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Heterostructure construction and heteroatom doping are powerful strategies for enhancing the electrolytic efficiency of electrocatalysts for overall water splitting. Herein, we present a P-doped MoS2/Ni3S2 electrocatalyst on nickel foam (NF) prepared using a one-step hydrothermal method. The optimized P[0.9mM]-MoS2/Ni3S2@NF exhibits a cluster nanoflower-like morphology, which promotes the synergistic electrocatalytic effect of the heterostructures with abundant active centers, resulting in high catalytic activity for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolyte. The electrode exhibits low overpotentials and Tafel slopes for the HER and OER. In addition, the catalyst electrode used in a two-electrode system for overall water splitting requires an ultralow voltage of 1.42 V at 10 mA·cm-2 and shows no obvious increase in current within 35 h, indicating excellent stability. Therefore, the combination of P doping and the heterostructure suggests a novel path to formulate high-performance electrocatalysts for overall water splitting.
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BACKGROUND: 20 million migrant workers in China lost their jobs during the economic crisis of 2008. Both urban migration and unemployment have long been documented to be associated with vulnerability to mental problems. This study aims to examine the mental health of unemployed migrant workers in Eastern China and its relation to duration of unemployment and coping strategy during the recent economic crisis. METHODS: The data were collected through interview-based survey with a sample of 210 unemployed migrant workers in Zhejiang Province of China from 2008 to 2009. Symptom Checklist-90-Revised, Coping Strategies Questionnaire, and seven short demographic questions were used. RESULTS: The majority of the unemployed migrant workers were found to be young male manufacturing industry workers with short-term unemployment and a relatively low education level. Nearly 50% of unemployed migrant workers were classified as mentally unhealthy and the most frequently reported symptom was depression. Compared with the adult norm of 1986, 2003, and 2007 in China, unemployed migrants had more mental problems. Long-term unemployed migrant workers had more psychiatric symptoms than the short-term unemployed workers and employed migrant workers. Unemployed migrant workers with immature coping strategies expressed significantly more psychiatric symptoms than those with mixed and mature coping strategies. Duration of unemployment and two coping strategies, problem-solving and self-blaming, predicted the mental problems of unemployed migrant workers. CONCLUSIONS: The results indicated that mental health status of unemployed migrant workers in Eastern China was poorer than the national adult norm. More psychiatric symptoms are evidenced among unemployed migrant workers who lost their jobs for a long term and who had immature coping strategies. These findings can be used for prevention and intervention of mental illness among unemployed migrant workers.
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Adaptación Psicológica , Recesión Económica , Salud Mental , Migrantes/psicología , Desempleo/psicología , Adolescente , Adulto , China , Estudios Transversales , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Análisis de Regresión , Migrantes/estadística & datos numéricos , Desempleo/estadística & datos numéricos , Adulto JovenRESUMEN
In order to improve the construction method of highway tunnel fault, improve the excavation level, improve the construction efficiency, reduce the project cost, and shorten the construction period, so as to find a specific road, this paper puts forward the research method of tunnel stability analysis and construction parameter optimization in the fault fracture zone. First, this paper analyzes the specific geographical and geological environment of the construction site. Second, this paper compares and analyzes the effects of the drilling and blasting method and full-face tunnel boring machine (TBM) in construction and further analyzes the surrounding rock deformation, over excavation, and under excavation, as well as the range of loose circles when the surrounding rock is stable. Then, this paper discusses the minimum smooth blasting parameters under these conditions. Finally, the actual blasting effect of tunnel construction is tested and the optimization algorithm model of tunnel fault drilling and blasting parameters is established. The results show that the proposed optimization model of drilling and blasting construction parameters for highway tunnel faults based on the Support Vector Regression (SVR) algorithm combined with a genetic algorithm (GA) has a short calculation time and high parameter optimization accuracy. It is very feasible to optimize the construction parameters of the fault drilling and blasting method, which can greatly improve the construction efficiency, carry out the detailed simulation, reduce the cost, and increase safety. In summary, it has a certain reference significance for the optimization of highway tunnel construction and future research by drilling and blasting method under complex geological conditions in my country.
