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Frictional resistance of a hollow rubber cylinder steadily sliding inside a rigid sleeve has been studied theoretically and reported here. This is inspired by a new class of elastomeric friction damper consisting of an unbonded rubber cylinder, axially compressed and radially expanding to contact an outer rigid sleeve and generate friction. By considering the force equilibrium of each thin section of the rubber cylinder and adapting the principle of superposition, the tri-bological problem was decomposed into three fundamental sub-problems, which were solved consecutively. The results shed lights on the functional effects of various design parameters such as part dimensions, friction coefficient, and Young's modulus on the total friction force. Finite element analyses were also performed, and the results were compared with the closed-form solutions.

The spectroscopy of $^{73}\text{Ge}$ has been investigated via the $^{70}\text{Zn}(^{7}\text{Li},3np)^{73}\text{Ge}$ fusion-evaporation reaction. A previously known band built on the $\ensuremath{\nu}({f}_{5/2})$ orbital is extended up to higher-spin states and a new rotational band built on the $\ensuremath{\nu}({g}_{9/2})$ orbital is established. The observed band crossing and shape evolution induced by the alignment in $^{73}\text{Ge}$ are studied in comparison with the similar structures in the neighboring $N=41$ isotones and the cranked Woods--Saxon--Strutinsky calculations by means of total-Routhian-surface (TRS) methods. The inversion of the order of the ${g}_{9/2}$ neutron and the ${g}_{9/2}$ proton crossing frequency observed in the negative-parity $\ensuremath{\nu}({f}_{5/2})$ bands between $^{73}\text{Ge}$ and $^{75}\text{Se}$, $^{77}\text{Kr}$ can be ascribed to their different triaxial deformations. At higher spins, both the $\ensuremath{\nu}({f}_{5/2})$ and $\ensuremath{\nu}({g}_{9/2})$ bands in $^{73}\text{Ge}$ undergo a shape evolution with sizable alignments occurring. The characters of large signature splitting in $\ensuremath{\nu}({g}_{9/2})$ band of $^{73}\text{Ge}$ are discussed.

The spectroscopy of $^{76}\mathrm{Se}$ has been studied using the $^{70}\mathrm{Zn}(^{12}\mathrm{C}, \ensuremath{\alpha}2{\mathrm{n})}^{76}\mathrm{Se}$ fusion evaporation reaction. The yrast band of $^{76}\mathrm{Se}$ has been extended to substantially higher spin, allowing observation of the second band crossing. The much-delayed ${g}_{9/2}$ proton-pair alignment is discussed in terms of the cranked shell model and most likely is caused by a shape transition from prolate to oblate along the yrast line occurring in $^{76}\mathrm{Se}$. Based on the systematic investigation of the band crossings associated with the ${g}_{9/2}$ quasiparticle alignments and their relationships with the shape evolutions in the even-$A$ Se and Kr isotopes, a comprehensive picture of shape evolution along with spin and isospin in these nuclei is obtained.

This paper proposes a new approach to automate the design of parting surfaces for plastic injection moulds. The new method tackles the issue of the automatic generation of a polygonal complex that is required for boundary curve interpolation. The mesh that defines the ‘interior’ of the surface patch is generated using medial axis transform and optimization. Upon subdivision, the mesh generates a smooth surface patch that connects to neighbouring patches to form the entire parting surface. This new method has been integrated with our previous result to develop an experimental system that automates parting surface design for a plastic part with a complex parting line. The major advantage of this new approach is that the subdivision surface is generated by a standard subdivision scheme which facilitates the development of any downstream applications, such as CNC toolpath extraction, on the surface. Examples and a design case study are presented to demonstrate the major steps and verify the feasibility of the...

In conclusion, from the evidence gathered, it may be appropriate to suggest that CHMs may have efficacy for the treatment of patients with LC, and combination of CHMs with chemotherapy or radiotherapy may be additive or synergistic in controlling LC. In addition, CHMs may reduce some adverse effects associated with chemotherapy or radiotherapy. Moreover, CHMs may be beneficial for improving quality of life and prolonging survival time of patients with LC. However, we are cautious because of methodological flaws in the majority of the clinical studies reviewed. It is difficult to draw conclusions with regard to efficacy of CHMs. The mechanisms of actions of CHMs for LC largely remain unknown. Thus, more rigorous studies that address weaknesses identified are required for further evaluation of efficacy and safety of different Chinese herbs and formulae in the management of LC.

