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Targeted alpha therapy (TAT) is a kind of nuclear medicine treatment based on alpha-emitting radionuclides and tumor-selective carrier molecules for targeted cancer cells. Due to its strong toxicity to targeted cancer cells and relatively less toxic to normal tissues, TAT has been a promising tumor treatment method. Attributed to its suitable half-life (9.9 d), unique decay properties (decay produceing 4α+2β particles), and suitable coordination, 225Ac has become one of the best choice for α nuclides in TAT. Studies have shown that the targeted 225Ac-radiopharmaceuticals exhibit excellent effectiveness on cancer treatment, but the preparation of 225Ac is facing research difficulties. This article summarized the properties of 225Ac nuclide, the status of the preparation process and 225Ac-radiopharmaceuticals for TAT. And prospects were proposed for the production process of 225Ac and its medical application. It is expected that the large-scale production of medical 225Ac will be standardized, and 225Ac-radiopharmaceuticals will be approved for tumor treatment in the future.

In order to obtain the appropriate target backing material for 64Cu production which will meet radiolabeling requirements, and to reduce the content of stable copper impurity generated from copper target substrate in the final 64Cu product, tantalum is selected as the target backing material. By carrying out a series of experiments including thermal fluid solid coupling analysis, nickel plating experiment, dissolution experiment, irradiation experiment, falling test, thermal shock test on the tantalum target substrate, tantalum target substrate is finally utilized for 64Cu production. The results showed that tantalum target substrate could be applied to 64Cu production, which has simplified the whole production process of 64Cu, the yield can reach 38.1 GBq (EOB) or 190.5 MBq·μA-1·h-1 (EOB). The tests of ［64Cu］CuCl2 solution showed that the radionuclide purity was greater than 99.9%, radiochemical purity was greater than 95% and the metal impurity content was less than 1.5 μg·GBq-1. The research verifies that the tantalum target substrate can be used in 64Cu production, which avoids the process of electroplating gold and produces 64Cu more efficiently.

The spotted scat (Scatophagus argus) is an important ornamental species with sexually biased ornamental values that favor males. Therefore, it makes sense to breed mono-male fingerlings as ornamental fish. The spotted scat has an XX/XY sex determination system; therefore, the first step in producing genetically all-male offspring should be the induction of a fertile sex-reversed XY pseudo-female, which would then be mated with a normal XY male to produce a YY super-male. However, the XY pseudo-female produced by estradiol (E2) treatment failed due to ovarian malformations. Here, male to female sex reversal was induced in spotted scat through a combination of E2 and an androgen inhibitor (trilostane, TR). Spotted scat fingerlings of approximately 2.8–3.5 cm were fed a diet containing both E2 (300 µg/g) and TR (300 µg/g). The fish were treated for 90 days and then fed a normal diet until they reached one year of age, when they were sampled. Twenty-eight treated XY individuals were identified using sex-linked markers. According to their gonadal histological characteristics, these treated XY fish could be divided into three groups: males with testes (n = 21), intersex individuals with ovaries–testes (n = 3), and fully sex-reversed individuals with ovaries (n = 4). All treated XX fish (n = 8) developed into normal females. There were no obvious abnormalities in the ovaries of the XY sex-reversed fish compared to the treated XX fish. Serum 11-ketotestosterone (11-KT) levels were significantly lower in XY-reversed females and treated XX females than in XY males. Compared with XY male fish, the expression of female (42sp50, foxl2, figla, zar1, and zp2) and male (dmrt1, gsdf, amh and cyp11b2) biased genes was up- and down-regulated, respectively, in the gonads of XY-completely sex-reversed fish. Immunohistochemical results indicate that 42Sp50 was expressed in oocytes of XY-partially and completely sex-reversed fish, while strong Gsdf signals were mainly detectable in testicular somatic cells of XY-partially sex-reversed fish and XY male fish. XY females were successfully produced by the combined treatment of E2 and TR in the spotted scat. Their fertility will be tested in the future. [ABSTRACT FROM AUTHOR]

