bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene expression–based classification and regulatory networks of pediatric acute lymphoblastic leukemia
Authors: Li Zhigang , Zhang Wei , Wu Minyuan , Zhu Shanshan , Gao Chao , Sun Lin , Zhang Ruidong , Qiao Nan , Xue Huiling , Hu Yamei , Bao Shilai , Zheng Huyong , Han Jing-Dong J.
Published: September 2009

Pediatric acute lymphoblastic leukemia (ALL) contains cytogenetically distinct subtypes that respond differently to cytotoxic drugs. Subtype classification can be also achieved through gene expression profiling. However, how to apply such classifiers to a single patient and correctly diagnose the disease subtype in an independent patient group has not been addressed. Furthermore, the underlying regulatory mechanisms responsible for the subtype-specific gene expression patterns are still largely unknown. Here, by combining 3 published microarray datasets on 535 mostly white children's samples and generating a new dataset on 100 Chinese children's ALL samples, we were able to (1) identify a 62-gene classifier with 97.6% accuracy from the white children's samples and validated it on the completely independent set of 100 Chinese samples, and (2) uncover potential regulatory networks of ALL subtypes. The classifier we identified was, thus far, the only one that could be applied directly to a single sample and that sustained validation in a large independent patient group. Our results also suggest that the etiology of ALL is largely the same among different ethnic groups, and that the transcription factor hubs in the predicted regulatory network might play important roles in regulating gene expression and development of ALL.
Genome-wide expression profiling of in vivo- derived bloodstream parasite stages and dynamic analysis of mRNA alterations during synchronous differentiation in Trypanosoma brucei
Authors: Kabani Sarah , Fenn Katelyn , Ross Alan , Ivens Al , Smith Terry K , Ghazal Peter , Matthews Keith
Published: September 2009

Background

Trypanosomes undergo extensive developmental changes during their complex life cycle. Crucial among these is the transition between slender and stumpy bloodstream forms and, thereafter, the differentiation from stumpy to tsetse-midgut procyclic forms. These developmental events are highly regulated, temporally reproducible and accompanied by expression changes mediated almost exclusively at the post-transcriptional level.

Results

In this study we have examined, by whole-genome microarray analysis, the mRNA abundance of genes in slender and stumpy forms of T.brucei AnTat1.1 cells, and also during their synchronous differentiation to procyclic forms. In total, five biological replicates representing the differentiation of matched parasite populations derived from five individual mouse infections were assayed, with RNAs being derived at key biological time points during the time course of their synchronous differentiation to procyclic forms. Importantly, the biological context of these mRNA profiles was established by assaying the coincident cellular events in each population (surface antigen exchange, morphological restructuring, cell cycle re-entry), thereby linking the observed gene expression changes to the well-established framework of trypanosome differentiation.

Conclusion

Using stringent statistical analysis and validation of the derived profiles against experimentally-predicted gene expression and phenotypic changes, we have established the profile of regulated gene expression during these important life-cycle transitions. The highly synchronous nature of differentiation between stumpy and procyclic forms also means that these studies of mRNA profiles are directly relevant to the changes in mRNA abundance within individual cells during this well-characterised developmental transition.
A profile of the online dissemination of national influenza surveillance data
Authors: Cheng Calvin KY , Lau Eric HY , Ip Dennis KM , Yeung Alfred SY , Ho Lai Ming , Cowling Benjamin J
Published: September 2009

Background

Influenza surveillance systems provide important and timely information to health service providers on trends in the circulation of influenza virus and other upper respiratory tract infections. Online dissemination of surveillance data is useful for risk communication to health care professionals, the media and the general public. We reviewed national influenza surveillance websites from around the world to describe the main features of surveillance data dissemination.

Methods

We searched for national influenza surveillance websites for every country and reviewed the resulting sites where available during the period from November 2008 through February 2009. Literature about influenza surveillance was searched at MEDLINE for relevant hyperlinks to related websites. Non-English websites were translated into English using human translators or Google language tools.

Results

A total of 70 national influenza surveillance websites were identified. The percentage of developing countries with surveillance websites was lower than that of developed countries (22% versus 57% respectively). Most of the websites (74%) were in English or provided an English version. The most common surveillance methods included influenza-like illness consultation rates in primary care settings (89%) and laboratory surveillance (44%). Most websites (70%) provided data within a static report format and 66% of the websites provided data with at least weekly resolution.

Conclusion

Appropriate dissemination of surveillance data is important to maximize the utility of collected data. There may be room for improvement in the style and content of the dissemination of influenza data to health care professionals and the general public.
Risk factors for operated carpal tunnel syndrome: a multicenter population-based case-control study
Authors: Mattioli Stefano , Baldasseroni Alberto , Bovenzi Massimo , Curti Stefania , Cooke Robin MT , Campo Giuseppe , Barbieri Pietro G , Ghersi Rinaldo , Broccoli Marco , Cancellieri Maria Pia , Colao Anna Maria , dell'Omo Marco , Fateh-Moghadam Pirous , Franceschini Flavia , Fucksia Serenella , Galli Paolo , Gobba Fabriziomaria , Lucchini Roberto , Mandes Anna , Marras Teresa , Sgarrella Carla , Borghesi Stefano , Fierro Mauro , Zanardi Francesca , Mancini Gianpiero , Violante Francesco S
Published: September 2009

Background

Carpal tunnel syndrome (CTS) is a socially and economically relevant disease caused by compression or entrapment of the median nerve within the carpal tunnel. This population-based case-control study aims to investigate occupational/non-occupational risk factors for surgically treated CTS.

