bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodiversity: A continuing source of novel drug leads
Authors: Cragg Gordon M. , Newman David J. 
Published: February 2005

Abstract
Nature has been a source of medicinal agents for thousands of years and continues to be an abundant source of novel chemotypes and pharmacophores. With only 5 to 15 % of the approximately 250 000 species of higher plants systematically investigated, and the potential of the marine environment barely tapped, these areas will remain a rich source of novel bioactive compounds. Less than 1 % of bacterial and 5 % of fungal species are currently known, and the potential of novel microbial sources, particularly those found in extreme environments, seems unbounded. To these natural sources can be added the potential to investigate the rational design of novel structure types within certain classes of microbial metabolites through genetic engineering. It is apparent that Nature can provide the novel chemical scaffolds for elaboration by combinatorial approaches (chemical and biochemical), thus leading to agents that have been optimized on the basis of their pharmacological activities. The proven natural product drug discovery track record, coupled with the continuing threat to biodiversity through the destruction of terrestrial and marine ecosystems and the current low number of new chemical entities in pharmaceutical industry pipelines, provides a compelling argument in favor of expanded multidisciplinary and international collaboration in the exploration of Nature as a source of novel leads for the development of drugs and other valuable bioactive agents.
Investigations toward new lead compounds from medicinally important plants
Authors: Prasad Ashok K. , Kumar Vineet , Arya Pragya , Kumar Sarvesh , Dabur Rajesh , Singh Naresh , Chhillar Anil K. , Sharma Gainda L. , Ghosh Balaram , Wengel Jesper , Olsen Carl E. , Parmar Virinder S. 
Published: February 2005

Abstract
Extensive phytochemical investigations on 30 Piper species growing in India and other medicinal plants have revealed the presence of a large number of novel compounds belonging to different classes. The antiviral activity of several lignans and neolignans belonging to different structural types has been evaluated against six different viral strains. Further, the effects of ethanol, chloroform, and hexane extracts of Piper longum and Piper galiatum on TNF-α induced expression of intercellular adhesion molecule-1 (ICAM-1) on human umbilical vein endothelial cells have been studied, a novel aromatic ester was isolated from the most active extract of P. longum. A potential antifungal compound having implications in treating aspergillosis was isolated from an important Indian medicinal plant, Datura metel.
New anti-invasive compounds: Results from the Indo-Belgian screening program
Authors: Vanhoecke Barbara W. , Depypere Herman T. , De Beyter Anicée , Sharma Sunil K. , Parmar Virinder S. , De Keukeleire Denis , Bracke Marc E. 
Published: February 2005

Abstract
The development of anti-invasive and anti-metastatic drugs is a major challenge in current cancer research. A model to study invasion in vitro consisted of organotypic confronting cultures of human MCF-7/6 mammary cancer cells with embryonic chicken heart fragments. Untreated cultures show occupation and destruction of the normal heart fragments within eight days. Inhibition of invasion was observed after addition of the following alkaloids and (poly)phenolics to the culture medium: (+)-catechin, tangeretin, xanthohumol, 3,7-dimethoxyflavone, prenylated chalcones, a pyrazole derivative, an isoxazolylcoumarin, and a prenylated desoxybenzoin. The action targets have been found both in the cancer cells and the surrounding host tissue. We hope that the further characterization of these targets will eventually lead to the development of clinically applicable anti-invasive drugs.
Noniterative approach to the total asymmetric synthesis of 15-carbon polyketides and analogs with high stereodiversity
Authors: Vogel Pierre , Gerber-Lemaire Sandrine , Carmona Ana T. , Meilert Kai Torsten , Schwenter Marc-Etienne 
Published: February 2005