Resistance to the steady sliding of a cylinder over a thin rubber layer is studied theoretically. This problem underlies a model being developed for a new class of damping devices. A quantitatively accurate model requires an accounting for the amplitude-dependent dynamic moduli of industrial-grade rubbers filled with carbon black. This accounting is hindered, however, by the lack of a full multiaxial constitutive law reflecting the nonlinear, amplitude-dependent behavior of filled rubbers. Accordingly, this paper sets forth approximate methods of analysis which indirectly account for the nonlinear behavior; these ultimately lead to compact solutions which can be used in the design of new devices.

Using the upgraded Beijing Spectrometer, we have measured the total cross section for e(+)e(-) annihilation into hadronic final states at center-of-mass energies of 2.6, 3.2, 3.4, 3.55, 4.6, and 5.0 GeV. Values of R, sigma(e(+)e(-)-->hadrons)/sigma(e(+)e(-)-->m(+)m(-)), are determined.

Endothelial nitric oxide synthase (NOS) protein and mRNA have been identified and calcium-dependent NOS activity has been measured in human placentae during normal pregnancy. Recently, mRNA and protein for the inducible isoform of NOS have been detected in placentae of women with gestational diabetes. The aim of this study was to determine whether calcium-independent (ciNOS) and/or total (tNOS) NOS activities were increased in placentae obtained after vaginal delivery or Caesarean section from women assigned to the following groups according to standard obstetric criteria: gestational diabetes, diabetes before pregnancy and non-diabetic controls. tNOS and ciNOS were assessed by measuring the conversion of [3H]⌊-arginine to [3H]⌊-citrulline in the three groups. Michaelis–Menten constants (Km) and maximum velocities of reaction (Vmax) were calculated using Lineweaver–Burk analysis for tNOS. There were no significant differences in either ciNOS, Vmax or Km values between any of the three groups (normal, ciNOS 12.7±1.6%, Vmax 16.6±3.3 pmol⋅min-1⋅mg-1 protein, Km 15.30±2.6 µmol/l; gestational diabetes, ciNOS 15.4±1.4%, Vmax 14.8±5.2 pmol⋅min-1⋅mg-1 protein, Km 10.5±1.7 µmol/l; diabetes before pregnancy, ciNOS 13.4±1.1%, Vmax 14.9±3.4 pmol⋅min-1⋅mg-1 protein, Km 17.7±2.2 µmol/l). The presence of macrosomia did not affect tNOS activity in those with diabetes before pregnancy, and glycosylated haemoglobin levels measured between weeks 27 and 39 were not correlated with ciNOS activity. The results from the present study do not provide evidence for increased placental tNOS or ciNOS activities in pregnancies complicated by gestational diabetes or diabetes present before pregnancy.

Author(s): Bai, JZ; Bian, JG; Blum, I; Chai, ZW; Chen, GP; Chen, HF; Chen, J; Chen, JC; Chen, Y; Chen, YB; Chen, YQ; Cheng, BS; Cui, XZ; Ding, HL; Ding, LY; Dong, LY; Du, ZZ; Dunwoodie, W; Feng, S; Gao, CS; Gao, ML; Gao, SQ; Gratton, P; Gu, JH; Gu, SD; Gu, WX; Gu, YF; Guo, YN; Han, SW; Han, Y; Harris, FA; He, J; He, JT; He, M; Hitlin, DG; Hu, GY; Hu, HM; Hu, JL; Hu, QH; Hu, T; Hu, XQ; Huang, JD; Huang, YZ; Izen, JM; Jiang, CH; Jin, Y; Ke, ZJ; Kelsey, MH; Kim, BK; Kong, D; Lai, YF; Lang, PF; Lankford, A; Li, CG; Li, D; Li, HB; Li, J; Li, PQ; Li, RB; Li, W; Li, WD; Li, WG; Li, XH; Li, XN; Liu, HM; Liu, J; Liu, JH; Liu, RG; Liu, Y; Lou, XC; Lowery, B; Lu, F; Lu, JG; Lu, JY; Lu, LC; Luo, CH; Ma, AM; Ma, EC; Ma, JM; Malchow, R; Mao, HS; Mao, ZP; Meng, XC; Nie, J; Olsen, SL | Abstract: The decays of the ψ(2S) into vector plus tensor meson final states have been studied for the first time using the BES detector. We determine upper limits on branching fractions for ψ(2S) decays into ωf2, ρa2, K*0K*02 + c.c., and φf'2(1525) that are, in each case, significantly smaller than the corresponding branching fractions for the J/ψ meson, scaled according to the expectations of perturbative QCD. © 1998 The American Physical Society.

