Clinical effect of recombinant adenovirus containing thymidine kinase suicide gene in preventing postoperative recurrence of hepatocellular carcinoma

ObjectiveTo investigate the clinical effect of surgical operation combined with gene therapy in preventing postoperative recurrence of hepatocellular carcinoma (HCC). MethodsA total of 102 patients with single HCC (TNM stage 1-2, tumor diameter ＜10 cm) who were admitted to Beijing YouAn Hospital, Capital Medical University, from July 2006 to February 2013 were enrolled, and among these patients, 60 underwent the gene therapy with recombinant adenovirus containing thymidine kinase suicide gene (ADV-TK) before and after surgery (gene group) and 42 underwent surgical resection alone (surgery group). The patients were followed up regularly after surgery to observe postoperative recurrence. The t-test was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups. The log-rank test was used for the analysis of cumulative recurrence rate, and univariate and multivariate Cox regression analyses were used to identify influencing factors for recurrence rate. ResultsThe 1-, 3-, and 5-year recurrence rates of tumor were 13.8%, 33.7%, and 47.7% in the gene group and 18.5%, 53.2%, and 69.2% in the surgery group, and there was a significant difference between the two groups (χ2=2643,P=0.041). The gene group had a significantly higher proportion of patients with pyrexia after surgery than the surgery group, and there were no significant differences in the incidence rates of other complications and length of hospital stay between the two groups. The multivariate analysis showed that gene therapy was an independent influencing factor for cumulative rumulative recurrence rate (odds ratio=2752,95 confidence interval:1164-4251,P=0038). ConclusionGene therapy combined with surgical resection can effectively reduce postoperative recurrence of tumor, and therefore, it holds promise for clinical application

Research on the Manufacturing Process and Heat Transfer Performance of Ultra-Thin Heat Pipes: A Review

This paper reviews the manufacturing process of ultra-thin heat pipes and the latest process technologies in detail, focusing on the progress of the shape, structure, and heat transfer mechanism of the wick. The effects of the filling rate and tilt angle on the heat transfer performance of the ultra-thin heat pipe, as well as the material selection of ultra-thin heat pipes, is sorted out, and the surface modification technology is analyzed. Besides, the optimal design based on heat pipes is discussed. Spiral woven mesh wick and multi-size composite wick have significant advantages in the field of ultra-thin heat pipe heat transfer, and comprehensive surface modification technology has huge potential. Finally, an outlook on future scientific research in the field of ultra-thin heat pipes is proposed

Effect of low storage temperature on pollen viability of fifteen herbaceous peonies

In order to develop rich new varieties of peony flowers and solve the problems associated with non-synchronised flowering, a study was conducted to investigate pollen viability of fifteen herbaceous peony cultivars. Pollen was stored for more than one year under four storage conditions (4 °C, −4 °C, −20 °C, and −76 °C). In vitro germination and the I2-KI staining method were used to test pollen viability. For all cultivars, pollen stored at −76 °C showed a significantly slower rate of viability reduction when compared to all the other storage conditions. The differential results obtained using different pollen viability assays confirmed that the in vitro germination test showed lower viability compared to I2-KI staining method. The pollen tube length grew longer as storage temperature rose such as ‘Hongfeng’. From the present study, it has been proved that the I2-KI staining method is more convenient and reliable than the in vitro germination test. Herbaceous peony pollen can be stored at 4 °C for hand-pollination among cultivars having non-synchronised flowering in a season, and that different storage temperature is suited to different herbaceous peony pollen for more than one year. Keywords: Herbaceous peony, Pollen viability, In vitro germination, I2-KI staining method, Cross pollinatio

LC/8YSZ TBCs Thermal Cycling Life and Failure Mechanism under Extreme Temperature Gradients

