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Numerous scientific satellites require micronewton thrusters for compensating environmental disturbances. The mass flow control proportional valve plays a crucial role in precisely regulating the thrust. To meet the high resolution and wide range requirements of the thrusters, this paper introduces a novel proportional valve with two sets of independently controllable piezoelectric stack. One set of the piezo-stack is used to compensate the stroke loss of the valve core, mainly caused by the deformation of the valve seat. The valve sealing mechanism is carefully analyzed to reduce the stroke loss. Another set of the stack works as the primary actuator, enabling the high mass flow control resolution. Two sets of independently controlled piezoelectric stacks not only expand the range and improve the range ratio but also provide redundancy and enhance reliability. This means that the actuator can still operate at lower ranges even if one piezo-stack is damaged. The piezo-actuators are assembled using U-shaped connectors, creating a compact and space-efficient overall design. Experimental tests have been conducted to verify the performance of the valve, which demonstrated a mass flow range of 0-675 µg/s with a resolution better than 0.1 µg/s and a flow noise below 0.1 µg/s/Hz1/2 at 0.1 mHz-1 Hz.
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BACKGROUND: Mediastinal emphysema is a condition in which air enters the mediastinum between the connective tissue spaces within the pleura for a variety of reasons. It can be spontaneous or secondary to chest trauma, esophageal perforation, medically induced factors, etc. Its common symptoms are chest pain, tightness in the chest, and respiratory distress. Most mediastinal emphysema patients have mild symptoms, but severe mediastinal emphysema can cause respiratory and circulatory failure, resulting in serious consequences. CASE SUMMARY: A 75-year-old man, living alone, presented with sudden onset of severe epigastric pain with chest tightness after drinking alcohol. Due to the remoteness of his residence and lack of neighbors, the patient was found by his nephew and brought to the hospital the next morning after the disease onset. Computed tomography (CT) showed free gas in the abdominal cavity, mediastinal emphysema, and subcutaneous pneumothorax. Upper gastrointestinal angiography showed that the esophageal mucosa was intact and the gastric antrum was perforated. Therefore, we chose to perform open gastric perforation repair on the patient under thoracic epidural anesthesia combined with intravenous anesthesia. An operative incision of the muscle layer of the patient's abdominal wall was made, and a large amount of subperitoneal gas was revealed. And a continued incision of the peritoneum revealed the presence of a perforation of approximately 0.5 cm in the gastric antrum, which we repaired after pathological examination. Postoperatively, the patient received high-flow oxygen and cough exercises. Chest CT was performed on the first and sixth postoperative days, and the mediastinal and subcutaneous gas was gradually reduced. CONCLUSION: After gastric perforation, a large amount of free gas in the abdominal cavity can reach the mediastinum through the loose connective tissue at the esophageal hiatus of the diaphragm, and upper gastrointestinal angiography can clarify the site of perforation. In patients with mediastinal emphysema, open surgery avoids the elevation of the diaphragm caused by pneumoperitoneum compared to laparoscopic surgery and avoids increasing the mediastinal pressure. In addition, thoracic epidural anesthesia combined with intravenous anesthesia also avoids pressure on the mediastinum from mechanical ventilation.
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The Boer goat is one of the top meat breeds in modern animal husbandry and has attracted widespread attention for its unique growth performance. However, the genetic basis of muscle development in the Boer goat remains obscure. In this study, we identified specific structural variants in the Boer goat based on genome-wide selection signals and analyzed the basis of the molecular heredity of related candidate genes in muscle development. A total of 9â¯959 autosomal copy number variations (CNVs) were identified through selection signal analysis in 127 goat genomes. Specifically, we confirmed that the highest signal CNV (HSV) was a chromosomal arrangement containing an approximately 1.11 Mb (CHIR17: 60062304-61171840 bp) duplicated fragment inserted in reverse orientation and a 5â¯362 bp deleted region (CHIR17:60145940-60151302 bp) with overlapping genes (e.g., ARHGAP10, NR3C2, EDNRA, PRMT9, and TMEM184C). The homozygous duplicated HSV genotype (+/+) was found in 96% of Boer goats but was not detected in Eurasian goats and was only detected in 4% of indigenous African goats. The expression network of three candidate genes ( ARHGAP10, NR3C2, and EDNRA) regulating dose transcription was constructed by RNA sequencing. Results indicated that these genes were involved in the proliferation and differentiation of skeletal muscle satellite cells (SMSCs) and their overexpression significantly increased the expression of SAA3. The HSV of the Boer goat contributed to superior skeletal muscle growth via the dose effects of overlapping genes.