Methods

Cases (n = 220) aged 18-65 years were randomly drawn from 13 administrative databases of citizens who were surgically treated with carpal tunnel release during 2001. Controls (n = 356) were randomly sampled from National Health Service registry records and were frequency matched by age-gender-specific CTS hospitalization rates.

Results

At multivariate analysis, risk factors were blue-collar/housewife status, BMI ≥ 30 kg/m2, sibling history of CTS and coexistence of trigger finger. Being relatively tall (cut-offs based on tertiles: women ≥165 cm; men ≥175 cm) was associated with lower risk. Blue-collar work was a moderate/strong risk factor in both sexes. Raised risks were apparent for combinations of biomechanical risk factors that included frequent repetitivity and sustained force.

Conclusion

This study strongly underlines the relevance of biomechanical exposures in both non-industrial and industrial work as risk factors for surgically treated CTS.
HIV/AIDS, growth and poverty in KwaZulu‐Natal and South Africa: an integrated survey, demographic and economy‐wide analysis
Authors: Thurlow James , Gow Jeff , George Gavin
Published: September 2009

Background

This paper estimates the economic impact of HIV/AIDS on the KwaZulu‐Natal province and the rest of South Africa.

Methods

We extended previous studies by employing: an integrated analytical framework that combined firm surveys of workers' HIV prevalence by sector and occupation; a demographic model that produced both population and workforce projections; and a regionalized economy‐wide model linked to a survey‐based micro‐simulation module. This framework permits a full macro‐microeconomic assessment.

Results

Results indicate that HIV/AIDS greatly reduces annual economic growth, mainly by lowering the long‐run rate of technical change. However, impacts on income poverty are small, and inequality is reduced by HIV/AIDS. This is because high unemployment among low‐income households minimises the economic costs of increased mortality. By contrast, slower economic growth hurts higher income households despite lower HIV prevalence.

Conclusion

We conclude that the increase in economic growth that results from addressing HIV/AIDS is sufficient to offset the population pressure placed on income poverty. Moreover, incentives to mitigate HIV/AIDS lie not only with poorer infected households, but also with uninfected higher income households.

Our findings reveal the substantial burden that HIV/AIDS places on future economic development in KwaZulu‐Natal and South Africa, and confirms the need for policies to curb the economic costs of the pandemic.
The Gaza War and the Changing Strategic Landscape in the Middle East: An Assessment
Authors: Bahgat Gawdat
Published: September 2009

On 27 December 2008, Israeli forces attacked Gaza to stop missile attacks by Hamas. The military operation lasted twenty-two days and ended with a fragile cease-fire. This study seeks to provide an assessment of all involved parties' stances. The author argues that some parties gained more than others, but the operation dealt a heavy blow to an already fragile peace process. Indeed, the Gaza war has further reinforced the current and growing polarization between the Palestinians and the Israelis. The continuing disagreement between the Palestinian factions and the election of a right-wing Israeli government suggest that the prospects for peace in the foreseeable future are dim.
Galectin-3 promotes lamellipodia formation in epithelial cells by interacting with complex N-glycans on α3β1 integrin
Authors: Saravanan Chandrassegar , Liu Fu-Tong , Gipson Ilene K. , Panjwani Noorjahan
Published: September 2009

Recent studies have shown that galectin-3 (Gal-3; also known as LGALS3), a β-galactoside-binding lectin, promotes cell migration during re-epithelialization of corneal wounds. The goal of this study was to characterize the molecular mechanism by which Gal-3 stimulates cell migration. We demonstrate here that exogenous Gal-3, but not Gal-1 or Gal-8, promotes cell scattering and formation of lamellipodia in human corneal epithelial cells in a β-lactose-inhibitable manner. α3β1 integrin was identified as the major Gal-3-binding protein in corneal epithelial cells by affinity chromatography of cell lysates on a Gal-3-Sepharose column. Preincubation of cells with anti-α3 integrin function-blocking antibody significantly inhibited the induction of lamellipodia by Gal-3. Furthermore, exogenous Gal-3 activated both focal adhesion kinase, a key regulator of integrin-dependent intracellular signaling, and Rac1 GTPase, a member of the family of Rho GTPases, well known for its role in the reorganization of the actin cytoskeleton and formation of lamellipodial extensions. Experiments involving knockdown of β-1,6-N-acetylglucosaminytransferase V, an enzyme that synthesizes high-affinity glycan ligands for Gal-3, revealed that carbohydrate-mediated interaction between Gal-3 and complex N-glycans on α3β1 integrin plays a key role in Gal-3-induced lamellipodia formation. We propose that Gal-3 promotes epithelial cell migration by cross-linking MGAT5-modified complex N-glycans on α3β1 integrin and subsequently activating α3β1-integrin–Rac1 signaling to promote lamellipodia formation.
Delivery of Antifungal Agents Using Bioactive and Nonbioactive Bone Cements
Authors: Sealy Patricia I , Nguyen Cam , Tucci Michelle , Benghuzzi Ham , Cleary John D
Published: September 2009

Background:

Management of fungal osteomyelitis is prolonged and frequently unsuccessful. Antifungal-impregnated cement is sometimes used as adjunctive therapy.

