RESUMO
Aluminum hydroxide is an effective defluoridation adsorbent; however, the poor defluoridation performance limits its wide application. In this work, amorphous and crystalline AlOOH adsorbents are synthesized through hydrolysis of Al salts, and their defluoridation performances are evaluated in terms of adsorption capacity and rate, sensitivity to pH value, and water quality after defluoridation. The defluoridation performance of AlOOH is closely related to the hydrolysis pH value, but hardly to the type of Al salts. The adsorbent can remove >95% fluoride in the first 2 min and reach adsorption equilibrium within 2 h, and the maximum defluoridation capacity is 41.9 mg/g. Furthermore, the adsorbent exhibits an excellent defluoridation efficiency at a wide pH range of 4.5-10.5. After fluoride removal, the adsorbents prepared at pH values of 6 and 7 exhibit low residual Al concentration. The Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results confirm that the fluoride removal mechanism is the ligand exchange between fluoride and hydroxyl groups. The excellent defluoridation capacity and low residual Al demonstrate that AlOOH is a potential adsorbent for fluoride separation from water.
RESUMO
With rapid spread of the urbanization, many environmental factors, such as climate, soil pH and nutrients have been changed. However, the plant pollination affected by urbanization was seldom conducted. Here, we studied the flower visitation rates, seed production, pollen limitation and flower morphological characters of Gentiana dahurica at 3 populations along an urban-peri-urban gradient around Xi'ning over 4 consecutive years, aiming to test the effects of urbanization on plant pollination service. Our results showed that the pollinator visit frequencies, interannual stability of pollinator assemblages and visit frequencies declined with the intensification of urbanization. As urbanization intensified, plant borne more flowers and the flower morphological sizes became "longer" (the length of flowers, filaments and styles were increased, but the width of flowers kept stable at the 3 populations); the flower duration, especially the female phase duration prolonged. The seed-set ratio of G. dahurica in natural condition decreased and more severe pollen limitation occurred in more urbanized populations. Also, an interannual variation of seed-set ratio and index of pollen limitation (IPL), which related with the variation of pollinator visit frequencies, were found in this study. These results suggest that the pollination service can be threatened by urbanization over a long-time interval for G. dahurica. This finding highlights the importance of pollinator affections acting on plant pollination system. Additionally, as pollinator assemblages and visit frequencies interannually changed, a long-time scale observation is needed to understand the plant-pollinator relationships.
Assuntos
Gentiana/crescimento & desenvolvimento , Polinização , Reprodução , Urbanização , Exposição Ambiental , Flores/anatomia & histologia , Flores/crescimento & desenvolvimento , Gentiana/anatomia & histologia , Sementes/anatomia & histologia , Sementes/crescimento & desenvolvimentoRESUMO
Reproductive isolation, the key process to prevent interspecific hybridization and keep the completeness and independence of species, is crucial to the formation and maintenance of biodiversity. The forming steps, methods and intensities of reproductive isolation between different species are not completely the same. Literatures on reproductive isolation between species provide valuable evidence for speciation and its maintenance. Flowering phenology, flowering-visiting insects, and pollen-stigma compatibility were observed for Ligularia virgaurea and L. sagitta, two species of weeds sympatrically distributed in eastern Qinghai-Tibet Plateau. The characteristics of reproductive isolation mechanism of both species and its role in reproductive isolation were also studied. The results showed that the flowering period of L. virgaurea was 20 d earlier than that of L. sagitta. Although the full-blooming period separated, there was a roughly 10 d overlap between the two species. Meanwhile, the pollens and stigmas of the two species were both viability in the overlapped 10 d. L. virgaurea and L. sagitta shared the same types of pollinating insects, which was a generalized pollination type. Besides, the flower-visiting behavior towards the two species from the pollinators was similar, along with the interleaved access between the two species. There was no complete time isolation and no complete pollinator isolation between the two species, but the stigma had poor compatibility towards heterogenic pollen. The germination of pollen on stigma and growth of the pollen tube was hampered. Furthermore, the rejection of pollen-stigma was likely to be an important prezygotic reproductive isolation between L. virgaurea and L. sagitta, thus avoiding the natural hybridization and maintaining the diversity and genetic stability of the two species.