Objective and Design: The aim of the study was to evaluate the effects of GMDP on angiogenesis in vivo and as a modulator of human umbilical vein endothelial cell proliferation, cell surface antigen expression and cell adhesion in vitro.¶Materials: Human umbilical vein endothelial cells (HUVEC), fertilized white leghorn chicken eggs, antibodies against adhesion molecules and glucosaminylmuramyl dipeptide (GMDP).¶Treatment: GMDP [0.01–100 μg/ml] applied to cell cultures for 6–72 h and to the chick chorioallantoic membrane (CAM) for four days.¶Methods: Angiogenic activity of GMDP in vivo was assessed using the CAM assay; HUVEC proliferation was measured by tritiated thymidine incorporation and cell cycle studies; cell surface antigen expression by indirect immunofluorescence and flow cytometry; cell adhesion by quantification of [3H]-thymidine labeled leukocyte adherence to HUVEC monolayers. Statistical analysis was performed using one-way ANOVA and if necessary was followed by Duncan's multiple range test for variables.¶Results: GMDP induced [3H]-thymidine incorporation in a concentration- and time-dependent manner (p < 0.003) and significantly increased the proportion of cells in the S phase of the cell cycle (p < 0.03). It weakly augmented the expression of ICAM-1 and CD31 but not adhesion of leukocytes to HUVEC monolayers GMDP was not angiogenic in the CAM assay.¶Conclusions: GMDP can modulate endothelial cell activity without the induction of angiogenesis in vivo which may have implications for its use as a therapeutic agent.

The synthesis, processing and mechanical properties of the lightweight metals, aluminum, magnesium and titanium produced by powder metallurgy approaches are reviewed. Synthesis techniques to be addressed will include rapid solidification, spray deposition, mechanical alloying, plasma processing and vapor deposition.

In this paper, some of the recent research progress on advanced materials supported by National Advanced Materials Committee of China are reviewed. The basic characteristics of plasticity and superplasticity, such as stress-strain curves, strain rate,m-value etc. are discussed. The P/M superalloy, ceramics, aluminumlithium alloys, metal matrix composites, intermetallic compounds, magnetic alloys and high transition temperature superconductive materials have been selected as advanced materials for plasticity and superplasticity study.

A new methodology using mechanism to model fixture location error (FLE) is proposed. Typically, there are four elements related to accumulation and propagation of FLE in workpiece-fixture system (WFS), which are machining feature, process datum, location datum and locators, and the relative position variations among them correspond to various FLEs. In this research, the four elements are treated as link mechanism components, the concatenation between location datum and locators is represented by contact pair, which is transformed to kinematic pair in equivalent mechanism, and geometry & dimension tolerances are simulated by link mechanisms. The rules mapping from FLE elements to their equivalent mechanisms are established, and by which the WFS is transformed into an equivalent mechanism model system. The method is studied that the process parameters of WFS are calculated by the structure parameters and kinematic parameters of equivalent mechanism. Thus, the solution of location error can be realized by means of the position analysis methods of mechanism.Copyright © 2012 by ASME

The cooling system is one of the most important systems in a plastic injection mould. It affects the quality and productivity of the molded part. In this paper, we extend our previous research on the automatic plastic injection cooling system layout design to multiple inlet and outlet systems, and propose an evolutionary approach with ad hoc operators to concurrently optimize the topological connection and geometric position of a cooling system. A mixed encoding scheme is developed to encode a candidate solution, which is represented in the form of a variant-length chromosome. Ad hoc evolutionary operators and parameters adapting to the characteristics of cooling system design are devised. An experimental system is implemented to verify the feasibility of the approach, and the results of case study illustrate the validity of this approach. It can be expected this research will well facilitate the automation of plastic injection mould cooling system design.

This research carries out a systematic investigation on the automation of fixture location planning. A novel classification and representation method of constrained degrees of freedom (DOF) is proposed. Constrained DOFs are classified into four types: linear translation DOF, linear rotation DOF, planar translation DOF and planar rotation DOF, and they are represented in the form of vector. On the basis of the classification and representation, constrained DOFs are automatically obtained from process requirement. By analyzing datum constraint DOF capability and datum location ability, the operation rules of constrained DOF: union, decomposition and coordinate transformation, are established. The approach to the evaluation of datum location ability and the judgment of datum conflict is explored, and the solution of datum conflict and datum location problem is presented. Eventually, the rules of location point layout are formalized.Copyright © 2010 by ASME

In this paper, a new rotor-ball bearings-support-stator coupling system dynamic model with rubbing coupling faults is established for practical aeroengine. In the model, the rubbing fault is modeled, the stator motion is considered, the flexible support and squeeze film damper are established, and the nonlinear factors of ball bearing, such as the clearance of the bearing, the nonlinear Hertzian contact force between balls and races, and the varying compliance vibration because of the periodical variety of the contact position between balls and races, are modeled. The numerical integral method is used to obtain the system responses, the effect of support stiffness on rotor responses is studied using a vibration amplitude-rotating speed plot, and the characteristics of the rubbing fault is analyzed using a 3D cascade plot. An aeroengine tester with a stator is established to carry out the rubbing fault experiments, the simulation results from the rotorball bearings-support-stator coupling model are compared with the experimental results, and the consistency of the results show fully the effectiveness of the new rotor-ball bearings-support-stator coupling model with rubbing fault. DOI: 10.1115/1.2940355

