The formation of tricalcium phosphate (TCP) from dicalcium phosphate and calcium carbonate was investigated using differential thermal analysis (DTA), thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD). DTA showed three distinct thermal events attributed to dehydration of dicalcium phosphate dihydrate (brushite, DCPD) to dicalcium phosphate anhydrous (monetite, DCPA), the formation of beta-calcium pyrophosphate (b-Ca2P2O7), and the calcination of calcium carbonate. TGA showed three weight losses corresponding to the three thermal events, respectively. XRD analysis showed that b-TCP formed, beginning at about 900°C, by the reaction of b-Ca2P2O7 with CaO and b-TCP changed to a-TCP above 1200℃. Further examination of the formation of TCP from calcium hydroxide (Ca(OH)2) and DCPA showed that b-TCP would form only after the decomposition of Ca(OH)2 to CaO and from the reaction of CaO with b-Ca2P2O7 at a fairly low temperature of 800℃. In addition, by naturally cooling a-TCP, formed at 1300℃ within the heating furnace, to room temperature, it was difficult to obtain a pure phase of b-TCP. The proposed mechanism of the reaction to form TCP may include the dehydration of brushite to monetite, dehydration of monetite to beta-calcium pyrophosphate, decomposition of calcium carbonate, the formation of b-TCP, and phase transition.

Although the fetal heart rate monitoring using ultrasound is widely used it is still not optimized for automatic measurements due to the complexity of the Doppler signal. This paper presents a new fetal heart rate (FHR) detecting algorithm, using sampling autocorrelation approach. The results obtained using the custom-built ultrasonic Doppler fetal heart rate monitoring system are presented and confirm the validity of the method.

The formation of calcium potassium sodium orthophosphate (Ca2KNa(PO4)2) from sodium dihydrogen phosphate dihydrate (NaH2PO4 2H2O), potassium dihydrogen phosphate (KH2PO4) and calcium carbonate (CaCO3) was investigated using differential thermal analysis (DTA), thermal gravimetric analysis (TGA) and powder X-ray diffraction (XRD). DTA showed five distinct thermal events attributed to dehydration of NaH2PO4 2H2O, dehydration of NaH2PO4 and KH2PO4, the transition of amorphous calcium sodium phosphate to-CaNaPO4, the decomposition of CaCO3 to CaO, and the crystallization of Ca2KNa(PO4)2. TGA showed 5.6% weight loss between 70 and 170℃ due to the dehydration of NaH2PO4 2H2O to NaH2PO4; the 7.3% weight loss between 170 and 280℃ is due to the dehydration of NaH2PO4 and KH2PO4; a continuous weight loss over 280-760℃ due to the reaction of melted alkali metal phosphates with CaCO3 and an approximate 8% weight loss between 670 and 840℃ due to the calcination of residual CaCO3. XRD analysis, as a function of temperature, supported the evolution of these events and phases, showed the formation of other intermediates: -CaKPO4 and calcium potassium pyrophosphate (CaK2P2O7). The proposed mechanism of the reaction to Ca2KNa(PO4)2 involves the formation and consumption of these intermediates: acid alkali metal pyrophosphate, metaphosphate, CaK2P2O7 and β-CaNaPO4.

The TiO2 nanoparticles are prepared by chemistry precipitating method and sol-gel method. The resulting materials are characterized by XRD. The ultraviolet catalyze on antibacterial property of TiO2 have been validated through experiment.

Gelatin microspheres (GMs) containing Pingyangmycin hydrochloride were prepared for the interventional embolization by a double-phase emulsified thermal gelation method using oxidized dextran (ox-dex) as the cross-linking agent. The average diameter of the microspheres was 82 m with 74% ranging from 50-200 m. Drug content and the characteristics of drug release in vitro and in vivo were evaluated using UV-spectroscopy and HPLC, respectively. The prepared microspheres showed a rather high percentage of encapsulation ranging from 85 to 88% and drug content at 7.2%. The results of in vitro experiments showed that about 65.5% of the total amount of the encapsulated drug was released after 6 h at 37

Irradiation of nanoabsorbers with pico-and nanosecond laser pulses could result in thermal effects with a spatial confinement of less than 50 nm. Therefore absorbing nanoparticles could be used to create controlled cellular effects. We describe a combination of laser irradiation with nanoparticles, which changes the plasma membrane permeability. We demonstrate that the system enables molecules to penetrate impermeable cell membranes. Laser light at 532 nm is used to irradiate conjugates of colloidal gold, which are delivered by antibodies to the plasma membrane of the Hodgkin's disease cell line L428 and/or the human large-cell anaplastic lymphoma cell line Karpas 299. After irradiation, membrane permeability is evaluated by fluorescence microscopy and flow cytometry using propidium iodide PI and fluorescein isothiocyanate FITC dextran. The fraction of transiently permeabilized and then resealed cells is affected by the laser parameter, the gold concentration, and the membrane protein of the different cell lines to which the nanoparticles are bound. Furthermore, a dependence on particle size is found for these interactions in the different cell lines. The results suggest that after optimization, this method could be used for gene transfection and gene therapy.

