestimated in referrals to rehabilitation services. We tested this by assessing how often patients with diabetes had this diagnosis mentioned when referred to a wheelchair clinic. Two hundred consecutive referrals to a wheelchair service were assessed to ascertain whether diabetes was mentioned in the referral letter compared to how many actually had a diagnosis of diabetes. This was then compared to other medical conditions to assess whether diabetes was being under‐mentioned in referrals.Only 7/29 (24.1%) patients with diabetes in the cohort had diabetes mentioned in their referral. By comparison, 34/42 (81%) of those with stroke/heart failure/chronic obstructive pulmonary disease were mentioned (χ2=22.69, df=1, p<0.001) There was no difference between those with diabetes mentioned or not mentioned in terms of age, gender, type of diabetes, HbA1c or complication rate.We conclude that diabetes is under‐mentioned in referrals to a rehabilitation service. It may be the case that health services are yet to appreciate the significance of diabetes as a cause of disability compared to other major conditions that cause disability. There seems to be a need to create an awareness of the importance of diabetes in disability. Copyright © 2006 John Wiley & Sons, Ltd.
Diabetes and alcohol: time for realistic advice based on the evidence
Authors: Evans KM , Kerr D , Flanagan DE 
Published: August 2006

AbstractThe recommendation at present is that, if you have diabetes, alcohol should be avoided or restricted. It is clear that for a significant proportion of people with diabetes this advice is ignored. However, there is now much evidence to challenge the once accepted view that alcohol is best avoided by the patient with diabetes. Current epidemiological evidence would support the view that moderate alcohol consumption has health benefits particularly in reducing the risk of vascular disease. The difficulty is how we translate this knowledge into advice for people living with diabetes on a daily basis. This article considers the relationships between alcohol and diabetes: from weighing the epidemiological evidence, to practical clinical advice. Copyright © 2006 John Wiley & Sons, Ltd.
Gel‐free mass spectrometry‐based high throughput proteomics: Tools for studying biological response of proteins and proteomes
Authors: Roe Mikel R. , Griffin Timothy J. 
Published: August 2006

AbstractRevolutionary advances in biological mass spectrometry (MS) have provided a basic tool to make possible comprehensive proteomic analysis. Traditionally, two‐dimensional gel electrophoresis has been used as a separation method coupled with MS to facilitate analysis of complex protein mixtures. Despite the utility of this method, the many challenges of comprehensive proteomic analysis has motivated the development of gel‐free MS‐based strategies to obtain information not accessible using two‐dimensional gel separations. These advanced strategies have enabled researchers to dig deeper into complex proteomes, gaining insights into the composition, quantitative response, covalent modifications and macromolecular interactions of proteins that collectively drive cellular function. This review describes the current state of gel‐free, high throughput proteomic strategies using MS, including (i) the separation approaches commonly used for complex mixture analysis; (ii) strategies for large‐scale quantitative analysis; (iii) analysis of post‐translational modifications; and (iv) recent advances and future directions. The use of these strategies to make new discoveries at the proteome level into the effects of disease or other cellular perturbations is discussed in a variety of contexts, providing information on the potential of these tools in electromagnetic field research.
Metabolomics: Current technologies and future trends
Authors: Hollywood Katherine , Brison Daniel R. , Goodacre Royston 
Published: August 2006

AbstractThe ability to sequence whole genomes has taught us that our knowledge with respect to gene function is rather limited with typically 30–40% of open reading frames having no known function. Thus, within the life sciences there is a need for determination of the biological function of these so‐called orphan genes, some of which may be molecular targets for therapeutic intervention. The search for specific mRNA, proteins, or metabolites that can serve as diagnostic markers has also increased, as has the fact that these biomarkers may be useful in following and predicting disease progression or response to therapy. Functional analyses have become increasingly popular. They include investigations at the level of gene expression (transcriptomics), protein translation (proteomics) and more recently the metabolite network (metabolomics). This article provides an overview of metabolomics and discusses its complementary role with transcriptomics and proteomics, and within system biology. It highlights how metabolome analyses are conducted and how the highly complex data that are generated are analysed. Non‐invasive footprinting analysis is also discussed as this has many applications toin vitrocell systems. Finally, for studying biotic or abiotic stresses on animals, plants or microbes, we believe that metabolomics could very easily be applied to large populations, because this approach tends to be of higher throughput and generally lower cost than transcriptomics and proteomics, whilst also providing indications of which area of metabolism may be affected by external perturbation.
Synthesis and characterization of functional gradient copolymers of allyl methacrylate and butyl acrylate
Authors: París Rodrigo , de la Fuente José Luis 
Published: August 2006