The purpose of this paper is to study the thermal shock resistance and failure mechanism of La2Ce2O7/8YSZ double-ceramic-layer thermal barrier coatings (LC/8YSZ DCL TBCs) under extreme temperature gradients. At high surface temperatures, thermal shock and infrared temperature measuring modules were used to determine the thermal cycling life and insulation temperature of LC/8YSZ DCL TBCs under extreme temperature gradients by an oxygen–acetylene gas flame testing machine. A viscoelastic model was used to obtain the stress law of solid phase sintering of a coating system using the finite element method. Results and Conclusion: (1) Thermal cycling life was affected by the surface temperature of LC/8YSZ DCL TBCs and decreased sharply with the increase of surface temperature. (2) The LC ceramic surface of the failure coating was sintered, and the higher the temperature, the faster the sintering process. (3) Accelerated life test results showed that high temperature thermal cycling life is not only related to thermal fatigue of ceramic layer, but is also related to the sintering degree of the coating. (4) Although the high temperature thermal stress had great influence on the coating, great sintering stress was produced with sintering of the LC ceramic layer, which is the main cause of LC/8YSZ DCL TBC failure. The above results indicate that for new TBC ceramic materials, especially those for engines above class F, their sinterability should be fully considered. Sintering affects the thermal shock properties at high temperature. Our research results can provide reference for material selection and high temperature performance research

Time-Marching Throughflow Analysis of Centrifugal Compressors with Boundary Conditions Based on Newton’s Method

The meridional distribution of the flow parameters inside the centrifugal compressor is of great importance to its overall performance, as well as its matching performance under a thermal cycle. A time-marching throughflow method for the off-design performance analysis of the centrifugal compressor is described. The method is based on the strictly conservative throughflow-governing equations, and an improved method of boundary-condition enforcement is developed based on Newton’s method to achieve a robust and fast throughflow simulation. An inviscid blade force model was adopted to obtain the flow deflection inside the blade passage. Empirical loss models were integrated into the throughflow model to simulate the viscous force effects in the real three-dimensional flow. Two test cases are presented to validate the throughflow method by comparisons with the experimental data or CFD results, including the NASA low-speed centrifugal compressor (LSCC) and the Allison high-performance centrifugal compressor (HPCC). The simulation indicated that the developed enforcement method for the inlet and outlet boundary conditions significantly improves the computational robustness. For both the LSCC and HPCC cases, reasonable flow-parameter distribution was obtained and accurate overall characteristics were also predicted under the off-design conditions. The results indicated that the developed time-marching throughflow method is effective and efficient for the performance analysis of centrifugal compressors

Time-Marching Throughflow Analysis of Centrifugal Compressors with Boundary Conditions Based on Newton’s Method

The meridional distribution of the flow parameters inside the centrifugal compressor is of great importance to its overall performance, as well as its matching performance under a thermal cycle. A time-marching throughflow method for the off-design performance analysis of the centrifugal compressor is described. The method is based on the strictly conservative throughflow-governing equations, and an improved method of boundary-condition enforcement is developed based on Newton’s method to achieve a robust and fast throughflow simulation. An inviscid blade force model was adopted to obtain the flow deflection inside the blade passage. Empirical loss models were integrated into the throughflow model to simulate the viscous force effects in the real three-dimensional flow. Two test cases are presented to validate the throughflow method by comparisons with the experimental data or CFD results, including the NASA low-speed centrifugal compressor (LSCC) and the Allison high-performance centrifugal compressor (HPCC). The simulation indicated that the developed enforcement method for the inlet and outlet boundary conditions significantly improves the computational robustness. For both the LSCC and HPCC cases, reasonable flow-parameter distribution was obtained and accurate overall characteristics were also predicted under the off-design conditions. The results indicated that the developed time-marching throughflow method is effective and efficient for the performance analysis of centrifugal compressors

Evaluation of ITS2 for intraspecific identification of Paeonia lactiflora cultivars

Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental and medicinal plant. DNA barcodes can reveal species identity via the nucleotide diversity of short DNA segments. In this study, two main candidate DNA barcodes (ITS2 and psbA-trnH) were tested to identify twenty-one cutting cultivars of P. lactiflora and their wild species. The efficacy of the candidate DNA barcodes was assessed by PCR amplification, sequence quality, sequence diversity, rate of correct identification, and phylogenetic analysis. ITS2 was easy to be amplified and sequenced among the samples. The identification by Blastn and phylogenetic analysis was 95.4% and 63.6%, respectively. For psbA-trnH, the presence of poly A-T led to sequencing failure which limited its use as DNA barcode candidate. Moreover, the authentic efficiency of psbA-trnH was lower than ITS2. The results showed that ITS2 is suitable as a candidate DNA barcode for the intraspecific identification of P. lactiflora cultivars

Broad-spectrum chemicals block ROS detoxification to prevent plant fungal invasion.

