bluuebunny/crossref_metadata_2025 huggingface dataset:
On the role of transforming growth factor-β in the growth inhibitory effects of retinoic acid in human pancreatic cancer cells
Authors: Singh Brahmchetna , Murphy Richard F , Ding Xian-Zhong , Roginsky Alexandra B , Bell Richard H , Adrian Thomas E
Published: December 2007

Background

Retinoids are potent growth inhibitory and differentiating agents in a variety of cancer cell types. We have shown that retinoids induce growth arrest in all pancreatic cancer cell lines studied, regardless of their p53 and differentiation status. However, the mechanism of growth inhibition is not known. Since TGF-β2 is markedly induced by retinoids in other cancers and mediates MUC4 expression in pancreatic cancer cells, we investigated the role of TGF-β in retinoic acid-mediated growth inhibition in pancreatic cancer cells.

Results

Retinoic acid markedly inhibited proliferation of two cell lines (Capan-2 and Hs766T) in a concentration and time-dependent manner. Retinoic acid increased TGF-β2 mRNA content and secretion of the active and latent forms of TGF-β2 (measured by ELISA and bioassay). The concentrations of active and TGF-β2 secreted in response to 0.1 – 10 μM retinoic acid were between 1–5 pM. TGF-β2 concentrations within this range also inhibited proliferation. A TGF-β neutralizing antibody blocked the growth inhibitory effects of retinoic acid in Capan-2 cells and partially inhibitory the effects in Hs766T cells.

Conclusion

These findings indicate that TGF-β can cause growth inhibition of pancreatic cancer cells, in a p53-independent manner. Furthermore, it demonstrates the fundamental role of TGF-β in growth inhibition in response to retinoic acid treatment is preserved in vitro.
Thyroid metastasis in a patient with hepatocellular carcinoma: case report and review of literature
Authors: Liang Hung-Hua , Wu Chih-Hsiung , Tam Ka-Wai , Chai Chiah-Yang , Lin Sey-En , Chen Soul-Chin
Published: December 2007

Background

Despite the apparent low incidence of cancer metastatic to the thyroid, autopsy and clinical series suggest it is more common than generally. Although lung, renal, and breast cancer are probably the most common primary sites, a number of cancers have been reported to metastasize to the thyroid synchronously with diagnosis of primary tumor or years after apparently curative treatment.

Case presentation

We report a rare case of a hepatocellular carcinoma metasatic to the thyroid. The patient presented seven months after original diagnosis and treatment with hepatic lobectomy with multiple neck lesions producing a mass effect on the trachea and bilateral lymphadenopathy. Fine-needle aspiration revealed highly anaplastic carcinoma, and immunohistochemistry confirmed hepatocellular carcinoma. The patient received total thyroidectomy as palliative therapy because of the presence of multiple recurrent lesions in the liver.

Conclusion

Clinicians should consider the possibility of metastatic cancer in each patient who presents with a new thyroid mass, especially those with a history of cancer, however remote. In cases where cytology or histology is not diagnostic, immunohistochemistry may be definitive in making the diagnosis.
Activation of the Neurokinin-1 Receptor by Substance P Triggers the Release of Substance P from Cultured Adult Rat Dorsal Root Ganglion Neurons
Authors: Tang He-Bin , Li Yu-Sang , Arihiro Koji , Nakata Yoshihiro
Published: December 2007

Background:

Although substance P (SP) is an important primary afferent modulator in nociceptive processes, it is unclear whether SP regulates its own release from primary sensory neurons.

Results:

Using a highly sensitive radioimmunoassay for SP, we have demonstrated that the activation of neurokinin-1 receptor by SP or GR73632 (a potent neurokinin-1 receptor agonist) triggered an increase of SP release from cultured adult rat dorsal root ganglion (DRG) neurons depending on the dose and exposure time within 60 min, and thereafter, the SP release level gradually decreased over 360 min. Accompanying the SP release, a significant reduction in the percentage of neurons expressing neurokinin-1 receptor on their membranes during exposure to SP (200 pg/dish) occurred time dependently (56 ± 5% and 32 ± 2% at 180 and 360 min, respectively). The GR73632-evoked (10 nM, 60 min) SP release was attenuated by several inhibitors for mitogen-activated protein kinase kinase, p38 mitogen-activated protein (MAP) kinase and cyclooxygenase-2 (COX-2), protein kinase C (PKC), respectively. In contrast, a c-Jun NH2-terminal kinase inhibitor increased the GR73632-evoked SP release.

Conclusion:

These results indicate that the neurokinin-1 receptor activation by its agonists regulates the SP release process involving the activation of MAP kinases, PKCs and COX-2 from cultured DRG neurons.
Detection and identification of enterohemorrhagic Escherichia coli O157:H7 and Vibrio cholerae O139 using oligonucleotide microarray
Authors: Jin Da-Zhi , Xu Xiao-Jing , Chen Su-Hong , Wen Si-Yuan , Ma Xue-En , Zhang Zheng , Lin Feng , Wang Sheng-Qi
Published: December 2007

Background

The rapid and accurate detection and identification of the new subtype of the pathogens is crucial for diagnosis, treatment and control of the contagious disease outbreak. Here, in this study, an approach to detect and identify Escherichia coli O157:H7 and Vibrio cholerae O139 was established using oligonucleotide microarray. We coupled multiplex PCR with oligonucleotide microarray to construct an assay suitable for simultaneous identification of two subtypes of the pathogens.