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Cromossomos Humanos Par 17 , Cabras , Animais , Humanos , Cabras/genética , Variações do Número de Cópias de DNA , Genoma , Desenvolvimento MuscularRESUMO
This study aimed to explore the genetic basis of muscle development in goats. The transcriptome dataset for differentially expressed lncRNAs (DELs) and differentially expressed genes (DEGs) of goat muscle at different developmental stages were obtained using RNA-Seq. A total of 447,806,481 and 587,559,465 clean reads in the longissimus dorsi muscle of Dazu black goats between 75d embryonic stage and 1d after birth were generated through Illumina paired-end sequencing, and their mapping rates were 89.82 and 90.99%, respectively. Moreover, 4517 DEGs and 648 DELs were identified, and 4784 lncRNA-mRNA targeting relationships were predicted. Gene function annotation results showed that 4101 DEGs were significantly enriched to 1098 GO terms, and 2014 DEGs were significantly enriched to 40 KEGG pathways, including many GO terms and pathways related to muscle development, such as cell differentiation and Wnt signaling pathway. Then, 10 DELs and 20 DEGs were randomly selected for RT-qPCR verification, and the agreement rate between the verification and RNA-Seq results was 90%, indicating the high reliability of the RNA-Seq data analysis. In conclusion, this study obtained several mRNAs and lncRNAs related to the muscle development of Dazu black goats and identified several targeted regulatory pairs of lncRNA-mRNA. This study may serve as a reference to understand the genetic basis and molecular mechanism of muscle development in goats.
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RNA Longo não Codificante , Animais , RNA Longo não Codificante/genética , Perfilação da Expressão Gênica/veterinária , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento , Cabras/genética , RNA Mensageiro/genética , Reprodutibilidade dos Testes , Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Análise de Sequência de RNA/veterinária , Desenvolvimento Muscular/genéticaRESUMO
In the past decade, selenocyclization has been extensively exploited for the preparation of a wide range of selenylated heterocycles with versatile activities. Previously, selenium electrophile-based and FeCl3-promoted methods were employed for the synthesis of selenylated benzoxazines. However, these methods are limited by starting material availability and low atomic economy, respectively. Inspired by the recent catalytic selenocyclization approaches based on distinctive pathways, we rationally constructed an efficient and greener double-redox catalytic system for the access to diverse selenylated benzoxazines. The coupling of I2/I- and Fe3+/Fe2+ catalytic redox cycles enables aerial O2 to act as the driving force to promote the selenocyclization. Control and test redox experiments confirmed the roles of each component in the catalytic system, and a PhSeI-based pathway is proposed for the selenocyclization process.
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Oxigênio , Selênio , Oxigênio/metabolismo , Benzoxazinas , Oxirredução , CatáliseRESUMO
In domestic goats, wattles often appear in even numbers, mostly on the neck and a few under the ear. Goat wattle is composed of ectopic cartilage tissue covered by skin and was reported as a dominant inheritance. Thirty-eight goats from two Southwest Chinese breeds were studied to elucidate the genetic basis of wattle phenotype in goat. Their genomes were sequenced for wide-genome selective sweep analysis (WGSA) and a genome-wide association study (GWAS). The WGSA results revealed 500 candidate genes identified by fixation index and π ratio and 261 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched with 195 genes and 38 significantly enriched KEGG items. In particular, three chondrogenesis-related pathways (Wnt, Hippo and MAPK signaling pathways) were found. Among the 500 genes, 474 were enriched to 2855 Gene Ontology items, and four (BMP2, BMP4, RARA and MSX1) were annotated in the regulation and development of chondrogenesis. Four chondrogenesis-related genes (GREM1, NEDD4, ATG7 and ITGA1) were identified from 519 single-nucleotide polymorphisms (SNPs) with a GWAS above the threshold. Six and 11 SNPs on chromosome 10 are located on GREM1 and NEDD4 respectively, and the highest numbers of SNPs on chromosomes 20 and 22 are located on ITGA1 and ATG7 respectively. All of these genes are related to cartilage development. This study identified a series of genes related to chondroplasia by GWAS and WGSA and presented the possibility that wattle inheritance may be influenced by multiple genes. This work provides a new theoretical understanding of the hereditary basis of wattle phenotype.
