bluuebunny/crossref_metadata_2025 huggingface dataset:
Using an oblique incident laser beam to measure the optical properties of stomach mucosa/submucosa tissue
Authors: Wei Hua Jiang , Xing Da , He Bo Hua , Gu Huai Min , Wu Guo Yong , Chen Xue Mei
Published: August 2009

Background

The purpose of the study is to determine the optical properties and their differences for normal human stomach mucosa/submucosa tissue in the cardiac orifice in vitro at 635, 730, 808, 890 and 980 nm wavelengths of laser.

Methods

The measurements were performed using a CCD detector, and the optical properties were assessed from the measurements using the spatially resolved reflectance, and nonlinear fitting of diffusion equation.

Results

The results of measurement showed that the absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at five different wavelengths vary with a change of wavelength. The maximum absorption coefficient for tissue samples is 0.265 mm-1 at 980 nm, and the minimum absorption coefficient is 0.0332 mm-1 at 730 nm, and the maximum difference in the absorption coefficients is 698% between 730 and 980 nm, and the minimum difference is 1.61% between 635 and 808 nm. The maximum reduced scattering coefficient for tissue samples is 1.19 mm-1 at 635 nm, and the minimum reduced scattering coefficient is 0.521 mm-1 at 980 nm, and the maximum difference in the reduced scattering coefficients is 128% between 635 and 980 nm, and the minimum difference is 1.15% between 890 and 980 nm. The maximum optical penetration depth for tissue samples is 3.57 mm at 808 nm, and the minimum optical penetration depth is 1.43 mm at 980 nm. The maximum diffusion constant for tissue samples is 0.608 mm at 890 nm, and the minimum diffusion constant is 0.278 mm at 635 nm. The maximum diffuse reflectance is 3.57 mm-1 at 808 nm, and the minimum diffuse reflectance is 1.43 mm-1 at 980 nm. The maximum shift Δx of diffuse reflectance is 1.11 mm-1 at 890 nm, and the minimum shift Δx of diffuse reflectance is 0.507 mm-1 at 635 nm.

Conclusion

The absorption coefficients, the reduced scattering coefficients, the optical penetration depths, the diffusion coefficients, the diffuse reflectance and the shifts of diffuse reflectance of tissue samples at 635, 730, 808, 890 and 980 nm wavelengths vary with a change of wavelength. There were significant differences in the optical properties for tissue samples at five different wavelengths (P < 0.01).
Heparanase activity in alveolar and embryonal rhabdomyosarcoma: implications for tumor invasion
Authors: Masola Valentina , Maran Claudio , Tassone Evelyne , Zin Angelica , Rosolen Angelo , Onisto Maurizio
Published: August 2009

Background

Rhabdomyosarcoma (RMS) is a malignant soft tissue sarcoma of childhood including two major histological subtypes, alveolar (ARMS) and embryonal (ERMS) RMS. Like other human malignancies RMS possesses high metastatic potential, more pronounced in ARMS than in ERMS. This feature is influenced by several biological molecules, including soluble factors secreted by tumor cells, such as heparanase (HPSE). HPSE is an endo-β-D-glucuronidase that cleaves heparan sulphate proteoglycans.

Methods

We determined HPSE expression by Western blot analysis in ARMS and ERMS cells lines and activity in supernatants by an ELISA assay. Stable HPSE silencing has been performed by shRNA technique in RH30 and RD cell lines and their invasiveness has been evaluated by Matrigel-invasion assay. HPSE activity and mRNA expression have also been quantified in plasma and biopsies from RMS patients.

Results

HPSE expression and activity have been detected in all RMS cell lines. Stable HPSE silencing by shRNA technique determined a significant knockdown of gene expression equal to 76% and 58% in RH30 and RD cell lines respectively and induced a less invasive behaviour compared to untreated cells. Finally, we observed that HPSE mRNA expression in biopsies was higher than in foetal skeletal muscle and that plasma from RMS patients displayed significantly more elevated HPSE levels than healthy subjects with a trend to higher levels in ARMS.

Conclusion

In conclusion, our data demonstrate for the first time HPSE expression and activity in RMS and highlight its involvement in tumor cell invasion as revealed by shRNA silencing. Moreover, HPSE expression in RMS patients is significantly higher with respect to healthy subjects. Further studies are warranted to assess possible relationships between HPSE and clinical behaviour in RMS.
siRNA and shRNA screens advance key understanding of host factors required for HIV-1 replication
Authors: Kok Kin-Hang , Lei Ting , Jin Dong-Yan
Published: August 2009

A recent RNAi screen used a genome-wide shRNA library to search for cellular factors required for HIV-1 replication. This work complements three other siRNA-based screening studies and potentially opens the door to the discovery of factors that are important for HIV-1 replication in physiological host cells such as T lymphocytes. shRNA screens can be further improved, and they could promise to unravel new pathways and new facets of virus-cell interactions.
Downregulation of heat shock protein 70 protects rheumatoid arthritis fibroblast-like synoviocytes from nitric oxide-induced apoptosis
Authors: Kang Eun Ha , Kim Dong Jo , Lee Eun Young , Lee Yun Jong , Lee Eun Bong , Song Yeong Wook
Published: August 2009

Introduction

Heat shock protein 70 (Hsp70) is a well-known anti-apoptotic protein that blocks multiple steps in the stress-induced apoptotic pathway. Enhanced Hsp70 expression has previously been demonstrated in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs). The authors investigated the role of Hsp70 in the survival of RA FLSs in a sodium nitroprusside (SNP)-treated environment.