Objective:

To examine the release of antifungals from biodegradable and nonbiodegradable cement carriers.

Methods:

In vitro methods were used to assess antifungal drug release and antifungal activity of impregnated cements commonly used as adjunctive treatment of osteomyelitis. Cements included thermoplastic, nonbioactive polymers (polymethylmethacrylate [PMMA]) or bioactive agents (hydroxyapatite [HAP], β-tricalcium phosphate [β-TCP]) and were formed into spheres (beads).

Results:

Amphotericin B provided consistent supernatant concentrations (release), between 1.75 and 2.0 ug/mL, over 110 days from all bone cements. Flucytosine and fluconazole were observed for 33–42 days before becoming undetectable from a nonbioactive sphere and 18–22 days from a bioactive sphere. Serum concentrations for micafungin, terbinafine, and anidulafungin impregnated into PMMA rapidly became undetectable, regardless of the matrix used. Investigational β-TCP spheres prolonged release for fluconazole and micafungin, but had no effect on amphotericin B. Serum calcium concentrations decreased 60–80% in all HAP-impregnated drug sphere supernatants. Only amphotericin B–impregnated PMMA impacted supernatant calcium, decreasing concentrations by 50–60%. The antifungal-impregnated beads did not appear to be toxic to osteoblasts during 72 hours of exposure in tissue culture medium.

Conclusions:

Elution characteristics of most antifungals from bone cement spheres are probably not optima) for treatment of deep-seated fungal infections if a similar phenomenon of antifungal release manifests in vivo. Ceramic nonabsorbable impregnated devices must be removed after their lifespan expires and may necessitate another surgical procedure that can increase surgical risk and cost. Bioactive osteoconductive materials may provide a surgical alternative to nonabsorbable matrices. However, there have been no controlled trials demonstrating improved therapeutic outcomes with local therapy and assessing whether biodegradable materials act as a new focus for infection.
Morphine-Induced Muscle Rigidity in a Term Neonate
Authors: Lee Robin van der , Ceelie Ilse , Wildt Saskia N de
Published: September 2009

Objective:

To describe a potentially fatal adverse drug event after administration of morphine to a term neonate.

Case Summary:

A 2-day-old term neonate experienced generalized muscle rigidity and laryngeal spasm resulting in acute respiratory failure on 2 separate occasions after morphine administration. The first occasion was after administration of bolus doses of fentanyl and morphine 100 μg/kg in the operating theater; administration of intravenous propofol 2 mg/kg resulted in relief of muscle rigidity. The second occasion occurred a few hours later, when the patient received a continuous infusion of morphine 4.4 μg/kg/h in the intensive care unit and experienced generalized muscle rigidity with respiratory compromise. The opioid antagonist naloxone 30 μg/kg was administered intravenously, which immediately resulted in a patent airway and spontaneous breathing. An objective causality assessment using the Naranjo probability scale revealed that the likelihood of morphine causing the patient's muscle rigidity on the second occasion was highly probable to definite. It is not clear whether the first occurrence of muscle rigidity was morphine-induced.

Discussion:

We searched PubMed and EMBASE (through August 2009) for previous reports of morphine-related muscle rigidity and/or laryngeal spasm, using the search terms (muscle rigidity OR chest rigidity OR laryngeal spasm) AND (morphine OR fentanyl OR opioid). Sudden onset of muscle rigidity and laryngeal spasm is described in the literature as a rare but serious adverse event after infusion of fentanyl and similar opioids in both adults and young infants. However, there are no reports of this potentially fatal adverse event after administration of morphine. To our knowledge this is the first case reported of life-threatening muscle rigidity and laryngeal spasm after therapeutic doses of morphine in humans.

Conclusions:

A serious adverse event consisting of generalized muscle rigidity and laryngospasm can occur after bolus administration of morphine as well as during continuous infusion. Clinicians should be aware of this possibility.
The lay of the land: European career research and its future
Authors: Mayrhofer Wolfgang , Schneidhofer Thomas M.
Published: September 2009

Over the past two decades, career research in Europe has developed into a dynamic discourse of its own. However, few if any considerations deal with its future development. Against the backdrop of the unique European context consisting of specific European macro‐themes, its methodological heritage and the current research landscape, this conceptual paper outlines core dimensions of a future agenda for European career research. They include units of analysis with varying degree of social complexity, the underlying scientific concern, thematic foci stemming from the European situation, and the role of time. This devises a ‘research space’ providing orientation for future career research in Europe. Concluding, the article touches on contributions of the European career discourse to its global counterpart.
Identification of a New Seven-span Transmembrane Protein: NGX6a Is Downregulated in Nasopharyngeal Carcinoma and Is Associated With Tumor Metastasis
Authors: Wang Li , Xiang Bo , Yi Mei , Zhang Wen-Ling , Yang Jian-Bo , Peng Shu-Ping , Li Xiao-Ling , Li Gui-Yuan
Published: September 2009