Hypothalamus are the important endocrine organs, which play key roles in regulating body growth, reproduction and hormone activity in other endocrine glands and organs. Estrogen, an important sex steroid hormone, is mainly synthesized and secreted in the gonads. It could regulate the reproduction and growth related genes expression in hypothalamus through feedback, and then participate in the regulation of corresponding physiological activities. Spotted scat (Scatophagus argus) is a good model to investigate the sexual growth dimorphism with a faster growth in females than males. The effect of 17β-estradiol (E2) injection in vivo on genes expression in hypothalamus of XY male spotted scat and the differences in genes expression between XY males and XX females remain unclear. In order to explore gene expression difference between XY male and XX female spotted scat hypothalamus and effect of in vivo injection in XY males, transcriptome analysis of hypothalamus were carried out, including sequencing data quality control, gene function annotation, differentially expressed gene (DEGs) screening and identification and pathway enrichment analysis, then real-time quantitative PCR (qPCR) was performed to detect genes expression. A total of 275833710 Clean reads were sequenced in this study, and the Q30 and GC value were more than 95% and 48%, respectively. In Ctrl-XX-H vs. Ctrl-XY-H group, 91 DEGs were screened and identified successfully, including 36 up-regulated and 55 down-regulated genes. In Ctrl-XX-H vs. E2-XY-H group, 28 DEGs were screened and identified, including 11 up-regulated and 17 down-regulated genes. GO and KEGG pathway analysis showed that DEGs was significantly enriched in biological processes such as cells, single cell, membrane, membrane components, and signal pathways such as ubiquinone and other terpene quinone biosynthesis, steroid hormone biosynthesis. By transcriptome and qPCR analyses, the expression of nrip1b, prl, hspa8b, snx21, cep63, ccna1, hsp90aa1.1, slc1a5, zar1, slc25a1b and loc124068175, were significantly different between XX and XY spotted scat, while the reproductive axis genes (sbGnRH, sGnRH and cGnRH) and growth axis genes (ghrh, sst1, sst3, sst5 and sst6) expression showed no significant differences. In XY male fish, six hours after E2 injection, the expression of cdc42ep1a, cyp19a1b, greb1, kank1a, snx21, and tmem30c in hypothalamus were significantly up-regulated, while prl expression was significantly down-regulated. Above results suggest that E2 might regulate some reproduction related genes expression in hypothalamus through feedback effects, which plays the critical roles in gametogenesis and reproduction regulation. [ABSTRACT FROM AUTHOR]

The multiple injection strategies have been widely employed in many new diesel applications, such as HCCI (Homogeneous Charge Compression Ignition) and LTC (Low Temperature Combustion), which are very effective in improving fuel-air mixture and entrainment. In this paper, using high injection pressure of common rail and high-speed camera system, the experimental studies on the spray characteristics of the single, double and triple injections are conducted. The spray average fuel/air equivalence ratio is employed to evaluate the overall effects of the fuel-air mixture, which is the ratio of the fuel/air mass ratio in the spray and the fuel/air stoichiometric mass ratio. It is shown that the spray average fuel/air equivalence ratio decreased with the increased injection pressure, indicating that increasing injection pressure could intensify fuel-air mixture. For double injections, spray tip penetrations and volumes increase with the increased injected volume percentage. It is also found that spray development rate of the second injection is higher than the first injection. Double injections lead to lower spray average fuel/air equivalence ratios than the single injections. For triple injections, the spray average fuel/air equivalence ratios are almost lower than stoichiometry. The triple injection of which the volume distribution of every injection time is evenly has the lowest spray average fuel/air equivalence ratio, and has the best effect of fuel-air mixture.

Background: Hong Kong catfish (Clarias fuscus) is an ecologically and economically important species that is widely distributed in freshwater regions of southern China. Hong Kong catfish has significant sexual growth dimorphism. The genome assembly of the Hong Kong catfish would facilitate study of the sex determination and evolution mechanism of the species. Results: The first high-quality chromosome-level genome of the Hong Kong catfish was constructed. The total genome was 933.4 Mb, with 416 contigs and a contig N50 length of 8.52 Mb. Using high-throughput chromosome conformation capture (Hi-C) data, the genome assembly was divided into 28 chromosomes with a scaffold N50 length of 36.68 Mb. A total of 23,345 protein-coding genes were predicted in the genome, and 94.28% of the genes were functionally annotated in public databases. Phylogenetic analysis indicated that C. fuscus and Clarias magur diverged approximately 63.7 million years ago. The comparative genome results showed that a total of 60 unique, 353 expanded and 851 contracted gene families were identified in Hong Kong catfish. A sex-linked quantitative trait locus identified in a previous study was located in a sex-determining region of 30.26 Mb (0.02 to 30.28 Mb) on chromosome 13 (Chr13), the predicted Y chromosome. This QTL region contained 785 genes, of which 18 were identified as sex-related genes. Conclusions: This study is the first to report the chromosome-level genome assembly of Hong Kong catfish. The study provides an excellent genetic resource that will facilitate future studies of sex determination mechanisms and evolution in fish. [ABSTRACT FROM AUTHOR]