Abstract
Starting from inexpensive furan and furfuryl alcohol, a noniterative approach to the synthesis of pentadeca-1,3,5,7,9,11,13,15-octols and their derivatives has been developed. The method relies upon the double [4+3]-cycloaddition of 1,1,3-trichloro-2-oxylallyl cation with 2,2'-methylenedifuran and conversion of the adducts into meso and (±)-threo-1,1'-methylenebis (cis- and trans-4,6-dihydroxycyclohept-1-ene) derivatives. The latter undergo oxidative cleavage of their alkene moieties, generating 5-hydroxy-7-oxoaldehydes that are reduced diastereoselectively into either syn or anti-5,7-diols. Asymmetry is realized using either chiral desymmetrization with Sharpless asymmetric dihydroxylation or by kinetic resolution of polyols using lipase-catalyzed acetylations. All of the possible stereomeric pentadeca-1,3,5,7,9,11,13,15-octols and derivatives can be obtained with high stereoselectivity applying simple operations, thus demonstrating the high stereodiversity of this new, noniterative approach to the asymmetric synthesis of long-chain polyketides.
Selective transacylation reactions on 4-aryl-3,4-dihydropyrimidin-2-ones and nucleosides mediated by novel lipases
Authors: Poonam  , Prasad Ashok K. , Mukherjee Chandrani , Shakya Gaurav , Meghwanshi Gautam K. , Wengel Jesper , Saxena Rajendra K. , Parmar Virinder S. 
Published: February 2005

Abstract
Different (±)-4-(3/4-acetoxyaryl)-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2-ones have been synthesized and subjected to enantioselective deacetylation reactions mediated by different lipases in organic media. Novozyme 435 in tetrahydrofuran:diisopropyl ether was found to be the catalyst of choice for efficient enantioselective deacetylation of dihydropyrimidinones under study. Further, we discovered that lipase isolated from Pseudomonas aeruginosa can be used for selective acylation of secondary hydroxyl groups in nucleosides. This observation can be very useful for selective manipulation of different hydroxyl groups in nucleosides.
Electrostatic cross-modulation of the pseudoaromatic character in single-stranded RNA by nearest-neighbor interactions
Authors: Acharya Parag , Chattopadhyaya Jyoti 
Published: February 2005

Abstract
The generation of a single anionic or cationic center at an alkaline or acidic pH in a given molecule presents a unique opportunity to examine the electrostatic make-up of these molecules both at the neutral or ionic state. The generation of a single cationic center in the phenyl-nicotinamide system provided new straightforward evidence showing that the charge density of the electron-deficient pyridinium was actually enhanced by the donation of the charge from the electron-rich phenyl group (i.e., the pyridinyl became more basic by ca. 0.5 pK
a unit compared to an analogous system where phenyl was absent) owing to the electrostatic interactions between these two moieties. On the other hand, the generation of the 5'-guanylate ion in the hexameric single-strand (ss) RNA [5'-GAAAAC-3'], in comparison with the constituent trimeric, tetrameric, and pentameric-ssRNAs, has unequivocally shown how far the electrostatic cross-talk (as an interplay of Coulombic attractive or repulsive forces) in this electronically coupled system propagates through the intervening pAp nucleotide steps until the terminal pC-3' residue in comparison with the neutral counterpart. The footprint of the propagation of this electrostatic cross-talk among the neighboring nucleobases is evident by measurement of pK
as from the marker protons of ionization point (i.e., of G) as well as from the neighboring marker protons (i.e., of A or C) in the vicinity, as well as from the change of the chemical environment (i.e., chemical shifts) around their aromatic marker protons (δH2, δH8, δH5, and δH6) owing to a change of the stacking-destacking equilibrium as a function of pH.
A Correlation Between Dynamic Cone Penetrometer Values and Pavement Layer Moduli
Authors: Chen D-H , Lin D-F , Liau P-H , Bilyeu J 
Published: February 2005

AbstractThe Dynamic Cone Penetrometer (DCP) is one of the least expensive testing devices able to characterize base and subgrade properties. To fully use the DCP in pavement evaluation, an empirical relationship between DCP penetration rate and layer modulus is required. However, the literature on this correlation is limited. This study incorporates a total of 198 DCP and Falling Weight Deflectometer (FWD) tests done over 8 years on various types of highways (Interstate Highway, US, and Farm-to-Market). The computer program MODULUS was employed to backcalculate the layer moduli from the FWD results to build a correlation with DCP results. A comparison was made with the widely-used model by Powell et al. (1984). It is found that the difference between the two models decreases as the Penetration Rate (PR) increases. For a PR of less than 10 mm/blow, the difference between these two models was over 10%. The difference is only about 1.7 % when the PR is 80 mm/blow. Without knowing the true moduli, it is impossible to tell which equation is better. The correlation developed here provides another option and allows researchers to recognize the range of variability.
Flexible Crumb Tire Rubber-Filled Cement Mortars as a Protective System for Buried Infrastructure
Authors: Nehdi M , Khan A , Sumner J 
Published: February 2005