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OBJECTIVE: This study was conducted to investigate the effect of long non-coding RNA (lncRNA) Gm37494 on osteoarthritis (OA) and its related molecular mechanism. METHODS: The cartilage tissues were obtained from OA patients, and an OA mouse model was induced by the destabilization of the medial meniscus, followed by measurement of Gm37494, microRNA (miR)-181a-5p, GABRA1 mRNA, and the encoded GABAARα1 protein expression. Thereafter, a cellular model was induced by interleukin-1ß (IL-1ß) treatment in chondrocytes, followed by ectopic and silencing experiments. Chondrocyte proliferation was detected by CCK-8 and EdU assays, chondrocyte apoptosis by flow cytometry and western blot, and the levels of inflammatory factors by ELISA. The binding of Gm37494 to miR-181a-5p was evaluated by dual-luciferase reporter gene and RIP assays, and that of GABRA1 to miR-181a-5p by dual-luciferase reporter gene and RNA pull-down assays. RESULTS: OA patients and mice had decreased GABRA1 mRNA and GABAARα1 protein levels and elevated miR-181a-5p expression in cartilage tissues. Additionally, Gm37494 was poorly expressed in OA mice. Mechanistically, Gm37494 directly bound to and inversely modulated miR-181a-5p that negatively targeted GABRA1. In IL-1ß-induced chondrocytes, Gm37494 overexpression enhanced cell proliferation and suppressed cell apoptosis and inflammation, whereas further miR-181a-5p up-regulation or GABRA1 silencing abolished these trends. CONCLUSIONS: Conclusively, Gm37494 elevated GABRA1 expression by binding to miR-181a-5p, thus ameliorating OA-induced chondrocyte damage.
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MicroARNs , Osteoartritis , ARN Largo no Codificante , Animales , Apoptosis/genética , Condrocitos/metabolismo , Regulación hacia Abajo , Humanos , Interleucina-1beta/metabolismo , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Osteoartritis/genética , Osteoartritis/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN Mensajero/metabolismo , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo , Ácido gamma-AminobutíricoRESUMEN
Osteoporosis is a systemic bone disease characterized by reduced bone mass and destruction of bone microarchitecture, leading to increased bone fragility and susceptibility to fracture. However, the pathogenesis and molecular mechanisms of this disease remain unclear. Extracellular vesicles, structures originating from the plasma membrane and ranging from 30 nm to 5 µm in diameter, play an important role in intercellular communication in the bone microenvironment. Exosomes are extracellular vesicles that deliver cargo molecules, including endogenous proteins, lipids and nucleic acids. These cargo molecules are encapsulated in a lipid bilayer and internalized by target cells through receptor-ligand interactions or lipid membrane fusion. With the advancement of exosome research, exosome therapy for osteoporosis is fast becoming a research hotspot for researchers. This review aims to discuss the role of exosomes in the pathogenesis of osteoporosis. In addition, emerging diagnostic and therapeutic properties of exosomes are described to highlight the potential role of exosomes in osteoporosis.
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Exosomas , Vesículas Extracelulares , Osteoporosis , Humanos , Exosomas/metabolismo , Huesos , Comunicación Celular , Osteoporosis/tratamiento farmacológico , Osteoporosis/metabolismoRESUMEN
In this study, the feasibility of fabricating protein-based bionanocomposite films (PBBFs) was analysed by applying capsicum leaf protein (CLP) and cellulose nanofiber (CNF) as raw materials. The effects of different amounts of CNF (solid content 2%) on physicochemical and material properties of PBBFs were investigated. The results showed nanoscale CNFs exhibited good interfacial compatibility with CLP. The hydroxyl groups on the CNF surface promoted the association of hydrogen bonds between CLP, glycerol and CNF, which improved the crystal structure and thermal stability of PBBFs. Concurrently, the mechanical properties and hydrophobicity of PBBFs are also enhanced. PBBFs with 60% CNF content have maximum flexibility and hydrophobicity. All PBBFs exhibited ultraviolet barrier performance, indicating that PBBFs had potential application prospects in the development of degradable food packaging materials. The results of the present study can provide a theoretical basis for the efficient utilisation of capsicum planting waste while improving the ecosystem.