Methods

Targeted knock-down of Hsp70 was performed by RNA interference in RA FLSs at passage 3-7. After SNP treatment, the morphological features of apoptosis were observed by phase-contrast microscopy. Cell survival was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and by flow cytometric analysis after propidium iodide (PI) staining. Bcl-2 expression and signaling pathways (Akt, extracellular signal-regulated kinase, p38, c-Jun N-terminal kinase) were examined with or without Hsp70 downregulation.

Results

Hsp70 downregulation in RA FLSs, induced by small interfering RNA (siRNA), was confirmed by reverse transcriptase-polymerase chain reaction and Western blotting. When treated with SNP, Hsp70 downregulated cells showed markedly less cell blebbing, cytoplasmic condensation, and nuclear shrinkage than non-downregulated control cells. Furthermore, Hsp70 downregulated cells were found to survive better than control cells in MTT assays (mean of absorbance ratio, 4.39 in target cells versus 1.00 in control siRNA-treated cells versus 1.09 in lipofectamine-treated cells, P = 0.001) and according to PI staining results (mean M1 ratio, 0.21 in target cells versus 1.00 in control siRNA-treated cells versus 1.03 in lipofectamine-treated cells, P = 0.001). Bcl-2 expression and Akt phosphorylation were higher in Hsp70 downregulated RA FLSs than in control cells. When cells were treated with LY294002, a potent phosphoinositide 3-kinase inhibitor, Akt phosphorylation and Bcl-2 levels were reduced and Hsp70 downregulation no longer had a cytoprotective effect.

Conclusions

Knock-down of Hsp70 protects RA FLSs from nitric oxide-induced apoptosis by activating the Akt signaling pathway. These results suggest that Hsp70 has a pro-apoptotic role in RA FLSs.
Rituximab therapy reduces activated B cells in both the peripheral blood and bone marrow of patients with rheumatoid arthritis: depletion of memory B cells correlates with clinical response
Authors: Nakou Magda , Katsikas Georgios , Sidiropoulos Prodromos , Bertsias George , Papadimitraki Eva , Raptopoulou Amalia , Koutala Helen , Papadaki Helen A , Kritikos Herakles , Boumpas Dimitrios T
Published: August 2009

Introduction

Bone marrow (BM) is an immunologically privileged site where activated autoantibody-producing B cells may survive for prolonged periods. We investigated the effect of rituximab (anti-CD20 mAb) in peripheral blood (PB) and BM B-cell and T-cell populations in active rheumatoid arthritis (RA) patients.

Methods

Active RA patients received rituximab (1,000 mg) on days 1 and 15. PB (n = 11) and BM (n = 8) aspirates were collected at baseline and at 3 months. We assessed B-cell and T-cell populations using triple-color flow cytometry.

Results

Rituximab therapy decreased PB (from a mean 2% to 0.9%, P = 0.022) but not BM (from 4.6% to 3.8%, P = 0.273) CD19+ B cells, associated with a significant reduction in the activated CD19+HLA-DR+ subset both in PB (from 55% to 19%, P = 0.007) and in BM (from 68% to 19%, P = 0.007). Response to rituximab was preceded by a significant decrease in PB and BM CD19+CD27+ memory B cells (P = 0.022). These effects were specific to rituximab since anti-TNF therapy did not reduce total or activated B cells. Rituximab therapy did not alter the number of activated CD4+HLA-DR+ and CD4+CD25+ T cells.

Conclusions

Rituximab therapy preferentially depletes activated CD19+HLA-DR+ B cells in the PB and BM of active RA patients. Clinical response to rituximab is associated with depletion of CD19+CD27+ memory B cells in PB and BM of RA patients.
Serum 25-hydroxyvitamin D concentrations and postmenopausal breast cancer risk: a nested case control study in the Cancer Prevention Study-II Nutrition Cohort
Authors: McCullough Marjorie L , Stevens Victoria L , Patel Roshni , Jacobs Eric J , Bain Elizabeth B , Horst Ronald L , Gapstur Susan M , Thun Michael J , Calle Eugenia E
Published: August 2009

Introduction

Vitamin D status measured during adulthood has been inversely associated with breast cancer risk in some, but not all, studies. Vitamin D has been hypothesized to prevent breast cancer through genomic and non-genomic actions in cell-cycle regulation.

Methods

A subset (n = 21,965) of female participants from the prospective Cancer Prevention Study-II (CPS-II) Nutrition Cohort provided a blood sample from 1998-2001 and were followed through 2005. We measured serum 25-hydroxyvitamin D (25(OH)D) in 516 verified incident cases and 516 controls, matched on birth date (± 6 months), date of blood draw (± 6 months) and race. Information on medical history, risk factors and lifestyle was available from repeated questionnaires. We computed multi-variable odds ratios (OR) and 95% confidence intervals (95% CI) for the association between 25(OH)D quintile and breast cancer risk using unconditional logistic regression, controlling for matching factors and additional confounders.