Nasopharyngeal carcinoma (NPC)-associated gene 6 ( NGX6) is a novel candidate metastasis suppressor gene that can significantly decrease the growth, motility, and invasion of NPC cells. In this study, we generated a highly specific NGX6 polyclonal antibody and analyzed its distribution in the human fetus by Western blot and immunohistochemistry. The result of the Western blot showed the protein of NGX6 had two types of isoforms, isoform a (NGX6a) and isoform b (NGX6b). Isoform a is composed of 472 amino acids with a calculated molecular mass of 52 kDa, whereas isoform b is composed of 338 amino acids with a calculated molecular mass of 37 kDa. It is predicated that there is an epidermal growth factor domain in the N terminal of both a and b isoforms, and seven transmembrane domains in NGX6a, but only two transmembrane domains in NGX6b. The expression level of NGX6a was higher than that of NGX6b in human fetal tissue. Obvious high expression of NGX6a protein presents in the nervous system and epithelial tissues of the human fetus, but the NGX6b protein (37 kDa) is mainly expressed in the nervous system. We further analyzed the tissue microarray, which contained 154 NPC biopsies and 70 non-NPC biopsies, and found that NGX6a was significantly downregulated in NPC and associated with tumor metastasis.
The Dark Side of the Immunohistochemical Moon: Industry
Authors: Kalyuzhny Alexander E.
Published: September 2009

Modern biological research is dependent on tools developed and provided by commercial suppliers, and antibodies for immunohistochemistry are among the most frequently used of these tools. Not all commercial antibodies perform as expected, however; this problem leads researchers to waste time and money when using antibodies that perform inadequately. Different commercial suppliers offer antibodies of varying degrees of quality and, in some cases, are unable to provide expert technical support for the immuno-histochemical use of their antibodies. This article briefly describes the production of commercial antibodies from the manufacturer's perspective and presents some guidelines for choosing appropriate commercial antibodies for immunohistochemistry. Additionally, the article suggests steps to establish mutually beneficial relationships between commercial antibody suppliers and researchers who use them.
Simulating the Behavior of Zirconium-Alloy Components in Nuclear Reactors
Authors: Coleman CE
Published: September 2009

To prevent failure in nuclear components, one needs to understand the interactions between adjacent materials and the changes in their physical properties during all phases of reactor operation. Three examples from CANDU reactors are described to illustrate the use of simulations that imitate complicated reactor situations. These are: • swelling tests that led to a method for increasing the tolerance of Zircaloy fuel cladding to power ramps • observations of the behavior of leaking cracks in Zr-2.5Nb pressure tubes that provide confidence in the use of leak-before-break as part of the defense against flaw development • contact boiling tests on modifications to the surfaces of Zircaloy calandria tubes that enhance the ability of the heavy water moderator to act as a heat sink after a postulated loss-of-coolant accident
Activated Slip Systems and Localized Straining of Irradiated Zr Alloys in Circumferential Loadings
Authors: Regnard C , Verhaeghe B , Lefebvre-Joud F , Lemaignan C
Published: September 2009

During the plastic deformation of irradiated Zr alloys, specific slip systems are activated. Indeed, the dislocation loops of  type are strong obstacles for the dislocations gliding on the classical prismatic planes. An increase in yield strength is observed. This allows the activation of other slip systems. The basal slip, having a  Burgers vector can interact with the irradiation-induced dislocation loops. This interaction leads to the annealing of the loops by various mechanisms and leads to the formation of dislocation free bands after limited plastic strain (channeling).

TEM examinations of Zry-4 samples strained after irradiation have been performed. High density of basal slip has been observed on channels. With such a mechanism, the irradiated Zr alloys exhibit a strain-softening behavior for loading orientations allowing this kind of interaction. A modeling of the interaction between the gliding dislocations and the loops has been performed to analyze the channel formation kinetics. Fine element (FE) computation of strain-softening materials has shown strong effects on the plastic zone shape ahead of crack tips.

The results are discussed, focusing on the impact of this behavior on the mechanical properties of irradiated cladding. Specific attention is given on hoop straining with respect to PCI, RIA, or axial splitting.
Plastic Deformation and Fracture During the Zr1%Nb Tube Production
Authors: Zavodtchikov SY , Zuev LB , Belov VI , Lositskiy AF , Shevnin YP
Published: September 2009

The deformation of ZrNb alloy tubes involves plastic flow localization in the metal, which is one of the most complex in the theory of material plasticity. The plastic deformation is accompanied by initiation of auto-waves in the body of material. The auto-wave model of plastic deformation was used as a very informative source for getting information to optimize the cold deformation process of zirconium alloy material, in particular for Zr1%Nb alloy cladding tubes. The results of local X-ray measurements of residual stresses were compared with the results of ultrasonic speed measurements in the same tubing material. The correlation between ultrasonic speed and residual stresses has been found and investigations conducted have allowed the improvement of the process of zirconium alloy tube manufacturing. The results obtained were used in developing the optimal processes of cold deformation of tubes made from Zr1%Nb alloy. Those processes provided, together with optimal heat treatment regimes, high cladding tube performances in comparison with those obtained with other well-known manufacturing processes.
An In-Reactor Simulation Test to Evaluate Root Cause of Secondary Degradation of Defective BWR Fuel Rod
Authors: Cheng B , Oberländer BC , Wiesenack W , Yagnik S , Turnbull J
Published: September 2009

Zircaloy-2 fuel cladding is susceptible to several forms of secondary degradation following steam ingress in defective rods in BWRs. Hydride blister, circumferential, and axial cracks have been reported. An in-core test was performed at the Halden reactor to evaluate the root cause of the secondary degradation, with particular attention paid to the axial cracking issue.