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Capsicum , Nanofibras , Celulosa/química , Ecosistema , Estudios de Factibilidad , Nanofibras/química , Hojas de la PlantaRESUMEN
This research aims to develop a prognostic glioma marker based on m6A/m5C/m1A genes and investigate the potential role in the tumor immune microenvironment. Data for patients with glioma were downloaded from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA). The expression of genes related to m6A/m5C/m1A was compared for normal and glioma groups. Gene Ontology and Kyoto Encyclopedia of Genes and Gene enrichment analysis of differentially expressed genes were conducted. Consistent clustering analysis was performed to obtain glioma subtypes and complete the survival analysis and immune analysis. Based on TCGA, Lasso regression analysis was used to obtain a prognostic model, and the CGGA database was used to validate the model. The model-based risk scores and the hub genes with the immune microenvironment, clinical features, and antitumor drug susceptibility were investigated. The clinical glioma tissues were collected to verify the expression of hub genes via immunohistochemistry. Twenty genes were differentially expressed, Consensus cluster analysis identified two molecular clusters. Overall survival was significantly higher in cluster 2 than in cluster 1. Immunological analysis revealed statistically significant differences in 26 immune cells and 17 immune functions between the two clusters. Enrichment analysis detected multiple meaningful pathways. We constructed a prognostic model that consists of WTAP, TRMT6, DNMT1, and DNMT3B. The high-risk and low-risk groups affected the survival prognosis and immune infiltration, which were related to grade, gender, age, and survival status. The prognostic value of the model was validated using another independent cohort CGGA. Clinical correlation and immune analysis revealed that four hub genes were associated with tumor grade, immune cells, and antitumor drug sensitivity, and WTAP was significantly associated with microsatellite instability(MSI). Immunohistochemistry confirmed the high expression of WTAP, DNMT1, and DNMT3B in tumor tissue, but the low expression of TRMT6. This study established a strong prognostic marker based on m6A/m5C/m1A methylation regulators, which can accurately predict the prognosis of patients with gliomas. m6A/m5C/m1A modification mode plays an important role in the tumor microenvironment, can provide valuable information for anti-tumor immunotherapy, and have a profound impact on the clinical characteristics.
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Antineoplásicos , Neoplasias Encefálicas , Glioma , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Expresión Génica , Glioma/tratamiento farmacológico , Glioma/genética , Humanos , Microambiente Tumoral/genéticaRESUMEN
PURPOSE: Osteosarcoma (OS) universally exhibits heterogeneity and cisplatin (CDDP) resistance. Although the Wee1/CDC2 and nuclear factor кB (NF-κB) pathways were reported to show abnormal activation in some tumor cells with CDDP resistance, whether there is any concrete connection is currently unclear. We explored it in human OS cells. MATERIALS AND METHODS: Multiple OS cell lines were exposed to a Wee1 inhibitor (AZD1775) and CDDP to assess the half-maximal inhibitory concentration values. Western blot, coimmunoprecipitation, confocal immunofluorescence, cell cycle, and Cell Counting Kit-8assays were performed to explore the connection between the Wee1/CDC2 and NF-κB pathways and their subsequent physiological contribution to CDDP resistance. Finally, CDDP-resistant PDX-OS xenograft models were established to confirm that AZD1775 restores the antitumor effects of CDDP. RESULTS: A sensitivity hierarchy of OS cells to CDDP and AZD1775 exists. In the highly CDDP-tolerant cell lines, Wee1 and RelA were physically crosslinked, which resulted in increased abundance of phosphorylated CDC2 (Y15) and RelA (S536) and consequent modulation of cell cycle progression, survival, and proliferation. Wee1 inhibition restored the effects of CDDP on these processes in CDDP-resistant OS cells. In addition, animal experiments with CDDP-resistant PDX-OS cells showed that AZD1775 combined with CDDP not only restored CDDP efficacy but also amplified AZD1775 in inhibiting tumor growth and prolonged the median survival of the mice. CONCLUSION: Simultaneous enrichment of molecules in the Wee1/CDC2 and NF-κB pathways and their consequent coactivation is a new molecular mechanism of CDDP resistance in OS cells. OS with this molecular signature may respond well to Wee1 inhibition as an alternative treatment strategy.