Sanguis draxonis (SD) is a Chinese traditional herb that is prescribed for the handling of diabetic disorders. In this study, the effects of an oral administration of SD at dosages of 100, 300, and 500 mg kg 1 once a day, respectively, on the formation of insulin resistance were investigated in vivo in two models of insulin-resistant rats, HFD rats (high-fat diet-induced insulinresistant rats) and IILI rats (induced by the intraperitoneal injections of long-acting insulin at dosage of 0.5 U kg 1 three times daily). The insulin resistance was indicated using the loss of tolbutamide-induced hypoglycemic activity. After the oral administration of SD (300 and 500 mg kg 1 once a day for 7 days) to HFD rats, both plasma glucose and insulin concentration were decreased significantly, while the hypoglycemic activity of tolbutamide (10 mg kg 1, i.p.) was significantly enhanced as compared with that of the vehicle-treatment (0.9% saline solution used as vehicle to disperse SD, w/v). Moreover, the formation of insulin resistance in IILI rats had been improved significantly with SD treatment (100, 300, 500 mg kg 1 once a day for 14 days), but the influence of SD treatment on both plasma glucose and insulin concentration was not observed. For STZ-induced diabetic rats, the action of SD (300 and 500 mg kg 1 once a day for 14 days) showed more effective on an increase of response to the exogenous short-acting porcine insulin than that of the metformin administrated orally at dosage of 320 mg kg 1 three times daily. The present studies suggest that an oral administration of SD can increase insulin sensitivity and improve the development of insulin resistance in rats. # 2004 Elsevier Ireland Ltd. All rights reserved.

Materials based on calcium alkali orthophosphate using for filling bone defects have been fabricated by means of solid state reaction method. The starting materials were selected from chemical reagents: CaHPO4•2H2O, CaCO3, Na2CO3, K2CO3 and H3PO4(85%). After these materials were mixed stoichiometrically and dried at 200◦C for 2 hours, the mixture was sintered in air at high temperature for 2 hours. The samples were characterized by X-ray diffraction. The results showed that the new materials contained only one crystal phase: Ca2KNa(PO4)2, whether the sintering temperature was 1350 degrees C or higher if the material was designed as Ca2KNa(PO4)2. Furthermore, the solubility was tested and it revealed that these materials containing Ca2KNa(PO4)2 had higher solubility than α-TCP.

The underlying ionic mechanisms of ischemic-induced arrhythmia were studied by the computer simulation method. To approximate the real situation, ischemic cells were simulated by considering the three major component conditions of acute ischemia (elevated extracellular K+ concentration, acidosis and anoxia) at the level of ionic currents and ionic concentrations, and a round ischemic zone was introduced into a homogeneous healthy sheet to avoid sharp angle of the ischemic tissue. The constructed models were solved using the operator splitting and adaptive time step methods, and the perturbation finite difference (PFD) scheme was first used to integrate the partial differential equations (PDEs) in the model. The numerical experiments showed that the action potential durations (APDs) of ischemic cells did not exhibited rate adaptation characteristic, resulting in flattening of the APD restitution curve. With reduction of sodium channel availability and long recovery of excitability, refractory period of the ischemic tissue was significantly prolonged, and could no longer be considered as same as APD. Slope of the conduction velocity (CV) restitution curve increased both in normal and ischemic region when pacing cycle length (PCL) was short, and refractory period dispersion increased with shortening of PCL as well. Therefore, dynamic changes of CV and dispersion of refractory period rather than APD were suggested to be the fundamental mechanisms of arrhythmia in regional ischemic myocardium.

取健康人的静脉血，首次实验测量了人血液的三维荧光光谱，并通过分析荧光激发2发射矩阵研究了血液自体荧光的物质来源。结果表明：人血液的荧光激发2发射对主要有2602630，2802340，3402460，4502520 nm，它们所对应的内源性荧光物质分别来源于血液中的内源性卟啉，色氨酸，还原烟碱腺嘌呤二核苷酸（磷酸盐）和黄素腺嘌呤二核苷酸。这些物质的荧光激发效率随着激发光波长的变化而表现出显著差异。