The test included four instrumented rods of one meter long. Three rods had Zr-lined Zircaloy-2 cladding, and the other was a nonlined cladding. Two initial diametral gap sizes and two steam ingress conditions were designed. The rods were irradiated to 8 GWd/MtU before steam was admitted into the rods when the rods were operated at power. Subsequently, a power ramp from 33 to 43 kW/m was executed to cause mechanical stresses on the cladding. The test was terminated following detection of a significant activity release.

Three of the four rods, including two Zr-lined and the nonlined ones, exhibited hydride bulges and short axial cracks; the remaining Zr-lined rod did not develop secondary defects. The secondary defects developed first by heavy localized hydriding in all cases. Steam ingress causes increase in fuel temperature, formation of central voids, and pellet swelling at the initial hydride defects, resulting in local plastic strains on the cladding at the crack tip. Susceptibility of the cladding to cracking depended on the hydriding characteristics of the cladding. Unlined Zircaloy cladding was susceptible to sunburst hydriding locally within a short axial length. Zr-lined cladding was more resistant to localized sunburst hydriding; hydrogen was absorbed more uniformly by the cladding over a substantially longer cladding length and formed thick hydride rims near the cladding outer surface. The hydride rim ahead of the crack tip in a Zr-lined cladding produced radial hydrides intruding deep into the cladding wall under plastic strains. Repeated crack tip straining by central void formation and deep radial hydride penetration into the cladding from hydride rims would assist the crack to penetrate the cladding wall perpendicular to the cladding surfaces and propagate axially over a long distance. Unlined Zircaloy cladding can also propagate axial cracks by the same mechanism, but its susceptibility to localized sunburst hydriding would limit the length of such axial cracks to a short length nearby the sunburst hydride region.

Results from this program suggest that the hydriding characteristics of the cladding inner surface determine the susceptibility of the cladding to long axial cracking. A low corrosion resistance Zr-liner and, particularly, a dry hydrogen environment, which accelerates the hydriding rate, can increase the rate of axial cracking. The findings from this program are consistent with observations of high susceptibility of high purity Zr-liner to axial cracking in BWRs, and provide basis for its mitigation.
Symposium on Non-Destructive Testing
Authors: Committee E-7
Published: September 2009

Description

Present information on statistical methods and quality control methods. Part 1 discusses the application of statistical methods in condensing information. Part 2 is on the problem of presenting limits to indicate the uncertainty. Part 3 covers the control chart method of analysis of data
Symposium on Advances in Electron Metallography
Authors: ASTM Committee E-4
Published: September 2009

Description

Eleven papers present comprehensive techniques for the study of materials through the electron microscope such as: titanium alloys; aluminum foils; nickel alloys and magnesium alloys. Five advanced techniques are described and illustrated.
Vibratory Polishing of Metallographic Specimens for Optical and Electron Microscopy
Authors: Long EL , Gray RJ
Published: September 2009

In principle, the art of preparing metallographic specimens with abrasives has not altered for more than 50 years. In 1956, vibratory polishing was introduced to the field of metallography. At that time the technique was used only on aluminum alloys. Since that time, much effort has been expended by the Metallography Department of the Oak Ridge National Laboratory toward the development of this new mode of polishing. The technique was used on ferrous alloys and non-ferrous alloys other than aluminum. Preliminary experiments with small-diameter polishing bowls showed promise. Later experiments with larger (12-in. diameter) bowls were more successful from the standpoint of polishing speed and capacity of the polishing bowl. Details of the equipment and the technique are given, together with results and illustrative micrographs obtained on plain carbon steel, nickel-molybdenum alloy, and the interface of a europium oxide particle surrounded by stainless steel.

After a 14-month test period many advantages are apparent when compared with conventional hand-polishing techniques and many automatic polishing machines: Other work can be done while the polishing operation is going on; over-polishing is less likely to occur; less time is required to train personnel; and finishes obtained are comparable if not superior to those obtained by hand polishing.
A Technique for Easy Removal of Direct Replicas for Electron Microscopy
Authors: Bridges WH , Long EL
Published: September 2009

The advantages of shadowing directly on the specimen surface in the preparation of replicas for electron microscopy are twofold. First, there is no ambiguity to the interpretation-one does not have to invert the shadow direction. Second, there is no chance for artifacts due to swelling, shrinking, or straining such as are apt to develop with replicas shadowed after removal. There is, however, a serious difficulty which arises when shadowing a metal directly on a clean metal surface. The replicas are invariably bound so tightly to the specimen surface that it is necessary to etch away the specimen to release the replica. The chemical attack usually results in breaking the replica into small pieces and negates the re-replication of the specimen without repolishing and etching.
Examination of Metals by Transmission Electron Microscopy
Authors: Boswell FWC , Smith E
Published: September 2009