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Resistencia a Antineoplásicos , Osteosarcoma/fisiopatología , Transducción de Señal , Animales , Proteína Quinasa CDC2/antagonistas & inhibidores , Ciclo Celular/efectos de los fármacos , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Osteosarcoma/genética , Proteínas Tirosina Quinasas/antagonistas & inhibidoresRESUMEN
Magnetic resonance diffusion-weighted imaging (DTI) provides a unique perspective on the pathophysiological and microstructural changes during spinal cord injury, with high spatial specificity; meanwhile, NM reflects the conduction and integrity of neuroelectrical signals in spinal cord fiber tracts, with time-specific and dynamic evaluation effects. The fractional anisotropy (FA) value, SEP amplitude, and neurological function score or improvement rate are correlated. The combination of DTI and NM can more reliably quantify the spinal cord function, evaluate the effectiveness of treatment, and determine the patient's prognosis, which can provide reference for clinical decision making and future research for SCI patients. That is, the lower the preoperative FA value and the lower the SEP amplitude, the worse the preoperative and postoperative neurological function, the lower the improvement rate, and the worse the prognosis of patients. Therefore, we believe that spinal cord function can be graded according to JOA scores to find the corresponding FA and SEP amplitude ranges and that, by measuring FA and SEP amplitude in the future, we can reverse the assessment of spinal cord function, expected postoperative improvement, and long-term prognosis. At the same time, FA values can also help determine the nature of the lesion to some extent.
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Imagen de Difusión Tensora , Hernia/etiología , Traumatismos de la Médula Espinal , Anisotropía , Humanos , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/diagnóstico por imagenRESUMEN
Glioblastoma (GBM) is a type of malignant tumor occurring in the brain that severely influences the life of affected individuals. GBM cells are highly infiltrative, which is one of the main obstacles in the treatment of the disease. Numerous microRNAs (miRNAs/miRs) are associated with the development of GBM. However, the effects of miR-15a-5p on GBM remain elusive. In the present study, reverse transcription-quantitative PCR and western blot analysis were applied for the detection of RNA and protein levels, respectively. Cell Counting Kit-8 and Transwell assays were performed to examine cell proliferation and invasion, respectively. TargetScan 7.1 and dual-luciferase reporter assay were utilized for the prediction and verification of the association between miRNAs and mRNAs. The present study revealed that miR-15a-5p expression was upregulated in the GBM T98G cell line. The results further demonstrated that, through the inhibition of cell adhesion molecule 1 expression and the promotion of Akt phosphorylation, miR-15a-5p was able to promote GBM cell proliferation and invasion. Overall, the present findings revealed a novel mechanism responsible for the development of GBM and provided an experimental basis for the diagnosis and treatment of GBM.
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Circular RNAs (circRNAs) are a type of non-coding RNAs generated from back splicing to enhance or inhibit the progression of multiple human cancers including osteosarcoma (OS). Although circ_0102049 has been found to be highly expressed in OS cell lines, the role and specific mechanism of circ_0102049 in OS remains unclear. Here, we found that silence of circ_0102049 could significantly exacerbate the tumorigenesis of OS in vivo through sponging microRNA-520g-3p. Polo-like kinase 2 (PLK2) was predicted to be a target of miR-520g-3p, and luciferase reporter assay revealed that overexpression of miR-520g-3p dramatically suppressed the expression of PLK2, whereas miR-520g-3p inhibitor promoted the PLK2 expression. Moreover, the silence of circ_0102049 could markedly promote the proliferation, invasion, migration and cell-cycle promotion while inhibiting the apoptosis of OS cell line MG63 cells in vitro through regulating miR-520g-3p/PLK2 axis. Taken together, the present study indicated that circ_0102049 suppressed the progression of osteosarcoma via modulating miR-520g-3p/PLK2/TAp73 axis, providing a potential therapeutic target for OS.