AbstractFunctional spontaneous gradient copolymers of allyl methacrylate (A) and butyl acrylate (B) were synthesized via atom transfer radical polymerization. The copolymerization reactions were carried out in toluene solutions at 100 °C with methyl 2‐bromopropionate as the initiator and copper bromide with N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the catalyst system. Different aspects of the statistical reaction copolymerizations, such as the kinetic behavior, crosslinking density, and gel fraction, were studied. The gel data were compared with Flory's gelation theory, and the sol fractions of the synthesized copolymers were characterized by size exclusion chromatography and nuclear magnetic resonance spectroscopy. The copolymer composition, demonstrating the gradient character of the copolymers, and the microstructure were analyzed. The experimental data agreed well with data calculated with the Mayo–Lewis terminal model and Bernoullian statistics, with monomer reactivity ratios of 2.58 ± 0.37 and 0.51 ± 0.05 for A and B, respectively, an isotacticity parameter for A of 0.24, and a coisotacticity parameter of 0.33. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5304–5315, 2006
Direct dehydration polycondensation of lactic acid catalyzed by water‐stable Lewis acids
Authors: Takasu Akinori , Narukawa Yuuki , Hirabayashi Tadamichi 
Published: August 2006

AbstractPoly(L‐lactic acid) (PLLA) is generally produced by ring‐opening polymerization of (S,S)‐lactide, which is prepared from dehydration polycondensation of lactic acid and successive depolymerization. Results of this study show that scandium trifluoromethanesulfonate [Sc(OTf)3] and scandium trifluoromethanesulfonimide [Sc(NTf2)3] are effective for one‐step dehydration polycondensation of L‐lactic acid. Bulk polycondensation of L‐lactic acid was carried out at 130–170 °C to give PLLA with Mn of 5.1 × 104 to 7.3 × 104 (yield 32–60%). The solution polycondensation was performed at 135 °C for 48 h to afford PLLA with Mn of 1.1 × 104 with good yield (90%). In no case did 1H NMR, specific optical rotation, or DSC measurement confirm racemizations. The catalyst was recovered easily by extraction with water and reused for polycondensation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5247–5253, 2006
Synthesis and characterization of conducting polythiophene/carbon nanotubes composites
Authors: Karim Mohammad Rezaul , Lee Chul Jae , Lee Mu Sang 
Published: August 2006

AbstractConducting polythiophene (PTh)/single‐wall carbon nanotubes (SWNTs) composites were synthesized by the in situ chemical oxidative polymerization method. The resulting cablelike morphology of the composite (SWNT–PTh) structures was characterized with elemental analysis, X‐ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared, ultraviolet–visible spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, X‐ray diffraction, and transmission electron microscopy. The standard four‐point‐probe method was used to measure the conductivity of the samples. Field emission scanning electron microscopy and transmission electron microscopy analysis revealed that the SWNT–PTh composites were core (SWNTs) and shell (PTh) hybrid structures. Spectroscopic analysis data for the composites were almost identical to those for PTh, supporting the idea that SWNTs served as templates in the formation of a coaxial nanostructure for the composites. The physical properties of the composites were measured and also showed that the SWNTs were modified by conducting PTh with an enhancement of various properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5283–5290, 2006
Copolymerization of norbornene and styrene catalyzed by a novel anilido–imino nickel complex/methylaluminoxane system
Authors: Gao Haiyang , Chen Yan , Zhu Fangming , Wu Qing 
Published: August 2006