Results

We observed no association between 25(OH)D and breast cancer (OR = 1.09, 95% CI 0.70-1.68, P = 0.60) for the top vs bottom quintile. Using a priori cut-points, the OR was 0.86 (95% CI 0.59-1.26), for ≥75 vs <50 nmol/L. Results were not different when the first two years of follow-up were excluded, or in analyses stratified by season, latitude, BMI, postmenopausal hormone use, or by tumor grade or estrogen receptor status.

Conclusions

These results do not support an association between adulthood serum 25(OH)D and postmenopausal breast cancer. We cannot rule out an association with 25(OH)D status earlier in life.
Tibetan Medicine
Authors: Loizzo Joseph J. , Blackhall Leslie J. , Rapgay Lobsang
Published: August 2009

Traditional medical systems are challenging because their theories and practices strike many conventionally trained physicians and researchers as incomprehensible. Should modern medicine dismiss them as unscientific, view them as sources of alternatives hidden in a matrix of superstition, or regard them as complementary sciences of medicine? We make the latter argument using the example of Tibetan medicine. Tibetan medicine is based on analytic models and methods that are rationally defined, internally coherent, and make testable predictions, meeting current definitions of “science.” A ninth century synthesis of Indian, Chinese, Himalayan, and Greco‐Persian traditions, Tibetan medicine is the most comprehensive form of Eurasian healthcare and the world's first integrative medicine. Incorporating rigorous systems of meditative self‐healing and ascetic self‐care from India, it includes a world‐class paradigm of mind/body and preventive medicine. Adapting the therapeutic philosophy and contemplative science of Indian Buddhism to the quality of secular life and death, it features the world's most effective systems of positive and palliative healthcare. Based on qualitative theories and intersubjective methods, it involves predictions and therapies shown to be more accurate and effective than those of modern medicine in fields from physiology and pharmacology to neuroscience, mind/body medicine, and positive health. The possibility of complementary sciences follows from the latest view of science as a set of tools—instruments of social activity based on learned agreement in aims and methods—rather than as a monolith of absolute truth. Implications of this pluralistic outlook for medical research and practice are discussed.
“Subtle” Psychosomatic Aspects of Tibetan Medicine
Authors: Dakpa Tenzing , Dodson‐Lavelle Brooke
Published: August 2009

The theory and practice of traditional Tibetan medicine (TTM) is based on an understanding of a tri‐level psycho‐physical system; this bi‐directional connection between the psycho‐somatic realms is mediated by a distinct, yet inseparable energetic system – the subtle body. TTM practitioners approach both diagnosis and treatment from an understanding of this subtle energetic system. In the Tibetan yogic tradition, control of this system via advanced yogic and meditative technologies is the path to realize extraordinary levels of health, happiness, and longevity. As a result, understanding this intricately linked philosophical, medical, and yogic system is critical for engaging in dialogue about longevity‐enhancement within this tradition.
Introduction: The Americas, Otherwise
Authors: SPITTA SILVIA , ZAMORA LOIS PARKINSON
Published: August 2009

Taking as their point of departure the murals painted by the Mexican artists Diego Rivera and Miguel Covarrubias for the 1939 Golden Gate International Exposition in San Francisco, the editors address the development of comparative literature as an academic discipline in the U.S. and, more particularly, the recent development of the comparative study of the Americas. This growing field is variously referred to as Americas Studies, Transamerican Studies, Interamerican Studies, Hemispheric Studies and, depending upon the program or curriculum, it may also involve area studies programs that focus on the U.S./Mexico border, the circum-Atlantic, the Pacific rim, the Caribbean, and/or the recently developed conceptual area of the Global South. The editors address these emerging American comparativisms—their limitations and potentials, their disciplinary commitments and conditions, their theories and practices, and their shifting regions and relations. The editors call for a more expansive definition of academic work in the U.S., a definition based on the example of Latin American public intellectuals, and they also call for greater commitment to the teaching and learning of languages and to the translation of literature and literary theory from all areas of the hemisphere.
Hugo Meltzl and That Dangerous American Supplement; Or, A Tale of Two 1877s
Authors: LÓPEZ ALFRED J.
Published: August 2009

Hugo Meltzl de Lomnitz's 1877 list of ten “founding” languages for comparative literature implicitly includes the Americas, where at least five of the originary ten languages (English, French, Dutch, Portuguese, Spanish) were widely spoken at the time. Yet until very recently American texts in these languages have been largely excluded from comparative literary studies. A comparative reading of two 1877 texts—Meltzl's “Tasks of Comparative Literature” and José Martí's prospectus for the Revista Guatemalteca—reveals that the literatures of the Americas, and the Caribbean especially, are a supplement (in the Derridean sense) to Meltzl's Eurocentric model. Martí's 1877 prospectus for a comparative American literature is more inclusive than Meltzl's Eurocentric model of “polyglottism,” and it offers a vision of global comparative literary and cultural studies that we ignore to our peril.
A Great Bridge That Cannot Be Seen: Caribbean Literature as Comparative Literature
Authors: WINKS CHRISTOPHER
Published: August 2009

