胡芦巴碱超声提取工艺研究

目的 研究胡芦巴碱最佳超声提取工艺。方法 采用超声提取法，以胡芦巴碱的提取率为指标，采用正交试验考察各因素对其提取率的影响，优选出胡芦巴碱最佳超声提取工艺。结果 胡芦巴碱最佳超声提取工艺为70%乙醇提取30 min、提取功率500 W，胡芦巴碱提取率最高，平均提取率为0.588%。结论 本实验确定的超声提取工艺可用于胡芦巴碱的提取。     

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??Root canal therapy is the general treatment for endodontic and periapical disease. However??the failure of the therapy still exists. Then root canal retreatment becomes an effective way to increase the conservation rate of those teeth. The aim of retreatment is to eliminate the infected site. The success rate of retreatment is related to many kinds of factors. With the development of implant technology and endodontic surgery??the indications of retreatment have changed. Besides??Niti instruments??ultrasonic and laser technology have improved the efficiency of the retreatment.     

Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self‐adhesive resin cement

Self‐adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self‐adhesive resin cement. A self‐adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light‐irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light‐irradiated, the sonic velocity rapidly increased and plateaued at 2,500–2,700 m s^?1. When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self‐adhesive resin cements is affected by the polymerization mode and the presence of water.     

A transendocardial delivery and intracardiac ultrasound irradiation treatment catheter

Abstract

Objectives: This study introduces the structural design, working principles, performance testing and treatment effects of a newly developed ultrasonic irradiation delivery and treatment catheter system that integrates interventional catheterization technology.

Background: Systemic administration method needs a high dose of gene and induces side effect of non-target organ delivery. Direct intramyocardial injection of a low-dose angiogenic gene followed by insonation treatment can enhance gene expression. So, a novel transendocardial gene delivery and intracardiac ultrasound irradiation strategy was tested.

Methods: The medical interventional ultrasonic therapeutic apparatus is comprised of an ultrasonic irradiation catheter and a host. The ultrasonic irradiation catheter, which is equipped with an advance-and-retreat convenient miniature syringe needle and a miniature piezoelectric transducer on the tip, was used. Twelve dogs were divided into three groups: (1) EGFP and US (EGFP?+?US), (2) EGFP alone and (3) control group. In the EGFP?+?US group, EGFP plasmid DNA (500?µg) was injected and followed by intracardiac insonation. In the EGFP alone group, EGFP plasmid DNA (500?µg) was injected without insonation. In the control group, saline was injected.

Results: The catheter can enter the heart through percutaneous intervention to realize intramyocardial injection, directly irradiate cardiac muscular tissues at close range and correctly control the ultrasonic irradiation energy delivered to cardiac muscular tissues. Compared with the EGFP gene group, an average sixfold enhancement in gene expression was achieved in the EGFP EGFP?+?US group (p?<?0.05).

Conclusions: The experimental results confirmed that the treatment catheter was safe and reliable, which can realize transendocardial intramyocardial gene injection in the left ventricular chamber, and the ultrasonic parameter can increase gene expression after intracardiac ultrasonic irradiation. The intracardiac ultrasound irradiation treatment catheter may be a useful delivery and therapy tool in the future.     

Environmental and Pharmacological Modulation of Amphetamine-Induced 50-kHz Ultrasonic Vocalizations in Rats

Rats emit high-frequency 50-kHz ultrasonic vocalizations (USV) in appetitive situations like social interactions. Drugs of abuse are probably the most potent non-social elicitors of 50-kHz USV, possibly reflecting their euphorigenic properties. Psychostimulants induce the strongest elevation in 50-kHz USV emission, particularly amphetamine (AMPH), either when applied systemically or locally into the nucleus accumbens (Nacc). Emission of AMPH-induced 50-kHz USV depends on test context, such as the presence of conspecifics, and can be manipulated pharmacologically by targeting major neurotransmitter systems, including dopamine (DA), noradrenaline (NA), and serotonin (5-HT), but also protein kinase C (PKC) signaling. Several D₁ and D₂ receptor antagonists, as well as typical and atypical antipsychotics block the AMPH-induced elevation in 50-kHz USV. Inhibiting D₁ and D₂ receptors in the Nacc abolishes AMPH-induced 50-kHz USV, indicating a key role for this brain area. NA neurotransmission also regulates AMPH-induced 50-kHz USV emission given that α₁ receptor antagonists and α₂ receptor agonists exert attenuating effects. Supporting the involvement of the 5-HT system, AMPH-induced 50-kHz USV are attenuated by 5-HT_2C receptor activation, whereas 5-HT_2C receptor antagonism leads to the opposite effect. Finally, treatment with lithium, tamoxifen, and myricitrin was all found to result in a complete abolishment of the AMPH-induced increase in 50-kHz USV, suggesting the involvement of PKC signaling. Neurotransmitter systems involved in AMPH-induced 50-kHz USV emission only partially overlap with other AMPH-induced behaviors like hyperlocomotion. The validity of AMPH-induced 50-kHz USV as a preclinical model for neuropsychiatric disorders is discussed, particularly with relevance to altered drive and mood seen in bipolar disorder.     

Ultrasonic atomization and subsequent desolvation for monoclonal antibody (mAb) to the glycoprotein (GP) IIIa receptor into drug eluting stent

An eluting-stent system with mAb dispersed in the PLLA (poly (L-lactic acid)) was validated in vitro. Specifically designed spray equipment based on the principle of ultrasonic atomization was used to produce a thin continuous PLLA (poly (L-lactic acid)) polymer coating incorporating monoclonal antibody (mAb). This PLLA coating was observed in light microscopy (LM) and scanning electron microscopy (SEM). The concentration of the monoclonal antibody (mAb) to the platelet glycoprotein (GP) IIIa receptor and the eluting rate were then measured by a radioisotope technique with ¹²⁵I-labelled GP IIIa mAb. An in vitro perfusion circuit was designed to evaluate the release rates at different velocities (10 or 20 ml min^?1). The PLLA coating was thin and transparent, uniformly distributed on the surface of the stent. Three factors influenced its thickness: PLLA concentration, duration and gas pressure. The concentration of mAb was influenced by the duration of absorption and the concentration of the mAb solution; the maximum was 1662.23 ± 38.83 ng. The eluting rate was fast for the first 2 h, then decreased slowly and attained 80% after 2 weeks. This ultrasonic atomization spray equipment and technological process to prepare protein eluting-stents were proved to be effective and reliable.     

Material Reaction of Diaphyseal Bone Under Torsion: An Experimental Study on Dogs

The formation of microcracks in entire canine diaphyseal bones under torsional loads was studied. the acoustic emission technique was used to register the stress waves which were generated in the bones by crack formation and/or growth. Acoustic emission signals, characteristic of crack formation and/or growth, were recorded exclusively during the non-linear deformation. This is a strong indication of the elastic behaviour of diaphyseal canine bone material.