We report the infrared reflection and absorption spectra of the highTcsuperconductor Tl2Ba2CaCu2O8in the temperature range from 10 K to 300 K. For temperatures above 100 K, the reflection spectra show only small changes with temperature. Just below 100 K, the reflectance suddenly increases for energies below 210 cm−1with very little change as the temperature is further decreased. Several peaks corresponding to normal modes of the material are observed in both reflection and absorption spectra.

InGaN/GaN multiple quantum well (MQW) structures have been grown by metalorganic chemical vapor deposition on c-plane sapphire substrates. Inverted diamond-like surface defects (i.e., V-pits) with a density of [Formula: see text][Formula: see text]cm[Formula: see text] have been observed in an eight-QW structure with Ga[Formula: see text]In[Formula: see text]N (3.6[Formula: see text]nm thick) and GaN (12.7[Formula: see text]nm thick) as the well- and barrier-material, respectively. The density of the surface defects has been significantly decreased by simply reducing the well-width to 2.7[Formula: see text]nm while keeping the other structural parameters nominally intact. The decrement in the well-width caused remarkable changes in depth profiles of In/Ga probed by secondary ion mass spectroscopy (SIMS) from the MQW structures, which is related to the varied effects of cratering roughness and accumulative interface roughness. The SIMS depth profiles also revealed increased In incorporations and QW-period in the QWs near the top surface for the MQW structure with larger well-width. They are most likely associated with surface defects, accumulative interface roughness, and strain evolutions along the growth direction.

Design and fabrication of an ultra selective 12‐pole HTS band‐pass filter with three pairs of transmission zeroes at finite frequencies is presented. This filter was designed to have quasi‐elliptic response with 5 MHz bandwidth in the 3G communication band (a fractional bandwidth of 0.0025). The filter was fabricated on a 2 inch‐diameter 0.43 mm‐thick sapphire wafer with double‐sided YBCO films. The measured results showed that the pass‐band center frequency of the filter is 2.038 GHz at 68 K with a pass‐band insertion loss of −0.67 dB and a return loss better than −15 dB. The measured filter also exhibited ultra high skirt slop of 200–300 dB/MHz and excellent out of band rejections (better than 60 dB for | f‐f0 | > 2.7 MHz and better than 90 dB for | f‐f0 | > 7.5 MHz, where f0 is the pass‐band center frequency).

To assess whether the addition of a Chinese herbal medicine formula to acupuncture affects the severity of symptoms and quality-of-life scores among patients with seasonal allergic rhinitis.Randomised double-blind placebo-controlled trial.University teaching and research clinic, Australia.Sixty-five patients with seasonal allergic rhinitis, who were recruited through public media.Between July and December 1999, patients received acupuncture twice a week for 8 weeks plus either a Chinese herbal drug formula (n=33) or placebo (n=32) at a dosage of four capsules, three times daily.The severity of nasal and non-nasal symptoms on a five-point scale, as assessed by both patients and an ear, nose, and throat specialist, and quality-of-life scores as measured by the Rhinoconjunctivitis and Rhinitis Quality of Life Questionnaire.Sixty-one patients completed the study (31 in the intervention group and 30 in the control group). After 8 weeks, no significant difference was found between the two groups in the severity of nasal and non-nasal symptoms and in the Rhinoconjunctivitis and Rhinitis Quality of Life Questionnaire scores. Intention-to-treat analysis of categorical variables showed moderate-to-marked improvement rates of 72.7% and 81.2% for intervention and control groups, respectively. Six patients reported mild adverse events-three from each of the study groups.The Chinese herbal formulation under investigation did not provide additional symptomatic relief or improvement in quality-of-life scores among patients with seasonal allergic rhinitis who were receiving acupuncture.

