Study on Temperature Control and Crack Prevention of Mass Concrete for Large Powerhouse Constructed in Cold Area

Due to complex structure, large scale, and cold climate, the temperature field and stress field during construction of BoYi Station is different with ordinary mass concrete. Therefore the corresponding crack prevention method must be explored. In order to simulate the complicated construction course, cold climate, multiple materials and unusual structure, a finite element program is adopted. In 5 numerical simulation cases, different temperature control methods are tried to decrease the tensile stress of mass concrete. Based on the simulation analysis and combined with the engineering experience, the scheme and indexes of temperature control and crack prevention are recommended. The mainly measures are controlling pouring temperature, insulation of concrete surface, pipe cooling, block partition and extra steel bar reinforcement. The values of temperature indexes are sharply lower than that of ordinary hydropower station mass concrete. The suggested measures and indexes in this paper, which are various with season, structure position and material, may provide some reference to similar large hydropower station workshop in cold area

EFFECT OF STRONG LIGHT THERAPY WITH COLD LIGHT SOURCE IN TREATMENT OF SEVERE NEONATAL HYPERBILIRUBINEMIA

Objective To investigate the clinical effect of strong light therapy with cold light source in the treatment of severe neonatal hyperbilirubinemia. Methods A total of 217 neonates with severe hyperbilirubinemia who were hospitalized in Department of Neonatology in our hospital from June 2016 to January 2022 were enrolled and treated with strong light therapy with cold light source. Serum total bilirubin (STB) was measured after 4-6 h, and if STB decreased or immunohemolytic STB decreased by ≥34-50 μmol/L, strong light therapy with cold light source was continued for 18-24 h, with STB tested once during 8-12 h. When STB decreased to below 342.0 μmol/L, the treatment was changed to standard phototherapy. If STB did not decrease to the target value after 4-6 h of strong light therapy with cold light source or the early manifestation of acute bilirubin encephalopathy was observed, phototherapy was stopped and switched to exchange transfusion immediately. Results Among the 217 neonates, 2 showed no response to strong light therapy with cold light source and were treated with exchange transfusion, and the other 215 neonates achieved a reduction in STB of (40.6±14.9), (61.2±17.7), and (114.7±49.4) μmol/L, respectively, after 4-6 h, 12-14 h, and 20-24 h of strong light therapy with cold light source. The mean duration of strong light therapy with cold light source was (32.3±14.5) h. After treatment for 5-9 d, the neonates were discharged when there was no increase in STB. Hearing screening within 1 week after discharge showed normal results; brainstem auditory evoked potential (BAEP) examination was performed for 96 neonates and showed no abnormality; all neonates had normal MRI results. Of all neonates, 134 were followed up for 1 year, 43 were followed up for 1-6 months, and 38 were lost to follow-up after 1 month. The neonates who were followed up had normal physical growth, motor development, neurobehavioral assessment, BAEP, and MRI results. Conclusion Strong light therapy with cold light source has a marked clinical effect in the treatment of severe neonatal hyperbilirubinemia, and comprehensive treatment such as non-exchange transfusion strong light irradiation with cold light source can be selectively used

Study on Temperature Control and Crack Prevention of Mass Concrete for Large Powerhouse Constructed in Cold Area

Due to complex structure, large scale, and cold climate, the temperature field and stress field during construction of BoYi Station is different with ordinary mass concrete. Therefore the corresponding crack prevention method must be explored. In order to simulate the complicated construction course, cold climate, multiple materials and unusual structure, a finite element program is adopted. In 5 numerical simulation cases, different temperature control methods are tried to decrease the tensile stress of mass concrete. Based on the simulation analysis and combined with the engineering experience, the scheme and indexes of temperature control and crack prevention are recommended. The mainly measures are controlling pouring temperature, insulation of concrete surface, pipe cooling, block partition and extra steel bar reinforcement. The values of temperature indexes are sharply lower than that of ordinary hydropower station mass concrete. The suggested measures and indexes in this paper, which are various with season, structure position and material, may provide some reference to similar large hydropower station workshop in cold area

Screening of Differentially Expressed Genes and Localization Analysis of Female Gametophyte at the Free Nuclear Mitosis Stage in <i>Pinus tabuliformis</i> Carr.