Results

The stx 1, stx 2 gene and uid A gene having the specific mutant spot were chosen as the targets for Escherichia coli O157:H7, and meanwhile the ctx A, tcp A, and LPSgt gene for Vibrio cholerae O139. The oligonucleotide microarray was composed of eight probes including negative control and positive control from 16S rDNA gene. The six primers were designed to amplify target fragments in two triplex PCR, and then hybridized with oligonucleotide microarray. An internal control would be to run a PCR reaction in parallel. Multiplex PCR did not produce any non-specific amplicons when 149 related species or genera of standard bacteria were tested (100% specificity). In addition, Escherichia coli O157:H7 and Escherichia coli O157:non-H7, Vibrio cholerae O139 and Vibrio cholerae O1 had been discriminated respectively. Using recombinant plasmid and target pathogens, we were able to detect positive hybridization signals with 102 copies/μL and 103 cfu/mL per reaction.

Conclusion

The DNA microarray assay reported here could detect and identify Escherichia coli O157:H7 and Vibrio cholerae O139, and furthermore the subtype was distinguished. This assay was a specific and sensitive tool for simultaneous detection and identification of the new subtype of two pathogens causing diarrhea in human.
Regulation of CD28 expression on CD8+ T cells by CTLA-4
Authors: Berg Martina , Zavazava Nicholas
Published: December 2007

CD28 and CTLA-4 are the critical costimulatory receptors that predominantly determine the outcome of T cell stimulation, with CD28 promoting positive costimulation and CTLA-4 inducing inhibitory signals. Blockage of the B7-CD28/CTLA-4 pathway leads to transplantation tolerance. However, the exact mechanism of the inhibitory function of CTLA-4 remains elusive. Here, we investigated the influence of CTLA-4 expression on CD28 using CTLA-4-transfected Jurkat T cells as well as primary T cells. Up-regulation of CTLA-4 induced abrogation of IL-2 production, indicating an anergic phenotype of CTLA-4high T cells. Besides the negative signaling function of CTLA-4, we show for the first time that CTLA-4 expression promotes the down-regulation of CD28 on the T cell surface as a result of enhanced internalization and degradation of CD28. These data suggest that apart from the established competition for B7.1 and B7.2 by CTLA-4, inhibition of T cells by CTLA-4 might be additionally explained by reduction of CD28 on the cell surface, which might impede T cell response to stimulation. Our data provide a previously unrecognized mechanism for T cell regulation.
Increased Uptake ofBRCA1/2Genetic Testing Among African American Women With a Recent Diagnosis of Breast Cancer
Authors: Susswein Lisa R. , Skrzynia Cécile , Lange Leslie A. , Booker Jessica K. , Graham Mark L. , Evans James P.
Published: December 2007

Purpose

Studies suggest that African American women are less likely to pursue BRCA1/2 genetic testing than white women. However, such studies are often confounded by unequal access to care.

Methods

Data from 132 African American and 636 white women, obtained from a clinical database at the University of North Carolina (Chapel Hill, NC) between 1998 and 2005, were analyzed to assess BRCA1/2 genetic testing uptake. Importantly, the clinical setting minimized barriers of both cost and access. Race and time of new breast cancer diagnosis (recent v > 1 year before genetic evaluation) were assessed for association with BRCA1/2 testing uptake using multivariable logistic regression models.

Results

Both race (P = .0082) and a recent diagnosis of breast cancer (P = .014) were independently associated with testing uptake. African American women had a lower estimated odds of pursuing testing than white women (odds ratio [OR], 0.54; 95%CI, 0.34 to 0.85), and women with a recent diagnosis had a higher OR than those with a remote diagnosis (OR, 1.58; 95% CI, 1.10 to 2.29). In a race-stratified analysis, there was no statistical evidence for association between recent status and testing uptake in the larger white stratum (OR, 1.38, P = .13) while there was for the smaller African American sample (OR, 2.77, P = .018). The test of interaction between race and remote status was not significant (P = .15).

Conclusion

African American race was associated with an overall decreased uptake of BRCA1/2 genetic testing, even when barriers of ascertainment and cost were minimized. However, among African American women, a recent diagnosis of breast cancer was associated with substantially increased uptake of testing.
Lymph Node Density Is Superior to TNM Nodal Status in Predicting Disease-Specific Survival After Radical Cystectomy for Bladder Cancer: Analysis of Pooled Data From MDACC and MSKCC
Authors: Kassouf Wassim , Agarwal Piyush K. , Herr Harry W. , Munsell Mark F. , Spiess Philippe E. , Brown Gordon A. , Pisters Louis , Grossman H. Barton , Dinney Colin P. , Kamat Ashish M.
Published: December 2007

Purpose

To compare the utility of lymph node density (LND) with TNM nodal status in predicting disease-specific survival (DSS) after radical cystectomy.

Patients and Methods

We identified 248 patients with nodal metastasis after radical cystectomy (without neoadjuvant chemotherapy): 162 patients from Memorial Sloan-Kettering Cancer Center (MSKCC) and 86 patients from M.D. Anderson Cancer Center (MDACC). We assessed the effect of several variables on DSS.