Building on Ngugi wa Thiong'o's concept of moving the cultural center away from Europe towards a multiplicity of creative centers and Gayatri Chakravorty Spivak's call for a revitalized comparative literature that would avail itself of the insights of a post-Cold War area studies, this essay explores the Caribbean as an exemplary inter-American and comparatist crossroads space and analyzes several elements that enter into the diverse poetics of the region as articulated by its major writers and theorists: from chaos to transculturation, from magical realism and the “imaginary eras” to the “Tout-monde.”
“Being-in-the-World-Hispanically”: A World on the “Border” Of Many Worlds
Authors: DUSSEL ENRIQUE
Published: August 2009

The present essay offers an interpretation of hispanos (Latin Americans and U.S. latinos) as historically, culturally, and geographically located “in-between” many worlds that combine to constitute an identity on the intercultural “border.” To illustrate how hispanos have navigated and continue to navigate their complex history in order to create a polyphonic identity, the essay sketches five historical-cultural “worlds” that come together to form the hispanic “world.”
The (Neo)Baroque Effect: A Critical Inquiry into the Transformation and Application of a Conceptual Field to Comparative American Studies
Authors: MALCUZYNSKI MARIE-PIERRETTE
Published: August 2009

This essay was written in 1987 in French by the late Polish theorist and critic Marie-Pierrette Malcuzynski and translated by Wendy B. Faris. Malcuzynski explores the theories of the New World Baroque and Neobaroque developed by the Cuban writers Alejo Carpentier and Severo Sarduy and the Brazilian poet and essayist Haroldo de Campos from the 1960s through the 1980s. Together, they represent a specifically Latin American combination of postmodernism and postcolonialism, a combination that is based in the historical and literary realities of the region. The author moves from a definition of the European Baroque, including a detailed discussion of its various possible etymologies, to the American Baroque and places Carpentier, Sarduy, and de Campos in the company of a number of European theorists to test their American arguments and applications. Mikhail Bakhtin is primary among the European theorists, but Saussure and Kristeva are also central to her evaluation of Sarduy. While Malcuzynski remains critical of certain aspects of these theories, she also implies that their historical rootedness in Latin America and the Caribbean make them more useful analytical tools than, say, Foucault, Lyotard, Bhabha, or Spivak—postmodernist and postcolonial theorists all too eagerly adopted in Latin America after passing through the “gate” of U.S.-American and European academia.
Latin America Translated (Again): Roberto Bolaño'sThe Savage Detectivesin the United States
Authors: POLLACK SARAH
Published: August 2009

This essay addresses the cultural and political agendas that influence the selection of Latin American novels to be translated by U.S. publishers and the reception of these novels by U.S. readers. Focusing on two Latin American writers who have had enormous success in the U.S., the author traces the shift from the magical realism of Gabriel García Márquez in the 1970s, 80s and 90s, to the gritty realism of Roberto Bolaño, and asks what these different paradigms can tell us about stereotypical U.S. notions of Latin American cultural and political realities. Although Bolaño's work ostensibly realigns the coordinates of the Latin American novel, breaking with the model of magical realism, it too foments a (pre)conception of alterity that satisfies the fantasies and collective imagination of U.S. cultural consumers. Citing the extremely low numbers of Latin American works translated and published in the U.S. yearly, she attributes this (pre)conception in part to the very small list of Latin American works available to U.S. readers—a list that comprises only a fraction of the total literary production of the region.
β1 integrin is necessary for ureteric bud branching morphogenesis and maintenance of collecting duct structural integrity
Authors: Zhang Xi , Mernaugh Glenda , Yang Dong-Hua , Gewin Leslie , Srichai Manakan B. , Harris Raymond C. , Iturregui Juan M. , Nelson Raoul D. , Kohan Donald E. , Abrahamson Dale , Fässler Reinhard , Yurchenco Peter , Pozzi Ambra , Zent Roy
Published: August 2009

The kidney collecting system develops from branching morphogenesis of the ureteric bud (UB). This process requires signaling by growth factors such as glial cell line derived neurotrophic factor (GDNF) and fibroblast growth factors (FGFs) as well as cell extracellular matrix interactions mediated by integrins. The importance of integrin signaling in UB development was investigated by deleting integrin β1 at initiation (E10.5) and late(E18.5) stages of development. Deletion at E10.5 resulted in a severe branching morphogenesis phenotype. Deletion at E18.5 did not alter renal development but predisposed the collecting system to severe injury following ureteric obstruction. β1 integrin was required for renal tubular epithelial cells to mediate GDNF- and FGF-dependent signaling despite normal receptor localization and activation in vitro. Aberrations in the same signaling molecules were present in the β1-null UBs in vivo. Thus β1 integrins can regulate organ branching morphogenesis during development by mediating growth-factor-dependent signaling in addition to their well-defined role as adhesion receptors.
The response of non-traditional natriuretic peptide production sites to salt and water manipulations in the rainbow trout
Authors: Johnson Keven R. , Olson Kenneth R.
Published: August 2009