Female sterility is a common phenomenon in the plant world, and systematic research has not been carried out in gymnosperms. In this study, the ovules of No. 28 sterile line and No. 15 fertile line Pinus tabuliformis were used as materials, and a total of 18 cDNA libraries were sequenced by the HiSeqTM 4000 platform to analyze the differentially expressed genes (DEGs) and simple sequence repeats (SSRs) between the two lines. In addition, this study further analyzed the DEGs involved in the signal transduction of plant hormones, revealing that the signal pathways related to auxin, cytokinin, and gibberellin were blocked in the sterile ovule. Additionally, real-time fluorescent quantitative PCR verified that the expression trend of DEGs related to plant hormones was consistent with the results of high-throughput sequencing. Frozen sections and fluorescence in situ hybridization (FISH) were used to study the temporal and spatial expression patterns of PtRab in the ovules of P. tabuliformis. It was found that PtRab was significantly expressed in female gametophytes and rarely expressed in the surrounding diploid tissues. This study further explained the molecular regulation mechanism of female sterility in P. tabuliformis, preliminarily mining the key factors of ovule abortion in gymnosperms at the transcriptional level

RNA-seq Analysis Reveals Gene Expression Profiling of Female Fertile and Sterile Ovules of Pinus Tabulaeformis Carr. during Free Nuclear Mitosis of the Female Gametophyte

The development of the female gametophyte (FG) is one of the key processes of life cycle alteration between the haploid gametophyte and the diploid sporophytes in plants and it is required for successful seed development after fertilization. It is well demonstrated that free nuclear mitosis (FNM) of FG is crucial for the development of the ovule. However, studies of the molecular mechanism of ovule and FG development focused mainly on angiosperms, such as Arabidopsis thaliana and further investigation of gymnosperms remains to be completed. Here, Illumina sequencing of six transcriptomic libraries obtained from developing and abortive ovules at different stages during free nuclear mitosis of magagametophyte (FNMM) was used to acquire transcriptome data and gene expression profiles of Pinus tabulaeformis. Six cDNA libraries generated a total of 71.0 million high-quality clean reads that aligned with 63,449 unigenes and the comparison between developing and abortive ovules identified 7174 differentially expressed genes (DEGs). From the functional annotation results, DEGs involved in the cell cycle and phytohormone regulation were highlighted to reveal their biological importance in ovule development. Furthermore, validation of DEGs from the phytohormone signal transduction pathway was performed using quantitative real-time PCR analysis, revealing the dynamics of transcriptional networks and potential key components in the regulation of FG development in P. tabulaeformis were identified. These findings provide new insights into the regulatory mechanisms of ovule development in woody gymnosperms

Combined Transcriptome Analysis Reveals the Ovule Abortion Regulatory Mechanisms in the Female Sterile Line of Pinus tabuliformis Carr.

Ovule abortion is a common phenomenon in plants that has an impact on seed production. Previous studies of ovule and female gametophyte (FG) development have mainly focused on angiosperms, especially in Arabidopsis thaliana. However, because it is difficult to acquire information about ovule development in gymnosperms, this remains unclear. Here, we investigated the transcriptomic data of natural ovule abortion mutants (female sterile line, STE) and the wild type (female fertile line, FER) of Pinus tabuliformis Carr. to evaluate the mechanism of ovule abortion during the process of free nuclear mitosis (FNM). Using single-molecule real-time (SMRT) sequencing and next-generation sequencing (NGS), 18 cDNA libraries via Illumina and two normalized libraries via PacBio, with a total of almost 400,000 reads, were obtained. Our analysis showed that the numbers of isoforms and alternative splicing (AS) patterns were significantly variable between FER and STE. The functional annotation results demonstrate that genes involved in the auxin response, energy metabolism, signal transduction, cell division, and stress response were differentially expressed in different lines. In particular, AUX/IAA, ARF2, SUS, and CYCB had significantly lower expression in STE, showing that auxin might be insufficient in STE, thus hindering nuclear division and influencing metabolism. Apoptosis in STE might also have affected the expression levels of these genes. To confirm the transcriptomic analysis results, nine pairs were confirmed by quantitative real-time PCR. Taken together, these results provide new insights into ovule abortion in gymnosperms and further reveal the regulatory mechanisms of ovule development