Results

After a median follow-up duration of 24 months, 134 patients died of their disease. The median DSS was 36 months, and the 1-year, 2-year, and 5-year DSS rates were 83.7%, 57.4%, and 36.6%, respectively. The median LND was 20%. The 5-year DSS rate was 54.6% for patients with LND ≤ 20% v 15.3% for patients with LND higher than 20% (P < .01). Pathologic nodal (pN) status in patients was 78 for pN1 (32%), 127 for pN2 (51%), and 43 for pN3 (17%). On univariate analysis, pN status and LND were significant predictors of DSS (P < .01). However, when pN status and LND were considered jointly in a multivariate model, only LND higher than 20% predicted decreased DSS (hazard ratio [HR], 2.75; P < .01). In addition, while nonorgan-confined (ie, > pT2) primary tumor (HR, 2.40; P < .01) and adjuvant chemotherapy (HR, 0.47; P < .01) were predictors of DSS, LND remained a predictor of DSS even after accounting for adjuvant chemotherapy.

Conclusion

LND is superior to TNM nodal status in predicting DSS for patients with lymph node–positive disease after radical cystectomy, even in the context of adjuvant chemotherapy.
Feeding and Metabolism in Mice Lacking Pituitary Adenylate Cyclase-Activating Polypeptide
Authors: Adams Bruce A. , Gray Sarah L. , Isaac Emma R. , Bianco Antonio C. , Vidal-Puig Antonio J. , Sherwood Nancy M.
Published: December 2007

Disruption of the pituitary adenylate cyclase-activating polypeptide (PACAP) gene in mice has demonstrated a role for this highly conserved neuropeptide in the regulation of metabolism and temperature control. Localization of PACAP neurons within hypothalamic nuclei that regulate appetite suggest PACAP may affect feeding and thus energy balance. We used PACAP-null mice to address this question, examining both food intake and energy expenditure. PACAP-null mice were leaner than wild-type littermates due to decreased adiposity and displayed increased insulin sensitivity. The lean phenotype in the PACAP-null mice was completely eliminated if animals were fed a high-fat diet or housed near thermoneutrality (28 C). Further metabolic analyses of PACAP-null mice housed at 21 C indicated that the reduced body weight could not be explained by decreased food intake, increased metabolic rate, or increased locomotor activity. The thyroid hormone axis of PACAP-null mice was affected, because mRNA levels of hypothalamic TRH and brown adipose tissue type 2 deiodinase were reduced in PACAP-null mice housed at room temperature, and brain deiodinase activity was lower in PACAP-null mice after an acute cold challenge compared with wild-type controls. These results demonstrate that PACAP is not required for the regulation of food intake yet is necessary to maintain normal energy homeostasis, likely playing a role in central cold-sensing mechanisms.
An Intracellular Loop (IL2) Residue Confers Different Basal Constitutive Activities to the Human Lutropin Receptor and Human Thyrotropin Receptor through Structural Communication between IL2 and Helix 6, via Helix 3
Authors: Feng Xiuyan , Müller Thomas , Mizrachi Dario , Fanelli Francesca , Segaloff Deborah L.
Published: December 2007

The human lutropin receptor (hLHR) and human TSH receptor (hTSHR) are G protein-coupled receptors that play key roles in reproductive and thyroid physiology, respectively. We show using a quantitative assessment of cAMP production as a function of cell surface receptor expression that the hTSHR possesses greater basal constitutive activity than the hLHR. Further studies were undertaken to test the hypothesis that different potential Gs-coupling motifs identified in IL2 of the hTSHR and hLHR contribute to their different basal constitutive activities. Although mutating the receptors to interchange their potential Gs-coupling motifs reversed their relative activities, we show this to be due to the swapping of one IL2 residue (Q476 in the hLHR; R531 in the hTSHR). Molecular dynamics simulations show that the effect of the hLHR(Q476R) mutation, switching the structural features of the hLHR toward those of the hTSHR, is greater than the switching effect of the hTSHR(R531Q) mutant toward the hLHR. The structural model of the hLHR(Q476R) mutant can be considered as a hybrid of wild-type (wt) hTSHR and constitutively active mutant hLHR forms. In this hLHR(Q476R) mutant, IL2 adopts a structure similar to IL2 of the wt hTSHR, but it shares with the hLHR constitutively active mutant the solvent exposure and the reciprocal arrangement of helices 3, 5, and 6, including the weakening of the wt native R3.50-D6.30 interaction. Our results suggest a H3-mediated structural connection between IL2 and the cytosolic extension of H6. Thus, IL2 contributes significantly to the inactive and active state ensembles of these G protein-coupled receptors.
The Melanocortin 2 Receptor Accessory Protein Exists as a Homodimer and Is Essential for the Function of the Melanocortin 2 Receptor in the Mouse Y1 Cell Line
Authors: Cooray Sadani N. , Almiro Do Vale Isabel , Leung Kit-Yi , Webb Tom R. , Chapple J. Paul , Egertová Michaela , Cheetham Michael E. , Elphick Maurice R. , Clark Adrian J. L.
Published: December 2007

