The androgenic gland(AG) is an important endocrine gland for male reproductive function in crustaceans. In the present study, we investigated the histological characteristics of the androgenic gland of peppermint shri...The androgenic gland(AG) is an important endocrine gland for male reproductive function in crustaceans. In the present study, we investigated the histological characteristics of the androgenic gland of peppermint shrimp, Lysmata wurdemanni. The peppermint shrimp matures as male first, then some individuals may become euhermaphrodite after several moltings(transitional phase). Euhermaphrodite-phase shrimp acts as male at intermolts. However, it can be fertilized as a female immediately after molting. Considering the male reproductive function acts in its lifespan except for at larval stages, and female reproductive system starts to develop at transitional phase, we hypothesized that AG activity might be reduced to allow and promote vitellogenesis onset in early transitional phase and the following euhermaphrodite phase. So AG cell structure might be different in three phases in L. wurdemanni. The results showed that AG exists in the male in transitional and euhermaphrodite phases. The gland cell clusters surrounding the ejaculatory ducts locate at the roots of the fifth pereopods. The nucleus diameters are similar in the three phases while the nucleus-to-cell ratio is the lowest in euhermaphrodite phase. Our results indicated that for the individuals that will become euhermaphrodite, the cellular structure of AG changes since transitional phase. Male reproductive function which is still available in euhermaphrodite-phase shrimp should be due to the existence of the gland.展开更多
Oral candidiasis causes pain in oral cavity or tongue. Antifungal drugs are commonly used for the treatment of candidiasis, however, there could be several problems such as side effects, drug resistance, or contraindi...Oral candidiasis causes pain in oral cavity or tongue. Antifungal drugs are commonly used for the treatment of candidiasis, however, there could be several problems such as side effects, drug resistance, or contraindication to concomitant use with drugs already taken. The development of substituting antimicrobial agents, which could be used internally or as gargling agents, is expected. Some essential oils have been known for the activities against microbes. We focused on the three chemotype essential oils from rosemary and five essential oils from Lamiaceae plants including rosemary, and examined their antifungal activity against Candida albicans by broth microdilution method. The activity with or without addition of Tween 80 or Tween 20 was statistically analyzed. Minimal inhibitory concentration (MIC) values of the essential oils were significantly decreased when either of the two surfactants was added. Among the tested oils, only CAMPHOR, a rosemary chemotype, showed a significantly lower MIC with addition of Tween 20 than Tween 80. It is inferred that the antifungal activity of essential oils is influenced by the type of surfactants. Some of the essential oils showed the same values of MIC and the minimal fungicidal concentration (MFC) when surfactant was added. Peppermint showed the same MICs and MFCs in most cases, and its low MFC indicated potent fungicidal activity against C. albicans, as observed in CINEOL. We will discuss peppermint oil as one of the potential candidates for antifungal agents against C. albicans.展开更多
Virtual screening is a computational technique widely used for identifying small molecules which are most likely to bind to a protein target. In the present work, a molecular docking study is carried out to propose po...Virtual screening is a computational technique widely used for identifying small molecules which are most likely to bind to a protein target. In the present work, a molecular docking study is carried out to propose potential candidates for preventing the RBD/ACE2 attachment. These candidates are sixteen different flavonoids present in the peppermint leaf. Results showed that Luteolin 7-O-neohesperidoside is the peppermint flavonoid with a higher binding affinity regarding the RBD/ACE2 complex (about -9.18 Kcal/mol). On the other hand, Sakuranetin presented the lowest affinity (about -6.38 Kcal/mol). Binding affinities of the other peppermint flavonoids ranged from -6.44 Kcal/mol up to -9.05 Kcal/mol. The binding site surface analysis showed pocket-like regions on the RBD/ACE2 complex that yield several interactions (mostly hydrogen bonds) between the flavonoid and the amino acid residues of the proteins. This study can open channels for the understanding of the roles of flavonoids against COVID-19 infection.展开更多