Assuntos
Asteraceae/fisiologia , Isolamento Reprodutivo , Simpatria , Animais , China , Flores , Polinização , TibetRESUMO
OBJECTIVE: To investigate clinical effects of calcaneal fracture with closed reduction and minimally invasive plate fixation assisted with bidirectional distractor distraction. METHODS: From September 2015 to October 2016, 11 male patients(13 feet) with calcaneal fractures treated with bidirectional distractor distraction assisted with minimally invasive plate fixation were retrospectively studied. They were aged from 24 to 57 years old with an average of 36.4 years old;8 feet were type IIand 5 feet were type III according to Sanders classification. Postoperative incision, fracture healing, Böhler angle, Gissane angle were observed and Maryland scoring system was used to evaluate clinical effects. RESULTS: All fractures healed well without incision inflammation and incision disunion. All patients were followed up from 12 to 15 months with an average of 13.5 months. Böhler angle were improved from (9.6±7.3)° before operation to (20.2±4.6) ° at 1 year after operation, and had statistical meaning; Gissane angle increased from (92.7 ±8.5)° before operation to (121.7 ±7.6) ° at 1 year after operation. Maryland score at 1 year after operation was 88.79±8.25, and 11 feet got excellent results and 2 feet moderate. CONCLUSIONS: Bidirectional distractor distraction assisted with minimally invasive plate fixation could effectively fix calcaneal fractures, reduce postoperative complications, and get satisfied results of postoperative images and functional recovery. It is one of effective methods for treating Sanders II and III calcaneal fractures.
Assuntos
Calcâneo , Fraturas Ósseas , Adulto , Placas Ósseas , Fixação Interna de Fraturas , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
Over-expression of the bromodomain and extraterminal (BET) family protein BRD4 is associated with hepatocellular carcinoma (HCC) progression. In the present study, we indentified a novel putative anti-BRD4 microRNA: microRNA-608 ("miR-608"). In HepG2 cells and primary human HCC cells, over-expression of miR-608, using a lentiviral construct, induced BRD4 downregulation and proliferation inhibition. Conversely, transfection of the miR-608 inhibitor increased BRD4 expression to promote HepG2 cell proliferation. Our results suggest that BRD4 is the primary target gene of miR-608 in HepG2 cells. shRNA-mediated knockdown or CRSIPR/Cas9-mediated knockout of BRD4 mimicked and overtook miR-608's actions in HepG2 cells. Furthermore, introduction of a 3'-untranslated region (3'-UTR) mutant BRD4 (UTR-A1718G) blocked miR-608-induced c-Myc downregulation and proliferation inhibition in HepG2 cells. In vivo, HepG2 xenograft tumor growth was significantly inhibited after expressing miR-608 or BRD4 CRSIPR/Cas9-KO construct. Importantly, BRD4 mRNA was upregulated in human HCC tissues, which was correlated with downregulation of miR-608. Together, we conclude that miR-608 inhibits HCC cell proliferation possibly via targeting BET family protein BRD4.
Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Animais , Sequência de Bases , Proteínas de Ciclo Celular , Proliferação de Células/genética , Regulação para Baixo/genética , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Camundongos SCID , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: To study the medicinal plant resources and their diversity in Kangle County, Gansu Province, and to provide scientific basis on utilization and protection of the medicinal plant resources of the county. METHODS: By field survey, sample collection, taxonomic identification and data verification methods. RESULTS: There were 258 species, 65 families in existing medicinal plants, of which 43 species, 39 genera and 24 families were national protection medicinal plants. Dominant families were mainly Asteraceae and Rosaceae. In this area,the plants used whole herbs and roots ( or rhizomes) as medicinal materials represented 40.31% and 25.19% respectively, and antipyretic and rheumatism medicine accounted for 28.68% and 12.79% respectively. 12 medicinal plants were cultivated and the cultivated area was 3,000 hectares. CONCLUSION: However, the reserves of most medicinal plants are less enough and the resources are diminishing increasingly in recent years. So we should accelerate the research progress as well as developing and utilizing rationally on the premise of protection.