The ACTH receptor [melanocortin 2 receptor (MC2R)] gene produces a functional receptor only when transfected into cells of adrenocortical origin, implying that it may require an adrenal-specific accessory factor. Recently we showed that the MC2R accessory protein (MRAP) is essential for the cell surface expression of the MC2R in such models. Using RNA interference (RNAi) technology, we have further explored the action of MRAP in the functioning of the MC2R in Y1 mouse adrenocortical cells that endogenously express MRAP and MC2R. We created stable cell lines expressing mouse MRAP short hairpin RNA (shRNAs) by transfecting cells with an expression vector containing the MRAP small interfering RNA sequence. The knockdown of MRAP resulted in a reduction in MC2R signaling. The overexpression of a mouse MRAP-Flag construct did not restore the expression of MRAP due to its degradation by the mouse shRNAs. The introduction of human MRAP that is resistant to silencing by mouse MRAP shRNAs resulted in the rescue of the MC2R signaling. MRAP migrates on SDS-PAGE with markedly lower mobility than predicted for a 14.1-kDa protein. Coimmunoprecipitation and mass spectroscopy suggests that MRAP exists as a homodimer that is resistant to dissociation by sodium dodecyl sulfate and reducing agents.
Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)
Authors: Shiraishi Eri , Yoshinaga Norifumi , Miura Takeshi , Yokoi Hayato , Wakamatsu Yuko , Abe Shin-Ichi , Kitano Takeshi
Published: December 2007

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.
The implications of low-speed fixed-wing aerofoil measurements on the analysis and performance of flapping bird wings
Authors: Spedding G. R. , Hedenström A. H. , McArthur J. , Rosén M.
Published: December 2007

Bird flight occurs over a range of Reynolds numbers (Re;104⩽Re⩽105, where Re is a measure of the relative importance of inertia and viscosity) that includes regimes where standard aerofoil performance is difficult to predict, compute or measure, with large performance jumps in response to small changes in geometry or environmental conditions. A comparison of measurements of fixed wing performance as a function of Re, combined with quantitative flow visualisation techniques, shows that, surprisingly, wakes of flapping bird wings at moderate flight speeds admit to certain simplifications where their basic properties can be understood through quasi-steady analysis. Indeed, a commonly cited measure of the relative flapping frequency, or wake unsteadiness, the Strouhal number, is seen to be approximately constant in accordance with a simple requirement for maintaining a moderate local angle of attack on the wing. Together, the measurements imply a fine control of boundary layer separation on the wings, with implications for control strategies and wing shape selection by natural and artificial fliers.
Escaping Flatland: three-dimensional kinematics and hydrodynamics of median fins in fishes
Authors: Tytell Eric D. , Standen Emily M. , Lauder George V.
Published: December 2007

Fish swimming has often been simplified into the motions of a two-dimensional slice through the horizontal midline, as though fishes live in a flat world devoid of a third dimension. While fish bodies do undulate primarily horizontally, this motion has important three-dimensional components, and fish fins can move in a complex three-dimensional manner. Recent results suggest that an understanding of the three-dimensional body shape and fin motions is vital for explaining the mechanics of swimming, and that two-dimensional representations of fish locomotion are misleading. In this study, we first examine axial swimming from the two-dimensional viewpoint, detailing the limitations of this view. Then we present data on the kinematics and hydrodynamics of the dorsal fin, the anal fin and the caudal fin during steady swimming and maneuvering in brook trout, Salvelinus fontinalis, bluegill sunfish, Lepomis macrochirus, and yellow perch, Perca flavescens. These fishes actively move the dorsal and anal fins during swimming, resulting in curvature along both anterio-posterior and dorso-ventral axes. The momentum imparted to the fluid by these fins comprises a substantial portion of total swimming force, adding to thrust and contributing to roll stability. While swimming, the caudal fin also actively curves dorso-ventrally, producing vortices separately from both its upper and lower lobes. This functional separation of the lobes may allow additional control of three-dimensional orientation, but probably reduces swimming efficiency. In contrast, fish may boost the caudal fin's efficiency by taking advantage of the flow from the dorsal and anal fins as it interacts with the flow around the caudal fin itself. During maneuvering, fish readily use their fins outside of the normal planes of motion. For example, the dorsal fin can flick laterally, orienting its surface perpendicular to the body, to help in turning and braking. These data demonstrate that, while fish do move primarily in the horizontal plane, neither their bodies nor their motions can accurately be simplified in a two-dimensional representation. To begin to appreciate the functional consequences of the diversity of fish body shapes and locomotor strategies, one must escape Flatland to examine all three dimensions.
New experimental approaches to the biology of flight control systems
Authors: Taylor Graham K. , Bacic Marko , Bomphrey Richard J. , Carruthers Anna C. , Gillies James , Walker Simon M. , Thomas Adrian L. R.
Published: December 2007

