A novel method for DNA detection was developed based on the excellent fluorescence properties of cationic conjugated polymer ( CCP)and the target DNA enrichment,separation function of nanoparticles. First,the quencher-labeled DNA capture probes were modified on the surface of Au nanoparticles,and complementary DNA strands were captured. Second,S1 nuclease was added,and the capture probes that had not captured the complementary DNA were removed from the nanoparticles.Finally,the complementary double-stranded DNA was cut by Dnase I,the quenchers were dissociated from nanoparticle and the fluorescence of CCP was quenched by means of combination of quenchers and CCP.The results showed that this method is specific.In the range of 5. 0 -40 nmol/L,the concentration of target DNA was proportional to the fluorescence quenching and the detection limit was 3.7 nmol/L(S/N = 3).

Objective To invent a set of novel veno-venous bypass (VVB) device based on magnetic anastomosis technique which can be used in ex situ liver resection, and verify its clinical value and performance in animal models.Methods Each VVB device was constructed using three magnetic rings and an inverted Y-shaped tube with magnetic rings on each end.The magnetic ring was made of NdFeB with electrode cutting, and the tube was made of polyvinyl chloride (PVC) and preconditioned with heparin coating on the surface of the lumen.Ten dogs underwent the ex situ liver resection, and VVB was established via magnetic anastomosis technique with the novel VVB device during the operation.The time for completing VVB was recorded, and the hemodynamic indexes including the venous flow velocity, carotid pressure, central venous pressure and portal pressure was detected.The changes of intestinal lumen and kidney were also observed.Results It only took 6 ～ 10 minutes to establish VVB by the novel VVB device in the operation,and the hemodynamics stability was maintained smoothly during the anheptic phase.The shunt index of inferior vena cava and portal vein was 76.2％ and 75.5％, respectively.The congestion of intestinal canal and kidney were also alleviated during the anheptic phase.Conclusions It could reduce the time to establish VVB with magnetic anastomosis technique in ex situ liver resection.This study showed that utilizing the novel VVB device for intraabdominal VVB during the anheptic phase could be helpful to maintain the hemodynamics stability.

BACKGROUND:Prostacyclin (PGI2) and its analogs have been reported to prevent pressure overload-induced cardiac hypertrophy, and to reduce cardiac ischemia/reperfusion injury. However, clinical application of PGI2 is chalenging due to its short half-life (< 2 minutes). Thus, we have generated PGI2 expressing rat endothelial progenitor cel strains (PGI2-EPCs) that constitutively secrete prostacyclin.
OBJECTIVE:To investigate the protective effectof PGI2-EPCs against oxidative stress-induced cardiomyocyte injury.
METHODS:Cultured H9c2 celsin vitrowere assigned into four groups: H9c2 cels treated by H2O2for 4 hours. H9c2 cels were pretreated by conditioned medium (colected form EPCs and PGI2-EPCs or colected form EPCs and PGI2-EPCs mixed with native EPCs) before the addition of H2O2. PBS instead of conditioned mediums served as negative control. The paracrine effect of PGI2-EPCs onin vitro angiogenesis of native EPCs was evaluated. MTT and Hoechst 33342 assays were used to examine the protective effect of conditioned medium on H2O2-induced rat embryonic cardiomyocyte apoptosis and cel viability. Finaly, the effect of conditioned medium on the electric activities of adult cardiomyocyteswas measuredby whole-cel patch clamp techniques.
RESULTS AND CONCLUSION:When native EPCs mixed with conditioned medium of PGI2-EPCs, the total length of tubes was significantly longer compared with those mixed with CM of EPC. Rat embryonic cardiomyocytes pretreated with conditioned medium of PGI2-EPCs significantly reduced H2O2-induced apoptosis and preserved cel viability compared with pretreatment with EPC-conditioned medium and without pretreatment (P< 0.01). Pretreatment of rat adult cardiomyocyteswith conditioned medium of PGI2-EPCs abolished H2O2-induced early afterdepolarization and shortened H2O2-induced action potential duration prolongation (P< 0.01) towards baseline.Our findings indicate thatPGI2-EPCs protect against oxidative stress-induced cardiomyocyte injury through paracrine action.ThisStudy providesthe groundwork for an innovative cel therapy approach to treat ischemic heart disease.