Natriuretic peptides (NPs) and their receptors (NPRs) comprise an evolutionarily conserved signaling system with profound physiological effects on vertebrate renal and cardiovascular systems. Some NPs (ANP, BNP and VNP)are primarily of cardiac origin whereas CNP is common in the brain. In mammals, non-traditional sites of NPs synthesis, BNP in brain and CNP in atrium, appear to have complementary actions. In the present study, trout were chronically adapted to freshwater (FW) (a volume-loading, salt-depleting environment), saltwater (SW) (a volume-depleting, salt-loading environment),FW and fed a high-salt diet (FW–HSD) (a volume- and salt-loading regime)or acutely volume depleted or expanded by hemorrhage or infusion with dialyzed plasma to perturb volume homeostasis. The responses of brain and atrial BNP and CNP mRNA, pro-peptide, NPR-A and NPR-B were evaluated using quantitative PCR and western analysis. Brain pro-BNP and NPR-A was increased in FW–HSD trout and decreased in SW trout. Brain pro-CNP was largely unaffected whereas NPR-B mRNA was increased in FW–HSD trout. Atrial CNP,although produced at lower levels than other cardiac NPs, was markedly elevated in chronically (FW–HSD) and acutely volume expanded trout(dialyzed-plasma infusion) whereas decreased in hemorrhaged trout. These findings indicate that non-traditional NP synthesis sites in the trout probably complement the broad hypovolemic and hypotensive actions of traditional (cardiac) NP synthesis sites in response to volume expansion but not to plasma osmolarity. This supports the hypothesis that the piscine and mammalian NP systems are fundamentally similar and appear to protect the heart from volume overload.
X-ray microanalysis of Rb+ entry into cricket Malpighian tubule cellsviaputative K+ channels
Authors: Marshall Alan T. , Clode Peta L.
Published: August 2009

Elemental imaging by X-ray microanalysis of fully frozen-hydrated samples shows that when Malpighian tubules of the black field cricket(Teleogryllus oceanicus L.) are incubated in saline in which Rb+ has been substituted for K+, Rb+ replaces much of the cellular K+ in the main segment of control Malpighian tubules and this is prevented by incubation in saline containing Ba2+, a non-selective K+ channel blocker. Similarly the amount of cellular K+ is greatly reduced when tubules incubated in normal, i.e. K+ containing, saline are exposed to Ba2+. By considering the amounts of cellular K and Rb remaining in the main segments of tubules incubated in either K+ containing saline or Rb+ containing saline after Ba+ treatment, it is suggested that: (a) a major part (56%) of cellular K+ enters by Ba2+ sensitive K+ channels and that Rb+ can also enter by this route; (b) a smaller fraction (26%) of cellular K+ enters by a previously proposed Na+/K+/2Cl– co-transporter, which can also transport Rb+; (c) a previously proposed Na+/K+-ATPase is responsible for maintaining a K+ pool (18%) in the tubule cells that is not exchangeable by Rb+; and (d) entry by this Na+/K+-ATPase is not available to Rb+.
Inference from Streaks in Random Outcomes: Experimental Evidence on Beliefs in Regime Shifting and the Law of Small Numbers
Authors: Asparouhova Elena , Hertzel Michael , Lemmon Michael
Published: August 2009

Using data generated from laboratory experiments, we test and compare the empirical accuracy of two models that focus on judgment errors associated with processing information from random sequences. We test for regime-shifting beliefs of the type theorized in Barberis et al. (Barberis, N., A. Shleifer, R. Vishny. 1998. A model of investor sentiment. J. Financial Econom. 49(3) 307–343) and for beliefs in the “law of small numbers” as modeled in Rabin (Rabin, M. 2002. Inference by believers in the law of small numbers. Quart. J. Econom. 117(3) 775–816). In our experiments, we show subjects randomly generated sequences of binary outcomes and ask them to provide probability assessments of the direction of the next outcome. Inconsistent with regime-shifting beliefs, we find that subjects are not more likely to predict that the current streak will continue the longer the streak. Instead, consistent with Rabin (2002), subjects are more likely to expect a reversal following short streaks and continuation after long streaks. Results of a “test-of-fit” analysis based on structural estimation of each model also favor the model in Rabin. To provide more insight on Rabin, we use an additional experimental treatment to show that as the perception of the randomness of the outcome-generating process increases, subjects are more likely to predict reversals of current streaks.
Stability and Reproducibility of a Single-Sample Urinary C-Peptide/Creatinine Ratio and Its Correlation with 24-h Urinary C-Peptide
Authors: McDonald Tim J , Knight Bridget A , Shields Beverley M , Bowman Pamela , Salzmann Maurice B , Hattersley Andrew T
Published: August 2009

Introduction: C-peptide measurement in blood or 24-h urine samples provides useful information regarding endogenous insulin secretion, but problems related to the rapid degradation of C-peptide in blood and difficulty of 24-h urine collection have limited widespread routine clinical use of this test. We assessed the feasibility of measuring urinary C-peptide (UCP) with correction for creatinine concentration in single urine samples.

Methods: We analyzed UCP using a routine electrochemiluminescence immunoassay in samples from 21 healthy volunteers. We investigated the stability of UCP with different preservatives and storage conditions and compared the reproducibility of urinary C-peptide/creatinine ratio (UCPCR) in first- and second-void fasting urines, then assessed correlations with 24-h collections.