Plant diseases cause a huge impact on food security and are of global concern. While application of agrochemicals is a common approach in the control of plant diseases currently, growing drug resistance and the impact of off-target effects of these compounds pose major challenges. The identification of pathogenicity-related virulence mechanisms and development of new chemicals that target these processes are urgently needed. One such virulence mechanism is the detoxification of reactive oxygen species (ROS) generated by host plants upon attack by pathogens. The machinery of ROS detoxification might therefore serve as a drug target for preventing plant diseases, but few anti-ROS-scavenging drugs have been developed. Here, we show that in the model system Botrytis cinerea secretion of the cytochrome c-peroxidase, BcCcp1 removes plant-produced H2O2 and promotes pathogen invasion. The peroxidase secretion is modulated by a Tom1-like protein, BcTol1, through physical interaction. We show that BcTol1 is regulated at different levels to enhance the secretion of BcCcp1 during the early infection stage. Inactivation of either BcTol1 or BcCcp1 leads to dramatically reduced virulence of B. cinerea. We identify two BcTol1-targeting small molecules that not only prevent B. cinerea invasion but also have effective activity against a wide range of plant fungal pathogens without detectable effect on the hosts. These findings reveal a conserved mechanism of ROS detoxification in fungi and provide a class of potential fungicides to control diverse plant diseases. The approach described here has wide implications for further drug discovery in related fields

A Thermal-Fluid-Solid Coupling Computation Model of Initiation Pressure Using Supercritical Carbon Dioxide Fracturing

With the characteristics of low fracturing pressure, little damage to the reservoirs, and assuming the role of carbon storage, supercritical carbon dioxide (SC-CO2) fracturing is suitable for the development of unconventional oil and gas resources. Based on the tensile failure mechanism of rocks, this paper establishes a thermal-fluid-solid coupling initiation pressure model for SC-CO2 fracturing. Using this model, the changes in formation temperature and pore pressure near a wellbore caused by invasion of CO2 into the formation are analyzed, as well as the impact of these changes on the tangential stress of reservoir rocks. The field data of SC-CO2 fracturing in a sandstone gas well are used to validate the reliability of the model. The results show that SC-CO2 fracturing can significantly reduce the initiation pressure, which decreases with the increase in fracturing fluid injection rate. The minimum value of tangential stress is located at the well wall, and the direction of tangential stress caused by formation temperature and pore pressure is opposite, with the former greater than the latter. The increase in Poisson’s ratio, the increase in elastic modulus and the decrease in bottom hole temperature can reduce the initial fracturing pressure of the reservoir. The computation model established in this paper provides an effective method for understanding the reservoir fracturing mechanism under the condition of SC-CO2 invasion

Feature Fusion Classifier With Dynamic Weights for Abnormality Detection of Amniotic Fluid Cell Chromosome

Chromosomal karyotype is important to determine whether a newborn has a genetic disorder. There are two main categories of chromosomal abnormalities: structural abnormalities, in which the chromosome structure is altered, and chromosome number abnormalities. Manual karyotyping is complex and takes a lot of time because it requires a high degree of domain expertise. Based on this investigation, we propose a new method of chromosome defect detection based on deep learning with 20,299 chromosome images from Dongguan Kanghua Hospital as data that integrates the diversity of chromosome features and trains a classifier model based on feature fusion for chromosome abnormality detection. We put forward a feature fusion classifier with dynamic weights (FFCDW) for chromosomal abnormality detection, after data augmentation with three deep learning networks, ResNet, SENet, and VGG19, the three trained models are combined using a dynamic weighting approach. Experiments prove the FFCDW method outperforms these mainstream models of ResNet, SENet, and VGG19. The proposed method based on FFCDW achieves a precision of 0.8902 and an F1-score of 0.8805 with a small standard deviation (0.00903 and 0.00892, respectively). In addition, the algorithm can automatically assign weights based on the results of a single model, and the strategy with dynamic weights outperforms the strategy with fixed weights in the proposed feature fusion classifier