It has recently been demonstrated by Bollmann (1,2), Hirsch, Home, and Whelan (3), and Whelan, Hirsch, Home, and Bollmann (4) that dislocation lines can be observed in thinned metal foils by transmission electron microscopy. This work was confined to foils of aluminum and austenitic stainless steel, and the observations were made in microscopes operating at 80 to 100 kv. Since it is apparent that the technique might provide a new approach to the investigation of a wide variety of metallurgical phenomena, particularly those involving dislocation mechanisms, a survey has been carried out in the Mines Branch Laboratory to determine what features of interest could be observed in metal foils using a RCA EMU-2C electron microscope operating at 50 kv. Observations have been made on foils of five metals. The thinning technique and some results of the investigations are reported in this paper.
Slip Velocity Direction Impacts Wear in Total Knee Arthroplasty
Authors: Schwenke T , Borgstede LL , Schneider E , Wimmer MA
Published: September 2009

Total knee arthroplasties are subjected to high slip velocities and constantly changing velocity vector directions, as they mimic the anatomical conditions of the natural joint. Together with fluid film thickness and applied load, the velocity difference between the two bodies defines the amount of energy that is induced into the contact. Particularly for polyethylene (PE), it is known that the angle describing the difference in motion direction is an important variable for material loss. In this study, a wheel-on-flat simulator scenario was used to apply a slip velocity vector with a constant magnitude and changing direction over the length of a polyethylene sample. The difference in vector orientation ranged from zero to 20.4°, while a constant axial load of 1600 N was applied, and the contact area was submersed in physiological testing fluid. After 500k cycles, the surface of the PE specimen was visually examined and scanned with a video-based measurement system to analyze the wear profile. Polishing was the predominant wear pattern, and minor striations were found in the end zone of the wear area. The wear depth increased with higher velocity angles—this relationship appeared to be linear. This study supports earlier publications that reported a correlation between cross-shear motion and wear. The presented experimental results will help in attempts to numerically simulate wear generation.
Subcommittee II (Drying Oils)
Authors: Scofield Francis
Published: September 2009

Subcommittee II on Drying Oils is a relatively recent subcommittee, having been formed about 1939, but it continues the work of subcommittees which date back to the beginning of Committee D-1. In the early days of the committee there was a Subcommittee on Linseed Oil which developed the original specifications for raw and boiled linseed oil (now D 234 and D 260) under the chairmanship of R. D. Bonney.
Subcommittee III (Bituminous Emulsions)
Authors: Cubberley R. N.
Published: September 2009

This Subcommittee was activated in 1942 to develop specifications and methods of test for bituminous emulsions. To elaborate on the scope somewhat, the subcommittee agreed that asphalt and coal-tar emulsions should be included. Also, end uses were to be confined to protective coatings for metal in order to avoid conflict with built-up roofing standards covered by ASTM Committee D-8 on Bituminous Waterproofing and Roofing Materials and road emulsions standards handled by Committee D-4 on Road and Paving Materials.
Subcommittee IX (Varnish)
Authors: Weaver J. C.
Published: September 2009

Subcommittee IX on Varnish was organized in 1910 (as Subcommittee (i)) with the stated purpose of devising a form of specification for varnish which would enable the manufacturer to understand the requirements of the consumer, and which would enable the consumer to ascertain reasonably how closely such specifications have been fulfilled. This practical viewpoint persists today. It was implied in 1907 when a group of five ASTM technical papers on paint problems included one by J. C. Smith on “The Physical Testing of Oil Varnishes.” It is to be noted that although Smith's principal interest was in practical tests for natural and forced drying, such tests were not written into the standard methods of testing varnish (D 154) until 1950. Even now there remain some differences of opinion on the details of technique.
Subcommittee X (Optical Properties)
Authors: Granville Walter C.
Published: September 2009

Subcommittee X was formed in 1944 as a result of a decision to divide Subcommittee XVIII into two groups—one on physical properties (now Subcommittee XVIII) and one on optical properties (Subcommittee X). Thus, it is believed appropriate to include in this report of the activities of Subcommittee X a brief reference to the work on optical properties of Subcommittee XVIII prior to 1944.
Subcommittee XIII (Shellac)
Authors: Hartman C. C.
Published: September 2009

Lac resin, a secretion of the insect Tachardia Lacca, is one of the oldest mediums employed by man to protect and decorate his household furnishings. Pliny, the Elder, in his Encyclopedia, written in A.D. 77, mentions an amber obtained from India. His description of this resin is clearly that of lac.
Subcommittee XVII (Flash Point)
Authors: Ktirtz Stewart S. , Brown A. L.
Published: September 2009