Results: UCPCR was unchanged at room temperature for 24 h and at 4 °C for 72 h even in the absence of preservative. UCPCR collected in boric acid was stable at room temperature for 72 h. UCPCR remained stable after 7 freeze-thaw cycles but decreased with freezer storage time and dropped to 82%–84% of baseline by 90 days at −20 °C. Second-void fasting UCPCRs were lower than first-void (median 0.78 vs 1.31, P = 0.0003) and showed less variation (CV 33% vs 52%), as second-void UCPCRs were not influenced by evening food-related insulin secretion. Second-void fasting UCPCR was highly correlated with 24-h UCP (r = 0.8, P = 0.00006).

Conclusions: Second-void fasting UCPCR is a reproducible measure that correlates well with 24-h UCP in normal samples. The 3-day stability of UCPCR at room temperature greatly increases its potential clinical utility.
Acid Resisting Properties of Porcelain Enamels
Authors: Wilson Harold C.
Published: August 2009

In considering acid attack on ceramic coatings, it should be pointed out that the degree of attack is a relative consideration. Just as it is meaningless to say that a material is heat resistant, so it is equally indefinite to classify a ceramic coating as acid resistant without further elaboration. Perhaps a good rule of procedure in considering any type of coating or finish, whether a ceramic type or a nonceramic type, is to adopt the premise that every coating is slightly soluble. Assuming that there is a solubility problem, however slight, it naturally follows that the requirements of the application under consideration should be studied to determine just what the conditions of exposure are, how much the conditions affect a given coating, and whether the established amount of attack for this exposure can be tolerated. To give point to the above statements it might be well to review a few types of exposures which illustrate different requirements in resistance to acid attack.
Requirements for and Expected Benefits from the Application of Coatings to High-Temperature Components of a Jet Engine
Authors: Francisco A. C. , Ault G. M.
Published: August 2009

Materials are still the key to the improvement of aircraft engines. Because of the high temperature, the corrosive atmosphere, and in some components the high stresses, materials in current engines are required to operate near their damage points. Further increase in engine performance through increase in operating temperature requires improvement in materials. It is the purpose in this discussion to show how coatings can be used to help alleviate the materials problem. We shall describe a typical engine, discuss the conditions under which the components operate, show the contribution that can be made by applying coatings to these materials, and discuss the requirements that the coatings must meet. Considering the characteristics of ceramics, ceramic coatings might be expected to serve several functions. Since they are essentially oxides, it would be expected that the most important function would be protection against oxidation and perhaps corrosion. Because of their low conductivity, they would also be expected to serve as insulation against high temperatures. If coatings can serve these functions of protection against oxidation and corrosion and insulation against high temperatures, appreciable strides may be made toward the major jet-engine development goals of increased service life, reduced use of strategic materials, and increased operating temperatures. The important engines today are the turbojet, the turboprop, the ramjet, and the rocket. For this discussion, we shall consider the application of coatings to the major production engine, the turbojet, shown schematically in Fig. 1. The turbojet is a typical heat engine in which air is compressed, heated, and expanded. Air enters the front of the engine and is compressed, in this case by an axial flow compressor. The axial flow compressor is made up of alternate stages of stationary and rotating blades and moves the air through the turbine much in the same manner as the house-hold fan. Compression is indicated by the difference in area of the duct at the inlet and the exit. The amount of compression may be of the order of 4 to 1. The compressed air then enters the combustion chamber where fuel is injected and burned. This greatly expands the volume of the air under conditions of constant pressure, and the high-velocity hot gases are directed by the stationary turbine inlet guide vanes against the rotating turbine blades. The turbine and compressor are on a common shaft and the entire output of the turbine is used to drive the compressor. The hot gases then expand out the rear, and forward thrust is achieved by the reaction of the jet.
High-Temperature Ceramic Coatings as Applied to Aircraft Power Plants
Authors: Paris B. L.
Published: August 2009

The Air Force has, for the past several years, sponsored a high-temperature ceramic coating research and development program directed toward the practical utilization of such coatings on the hot gas components of aircraft power plants. The results of this program will, in many cases, be directly applicable to various industrial high-temperature uses. The objectives as well as the fundamental reasons for initiating such a program are outlined in this paper. A summary of the expected benefits to be derived from the use of high-temperature ceramic coatings by both industry and the Armed Forces will be presented. Such coatings may be used to extend the life of relatively high alloys in such applications as reciprocating engine exhaust systems and high-temperature furnace components where failure is generally a result of such things as oxidation, corrosion, and embrittlement. Low-alloy steels may be coated to replace the critical and expensive alloys currently being used in the hot gas sections of gas turbine power plants. The properties of these coatings and the position of the industrial engineer relative to this over-all high-temperature coating program are presented.
Measurement and Purification of Steam to 0.01 ppm Total Dissolved Solids
Authors: Gurney W. B.
Published: August 2009

Accuracy of measurement of dissolvable solids in saturated steam at high pressures is greatly increased by separating out the moisture at 550 psia, then determining the solids in the separated moisture by conductivity or other means. The method is applicable to purification of saturated steam leaving modern boilers. The method supplements present conductivity measurements.
Comments on Corrections to Steam Conductivity Measurements
Authors: Parker R. O. , Ziobro R. J.
Published: August 2009