Here we consider how new experimental approaches in biomechanics can be used to attain a systems-level understanding of the dynamics of animal flight control. Our aim in this paper is not to provide detailed results and analysis, but rather to tackle several conceptual and methodological issues that have stood in the way of experimentalists in achieving this goal, and to offer tools for overcoming these. We begin by discussing the interplay between analytical and empirical methods, emphasizing that the structure of the models we use to analyse flight control dictates the empirical measurements we must make in order to parameterize them. We then provide a conceptual overview of tethered-flight paradigms, comparing classical `open-loop' and `closed-loop'setups, and describe a flight simulator that we have recently developed for making flight dynamics measurements on tethered insects. Next, we provide a conceptual overview of free-flight paradigms, focusing on the need to use system identification techniques in order to analyse the data they provide,and describe two new techniques that we have developed for making flight dynamics measurements on freely flying birds. First, we describe a technique for obtaining inertial measurements of the orientation, angular velocity and acceleration of a steppe eagle Aquila nipalensis in wide-ranging free flight, together with synchronized measurements of wing and tail kinematics using onboard instrumentation and video cameras. Second, we describe a photogrammetric method to measure the 3D wing kinematics of the eagle during take-off and landing. In each case, we provide demonstration data to illustrate the kinds of information available from each method. We conclude by discussing the prospects for systems-level analyses of flight control using these techniques and others like them.
Propulsive performance of biologically inspired flapping foils at high Reynolds numbers
Authors: Techet Alexandra H.
Published: December 2007

Propulsion and maneuvering underwater by flapping foil motion, optimized through years of evolution, is ubiquitous in nature, yet marine propulsors inspired by examples of highly maneuverable marine life or aquatic birds are not widely implemented in engineering. Performance data from flapping foils,moving in a rolling and pitching motion, are presented at high Reynolds numbers, Re=Uc/ν, or O(104), where U is the relative inflow velocity, c is the chord length of the foil, and νis the kinematic viscosity of the fluid, from water tunnel experiments using a foil actuator module designed after an aquatic penguin or turtle fin. The average thrust coefficients and efficiency measurements are recorded over a range of kinematic flapping amplitudes and frequencies. Results reveal a maximum thrust coefficient of 2.09, and for low values of angle of attack the thrust generally increases with Strouhal number, without much penalty to efficiency. Strouhal number is defined as St=2h0f/U, where f is the frequency of flapping, and 2h0 is the peak-to-peak amplitude of flapping. The thrust and efficiency contour plots also present a useful performance trend where, at low angles of attack, high thrust and efficiency can be gained at sufficiently high Strouhal numbers. Understanding the motion of aquatic penguins and turtle wings and emulating these motions mechanically can yield insight into the hydrodynamics of how these animals swim and also improve performance of biologically inspired propulsive devices.
Aerodynamic efficiency of flapping flight: analysis of a two-stroke model
Authors: Wang Z. Jane
Published: December 2007

To seek the simplest efficient flapping wing motions and understand their relation to steady flight, a two-stroke model in the quasi-steady limit was analyzed. It was found that a family of two-stroke flapping motions have aerodynamic efficiency close to, but slightly lower than, the optimal steady flight. These two-stroke motions share two common features: the downstroke is a gliding motion and the upstroke has an angle of attack close to the optimal of the steady flight of the same wing. With the reduced number of parameters,the aerodynamic cost function in the parameter space can be visualized. This was examined for wings of different lift and drag characteristics at Reynolds numbers between 102 and 106. The iso-surfaces of the cost function have a tube-like structure, implying that the solution is insensitive to a specific direction in the parameter space. Related questions in insect flight that motivated this work are discussed.
Making Stable Radicals of Heavy Elements of Groups 14 and 13: The Might of Silyl Substitution
Authors: Lee Vladimir Ya , Nakamoto Masaaki , Sekiguchi Akira
Published: December 2007

Recent developments in the field of stable free radicals centered on the heavy elements of groups 14 and 13, neutral and charged, are covered in this review. The diagnostic geometrical characteristics and bonding features of the title species are presented. The thermodynamic and kinetic factors, affecting the stability and electronic configuration of radicals, are also discussed, with particular emphasis being given to the stabilizing influence of the bulky silyl substituents.
DNA Photoligation in Two-color Detection of DNA Point Mutation
Authors: Ami Takehiro , Ozaki Genki , Yoshimura Yoshinaga , Fujimoto Kenzo
Published: December 2007

We report a method for the rapid differentiation of nucleic acid sequences with 5-carboxyvinyl-2′-deoxyuridine that allows the simultaneous observation of two colors and facilitates the SNP typing of a heterozygous sample.
White-light-emission Afterglow Phosphor CaZnGe2O6:Dy3+
Authors: Che Guangbo , Liu Chunbo , Wang Qingwei , Xu Zhanlin
Published: December 2007

A novel phosphor, CaZnGe2O6:Dy3+, which emits white long-lasting phosphorescence (LLP) upon UV excitation, is prepared by a conventional high-temperature solid-state method, and its luminescent properties are systematically reported in this letter. These phosphors are well crystallized by calcination at 1150 °C for 3 h and possess excellent performance. After irradiation under 240-nm UV light, CaZnGe2O6:2% Dy3+ emits intense white emission with color coordinate values of x=0.36, y=0.39, and its afterglow can be seen with the naked eye in the dark clearly for more than 3 h after removal of the excitation source.
Z-scheme Overall Water Splitting on Modified-TaON Photocatalysts under Visible Light (λ<500 nm)
Authors: Higashi Masanobu , Abe Ryu , Ishikawa Akio , Takata Tsuyoshi , Ohtani Bunsho , Domen Kazunari
Published: December 2007