AbstractCopolymerizations of norbornene with styrene were carried out with a catalytic system of anilido–imino nickel complex (ArNCHC6H4NAr)NiBr (Ar = 2,6‐dimethylphenyl) and methylaluminoxane in toluene. The influence of the comonomer feed content and polymerization temperature on the conversion and composition of the copolymers with (ArNCHC6H4NAr)NiBr/methylaluminoxane was investigated. An increase in the initial styrene feed content led to an increase in the incorporated styrene content of the resulting copolymer. The determination of the reactivity ratios showed a much high reactivity for norbornene (reactivity ratio for styrene = 0.26, reactivity ratio for norbornene = 20.78), which was consistent with a coordination mechanism. NMR analysis of the end groups further confirmed that the chain was initiated through a styrene secondary insertion or a norbornene insertion into NiH and terminated through β‐H elimination from an inserted styrene unit. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5237–5246, 2006
Defects and their removal in block copolymer thin film simulations
Authors: Bosse August W. , Sides Scott W. , Katsov Kirill , García‐Cervera Carlos J. , Fredrickson Glenn H. 
Published: August 2006

AbstractIn recent years, there has been increased interest in using microphase‐separated block copolymer thin films as submicrometer/suboptical masks in next generation semiconductor and magnetic media fabrication. With the goals of removing metastable defects in block copolymer thin film simulations and potentially examining equilibrium defect populations, we report on two new numerical techniques that can be used in field‐theoretic computer simulations: (1) aspectral amplitude filter(SF) that encourages the simulation to relax into high symmetry states (representing zero defect states), and (2) different variants of force‐biased,partial saddle point Monte Carloalgorithms that allow for barrier crossing toward lower energy defect‐free states. Beyond their use for removing defects, the force‐biased Monte Carlo algorithms will be seen to provide a promising tool for studying equilibrium defect populations. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2495–2511, 2006
Multiblock copolymers at selective liquid–liquid interfaces: Toward a block size chromatography
Authors: Corsi Andrea , Milchev Andrey , Rostiashvili Vakhtang G. , Vilgis Thomas A. 
Published: August 2006

AbstractWe report some very recent studies on the localization of hydrophobic‐polar regular copolymers at a selective solvent–solvent interface with emphasis on the impact of block length M on their static properties and dynamics. A simple scaling theory is developed and its predictions are compared with extensive Monte Carlo simulations to provide an adequate description of copolymers behavior at such penetrable phase boundary. We have derived and verified the scaling of various quantities such as the components of the radius of gyration parallel and perpendicular to the interface, the lateral diffusion constant, as well as the characteristic relaxation times for the localization of the polymer coil in terms of chain length N and block size M for various strength of the interface. The copolymer dynamics is elucidated by a Rouse‐mode analysis, which reveals a specific coupling of the modes once a copolymer is adsorbed at the selective interface. For the case of copolymer chains being dragged by an external field through the selective interface, we provide results, which suggest a possible application as a new type of chromatography designed to separate and purify complex mixtures with respect to the chain length and the block size of the individual macromolecules. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2572–2588, 2006
Anti‐fatigue activity of a triterpenoid‐rich extract from Chinese bamboo shavings (Caulis bamfusae in taeniam)
Authors: Zhang Yu , Yao Xiaobao , Bao Bili , Zhang Ying 
Published: August 2006

AbstractThe anti‐fatigue activity of a pentacyclic triterpenoid extract from bamboo shavings (EBS) from the bark of bamboo (Bambusa tuldoides Munro), was evaluated in BALB/c mice. EBS, isolated by the supercritical CO2 fluid extraction (SFE) technique, was given to mice at concentrations of 0.04 (low‐dose group), 0.08 (middle‐dose group) and 0.25 g/kg body weight (high‐dose group). The anti‐fatigue activity of EBS was estimated by the change in body weight, weight‐loaded swimming test and climbing test, and corresponding parameters including serum urea nitrogen, hepatic glycogen and blood lactic acid were measured. The results showed that an appropriate level of EBS could prolong the weight‐loaded swimming and climbing time, and had an active effect on the serum urea nitrogen, hepatic glycogen and blood lactic acid level in BALB/c mice, which significantly embodied the anti‐fatigue activity of EBS. Overall, it is predicted that EBS, being a composition mainly containing a group of pentacyclic triterpenoids, and its main triterpenoid components have great potential for application in relevant fields for its anti‐fatigue activity. Copyright © 2006 John Wiley & Sons, Ltd.
A performance evaluation of multiple classification models of human PEPT1 inhibitors and non‐inhibitors
Authors: Kamphorst Jurre , Cucurull‐Sanchez Lourdes , Jones Barry 
Published: August 2006