1. The effects of agents that inactivate free radical nitric oxide (carboxy-PTIO, hydroxocobalamin and pyrogallol) were tested on relaxations produced by the nitroxyl anion (NO(-)) donor Angeli's salt in rat aortic rings and anococcygeus muscles. The amount of NO(*) generated from Angeli's salt in the presence of these agents was measured using a NO(*)-selective electrode sensor. 2. Carboxy-PTIO (100, 300 microM), hydroxocobalamin (30, 100 microM) and pyrogallol (10, 30 microM) significantly reduced relaxations produced by Angeli's salt (0.3 microM) in aortic rings but not in anococcygeus muscles. 3. NO(*) generated from Angeli's salt (0.1 - 10 microM), as detected by the sensor electrode, was less than 0.5% of the amount of Angeli's salt added. Carboxy-PTIO (100 microM) and hydroxocobalamin (30 microM), but not pyrogallol significantly increased the amount of NO(*) detected. 4. In the presence of an oxidizing agent copper [II] (as CuSO(4) 100 microM), the amount of NO(*) detected from 0.3 microM of Angeli's salt increased from an undetectable level of 142.7+/-15.7 nM (equivalent to 47.6% of Angeli's salt added). Under these conditions, carboxy-PTIO, hydroxocobalamin and pyrogallol significantly reduced the amount of NO(*) detected from Angeli's salt as well as the signal generated by an equivalent amount of authentic NO (0.33 microM). 5. The difference in effects of these agents on relaxations to Angeli's salt in the aorta and the anococcygeus muscle may be explained by the ready conversion of NO(-) to NO(*) in the aorta through an unidentified mechanism, which makes NO(-) susceptible to inactivation by these agents. Furthermore, in addition to inactivating NO(*), carboxy-PTIO and hydroxocobalamin may themselves oxidize NO(-) to NO(*), albeit slightly.

Radiative decays of the radially excited charmonium resonance, \psi(2S), into \pi\pi, K Kbar and \eta\eta final states have been measured in a sample of 3.96 * 10^6 \psi(2S) events collected by the BES collaboration. The branching ratios B(\psi(2S) -> \gamma f_{2}(1270)) = (2.27 +- 0.26 +- 0.39) * 10^{-4} and B(\psi(2S) -> \gamma f_0(1710)) * B(f_0(1710) -> K^+ K^-) = (5.59 +- 1.12 +- 0.93) * 10^{-5} are obtained. When compared to the corresponding radiative J/\psi decays, the observed \psi(2S) radiative decay rates into \gamma f_2(1270) and \gamma f_0(1710) are consistent with the 15% rule., Comment: 7 pages, 5 figures

The physical conditions and locations of the emission regions for core and hollow cone emissions are very important in understanding the mechanism of radio pulsars. We present two related methods in an Inverse-Compton Scattering (ICS) model in this paper, which give a clear scenario for determining the location of the emission regions and are consistent with the results given by Cordes et al. (1984) and Rankin (1990).

In a sample of 7.8 million J/{psi} decays collected in the Beijing Spectrometer, the process J/{psi}{yields}{gamma}{eta}{sub c} is observed for five different {eta}{sub c} decay channels: K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}, {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}, K{sup {+-}}K{sub S}{sup 0}{pi}{sup {+-}} (with K{sub S}{sup 0}{yields}{pi}{sup +}{pi}{sup -}), {phi}{phi} (with {phi}{yields}K{sup +}K{sup -}) and K{sup +}K{sup -}{pi}{sup 0}. From these signals, we determine the mass of {eta}{sub c} to be 2976.6{+-}2.9{+-}1.3 MeV. Combining this result with a previously reported result from a similar study using {psi}(2S){yields}{gamma}{eta}{sub c} detected in the same spectrometer gives m{sub {eta}{sub c}}=2976.3{+-}2.3{+-}1.2 MeV. For the combined samples, we obtain {gamma}{sub {eta}{sub c}}=11.0{+-}8.1{+-}4.1 MeV. (c) 2000 The American Physical Society.

Author(s): Bai, JZ; Ban, Y; Bian, JG; Blum, I; Chen, GP; Chen, HF; Chen, J; Chen, JC; Chen, Y; Chen, YB; Chen, YQ; Cheng, BS; Cui, XZ; Ding, HL; Dong, LY; Du, ZZ; Dunwoodie, W; Gao, CS; Gao, ML; Gao, SQ; Gratton, P; Gu, JH; Gu, SD; Gu, WX; Gu, YF; Guo, YN; Guo, ZJ; Han, SW; Han, Y; Harris, FA; He, J; He, JT; He, KL; He, M; Heng, YK; Hitlin, DG; Hu, GY; Hu, HM; Hu, JL; Hu, QH; Hu, T; Hu, XQ; Huang, YZ; Huang, GS; Izen, JM; Jiang, CH; Jin, Y; Jones, BD; Ju, X; Ke, ZJ; Kelsey, MH; Kim, BK; Kong, D; Lai, YF; Lang, PF; Lankford, A; Li, CG; Li, D; Li, HB; Li, J; Li, JC; Li, PQ; Li, RB; Li, W; Li, WG; Li, XH; Li, XN; Liu, HM; Liu, J; Liu, RG; Liu, Y; Lou, XC; Lowery, B; Lu, F; Lu, JG; Luo, XL; Ma, EC; Ma, JM; Malchow, R; Mandelkern, M; Mao, HS; Mao, ZP; Meng, XC; Nie, J; Olsen, SL | Abstract: The first measurement of (Formula presented) and an upper limit for (Formula presented) are determined from 22.3 (Formula presented) of (Formula presented) annihilation data at a c.m. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied to charm threshold data to determine the charge of the D meson in the recoil from (Formula presented) reconstructed (Formula presented) (Formula presented) mesons. The branching fractions (Formula presented) and (Formula presented) are determined from 10 events with a reconstructed D and a recoiling (Formula presented) In addition, a 90% C.L. upper limit of (Formula presented) is determined from a search for semileptonic decays of the (Formula presented) © 2000 The American Physical Society.