Abstract
Due to population growth and urban congestion, the space available for the development of public infrastructure is sharply decreasing. Engineers are therefore resorting to the efficient use of underground space, which involves the construction of tunnels and other underground structures. Many such projects will be located in rock/soil with time-dependent behavior or under high overburden pressure. Thus, under such stress conditions, there may be a need for a deformable supporting system that can serve as a buffer layer to protect tunnel linings from time-dependent deformations of the excavated rock/soil. This paper investigates the use of cement mortars containing crumb recycled tire rubber to develop a flexible interface material for such applications. The effects of the w/c ratio, rubber content, and particle size on the mechanical properties of rubber filled mortars were studied using uniaxial and triaxial compression tests. A statistical factorial experimental plan was designed to obtain response surfaces for the parameters under study. A model tunnel was made, instrumented, and tested in a specially designed pressure cell under hydrostatic pressure to investigate the effect of using flexible rubber-filled mortar layers around tunnel linings on the development of stresses. The findings of this research suggest that cement mortars containing crumb tire rubber have superior ductility and may be used to accommodate deformations around tunnel linings, pipelines, and other buried infrastructure.
Evaluation of the Effect of Crack Tip Constraint on Fatigue Crack Growth Rate in Inconel 718
Authors: Joyce JA 
Published: February 2005

AbstractThe objective of this work has been to characterize the fatigue crack growth rate of Inconel 718 in the elastic and elastic-plastic regimes. The major new contribution here is to develop fatigue crack growth rate data on this alloy using shallow crack specimens subjected to cyclic loadings that involve material plasticity exceeding what is allowed by the standard Linear Elastic Fracture Mechanics (LEFM) procedures of ASTM E 647.Compact (C(T)) and three point bend (SE(B)) specimen geometries were used in this investigation. The SE(B) specimens were used to obtain shallow crack data using crack to depth ratios (a/W) as small as 0.08 in standard bend specimens with W = 50.8 mm. Compliance methods were used to estimate the crack length during the cyclic testing. The C(T) specimens were used to investigate the effect of fully reversed loading, i.e., R = −1.0. These specimens were tested only in deep crack configurations with a/W &gt; 0.3. Both C(T) and SE(B) specimens were used to obtain high cycle fatigue crack growth data as well as some component of the low cycle fatigue crack growth rate data. The cyclic elastic stress intensity range was used to characterize the crack growth driving “force” in the high cycle regime as defined in ASTM E 647. A cyclic J integral range, as originally utilized by Dowling and Begley [1], was used in the elastic-plastic regime.High cycle and low cycle fatigue crack growth data were successfully obtained from tests on shallow crack SE(B) specimens. High cycle fatigue crack growth was not affected by specimen geometry or by crack length ratio, even for a/W ratios as low as 0.08. The low cycle fatigue crack growth rate was similar, but not identical, to what one would get by extrapolating the high cycle fatigue crack growth rate, as proposed by Dowling and Begley [1]. Under conditions of increasing J range, the crack growth rate under elastic-plastic conditions was accelerated, while under decreasing J range conditions the crack growth rate was decelerated in comparison to the extrapolated high cycle fatigue crack growth rate measurements. The R ratio did not affect the crack growth rate for the two cases tested here, namely R = 0.1 and R = −1.0. More rapidly increasing J range conditions resulted in greater crack growth rate acceleration. In the elastic-plastic fatigue regime, shallow crack specimens demonstrated slower crack growth rates than deep crack specimens.
Evaluation of the Effect of Biaxial Loading on the To Reference Temperature Using a Cruciform Specimen Geometry
Authors: Joyce JA , Link RE , Gaies J 
Published: February 2005