Published conductivity correction curves for carbon dioxide and ammonia disagree. A new curve, based on stated equilibrium constants and ionic conductances, is compared with these. The corrections are tabulated over a range suitable for plotting a useful curve. To eliminate the gas correction, conductivity is frequently measured at the atmospheric boiling point. Erroneous impressions of purity obtained by this method result from: 1. Neglect of the relatively high conductivity of pure water at 100 C, 2. Use of too small a temperature coefficient in correcting the measurement to 25 C. Conductivity measured at 100 C is not necessarily free of gas correction; samples should be checked for gases and the appropriate correction made. The correction for ammonia at 100 C is given.
Evaluation of Hartmann and Braun Dissolved Oxygen Recorder for Boiler Feedwater
Authors: Ristaino A. J. , Dominick A. A.
Published: August 2009

The Hartmann & Braun dissolved oxygen meter for boiler feedwater measures and records the electric current generated by the action of dissolved oxygen on a voltaic cell. The calibration of this current in terms of dissolved oxygen by means of the ASTM referee chemical test is described. The instrument will record dissolved oxygen in three ranges, 0 to 0.03 ppm, 0 to 0.08 ppm, and 0 to 0.2 ppm. In the range 0 to 0.03, the meter checks the referee method within ±0.003 ppm. In the ranges 0 to 0.08 and 0 to 0.2 ppm dissolved oxygen, instrument values are within ±0.005 and ±0.01 ppm, repectively, of the referee procedure. The Hartmann & Braun meter requires about 7 1/2 min to respond completely to sudden surges of dissolved oxygen, and about 7 1/2 min to recover from such a surge. Temperature variation has a marked but reproducible effect on the dissolved oxygen record. Electrode fouling with corrosion products and leakage past the cathode gaskets affect sensitivity and reproducibility considerably.
Introduction
Authors: Woods K. B.
Published: August 2009

Developments in technology are occurring at a rate unmatched in the history of the world. Each of the basic sciences is expanding into the unknown at a faster and faster rate. This is true for mathematics, chemistry, physics, and for all of the biological sciences. These developments provide new tools to work with in such fields as agriculture, engineering, medicine, and many others. Corresponding changes are taking place in communications, transportation, and in such areas as rockets and missiles. All of this is common knowledge. What is not so well known—and in fact, not even well understood—is the impact of these great achievements and advancements of science on education, not only on college and university curricula, but also on high schools, elementary schools, and the technical institutes. Educators and parents alike see the need for offering more material in the sciences at all levels in the educational system. Employers are requiring higher standards of performance in mathematics, physics, and chemistry. These changes have a bearing on the status of art, music, languages, literature, and in fact, all of the offerings in the humanities, and related areas. There is a real possibility that undiscriminating and wholesale replacement of humanities courses by science courses may endanger the status of the humanities programs.
Nature and Properties of Materials—A Discussion of the Report of Asee Follow-Up Subcommittee on Materials
Authors: Murphy Glenn
Published: August 2009

It is indeed a pleasure to have the opportunity to discuss some aspects of education in materials. The subject of this symposium is not new, for education in materials has received the attention of many individuals. One of the first of whom we have a record is Vitrivius, a builder who lived in Rome in the first century. His writings are contained in a publication, Ten Books of Architecture. In them he describes and discusses the properties and the utilization of building materials. Much of what he has to say is almost identical with what can be found in certain college textbooks now being used in materials courses. Not only the same information but also the same methods of approach to problems are being given some of our engineering students today in their instruction in materials that was being given 2000 years ago. Of course, the physical and mechanical properties of certain natural building materials have not changed appreciably since the days of Vitrivius. Granites and limestones are about as they were in the first century, and the botanical processes influencing the properties of oak and cedar have not altered in 20 centuries. During the 2000-year interval the properties of some man-made materials have not been improved much either. The strength of concrete, for example, has changed less than an order of magnitude, although potentially the change could be four orders of magnitude. Until only a few years ago the same comment was true for metals. However, the uses to which the materials are put, the demands upon them in modern design, and our understanding of their properties have altered greatly. As one example, our understanding of metals has now progressed to the point where fibers having strengths nearly equivalent to their theoretical maximum strength of a few million pounds per square inch can be produced. In other instances, new materials have been designed and produced to meet desired specifications. Revolutionary developments of this type have directed attention to the need for reconsideration of instruction in materials. At the outset, it should be recognized that programs in materials include not only the formal courses in college, but also on-the-job training and informal self-study after graduation. Our question is whether or not present-day education in materials is well adapted to adjust the outlook of the engineer to the current revolutionary developments that will greatly affect the utilization of materials a few decades hence.
Diesel Fuel Specifications Requirements
Authors: Ward C. C.
Published: August 2009

The present ASTM Classifications D 975-53T for diesel fuel are satisfactory for the purpose for which they are used—because no one uses them. The engine builder does not like them, so he writes his own specifications. The big consumer purchases fuels on his own specifications, and the small consumer uses either the recommendation of the engine builder or of the refiner or takes what fuel is available in his locality. The refiner makes one or two distillate fuels of the same boiling range as burner fuels and then sells them for a wide variety of uses. These statements appear rather broad, but let us review the record.
Technical Problems Associated with Diesel Fuels in Contractors' Equipment
Authors: Vollentine J. W.
Published: August 2009