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Estudo de Associação Genômica Ampla , Cabras , Animais , Crista e Barbelas , Genoma , Estudo de Associação Genômica Ampla/veterinária , Cabras/genética , Fenótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Saikosaponin A (SSA)-a natural compound extracted from Radix bupleuri-possesses antitumor properties in several types of carcinomas. However, the role of SSA on bladder cancer and the mechanisms remain unclear. In this study, we have described the effect of SSA on human bladder cancer cell lines T24 and 5637 in the context of the regulation of mitochondrial pathways of apoptosis. In vitro, the Cell Counting Kit-8 (CCK-8) assay and cell wound healing assays were used to determine the proliferative effect of SSA treatment. Flow cytometry and Western blotting were performed to evaluate the apoptosis and related mechanisms. To further confirm that apoptosis is mediated through Caspase activation, Hoechst 33258 fluorescence staining assay was done after cells were treated with SSA and caspase inhibitor-Z-VAD-FMK. In vivo, an orthotopic xenograft mice model was adopted to evaluate the effect of SSA. The tumors were analyzed by hematoxylin-eosin (H&E) staining, immunohistochemical analysis, and Western blotting. In vitro, the results with CCK-8 assay showed obvious SSA-induced suppression in cell growth in a dose- and time-dependent manner. Flow cytometry analysis, Hoechst 33258 fluorescence staining assay and the assessment of the changes in the B-cell lymphoma 2 (Bcl-2) family protein expression level revealed that SSA could significantly induce cell apoptosis, which was associated with apoptosis via the mitochondrial pathways. In vivo, the results revealed a reduction in cell proliferation. In conclusion, our data suggest that SSA inhibits the growth of bladder cancer cells by activating the mitochondrial apoptosis pathway and inducing cell apoptosis.
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Carcinoma , Neoplasias da Bexiga Urinária , Animais , Apoptose , Bisbenzimidazol/farmacologia , Caspases , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Camundongos , Ácido Oleanólico/análogos & derivados , Saponinas , Bexiga Urinária , Neoplasias da Bexiga Urinária/tratamento farmacológicoRESUMO
The phenotypic characteristics of existing domestic pigs (DPs) greatly differ from those of wild boar (WB) populations thousands of years ago. After thousands of years of human domestication, WB and DP have diverged greatly in terms of genetics. Theoretically, worldwide local pigs have independent contributions from their local WBs at the beginning of Sus scrofa domestication. The investigation of the vicissitude of the heredity material between domestic populations and their wild ancestors will help in further understanding the domestication history of domestic animals. In the present study, we performed a genome-wide association scan (GWSA) and phylogeny estimation with a total of 1098 public European Illumina 60K single nucleotide polymorphism data, which included 650 local DPs and 448 WBs. The results revealed that the phylogenetic relationship of WBs corresponds to their geographical distribution and carries large divergence with DPs, and all WB breeds (e.g., HRWB, SBWB, and TIWB) presents a closely linkage with the middle WB (e.g., HRWB, and PLWB). In addition, 64 selected candidate genes (e.g., IDH2, PIP5K1B, SMARCA2, KIF5C, and TJP2) were identified from GWSA. A total of 63 known multiple biological functional pathways were annotated by 22 genes, and ubiquinone and other terpenoid-quinone biosynthesis pathways that belong to the metabolism of cofactors and vitamins were significantly enriched (p < 0.05). The most frequent (28.57%) pathways were classified under metabolism. We confirmed that the middle European WB has made an important genetic contribution to the entire European WB populations. A series of selected genes discovered from this study provides the scientific community with a deeper understanding of the heredity performance of metabolism and emotion and the real purpose behind domestication.