Overall water splitting was accomplished using a RuO2–TaON and Pt–TaON mixture with IO3−/I− redox couple under visible light (λ<500 nm). This is the first example of overall water splitting based on an oxynitride photocatalyst including a transition-metal element with d0-electronic configuration.
Preparation of Highly Ordered Mesoporous TiO2 Materials with Crystalline Framework from Different Mesostructured Silica Templates via Nanoreplication
Authors: Kim Sung Soo , Lee Hyung Ik , Shon Jeong Kuk , Hur Jae Young , Kang Min Suk , Park Sang Soo , Kong Soo Sung , Yu Ji Ae , Seo Miran , Li Donghao , Thakur Santosh Singh , Kim Ji Man
Published: December 2007

Highly ordered mesoporous TiO2 materials, exhibiting crystalline frameworks and various mesostructures, have been successfully obtained via nanoreplication using various kinds of mesoporous silicas as the rigid templates.
Cycle and Rate Properties of Mesoporous Tin Anode for Lithium Ion Secondary Batteries
Authors: Nara Hiroki , Fukuhara Yoshiki , Takai Azusa , Komatsu Masaki , Mukaibo Hitomi , Yamauchi Yusuke , Momma Toshiyuki , Kuroda Kazuyuki , Osaka Tetsuya
Published: December 2007

A mesoporous Sn anode was electrodeposited in the presence of lyotropic liquid crystals made of nonionic surfactants. The introduction of mesoporous structure was effective for the accommodation of volume change of Sn during charge and discharge cycling of Li ions. The discharge capacity of the mesoporous Sn anode at 1 C rate was as high as 425 mA h g−1 at the 100th cycle, and that was as high as 320 mA h g−1 at the 100th cycle even though at 5 C rate.
Experimental Vibrational Study of Imidazolium-Based Ionic Liquids: Raman and Infrared Spectra of 1-Ethyl-3-methylimidazolium Bis(Trifluoromethylsulfonyl)imide and 1-Ethyl-3-methylimidazolium Ethylsulfate
Authors: Kiefer Johannes , Fries Juergen , Leipertz Alfred
Published: December 2007

The vibrational structure of two room-temperature ionic liquids with the cation 1-ethyl-3-methylimidazolium [EMIM] and the respective anions bis(trifluoromethylsulfonyl)imide [TFSI] and ethylsulfate [EtOSO3] is investigated. In particular, attenuated total reflection (ATR) infrared (IR) as well as Raman spectra in the spectral range from 500 to 3500 cm−1 have been recorded and analyzed. Moreover, the depolarization ratios of the Raman lines are determined. The individual peaks are assigned to the corresponding vibrational modes of the molecules. While the CH stretching region around 3000 cm−1 is dominating in Raman spectra, it is remarkably weak in IR spectra. Finally, the results for 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide are compared to previous studies of single ions available in the literature. This comparison shows good agreement.
Reduction of Error in Spectrophotometry of Scattering Media Using Polarization Techniques
Authors: Stockford Ian M. , Lu Bo , Crowe John A. , Morgan Stephen P. , Morris David E.
Published: December 2007

Scattering can result in erroneous determination of the concentrations of constituent absorbers in spectrophotometry. This is due to the relationship between attenuation and absorption coefficient becoming nonlinear; hence, the use of the Lambert–Beer law becomes invalid. It has previously been shown that application of polarization techniques can reduce these effects, resulting in a more linear relationship. Here we quantify the impact of this improvement on measurement of the ratio of concentrations for two general absorbing species and show that measurement using polarization-maintaining light is more accurate. This is performed using a generalized version of theory previously dependent on selection of isosbestic wavelengths. For the absorbing species and geometries considered here, the mean error on the estimation of absorber concentration ratio is 18.2% for the case of detection without polarization discrimination. When polarization-maintaining light is extracted, mean errors of 1.2% and 5.1% are achieved for linear and circular polarizations, respectively. The improvement provided by the polarization techniques is observed regardless of the illuminating wavelengths but is achieved at the expense of a reduced signal-to-noise ratio. Taking this into account, for the detection scheme considered with a detector well capacity of 4 × 105 electrons the improvement provided by linear polarization-maintaining light is reduced to a factor of 3.6 and for circular polarizations a factor of 2.2.
Raman and Infrared Spectroscopic Investigations on Aqueous Alkali Metal Phosphate Solutions and Density Functional Theory Calculations of Phosphate—Water Clusters
Authors: Rudolph Wolfram W. , Irmer Gert
Published: December 2007