Author(s): Bai, JZ; Ban, Y; Bian, JG; Blum, I; Chen, GP; Chen, HF; Chen, J; Chen, JC; Chen, Y; Chen, YB; Chen, YQ; Cheng, BS; Cui, XZ; Ding, HL; Dong, LY; Du, ZZ; Dunwoodie, W; Gao, CS; Gao, ML; Gao, SQ; Gratton, P; Gu, JH; Gu, SD; Gu, WX; Gu, YF; Guo, ZJ; Guo, YN; Han, SW; Han, Y; Harris, FA; He, J; He, JT; He, KL; He, M; Heng, YK; Hitlin, DG; Hu, GY; Hu, HM; Hu, JL; Hu, QH; Hu, T; Hu, XQ; Huang, GS; Huang, YZ; Izen, JM; Jiang, CH; Jin, Y; Jones, BD; Ju, X; Ke, ZJ; Kelsey, MH; Kim, BK; Kong, D; Lai, YF; Lang, PF; Lankford, A; Li, CG; Li, D; Li, HB; Li, J; Li, JC; Li, PQ; Li, RB; Li, W; Li, WG; Li, XH; Li, XN; Liu, HM; Liu, J; Liu, RG; Liu, Y; Lou, XC; Lowery, B; Lu, F; Lu, JG; Luo, XL; Ma, EC; Ma, JM; Malchow, R; Mao, HS; Mao, ZP; Meng, XC; Nie, J; Olsen, SL; Oyang, J | Abstract: Using a sample of 3.8 M (Formula presented) events accumulated with the BES detector, the process (Formula presented) is studied. The angular distributions are compared with the general decay amplitude analysis of Cahn. We find that the dipion system requires some D wave amplitude, as well as S wave. On the other hand, the (Formula presented) relative angular momentum is consistent with being pure S wave. The decay distributions have been fit to heavy quarkonium models, including the Novikov-Shifman model. This model, which is written in terms of the parameter (Formula presented) predicts that D wave pions should be present. We determine (Formula presented) based on the joint (Formula presented) distribution. The fraction of D wave amplitude as a function of (Formula presented) is found to decrease with increasing (Formula presented) in agreement with the model. We have also fit the Mannel-Yan model, which is another model that allows D wave pions. © 2000 The American Physical Society.

1. The effects of L-cysteine were tested in rat aortic rings on responses to nitric oxide free radical (NO(*)), nitroxyl (NO(-)) derived from Angeli's salt and endothelium-derived relaxing factor (EDRF) activated by acetylcholine, ATP and the calcium ionophore A23187. Concentrations of 300 microM or less of L-cysteine had no effect on responses. 2. Relaxations produced by exogenous NO(*) (0.25 - 2.5 microM) were markedly prolonged and relaxations produced by sodium nitroprusside (0.001 - 0.3 microM) were enhanced by 1 and 3 mM L-cysteine. The enhancements by L-cysteine of responses to NO(*) and sodium nitroprusside may be attributed to the formation of S-nitrosocysteine. 3. Relaxations mediated by the nitroxyl anion (0.3 microM) donated from Angeli's salt were more prolonged than those produced by NO(*), and nitroxyl-induced relaxations were reduced by L-cysteine (1 and 3 mM). 4. EDRF-mediated relaxations produced by acetylcholine (0.01 - 10 microM), ATP (3 - 100 microM) and the calcium ionophore A23187 (0.1 microM) were significantly reduced by 3 mM L-cysteine. 5. The similarity between the inhibitory effects of L-cystei on responses to EDRF and on those to nitroxyl suggests that a component of the response to EDRF may be mediated by nitroxyl anion.