Abstract
A series of 12 cruciform geometry fracture toughness specimens has recently been tested using A533B base plate obtained from the decommissioned Shoreham plant pressure vessel. Specimens were tested at −100°C, placing them in the lower ductile to brittle transition of this ferritic structural steel. The overall objective of this work is to compare the results of these biaxial cruciform tests to the results of standard and shallow crack fracture toughness tests to assess the effect of biaxial loading on the measured master curve and the To reference temperature as defined by ASTM E 1921. Previous work done at Oak Ridge National Laboratory (ORNL) appeared to demonstrate an increase in the To reference temperature due to the presence of the biaxial stress field established in the cruciform test geometry. Because of the cost of the ORNL tests, only a few specimens could be run, and full statistical support of the “biaxial effect” could not be demonstrated. A second goal is to demonstrate that smaller size specimens, and hence lower cost tests, can be used to evaluate the magnitude of the biaxial effect in nuclear reactor pressure vessel materials. This report presents a brief overview of the test procedure, presents the test results, and compares the results to the database available on standard and shallow crack fracture toughness results available for the Shoreham plate material.
Microstructural Influences on the Development and Growth of Small Fatigue Cracks in the Near Threshold Regime
Authors: Schneider JA , Kenik E 
Published: February 2005

AbstractOrientation imaging microscopy (OIM) is being used to investigate the microstructural influence on small crack growth at the crack tip. Although grain and grain boundary orientations have been reported to influence small crack growth, the effect has been difficult to quantify. OIM uses electron backscattered diffraction (EBSD) patterns in a scanning electron microscope (SEM) to form a spatially resolved map of crystal orientation, providing information on intra- and inter-grain orientation relationships.Mini-extended compact tension (ECT) specimens were machined from an 1100 aluminum cold rolled sheet with a 45° angle, machined notch tip. The specimens were sized to fit into a Philips XL30/FEG SEM equipped with an EDAX/TSL EBSD/OIM system. Initial images were recorded prior to cycling of the mini-ECT specimen. Fatigue testing was conducted at constant amplitude loading in the near-threshold regime where small cracks are considered to be on the order of the corresponding grain size. The constant amplitude load testing was periodically interrupted to obtain EBSD images. The ability to map an area 800 × 1300 μm in front of the machined notch tip was demonstrated. This study determined that the plastic deformation, which occurs in a zone in front of the crack tip, did not degrade the EBSD image quality. Use of this technique provides the capability to characterize local crystal orientation during deformation processes such as fatigue crack growth.
Development of a Cooling Capability Test Method for Liquid-Cooled Textile System
Authors: Cao H , Branson DH , Nam J , Peksoz S , Farr CA 
Published: February 2005

Abstract
A test method to evaluate the cooling capability of a 30.5 cm × 30.5 cm or smaller liquid-cooled textile system used in liquid cooling garment development has been developed. The equipment used in this method is the sweating guarded hotplate, which is used primarily to measure thermal and evaporative resistance of clothing materials in accordance with ASTM F 1868. Using the sweating guarded hotplate, a constant heat flux from the hotplate to cold liquid can be obtained. Using the conductive heat transfer equation for data analysis, this test method provides consistent and reliable evaluation of the cooling capability over a wide range of cold liquid temperatures. This method can differentiate the cooling capabilities of alternative textile systems that might vary by fabric composition, tubing material, total tubing length, and other variables of interest. Based on the zero-intercept linear regression, the thermal resistance of the textile system can be estimated, and the cold temperature requirement for a target cooling capability can be predicted.
Effects of Thermal Properties on Skin Burn Predictions in Longer Duration Protective Clothing Tests
Authors: Torvi DA 
Published: February 2005

Abstract
Different methods of predicting skin burns during bench top and full-scale tests of protective clothing are compared. A skin heat transfer and burn prediction model is also used to determine the effects of thermal properties of skin and blood flow rates on first, second, and third degree skin burn predictions for exposures used in longer duration tests of single and multiple-layer protective fabrics. Epidermis thickness can have a large effect on second degree burn predictions, while the dermis thickness can have a very large effect on third degree burn predictions. Subcutaneous thickness does not significantly affect burn predictions, while blood flow can affect third degree burn predictions. Results also indicate that care must be taken when analyzing burn predictions, as relatively small differences in skin temperatures can produce deceptively large differences in burn predictions when Henriques' burn integral is used.
Evaluation of Three Chemical Protective Clothing Materials for Selected Performance Properties
Authors: Stull JO , McManus RE 
Published: February 2005