Subcommittee XVII on Flash Point was formed in 1950 to reconsider the question of standardizing the Tag open cup flash point procedure. In order to clarify the reason for the establishment of this committee, it is necessary to go back in the records of Subcommittee V of ASTM Committee D-1, formerly known as Subcommittee XI on Paint Thinners Other Than Turpentine. Before World War I this committee undertook a systematic investigation of the available equipment and procedures for determining the flash points of thinners.
New Development in Through Hardened Bearing Steel Grades for Use in Contaminated Lubrication
Authors: Daguier Pascal , Roesch Oliver , Trojahn Werner
Published: September 2009

Bearing steel quality has been improved over the past decades by reducing the level and the size of nonmetallic inclusions. Therefore, fatigue lifetime of bearings Is mainly governed by surface damage, such as debris denting due to foreign particles. Numerous studies have been performed to find out new steel grades or heat treatments to cope with such severe in-service conditions. Most of these studies argued that the level of retained austenite is the main parameter which governs fatigue lifetime. The present study relates to the effect of heat treatment and alloying elements on the fatigue lifetime of bearing steel in contaminated lubrication at room temperature. Several through hardened steel grades have been tested with different methodologies in order to investigate their behavior in case of: (1) Debris denting, (2) Resistance to Tempering, and (3) High loading conditions. An experimental procedure developed by FAG to simulate particle indentation on bearing has been used to study the behavior of each grade. On the other side, torsion tests at room and high temperature have been used to determine the evolution of fatigue limit. At last, flat washer testing at 4200 M Pa is used to determine fatigue lifetime in high loading conditions. Results of fatigue tests are presented in this paper and analyzed in terms of tempering resistance and level of retained austenite.
Characteristics of Vanadium Alloyed Carbonitrided Steel for Rolling Bearing Applications
Authors: Lee J. S. , Song B. H. , Yoo S. J. , Park C. N. , Han H. S.
Published: September 2009

Today, most bearings for automotive transmission operate in an environment of severe debris contaminated lubrication. Thus, to develop the bearings that have a long life under the lubrication environment, micro-alloyed forging steel with a vanadium element based on medium-carbon steel and a carbonitriding heat-treatment process have been developed. Initially, the variation of grain size caused by an amount of aluminum and nitrogen was investigated. The hot deformation behavior was evaluated by means of a Gleeble tester. In general, it is extremely difficult to obtain sufficient nitrogen in the case-hardened layer by a conventional carbonitriding process. However, the application of the newly developed steel has not only the increment of nitrogen content in the case-hardened layer, but also the additional benefit that heat treatment costs could be cut effectively. In addition, we have investigated the retained austenite and precipitation behavior of V(CN), and the evaluated rolling contact fatigue life of a heat-treated specimen. As a result, we identified that the fatigue life of developed steel samples, under contaminated lubrication environment, is about five times better than comparative steel. The micro-structural degradation mechanism during fatigue testing was elucidated.
The Development of an Austenitic Stainless Steel Bearing with High Corrosion Resistance and High Nonmagnetic Property
Authors: Tanaka Susumu , Ueda Koji , Mitamura Nobuaki , Oohori Manabu
Published: September 2009

Apparatus of the type used in liquid crystal and semiconductor production facilities, medical inspection facilities, and linear motor cars utilize a magnetic field. When operated, either driven or rotated, they may experience a disturbance of the ambient magnetic field. This is more likely to occur if the driven or rotating portion of the apparatus is formed from a magnetic material.In recent years, bearings use in apparatus utilizing a magnetic field were made in precipitation hardening stainless steels such as Mn-Cr-V series or Mn-Cr-Ni-V series. Although these steels have excellent corrosion resistance, compared to martensitic stainless steels like AISI 440C, it is still not sufficient. In addition, the typical hardness of a precipitation hardening stainless steel used for bearings is about 446 HV. The low hardness of the steel means that the durability of the bearing is often unsatisfactory.Therefore, work was undertaken to develop a bearing steel with improved properties. In addition, to having improved corrosion resistance and durability, the steel must also have a very low magnetic permeability. This led to the development of a carburized AISI 316L austenitic stainless steel. The carburizing was carried out at 500°C to produce a surface layer with a hardness around 800–1000 HV, while retaining the excellent corrosion resistance and low magnetic permeability associated with this type of steel.Tests carried out have shown that despite the thinness of the hardened layer and low core hardness, in certain applications bearings made in carburized AISI 316L exhibited excellent durability together with low friction characteristics.
Characterization of the Properties of Commercial Lime by Surface Area Measurements and Scanning Electron Microscopy
Authors: Eades J. L. , Sandberg P. A.
Published: September 2009

Reactivity of lime (CaO, CaO-MgO) is a function of surface area and pore space which is related to temperature or time of calcination or both. The development and distribution of pore space in calcined stone is poorly understood. The scanning electron microscope (SEM) now allows observation of porosity differences in the oxides calcined from the same stone at various temperatures and times.

The oxides formed from five limestones calcined in commercial kilns (four calcitic and one dolomitic) and one dolomitic stone calcined in a laboratory furnace were examined with the SEM, and their surface areas were determined by the Brunauer, Emmett, and Teller (BET) method using Krypton gas.