The effects of carboxy-PTIO and hydroxocobalamin were studied on nitrergic transmission in anococcygeus and retractor penis muscles taken during post mortem examination from young male pigs. In both muscles under resting conditions, electrical field stimulation (EFS) caused contractions that were sensitive to tetrodotoxin (1 microM) and were greatly inhibited by prazosin (1 microM) and guanethidine (10-30 microM), but were not significantly affected by atropine (1 microM). In the anococcygeus muscle, but not in the retractor penis muscle, guanethidine produced a prolonged contraction. After tone was raised by guanethidine in the anococcygeus or by phenylephrine (1 microM) in the presence of guanethidine in the retractor penis, EFS caused tetrodotoxin-sensitive relaxations. The EFS-induced relaxations were abolished by the NO synthase inhibitor N(G)-L-nitro-arginine methyl ester (L-NAME; 100 microM) and its effect was partly overcome by L-arginine (1 mM), indicating it was mediated by nitrergic nerves. Carboxy-PTIO (0.1-1 mM) had no significant effect in reducing stimulation-induced nitrergic relaxations in either muscle. However, hydroxocobalamin (0.1-1 mM) caused concentration-dependent reductions of nitrergic relaxations in both muscles. Relaxations to exogenous nitric oxide (1 microM) in both muscles were abolished by carboxy-PTIO (0.3 mM) and hydroxocobalamin (0.1 mM). There were no differences in reactivity to carboxy-PTIO or hydroxocobalamin between anococcygeus and retractor penis muscles from the same species (pig). The finding also confirms earlier observations that the nitrergic transmitter is generally resistant to the NO-scavenger carboxy-PTIO.

1. The effects of endogenous and exogenous acetylcholine (ACh) on nitrergic relaxations elicited by electrical field stimulation (EFS) were studied in guinea-pig endothelium-denuded basilar artery preparations precontracted with 1 micromol/L prostaglandin F(2 alpha) and a possible role of K+ channels in mediating the effects was investigated. 2. Acetylcholine (3 micromol/L) and physostigmine (10 micromol/L) produced small, yet statistically significant, inhibitions of EFS-induced nitrergic relaxations, while atropine (1 micromol/L) slightly enhanced the nitrergic response. The ACh-induced inhibition was atropine sensitive. Acetylcholine or atropine did not affect relaxations induced by sodium nitroprusside. 3. The inhibition of nitrergic relaxations by 3 micromol/L ACh was prevented by the K+ channel blockers tetraethylammonium and 4-aminopyridine, but was not changed by iberiotoxin, apamin or glibenclamide. 4. Neither vasoactive intestinal polypeptide nor the alpha2-adrenoceptor agonists noradrenaline and clonidine modulated nitrergic neurotransmission in the guinea-pig basilar artery. 5. The findings show that ACh acts on prejunctional muscarinic receptors of nitrergic nerves to inhibit nitrergic neurotransmission. It is suggested that endogenous ACh may have this effect; however, the physiological significance of this prejunctional modulation is not clear due to the relatively small effect produced. The prejunctional inhibitory action of ACh may involve opening of neuronal K+ channels.

The rapid progress of modern manufacturing technology has posed stringent requirements for inspecting techniques for vibration characterization and dynamic testing. Because of its simplicity, accuracy, and whole-field character, speckle interferometry has served as one of the major techniques for dynamic measurement, where normally a dense-sampled temporal speckle sequence is captured for phase retrieval using Fourier or wavelet transforms. In this Letter, a method is proposed for phase evaluation of sparse-sampled speckle patterns when the sampling rate is lower than two points per temporal cycle. Dynamic experiments using a high-speed camera demonstrated the effectiveness of the proposed method for complicated wrapped phase retrieval in electronic/digital speckle pattern interferometry.

The relative efficacy of electric lamps with double-walled carbon nanotube (DWNT) filaments is higher than that with tungsten filaments at the same input power. The luminescence of DWNT electric lamps shows a cold light performance besides blackbody radiation. At a color temperature of 2386 K, the visible light emitted by the DWNT electric lamp (filament diameter: 0.06 mm) occupies 7.6% of the total radiation energy, higher than that of tungsten lamps. The longevity of the DWNT electric lamp (filament diameter: 0.15 mm, 15 V) is no less than 3000 h. DWNT electric lamps are energy saving at low voltages and have potential applications.