AbstractThe human PEPT1 protein is an influx transporter known to influence the ADME profile of several bioactive compounds. A good example is acyclovir, which possesses high safety and selectivity but has a low bioavailability. The L‐valyl ester prodrug of this compound is transported by PEPT1, resulting in a three‐ to four‐fold increase in plasma levels. Therefore, knowledge of the Structure–Activity Relationships (SAR) of PEPT1 ligands can enable us to favourably manipulate the ADME properties of promising leads that suffer from low bioavailability. We applied three classification methods (naïve Bayesian classification, recursive partitioning and linear discriminant analysis) together with the descriptors best suited for each method to a large PEPT1 inhibitor/non‐inhibitor dataset. This dataset was assembled from literature and was divided into three groups: the ‘inhibitor’ group (Ki≤1 mM, 113 compounds), the ‘unknown’ group (Ki>1 mM and <4.48 mM, 21 compounds) and the ‘non‐inhibitor’ group (Ki≥4.48 mM, 69 compounds). The inhibitor and non‐inhibitor groups were used to build the models. The Bayesian classification model together with fingerprint descriptors was found to produce the best results. Of a test set of 46 compounds, it correctly classified 89% (concordance). It correctly classified 96% of the inhibitors and 78% of the non‐inhibitors. Although the model informs us only about structural requirements for inhibition and not necessarily for transportation, the SAR identified by the Bayesian model support previously published results. In addition, the results were obtained in a short‐time span, without the need of three‐dimensional configurations and with more compounds than in previous studies.
Learning in a personal context: Levels of choice in a free choice learning environment in science and natural history museums
Authors: Bamberger Yael , Tal Tali 
Published: August 2006

AbstractThe study aims to characterize contextual learning during class visits to science and natural history museums. Based on previous studies, we assumed that “outdoor” learning is different from classroom‐based learning, and free choice learning in the museums enhances the expression of learning in personal context. We studied about 750 students participating in class visits at four museums, focusing on the levels of choice provided through the activity. The museums were of different sizes, locations, visitor number, and foci. A descriptive‐interpretative approach was adopted, with data sources comprising observations, semistructured interviews with students, and museum worksheets. Analysis of the museum activities has yielded four levels of choice that affect learning from no choice to free choice activities. The effectiveness of learning was examined as well by looking at task behavior, linkage to the students' prior knowledge and their school's science curriculum, and linkage to the students' life and experience. Our findings indicate that activities of limited choice offered scaffolding, allowed the students to control their learning, and enhanced deeper engagement in the learning process. Within all the choice opportunities, the students connected the visit to their own life experiences and to their prior knowledge, even when the guided activity scarcely addressed it. Critical responses were obtained mainly when the museum environment allows a variety of learning opportunities without directing the students. © 2006 Wiley Periodicals, Inc. Sci Ed 91:75–95, 2007
Ultrasound finding of an echogenic mass in women with secondary postpartum hemorrhage is associated with retained placental tissue
Authors: Mulic‐Lutvica A. , Axelsson O. 
Published: August 2006

AbstractObjectivesTo describe sonographic findings associated with retained placental tissue in patients with secondary postpartum hemorrhage, and to compare these findings with those of women with a normal puerperium.MethodsThis was a prospective observational study of 79 women with secondary postpartum hemorrhage. Ultrasound examinations were performed on the day the patients presented with clinical symptoms and were scheduled for postpartum days 1, 3, 7, 14, 28 and 56, continuing until uterine surgical evacuation was performed or until the bleeding stopped. The maximum anteroposterior (AP) diameters of the uterus and uterine cavity were measured and morphological findings in the cavity were recorded. The findings were compared with previously published results from a normal population.ResultsThe patients were divided into two groups. Group 1 (n = 18) underwent surgery and Group 2 (n = 61) was treated conservatively. Sonography revealed an echogenic mass in the uterine cavity in 17 patients from Group 1, and in 14 of these patients histology confirmed placental tissue. The AP diameter of the uterine cavity was above the 90th percentile in all but two of the 18 Group 1 patients. In 18 patients from Group 2 the cavity was empty and in 43 a mixed‐echo pattern was found. The uterine cavity was wider compared with the controls, but the values largely overlapped.ConclusionThis report supports the opinion that the sonographic finding of an echogenic mass in the uterine cavity in women with secondary postpartum hemorrhage is associated with retained placental tissue. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.