BACKGROUND:C-reactive protein has been shown to rapidly increase during the occurrence of inflammation and tissue injury, and can indicate the degree of inflammatory reaction.
OBJECTIVE:To analyze the correlation between survival time and C-reactive protein in rabbits after transplantation of polytetrafluoroethene artificial trachea with support ring.
METHODS:The cervical trachea of rabbits was replaced by polytetrafluoroethene artificial trachea with support ring. Survival time of the rabbit, and the changes in serum C-reactive protein at 1-7 days after transplantation were observed. Linear regression was used to assess the univariate association between serum C-reactive protein and survival time.
RESULTS AND CONCLUSION:The linear correlation was observed between changes of serum C-reactive protein and survival time in rabbits with artificial trachea replacement operation. C-reactive protein levels in rabbits with<13 days of survival time were increased and positively associated with the number of days after transplantation. However, C-reactive protein levels in rabbits with>13 days were decreased and negatively associated with the number of days after transplantation. In rabbits with positive correlation and negative correlation, the median survival time and 95%confidence interval (CI) were respectively 10 days (95%CI 8.614-11.386 days) and 27 days (95%CI 23.970-30.030 days). The survival rate in negative correlation group was significantly higher than positive correlation group (x2=29.364, P<0.01). Results suggested that the prolonged survival time of rabbits after artificial trachea replacement operation was related to the decreased concentration of serum C-reactive protein.

Objective To compare the response capability of active personal dosimeters (APDs) in the pulse radiation field of interventional radiology, and to find APDs that can be used for dose optimization monitoring for interventional radiology staff. Methods Seven models of APDs and dose monitoring systems were tested in the following four types of radiation fields: continuous radiation field (Cs-137), single-pulse radiation field (80 kV, 10 mA, 10～1000 ms), multi-pulse standard radiation field (70 kV, 20～500 mA, 1～20 ms/pulse, frames per second 1～20), and multi-pulse scattering field (angiography machine, irradiation field: 15 cm × 15 cm, 22 cm × 22 cm, 27 cm × 27 cm, angiography: 65～74 kV, 6.2～8.2 mA; photography: 65 kV, 343～479 mA). Results All APDs showed good dose responses in the continuous radiation field. The ratio of the results obtained with and without phantom was 1～1.1. In the single-pulse radiation field, DMC3000 and TruDose showed good dose response, linearity, and repeatability. Under the main ray of the multi-pulse radiation field, DMC3000 and TruDose showed good dose response, linearity, and repeatability as the dose rate increased, and there were 5%～13% differences in the response ability between the two models. In angiography machine scattering field, the ratios of the results obtained from DMC3000, TruDose, and RaySafei3 to those from thermoluminescence dosimeter were 1.08 ± 0.09, 0.95 ± 0.11, and 1.13 ± 0.11, respectively. Conclusion DMC3000, TruDose, and RaySafei3 can be used in clinics as auxiliary dosimeters to optimize radiation dose monitoring and radiation protection measures for people at high risk of occupational diseases. Interventional radiology workers can implement actions to reduce the cumulative dose based on real-time dose information, thereby reducing the radiation dose.

Objective To predict and assess biomechanical responses and injury mechanisms of the thorax and abdomen for small-sized females in vehicle collisions. Methods The accurate geometric model of the thorax and abdomen was constructed based on CT images of Chinese 5th percentile female volunteers. A thoracic-abdominal finite element model of Chinese 5th percentile female with detailed anatomical structure was developed by using the corresponding software. The model was validated by reconstructing three groups of cadaver experiments (namely, test of blunt anteroposterior impact on the thorax, test of bar anteroposterior impact on the abdomen, test of blunt lateral impact on the chest and abdomen). Results The force-deformation curves and injury biomechanical responses of the organs from the simulations were consistent with the cadaver experiment results, which validated effectiveness of the model. Conclusions The model can be used for studying injury mechanisms of the thorax and abdomen for small-sized female, as well as developing small-sized occupant restraint systems and analyzing the forensic cases, which lays foundation for developing the whole body finite element model of Chinese 5th percentile female.

The magnetic anchoring lung nodule positioning device is composed of a target magnet, an anchor magnet, a coaxial puncture needle and a puncture navigation template, through these, a new type of accurate positioning technology for small pulmonary nodules is derived. The device inserts the target magnet into the both sides nearby the lung nodule under the guidance of CT. Helped by the mutual attraction of the two target magnets, they can be fixed in the lung tissue, avoiding the movement in the lung, and accurately positioning the target lung nodule before surgery. In thoracoscopic surgery, the anchor magnet and the target magnet attract each other to achieve the purpose of positioning the target nodule. The device uses the characteristics of non-contact suction of magnetic materials biomedical engineering technology, eliminating the previous procedure of direct interaction with the positioning marks, finally achieves the target of precise positioning of lung nodules and rapid surgical removal.
Humans ; Lung ; Lung Neoplasms ; Magnetic Phenomena ; Magnets ; Solitary Pulmonary Nodule ; Thoracic Surgery, Video-Assisted ; Tomography, X-Ray Computed