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Neoplasias Óseas/patología , MicroARNs/metabolismo , Osteosarcoma/patología , Proteínas Serina-Treonina Quinasas/metabolismo , ARN Circular/metabolismo , Animales , Neoplasias Óseas/genética , Neoplasias Óseas/metabolismo , Línea Celular Tumoral , Proliferación Celular , Progresión de la Enfermedad , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , MicroARNs/genética , Osteosarcoma/genética , Osteosarcoma/metabolismo , Proteínas Serina-Treonina Quinasas/genética , ARN Circular/genéticaRESUMEN
Insertion and Deletion (InDel) are common features in genomes and are associated with genetic variation. The whole-genome re-sequencing data from two parents (X1 and X2) of the elite cucumber (Cucumis sativus) hybrid variety Lvmei No.1 was used for genome-wide InDel polymorphisms analysis. Obtained sequence reads were mapped to the genome reference sequence of Chinese fresh market type inbred line '9930' and gaps conforming to InDel were pinpointed. Further, the level of cross-parents polymorphism among five pairs of cucumber breeding parents and their corresponding hybrid varieties were used for evaluating hybrid seeds purity test efficiency of InDel markers. A panel of 48 cucumber breeding lines was utilized for PCR amplification versatility and phylogenetic analysis of these markers. In total, 10,470 candidate InDel markers were identified for X1 and X2. Among these, 385 markers with more than 30 nucleotide difference were arbitrary chosen. These markers were selected for experimental resolvability through electrophoresis on an Agarose gel. Two hundred and eleven (211) accounting for 54.81% of markers could be validated as single and clear polymorphic pattern while 174 (45.19%) showed unclear or monomorphic genetic bands between X1 and X2. Cross-parents polymorphism evaluation recorded 68 (32.23%) of these markers, which were designated as cross-parents transferable (CPT) InDel markers. Interestingly, the marker InDel114 presented experimental transferability between cucumber and melon. A panel of 48 cucumber breeding lines including parents of Lvmei No. 1 subjected to PCR amplification versatility using CPT InDel markers successfully clustered them into fruit and common cucumber varieties based on phylogenetic analysis. It is worth noting that 16 of these markers were predominately associated to enzymatic activities in cucumber. These agarose-based InDel markers could constitute a valuable resource for hybrid seeds purity testing, germplasm classification and marker-assisted breeding in cucumber.