Phosphate (PO43−) solutions in water and heavy water have been studied by Raman and infrared spectroscopy over a broad concentration range (0.0091–5.280 mol/L) including a hydrate melt at 23 °C. In the low wavenumber range, spectra in R-format have been constructed and the R normalization procedure has been briefly discussed. The vibrational modes of the tetrahedral PO43−(aq) (Td symmetry) have been assigned and compared to the calculated values derived from the density functional theory (DFT) method for the unhydrated PO43− (Td) and phosphate–water clusters: PO43− · H2O (C2v), PO43− · 2H2O (D2d), PO43− · 4H2O (D2d), PO43− · 6H2O (Td), and PO43− · 12H2O (T), a cluster with a complete first hydration sphere of water molecules. A cluster with a second hydration sphere of 12 water molecules and 6 in the first sphere, PO43− · 18H2O (T), has also been calculated. Agreement between measured and calculated vibrational modes is best in the case of the PO43− · 12H2O cluster and the PO43− · 18H2O cluster but far less so in the case of the unhydrated PO43− or phosphate–water cluster with a lower number of water molecules than 12. The asymmetric, broad band shape of ν1(a1) PO43− in aqueous solutions has been measured as a function of concentration and the asymmetric and broad band shape was explained. However, the same mode in heavy water has only half the full width at half-height compared to the mode in normal water. The PO43− is strongly hydrated in aqueous solutions. This has been verified by Raman spectroscopy comparing ν2(H2O), the deformation mode of water, and the stretching modes, the ν1OH and ν3OH of water, in K3PO4 solutions as a function of concentration and comparison with the same modes in pure water. A mode at ∼240 cm−1 (isotropic R spectrum) has been detected and assigned to the restricted translational mode of the strong hydrogen bonds formed between phosphate and water, P–O ··· HOH. In very concentrated K3PO4 solutions ( C0 ≥ 3.70 mol/L) and in the hydrate melt, formation of contact ion pairs (CIPs) could be detected. The phosphate in the CIPs shows a symmetry lowering of the Td symmetry to C3v. In the less concentrated solutions, PO43−(aq) solvent separated ion pairs and doubly solvent separated ion pairs exist, while in very dilute solutions fully hydrated ions are present ( C0 ≤ 0.005 mol/L). Quantitative Raman measurements have been carried out to follow the hydrolysis of PO43−(aq) over a very broad concentration range. From the hydrolysis data, the pK3 value for H3PO4 has been determined to be 12.45 at 23 °C.
Nondestructive Varnish Identification by Ultraviolet Fluorescence Spectroscopy
Authors: Thoury Mathieu , Elias Mady , Frigerio Jean Marc , Barthou Carlos
Published: December 2007

The identification of the chemical nature of varnish is essential for art restorers in order to choose a suitable solvent during its removal. Until today, such identification has been performed using chemical analysis after sampling. An innovative technique is presented here, using ultraviolet (UV) fluorescence spectroscopy. The method is nondestructive, workable in situ, and leads to results in real time. It is based on the comparison between the emission spectrum of an unknown varnish with those of fresh, artificially aged, or old reference resins and varnishes, for different monochromatic excitation wavelengths. The resin and the nature of the varnish as spirit, oil, or mixed can thus be identified. Various examples are presented on home-made samples applied on fluorescent backgrounds and on real works of art.
Behaviors of the “Raman Spectroscopic Signature of Life” in Single Living Fission Yeast Cells under Different Nutrient, Stress, and Atmospheric Conditions
Authors: Huang Yu-San , Nakatsuka Takeshi , Hamaguchi Hiro-O
Published: December 2007

Time- and space-resolved Raman spectra of mitochondria in single living fission yeast cells have been measured under various nutrient, stress, and atmospheric conditions. A focus is placed on the behavior of the Raman band located at 1602 cm−1, which sensitively reflects the metabolic activity in mitochondria and which has been called by us the “Raman spectroscopic signature of life”. Addition of nutrients increases the intensity of this band by ∼1.5 times, confirming its correlation with the metabolic activity in mitochondria. The spectra of cells cultured under 100% N2, 100% O2, and N2/O2 (VN2:VO2 ≅ 4:1) atmospheres have been measured for both 16O2 and 18O2. Yeast cells have been found to lose their metabolic activity after the culture under 100% N2 and 100% O2 atmospheres. Cells cultured under a N2/16O2 (16O2 = 20%) atmosphere show strong “Raman spectroscopic signature of life”. No 18O isotopic shift has been found for the wavenumber 1602 cm−1, indicating that the origin of this signature is neither O2 nor an O-containing small molecule. Addition of H2O2 causes a quick decrease of the “Raman spectroscopic signature of life”, followed by the cis–trans isomerization in the unsaturated phospholipid chain. The “Raman spectroscopic signature of life” has thus been proved to be a reliable real-time and in vivo indicator for monitoring the metabolic activity in living cells.
Determination of Zonal Boundaries in Articular Cartilage Using Infrared Dichroism
Authors: Ramakrishnan Nagarajan , Xia Yang , Bidthanapally Aruna , Lu Mei
Published: December 2007

To determine the sub-tissue structural zonal boundaries in articular cartilage, a novel infrared (IR) microscopic imaging method based on the dichroic nature of the amide components has been developed and is discussed in this article. Thin canine cartilage-bone sections embedded in paraffin as well as in poly(methyl methyacrylate) (PMMA) were imaged under two orthogonal polarization states at 6.25 μm pixel size. The depth-dependent anisotropy of the amide components at perpendicular polarization states attributed by the collagen constituent in cartilage was analyzed. Since the transitional zone fibers are randomly arranged and the dichroic ratio value reaches unity in this zone, it is possible to identify the transitional zone boundaries, thus dividing the whole-depth tissue into three structural zones (superficial, transitional and radial). The zone division results from the infrared method agree well with the results from the established polarized light microscopy (PLM) method, which promises the potential of infrared imaging as an independent technique for the zonal boundary determination. The advantages of this dichroic ratio method are (1) it is independent of mode of operation (transmission/reflection), (2) it is independent of sample thickness, (3) either a polarizer or an analyzer can be used in experiments to determine zonal boundaries, and (4) it is sample orientation independent.
A Variable Selection Procedure for X-ray Diffraction Phase Analysis
Authors: Lee Daewon , Lee Hyeseon , Jun Chi-Hyuck , Chang Chang Hwan
Published: December 2007