Abstract
A study was conducted to evaluate selected properties of three different chemical protective clothing materials that are being considered for use by Dupont's DeLisle Site in Pass Christian, Mississippi for titanium chloride and related chemical service. Two of the materials represented new product offerings based on unique PTFE/fabric (HSF) laminates, while the third was a PVC/Nomex material currently used in chemical protective clothing at the Dupont DeLisle Site. The two PTFE/fabric laminates were further distinguished by the film thickness and type of surface finish. A number of tests were performed to measure permeation resistance against specific chemicals of interest: physical property testing to assess material strength and specialized tests to determine how the materials hold up to different environmental challenges (high temperature, cold temperature, and flame exposure). The study demonstrated how a series of test methods established by Committee F23 can be used to evaluate the material choices effectively for a specific set of chemical and physical exposure conditions.
The Correlation Between Microstructures and in-BWR Corrosion Behavior of Highly Irradiated Zr-based Alloys
Authors: Takagawa Y , Ishimoto S , Etoh Y , Kubo T , Ogata K , Kubota O 
Published: February 2005

Abstract
The microstructures of four kinds of Zircaloy-2-type materials with neutron exposure up to about 15 × 1025 n/m2 (E&gt;1MeV) were examined to investigate the microstructural evolution and to correlate it with the in-reactor corrosion behavior at very high fluences. The materials examined in this study included two advanced Zr-based alloys with good corrosion resistance, namely High Fe Zry and High FeNi Zry, and two other kinds of Zry-2 materials with slightly different elemental compositions and fabrication processes producing differing second phase particle sizes. All alloys showed good corrosion behavior and low hydrogen pickup when irradiated up to four cycles in dummy neutron source holders located outside of channel boxes. After six irradiation cycles, all four of the alloys had an increase in the rate of uniform corrosion and hydrogen pickup. The results of the microstructure examinations after six-cycle irradiation indicated two interesting points: (1) increased insight into the dissolution process for Zr-Fe-Cr particles, and (2) a correlation between the number density of Zr-Fe-Cr particles surviving through irradiation and the corrosion behavior at high fluences. From these results, it is suggested that increasing the initial particle size and/or controlling the alloy chemistry would be beneficial to improve the uniform corrosion performance and to lower hydrogen pickup, especially at very high fluences.
Estimating Unsaturated Hydraulic Conductivity of Fine-Grained Soils Using Electrical Resistivity Measurements
Authors: Sreedeep S , Singh DN 
Published: February 2005

Abstract
This paper presents a methodology that can be used for easily and rapidly estimating unsaturated hydraulic conductivity of fine-grained soils. The basis of this methodology is that the flow of fluid through a porous media is analogous to the flow of a current through a medium subjected to the electrical potential. Hence, soil hydraulic conductivity can be determined by knowing the soil's electrical resistivity corresponding to different states of compaction. However, as hydraulic conductivity of the soil depends on the suction, which in turn depends on the water content and composition, electrical resistivity can be related to hydraulic conductivity. To demonstrate the usefulness of this methodology, data of two very well characterized fine-grained soils have been used.
A New Test Method for Porosity Measurements of Portland Cement Pervious Concrete
Authors: Montes F , Valavala S , Haselbach LM 
Published: February 2005

Abstract
Pervious concrete is emerging as an alternative material for paving to help curtail nonpoint source pollution problems. The porosity of pervious concrete is an important variable needed for pavement system design and for material comparisons. This paper researches a method for measuring the porosity of pervious concrete from field-obtained cores by applying the Archimedes principle and using standard materials laboratory equipment. The error between different operators at different testing facilities was found to be around 2.2 % porosity.
Drugs, Violence, and Moral Panic in Urban America
Authors: Singer Merrill 
Published: February 2005

Beggars and Thieves: Lives of Urban Street Criminals. Mark S. Pleisher. Madison: University of Wisconsin Press, 1995. 332 pp.Life in the Gang: Family, Friends, and Violence. Scott H. Decker and Barrik Van Winkle. Cambridge: Cambridge University Press, 1996. 303 pp.