One of the stones was subjected to several different kiln conditions. The SEM made it possible to record the changes of the low-porosity quarry stone to a very porous oxide as it was calcined. However, with increased kiln time, the resulting CaO crystals coalesce, increasing pore space, and, with continued calcination, the pore space approached zero.
Influence of Lime in Mortar on the Expansion of Brick Masonry
Authors: Ritchie T.
Published: September 2009

Mortars containing normally hydrated dolomitic lime caused greater expansion of brickwork piers than other mortars. Because the expansion of brickwork was much greater in the vertical direction than horizontally, however, and because the expansion was inhibited greatly by a relatively slight load, mortars containing normally hydrated dolomitic lime did not damage the brickwork from their expansion. The results of this study offer an explanation for the satisfactory performance of brick buildings with mortars containing normally hydrated dolomitic lime even though such mortars have great capacity for expansion.
Curing of Cement-Lime Mortars
Authors: Davison J. I.
Published: September 2009

Masonry mortars are assessed on the basis of tests on specimens prepared and cured in the laboratory. Curing procedures differ depending on the relative amounts of cement and lime in the mortar, and the relation between the end result and that attained in the field, where no concession is made for the composition of the mortar, is often questioned. Laboratory and outdoor curing of a series of cement-lime mortars were compared on the basis of compressive strength values. Outdoor curing reflects a variety of weather conditions typical of six geographical areas of the continent. Results indicate increasing discrepancies in values as the amount of cement in the mortars was decreased and the lime increased. Drying laboratory cured cubes before testing substantially reduced these discrepancies for cement and cement-lime mortars, but values for laboratory cured lime mortars remained well below those cured outdoors.
Particle Collection Mechanisms Pertinent to Granular Bed Filtration
Authors: Lee Ken W.
Published: September 2009

Flow fields and particle collection mechanisms in the maximum penetration regime are reviewed. Simple equations are introduced for predicting the size of the aerosol particles that most effectively penetrate a granular bed, and the corresponding minimum collection efficiency. Influences of filter operating velocity and granule size are also discussed. The results show that the most penetrating particle size for a granular bed filter exists as a result of either the Brownian diffusion mechanism combined with gravitation or Brownian diffusion with the interceptional mechanism.
A Review of the Use of Sae Standard J726 in Heavy Duty Engine Air Cleaner Testing
Authors: Nicholson Robert M. , Weisert Lloyd E.
Published: September 2009

A brief review of the SAE J726 Standard for Heavy Duty Engine Air Cleaner Testing is conducted. Some limitations of the standard test dust, AC Coarse and AC Fine are presented. Recommendations for revising the Standard to include fractional or grade efficiency are made.
Mechanisms and Devices for Filtration of Critical Process Gases
Authors: Accomazzo Mauro A. , Grant Donald C.
Published: September 2009

The particle capture mechanisms in aerosol filtration result in a most penetrating particle size for process gases used by the micro-electronics industry. The most penetrating particle size for fibrous filter media and microporous membrane filter media have been measured to be typically 0.15μm and 0.05μm, respectively. Filter performance ratings should be based on the retention of particles at the most penetrating particle size. The retention ratings for HEPA fiberglass filters have been determined to be ≥99.99% and for typical membrane filters ≥99.9999999%.

The shedding of particles from the downstream side of various types of Point-of-Use filter devices was evaluated, using laser and condensation nucleus type particle counters. All types of filter devices performed similarly during steady flow operation but performance differences were observed when either pulsed flow or mechanical vibrations occurred. In general, the membrane filter devices shed less particles than the fiberglass filter devices, and the membrane filter devices that used stacked disc molded supports were cleaner than the pleated filter devices.
The Role of ANSI/NSF Standard 61 and Third-Party Certification in Providing Safe Drinking Water
Authors: Gregorka David A. , Greiner Peter F. , Hazan Stan S. , Kenel Michael F.
Published: September 2009

The NSF Drinking Water Additives Program is the model for health effects evaluation of products and materials in contact with drinking water, including buried plastics pipe. One of the standards developed by the program, ANSI/NSF Standard 61 (Drinking Water System Components - Health Effects), covers the toxicology of indirect additives to drinking water for all types of potable water contact products and materials, including plastics pipe. For many years, NSF Standard 14 (Plastics Piping Components and Related Materials) has been the model toxicological and performance standard for plastics pipe, serving regulators, users, industry, and the public. Although it remains a viable standard, health effects in NSF Standard 14 are now addressed by reference to ANSI/NSF Standard 61.

How these Standards address potential health effects of plastics pipe and their impacts on specifiers, users, and designers is addressed. Extraction testing and toxicology requirements are provided special emphasis. NSF's product Certification (Listing) program for plastics is explained, along with a discussion of the problems and opportunities presented by consensus standards and third-party product certification programs.
Ultrasonic Evaluation of Polyethylene Butt Fused Joints
Authors: Striplin T. H.
Published: September 2009

Technology in ultrasonic inspection of polyethylene heat fused joints is rapidly improving. Subtle flaws that could not be detected previously can now be found. Sophisticated methods of destructively testing the fusions appear to confirm these ultrasonic evaluations. Further study could reveal the possibility of predicting long term fusion joint reliability using state-of-the-art ultrasonics. It has been proven that the use of ultrasonic testing of fusion joints in the field and for requalification can greatly improve the quality of workmanship.