The contractors in this country generally have no operating conditions with diesel fuels which can be considered to constitute a field problem. Occasionally, however, annoying incidents occur which are the result of fuel characteristics or unsatisfactory fuel handling. The contractor is interested primarily in the following items which are in whole or in part affected by diesel fuels: 1. Engine starting, 2. Fuel handling, 3. Fuel injection equipment wear, 4. Piston, ring, and cylinder liner wear, 5. Engine maintenance, and 6. Fuel cost. The fuel characteristics which influence these items of operation will be considered here, as well as some characteristics that are considered to be relatively unimportant.
A Triaxial Apparatus for Testing Large Soil Specimens
Authors: Hall Earl B.
Published: August 2009

The object of this paper is to describe the construction and operation of a triaxial apparatus for testing soils containing material passing the 3-in. sieve size. Also, the presentation of a few typical results obtained on various types of soil will be made. The development of this type of equipment was accelerated, late in 1948, by the specific need for investigating the shear strength characteristics of foundation material for the Corps of Engineers' Folsom Project in California. This soil varied from gravel to clayey sandy gravel. Since, in general, the amount of clay present was of a significant amount, it was necessary to determine the shear resistance of the minus 3-in. portion of the material, in order to bring out the effect of the very plastic fines on the relatively high shearing resistance of the gravel. A second, and equally important, need for equipment of this magnitude was the testing of gravel without plastic fines under conditions of high lateral pressure. It was, therefore, necessary to devise equipment which would accommodate material of this size. No attempt was made to revolutionize the present equipment generally used in testing by triaxial methods the shear characteristics of soil; rather, an effort was made to adapt current ideas to new equipment capable of testing large soil specimens. Wherever possible, standard stock items were used in preference to prefabricating special parts, so that the unit could be made with a minimum of expense. Where commercial products are referred to by name in this paper, it is only for the purpose of clearer description. Competitive products can, in most cases, be satisfactorily substituted.
Environmental Effects on Fatigue of Structural Materials for a Supersonic Transport
Authors: Hardrath H. F.
Published: August 2009

The proposed supersonic commercial transport has posed formidable new design problems requiring information on mechanical behavior of new materials and on the effects of long exposure to elevated temperatures during service. Experimental studies of titanium alloys have been conducted at National Aeronautics and Space Administration (NASA) Langley Research Center to define fatigue behavior, effects of temperature, rates of fatigue crack propagation, residual static strength, effect of aqueous environment on residual strength, the effect of outdoor exposure at elevated temperature, and behavior during simulated flights of the supersonic transport. These results are summarized and discussed.
Fracture Toughness Testing
Authors: Kaufman J. G.
Published: August 2009

Fracture toughness testing is a new approach to measuring the specific conditions under which low-ductility fracture will take place as a result of a crack developing in an elastic stress field. It appears to be independent of the type of crack growth. The development of fracture-toughness test procedures is reviewed, and the areas of current interest are identified. Implications to the materials engineer and designer are suggested.
Opening Remarks
Authors: Pincus Howard J.
Published: August 2009

The number and diversity of classifications of rock material, rock mass, and rock structure used in geology and geotechnical engineering are functions not only of the variability of materials, properties, and features involved but also of the uses to which the classifications are to be put [1–4]. Some of these classifications [1–3] are in fact hierarchies of classifications, or classification systems, and are used to assist in arriving at engineering decisions requiring the disciplined consideration of many variables and their interactions. In such cases, perhaps these systems should be given some name other than classification, which connotes to some the processes of ordering and grouping for purposes other than arriving at engineering decisions. It is not the purpose of this symposium to serve as an elimination contest from which one classification will emerge as the winner, enshrined as a unique ASTM standard. The symposium has been organized with the intention that its main outcome will be the publication of at least several classifications, as ASTM standards, each of which will address a well-defined set of engineering needs. The final, full consensus, published standards may or may not closely resemble the methods presented in the following papers. A related purpose of the symposium is to give the rationale underlying each of the classifications. Do the criteria for classifications appear to be sensible? Is this classification really useful? Does one need to classify at all in order to accomplish the objectives to which the classification is said to be addressed?
A Case History Review from a Perspective of Design by Rock Mass Classification Systems
Authors: Nicholson Glenn A.
Published: August 2009

The design of the Park River Auxiliary Tunnel is reviewed. The tunnel is a 2800 m (9100 ft) long, 6.7 m (22 ft) inside diameter inverted siphon-shaped tunnel constructed to bypass flood water beneath the city of Hartford, Connecticut, and transmit it directly to the Connecticut River. The tunnel was designed by and constructed for the New England Division of the U.S. Army Corps of Engineers. The approach selected for design consisted of a rational evaluation of recommended supports and rock load heights as determined from two rock mass classification design systems. Rock load heights predicted by the two classification systems were cross checked with a discrete element numerical model. The three-tiered approach of checks and balances incorporated into the design of the Park River Auxiliary Tunnel resulted in significant cost savings in final support. A comparison is also made between support requirements recommended by two additional classification systems.
Rock Classification Systems for Engineering Purposes
Authors: Kirkaldie Louis
Published: August 2009

Description

Brings together in one volume discussions of the five major classification systems and procedures used to classify rock by engineering users. Also includes case studies in which rock classification is a critical factor. For engineering geologists; geotechnical engineers.