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Cromosomas de las Plantas , Cucumis sativus/genética , Marcadores Genéticos , Genoma de Planta , Mutación INDEL , Electroforesis en Gel de Agar , Filogenia , Especificidad de la Especie , Secuenciación Completa del GenomaRESUMEN
There are three subtypes of undifferentiated human conventional osteosarcoma (HCOS): osteoblastic osteosarcoma (OOS), chondroblastic osteosarcoma (COS), and fibroblastic osteosarcoma (FOS). HCOS also exhibits heterogeneous pathological maldifferentiation in individual patients. Currently, the mechanism regulating HCOS differentiation remains unclear, and therapies are ineffective. Osteopontin (OPN) and osteocalcin (OCN) are markers of osteoblast maturation, and their expression is inhibited in HCOS. A previous study found that PLK2 inhibited TAp73 phosphorylation and consequent anti-OS function of TAp73 in OS cells with enriched TAp73. TAp73 was also reported to regulate bone cell calcification. Here, OOS was found to have higher TAp73 levels and PLK2 expression than those in COS, which is correlated with HCOS maldifferentiation according to Spearman analysis and affects patient prognosis according to Kaplan-Meier survival analysis. In the conventional OS cell-line Saos2 and in patient-derived xenograft OS (PDX-OS) cells, increased PLK2 expression owing to abundant TAp73 levels affected OPN and OCN content as measured by RT-PCR and Western blotting, and alizarin red staining showed that PLK2 affected calcium deposition in OS cells. In addition, PLK2 inhibition in PDX-OS cells prohibited clone formation, as indicated by a clonogenic assay, and sensitized OS cells to cisplatin (CDDP) (which consequently limited proliferation), as shown by the CCK-8 assay. In an established PDX animal model with abundant TAp73 levels, PLK2 inhibition or CDDP treatment prevented tumor growth and prolonged median survival. The combined therapeutic effect of PLK2 inhibition with CDDP treatment was better than that of either monotherapy. These results indicate that increased PLK2 levels due to enriched TAp73 affect osteogenic differentiation and maturation and OS prognosis. In conclusion, PLK2 is a potential target for differentiation therapy of OS with enriched TAp73.
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Biomarcadores de Tumor/metabolismo , Diferenciación Celular , Regulación Neoplásica de la Expresión Génica , Osteogénesis , Osteosarcoma/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteína Tumoral p73/metabolismo , Animales , Antineoplásicos/farmacología , Apoptosis , Biomarcadores de Tumor/genética , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/genética , Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Proliferación Celular , Cisplatino/farmacología , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Osteosarcoma/tratamiento farmacológico , Osteosarcoma/genética , Osteosarcoma/metabolismo , Pronóstico , Proteínas Serina-Treonina Quinasas/genética , Células Tumorales Cultivadas , Proteína Tumoral p73/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
According to the stoichiometric ratios of Mo-10Si-7B, Mo-12Si-8.5B, Mo-14Si-9.8B, and Mo-25Si-8.5B, some new Mo-Si-B alloys doped with 0.3 wt % lanthanum (III) oxide (La2O3) were prepared via liquid-liquid (L-L) doping, mechanical alloying (MA), and hot-pressing (HP) sintering technology. The phase-composition and microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The worn surfaces of the plate specimens were studied by confocal laser scanning microscopy (CLSM). Then, the tribological properties of Mo-Si-B alloy doped with sliding plate specimens of 0.3 wt % La2O3 were investigated against the Si3N4 ball specimens. The friction coefficients of Mo-Si-B alloys decreased and the wear rates of the alloys increased with test load. The high-temperature friction and wear behavior of Mo-Si-B alloy are related to the surface-oxidation and contact-deformation of the alloy at a high temperature. The low friction coefficients and the reduced wear rates are thought to be due to the formation of low friction MoO3 films. MoO3 changed the contact state of the friction pairs and behaved as lubricating films.
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Genomic simple sequence repeat (SSR) markers were used to fingerprint and determine genetic similarity (GS) of the watermelon breeding lines, as well as the purity of their hybrid derivatives. Cluster analysis and Jaccard's distance coefficients using the unweighted pair group method with arithmetic mean (UPGMA) have classified these lines into three major groups. Notwithstanding,the genetic background of these lines is narrow as revealed by the restricted GS coefficients. Fifty-five sets of SSR markers were employed in this study. Fourteen of these markers were polymorphic between the breeding lines and were used for assessing hybrid purity. Cross-checking assay validated nine SSR markers as informative SSR markers for purity detection of these hybrids. To confirm the accuracy and efficiency of these markers, their derived PCR products were further sequenced, and ClSSR09643, ClSSR18153 and ClSSR01623 were selected as high-efficiency SSR markers. Interestingly, SSR markers ClSSR09643 and ClSSR18153 were broadly applied for purity detection of more than two different hybrids, while SSR marker ClSSR01623 behaved as a specific marker forpurity detection in this study. Genetic purity of six commercial watermelon hybrids was definitely evaluated using these SSR markers. Genetic purity of all tested hybrids exceeded 96% while the field purity was above 98%. Genetic purity test was an emergency for identifying off-types and selfed female in a lot of hybrid seeds. Here, we elucidated the potential of nine SSR markers including threewith higher breeding selection efficiency. We recommended them to seed company for purity improvement of watermelon commercial hybrid varieties.