The fatigue behavior of injection-molded tensile bars of short-fiber-reinforced theromplastics is described and related to the fatigue behavior of the matrices and the strength of the fiber/matrix interface. A brittle matrix system based on polyphenylene sulfide is shown to behave in a similar manner to long-fiber composites. Glass-fiber reinforcement in this matrix gives fatigue sensitivity that correlaes with that of unimpregnated glass fiber strands, while carbon-fiber rein-forcement gives better fatigue resistance. A well-bonded, due-tile matrix system based on nylon 6,6 gives matrix-controlled fatigue sensitivity. Fatigue data for glass- and carbon-fiber-reinfoced nylon 6,6 superimpose on the matrix fatigue data when normalized by the ultimate tensile strength. Another ductile matrix, polyetherther ketone, is very fatigue-resistant, but its composite progressively loses its reinforcing effect in fatigue, apparently due to interface failure. A transitional matrix, polysulfone, shifts from ductile to fatigue-crack-dominated failure as the cyclic stress is reduced. Its composites show an analogous failure mode shift, and the high cycle-fatigue response is correlated with fatigue-crack-growth data.

The carotid pressor reflex can be blocked by rhomotoxin. The intensity of the blocking effect depends upon the original level of blood pressure and is in correlation with the dosage of rhomotoxin given intravenously. Thus the antihypertensive effect may be ascribed to some extent to the blockade of carotid pressor reflex caused by rhomotoxin and is irrelevant to the changes of blood volume, since this depression of reflex is more prominent than that at the same blood pressure level induced by bloodletting.

The mechanism of tensile cyclic fatigue failure in conventional glass fiber dominated composites has been investigated using single fibers, strands, and composites. Surface damage to the fibers resulting from a fretting type of contact is identified as the dominant mechanism. Macrofibers of glass or glassceramic with residual surface compression have been developed to overcome the sensitivity both to cyclic and static fatigue. The macrofibers and their composites with several different matrices show greatly improved tensile fatigue resistance.

By using Gray''s relaxation theory of transport processes for monatomic liquids35 and the two-parameter (e*, γ*) corresponding states approximation, correlations for thermal conductivity and shear viscosity of halocarbon liquids and their mixtures have been developed. In order to make the relaxation concept useful, the relaxation time was assumed to be a simple function of the thermal speed, u = (3 kT/m)1/2, and the distance variable γ. Since the theory of intermolecular potential has not yet been established for halocarbons, the directly measurable properties of liquid volume, VB, and temperature, the normal boiling point, TB, were sleeted as the set of reducing constants. In spite of these simplifications, the average deviation of the correlated thermal conductivity of eleven halocarbons and two mixtures is within ±3% ; ''and the shear viscosity of five pure halocarbons and three mixtures is within ±5%.

Summary Objective Abnormal maturation and ossification of the endplate chondrocytes play a central role in the pathogenesis of degenerative disorders of the cervical spine. It is widely held that insulin like growth factor-1 (IGF-1) stimulates chondrocyte proliferation and inhibits chondrocyte terminal differentiation both in vitro and in vivo . However, the mechanism underlying such regulation is not fully understood. The present study aimed to determine the role of IGF-1 on the mRNA expression of collagen type II, alpha 1 (Col2a1) and matrix metallopeptidase 13 (MMP-13) in rat endplate chondrocytes. The possible pathways that transduce IGF-1 effects such as phosphatidylinositol-3 (PI-3)-kinase (PI3K) and mitogen activated protein kinase (MAPK) were also investigated in these cells. Methods Cultured endplate chondrocytes harvested from rat cervical spines were treated with IGF-1 (100ng/ml), and the changes in Col2a1 and MMP-13 mRNA were monitored with real-time polymerase chain reaction (PCR). MMP-13 activity was also assayed. Activation of signaling proteins was evaluated by western blot analysis. Cells were also treated with pharmacological agents that block PI3K and MAPK signaling pathways. Results IGF-1 increased Col2a1 mRNA expression in rat endplate chondrocytes in a time- and dose-dependent manner. IGF-1 treatment resulted in a fourfold increase of Col2a1 mRNA with the effect maximizing at 24h. In contrast, IGF-1 treatment for 24h caused a roughly 50% reduction in MMP-13 mRNA. Similar effects were seen on the protein levels of type II collagen (col2) and MMP-13. Consistent with these results, IGF-1 also repressed MMP-13 activity. IGF-1 activated both the PI3K and the extracellular signal-regulated kinase (ERK) pathways as evidenced by phosphorylation of either Akt or ERK1/2 (respectively). The PI3K inhibitor Wartmannin significantly inhibited the IGF-1 effect on Col2a1 mRNA expression but did not affect IGF-1-induced repression of MMP-13 expression. In contrast, the ERK/MAPK inhibitor PD98059 significantly inhibited the effect of IGF-1 on MMP-13 mRNA repression and enhanced IGF-1-induced Col2a1 mRNA expression. Conclusions In rat endplate chondrocytes the PI3K pathway mainly transduces IGF-1 effect on col2 expression while the ERK pathway mediates IGF-1 effect on MMP-13 expression.