The X-ray diffraction method has been widely used for qualitative and quantitative phase abundance analysis of crystalline materials. We propose the use of partial least squares when building the calibration model for a quantitative phase analysis based on X-ray diffraction spectra. We also propose a variable selection procedure to reduce the measurement points in terms of angles as an alternative to using the whole pattern. The proposed method is based on the variable importance in projection derived from the partial least squares and it considers some practical issues regarding the angle measurement. The method was particularly applied to the simultaneous determination of weight fractions of some iron oxides. It was found that the number of measurement points can be reduced to 30 percent of the total number of points with a small sacrifice in prediction error.
Investigating Dehydration from Compacts Using Terahertz Pulsed, Raman, and Near-Infrared Spectroscopy
Authors: Kogermann Karin , Zeitler J. Axel , Rantanen Jukka , Rades Thomas , Taday Philip F. , Pepper Michael , Heinämäki Jyrki , Strachan Clare J.
Published: December 2007

The purpose of this study was to investigate the dehydration of piroxicam monohydrate (PRXMH) in compacts using terahertz pulsed spectroscopy (TPS), Raman spectroscopy, and reflectance near-infrared (NIR) spectroscopy. Compacts were prepared by using PRXMH and poly(tetrafluoro)ethylene powders and combining them in three different manners before compression to produce compacts in which the PRXMH was dispersed throughout the compact, deposited on one face of the compact, or included as a layer within the compact. TPS was a suitable technique to assess the effect of sample preparation on dehydration, whereas Raman and NIR spectroscopy were limited by their sampling depth and the interference of the polymer matrix. TPS revealed that the dehydration behavior depended largely on the compact preparation method. Non-isothermal dehydration was investigated with all three spectroscopic techniques, combined with principal component analysis (PCA) on samples where the PRXMH was deposited on one face of the compact. In addition, variable temperature X-ray powder diffractometry (VT-XRPD) was used to verify the transformation from PRXMH to anhydrous PRX form I, while thermogravimetric analysis (TGA) was used to monitor the water loss. All three spectroscopic techniques allowed in situ monitoring of the dehydration from the surface layers of the compacts. TPS and Raman spectroscopy detected structural changes of the crystal, while NIR spectroscopy was more sensitive to water loss. PCA of the TPS, Raman spectroscopy, and XRPD data revealed similar dehydration profiles. In contrast, the NIR spectroscopy profile was more similar to the TGA results. The spectroscopic techniques were more suitable than slower techniques such as VT-XRPD for monitoring rapid structural changes that occurred during the dehydration.
Analysis of Heavy Metal Pollution in Soil Using Transversely Excited Atmospheric CO2 Laser-Induced Plasma by Trapping the Soil in Microstructured Holes on Metal Subtargets
Authors: Idris Nasrullah , Kagawa Kiichiro , Sakan Fujio , Tsuyuki Kenichiro , Miura Satoru
Published: December 2007

A unique technique for direct analysis of soil samples utilizing a special advantage of a transversely excited atmospheric (TEA) CO2 laser-induced plasma generated at atmospheric pressure on a metal target has been developed. In this technique, a metal subtarget, such as nickel plate, structured with intentional microholes on its surface, each with dimensions of around 100 μm in diameter and depth, was used to selectively trap small sized soil particles by immersing the metal plate subtarget into the polluted soil sample. The trapped small soil particles on the metal subtarget were irradiated by a TEA CO2 laser (10.6 μm, 1.5 J, 200 ns) at atmospheric pressure under defocused condition with a spot size of 3 mm × 3 mm. This trapping and confining scheme substantially suppresses the blowing off effect; thus, the trapped soil particles can effectively be dissociated and atomized in the microstructured holes. Using this method of a microstructured metal plate subtarget, quantitative analysis was carried out on loam soil samples polluted by Pb. A linear calibration curve was obtained with a detection limit of approximately 50 mg/kg. Preliminary quantitative studies were carried out for a quartz sand sample containing Cr and Hg, resulting in linear calibration curves with detection limits of approximately 25 mg/kg and 10 mg/kg, respectively, at this stage. This technique is promising as a potential field screening tool for soil analysis.
Nontoxic and Chemically Stable Hollow Optical Fiber Probe for Fourier Transform Infrared Spectroscopy
Authors: Kino Saiko , Matsuura Yuji
Published: December 2007

Remote spectroscopy systems based on hollow optical fiber probes are proposed and experimental results using a Fourier transform spectroscope are presented. A hollow optical-fiber probe with a silver and polymer inner coating is used to deliver incoherent light to a target and another separate hollow fiber is used to collect the reflected light. The reflectance spectra of teeth, skin, and oral mucosa were successfully measured with the probe even from surfaces with reflectances lower than 0.5%. The preliminary results obtained using attenuated total reflection spectroscopy are also presented. This remote infrared spectroscope is useful for endoscopic measurements inside the body because it is flexible, durable, nontoxic, and has the low transmission losses associated with hollow-fiber-based probes.