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Citrullus/genética , ADN de Plantas/genética , Repeticiones de Microsatélite/genética , Polimorfismo Genético , Citrullus/clasificación , ADN de Plantas/química , Hibridación Genética , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Arbuscular mycorrhizal (AM) colonization of plant roots causes the down-regulation of expression of phosphate (Pi) or nitrogen (N) transporter genes involved in direct nutrient uptake pathways. The mechanism of this effect remains unknown. In the present study, we sought to determine whether the expression of Pi or N transporter genes in roots of winter wheat colonized by AM fungus responded to (1) Pi or N nutrient signals transferred from the AM extra-radical hyphae, or (2) carbon allocation changes in the AM association. A three-compartment culture system, comprising a root compartment (RC), a root and AM hyphae compartment (RHC), and an AM hyphae compartment (HC), was used to test whether the expression of Pi or N transporter genes responded to nutrients (Pi, NH4+ and NO3-) added only to the HC. Different AM inoculation density treatments (roots were inoculated with 0, 20, 50 and 200 g AM inoculum) and light regime treatments (6 hours light and 18 hours light) were established to test the effects of carbon allocation on the expression of Pi or N transporter genes in wheat roots. The expression of two Pi transporter genes (TaPT4 and TaPHT1.2), five nitrate transporter genes (TaNRT1.1, TaNRT1.2, TaNRT2.1, TaNRT2.2, and TaNRT2.3), and an ammonium transporter gene (TaAMT1.2) was quantified using real-time polymerase chain reaction. The expression of TaPT4, TaNRT2.2, and TaAMT1.2 was down-regulated by AM colonization only when roots of host plants received Pi or N nutrient signals. However, the expression of TaPHT1.2, TaNRT2.1, and TaNRT2.3 was down-regulated by AM colonization, regardless of whether there was nutrient transfer from AM hyphae. The expression of TaNRT1.2 was also down-regulated by AM colonization even when there was no nutrient transfer from AM hyphae. The present study showed that an increase in carbon consumption by the AM fungi did not necessarily result in greater down-regulation of expression of Pi or N transporter genes.
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Carbono/metabolismo , Micorrizas/fisiología , Nitrógeno/metabolismo , Proteínas de Transporte de Fosfato/genética , Fosfatos/metabolismo , Proteínas de Plantas/genética , Raíces de Plantas/microbiología , Triticum/microbiología , Alimentos , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Simbiosis , Triticum/genética , Triticum/crecimiento & desarrolloRESUMEN
TiC-Ti-Al mixed powders and TC4 titanium alloy foils were overlapped layer-by-layer in the graphite die. The TC4-based laminated composite sheets reinforced by Ti aluminide and carbide were successfully fabricated via spark plasma sintering (SPS) at 1100 °C with a well-bonded interface. The composite layers were mainly composed of TiAl, Ti3Al, Ti2AlC, and Ti3AlC2 phases. The carbides particles distributed in the matrix played an important role in the deflection of cracks and the passivation of microcracks. TC4 titanium alloy layers had an obvious effect on the stress distribution during the loading process, and provided an energy dissipation mechanism, which could improve the mechanical properties of the laminated composite sheets obviously. When the theoretical amount of Ti2AlC was 20 wt %, the flexural strength and fracture toughness of the laminated composite sheets reached the maximum value in the arrester direction, which were 1428.79 MPa and 64.08 MPa·m1/2, respectively.
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Research in mesenchymal stem cells (MSCs) is mainly focused on applications for treatments of brain and spinal cord injury as well as mechanisms underlying effects of MSCs. However, due to numerous limitations, there is little information on selection of appropriate sources of MSCs for transplantation in clinical applications. Therefore, in this study we compared various properties of human umbilical cord-derived MSCs (HUCMSCs) with human placenta-derived MSCs (HPDMSCs), including cell proliferation, apoptosis, cellular morphology, ultrastructure, and their ability to secrete various growth factors (i.e. vascular endothelial growth factor, insulin-like growth factors-1, and hepatocyte growth factor), which will allow us to select appropriate MSC sources for cellular therapy. Cell culture, flow cytometry, transmission electron microscope (TEM) and atomic force microscope (AFM) were used for assessment of HUCMSCs and HPDMSCs. Results showed that the two types of cells appeared slightly different when they were observed under AFM. HUCMSCs appeared more fibroblast-like, whereas HPDMSCs appeared as large flat cells. HUCMSCs had higher proliferative rate and lower rate of apoptosis than HPDMSCs (p<0.05). However, HPDMSCs secreted more of the three growth factors than HUCMSCs (p<0.05). Results of TEM revealed that the two types of MSCs underwent active metabolism and had low degree of differentiation, especially HUCMSCs. Results of AFM showed that HUCMSCs had stronger ability of mass transport and cell migration than HPDMSCs. However, HPDMSCs displayed stronger adhesive properties than HUCMSCs. Our findings indicate that different sources of MSCs have different properties, and that care should be taken when choosing the appropriate sources of MSCs for stem cell transplantation.
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Apoptosis , Proliferación Celular , Células Endoteliales de la Vena Umbilical Humana/citología , Células Madre Mesenquimatosas/citología , Placenta/citología , Adulto , Femenino , Células Endoteliales de la Vena Umbilical Humana/ultraestructura , Humanos , Células Madre Mesenquimatosas/ultraestructura , Embarazo , Cultivo Primario de CélulasRESUMEN
Mesenchymal stem cells (MSCs) have been isolated from a variety of human tissues (eg, bone marrow, peripheral blood, muscle, fat, umbilical blood, amniotic fluid, embryonic tissues, and placenta). Placenta-derived MSCs (PDMSCs) have received considerable interest because of their wide availability and absence of ethical concerns. The authors characterized the biological properties, ultrastructure, growth factor production, and osteoblastic differentiation of PDMSCs and investigated their potential as seed cells for bone tissue engineering.
Asunto(s)
Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/inmunología , Osteoblastos/citología , Osteoblastos/inmunología , Osteogénesis/inmunología , Ingeniería de Tejidos/métodos , Técnicas de Cultivo Celular por Lotes/métodos , Diferenciación Celular/inmunología , Proliferación Celular , Células Cultivadas , Estudios de Factibilidad , Femenino , Humanos , Proyectos Piloto , Placenta , EmbarazoRESUMEN
BACKGROUND: Published data indicate that thyroid stimulating hormone receptor (TSHR) activities are associated with osteoporosis in some patients. AIM: This study aimed to elucidate whether a given polymorphism of the TSHR gene is associated with osteoporosis. MATERIALS AND METHODS: One hundred and fifty subjects with osteoporosis were recruited in this study. The diagnosis of osteoporosis was performed with quantitative ultrasound system. The TSHR gene polymorphism was examined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The results showed a nucleotide substitution in the first position of codon 36 of the TSHR gene. The nucleotide substitution was from G to C, leading to a (36)D â (36)H change (D36H) in the predicted amino acid sequence of the receptor. The change did not show significance between healthy subjects and patients with osteoporosis (P > 0.05). On the other hand, we identified another single nucleotide polymorphism that is a C-to-G substitution at codon 727 (GAC to GAG); its frequency was significantly higher in patients with osteoporosis than that in healthy subjects. Using logistic regression analysis, significant correlation was revealed between the genotype D727E and the serum levels of TSH, or the quantitative ultrasound value of the calcaneal bone. CONCLUSIONS: The present study suggests that the genotype D727E of the TSHR, but not the genotype D36H, may be a genetic risk factor for osteoporosis.