Drying crack is a common phenomenon occurring during moisture discharge from wood,reducing efficient wood utilization.Drying crack is primarily caused by drying stress,and the reasonable methods for determining drying...Drying crack is a common phenomenon occurring during moisture discharge from wood,reducing efficient wood utilization.Drying crack is primarily caused by drying stress,and the reasonable methods for determining drying stress are sparse.In this study,the initiation and propagation of cracks during wood discs drying were simulated using the extended finite element method(XFEM).The distribution of drying stress and displacement was analyzed at different crack conditions based on the simulation results.This study aimed to solve the problem of the limitation of drying stress testing methods and provide a new idea for the study of wood drying stress.The numerical simulation results are found in good agreement with the experimental results,thus corroborating the feasibility of XFEM in modeling drying crack of wood discs.The stress concentration was observed at the crack tip region,while a minor stress was presented in the region of crack passing through,indicating that the crack formation process was also a process of releasing drying stress.Further,more energy was required to form double cracks in comparison with the single crack mode.展开更多
基金supported by the Fundamental Research Fund of the East China Sea Fisheries Research Institute (No.2012M08)National Science Foundation of China (No.41276142)
文摘The androgenic gland(AG) is an important endocrine gland for male reproductive function in crustaceans. In the present study, we investigated the histological characteristics of the androgenic gland of peppermint shrimp, Lysmata wurdemanni. The peppermint shrimp matures as male first, then some individuals may become euhermaphrodite after several moltings(transitional phase). Euhermaphrodite-phase shrimp acts as male at intermolts. However, it can be fertilized as a female immediately after molting. Considering the male reproductive function acts in its lifespan except for at larval stages, and female reproductive system starts to develop at transitional phase, we hypothesized that AG activity might be reduced to allow and promote vitellogenesis onset in early transitional phase and the following euhermaphrodite phase. So AG cell structure might be different in three phases in L. wurdemanni. The results showed that AG exists in the male in transitional and euhermaphrodite phases. The gland cell clusters surrounding the ejaculatory ducts locate at the roots of the fifth pereopods. The nucleus diameters are similar in the three phases while the nucleus-to-cell ratio is the lowest in euhermaphrodite phase. Our results indicated that for the individuals that will become euhermaphrodite, the cellular structure of AG changes since transitional phase. Male reproductive function which is still available in euhermaphrodite-phase shrimp should be due to the existence of the gland.
文摘Oral candidiasis causes pain in oral cavity or tongue. Antifungal drugs are commonly used for the treatment of candidiasis, however, there could be several problems such as side effects, drug resistance, or contraindication to concomitant use with drugs already taken. The development of substituting antimicrobial agents, which could be used internally or as gargling agents, is expected. Some essential oils have been known for the activities against microbes. We focused on the three chemotype essential oils from rosemary and five essential oils from Lamiaceae plants including rosemary, and examined their antifungal activity against Candida albicans by broth microdilution method. The activity with or without addition of Tween 80 or Tween 20 was statistically analyzed. Minimal inhibitory concentration (MIC) values of the essential oils were significantly decreased when either of the two surfactants was added. Among the tested oils, only CAMPHOR, a rosemary chemotype, showed a significantly lower MIC with addition of Tween 20 than Tween 80. It is inferred that the antifungal activity of essential oils is influenced by the type of surfactants. Some of the essential oils showed the same values of MIC and the minimal fungicidal concentration (MFC) when surfactant was added. Peppermint showed the same MICs and MFCs in most cases, and its low MFC indicated potent fungicidal activity against C. albicans, as observed in CINEOL. We will discuss peppermint oil as one of the potential candidates for antifungal agents against C. albicans.
文摘Virtual screening is a computational technique widely used for identifying small molecules which are most likely to bind to a protein target. In the present work, a molecular docking study is carried out to propose potential candidates for preventing the RBD/ACE2 attachment. These candidates are sixteen different flavonoids present in the peppermint leaf. Results showed that Luteolin 7-O-neohesperidoside is the peppermint flavonoid with a higher binding affinity regarding the RBD/ACE2 complex (about -9.18 Kcal/mol). On the other hand, Sakuranetin presented the lowest affinity (about -6.38 Kcal/mol). Binding affinities of the other peppermint flavonoids ranged from -6.44 Kcal/mol up to -9.05 Kcal/mol. The binding site surface analysis showed pocket-like regions on the RBD/ACE2 complex that yield several interactions (mostly hydrogen bonds) between the flavonoid and the amino acid residues of the proteins. This study can open channels for the understanding of the roles of flavonoids against COVID-19 infection.
基金financed by a Grant-in-Aid for Scientific Research from the Youth Program of National Natural Science Foundation of China(No.31800478)the National Natural Science Foundation of China(Grant Nos.31870535,32122058)。
文摘Drying crack is a common phenomenon occurring during moisture discharge from wood,reducing efficient wood utilization.Drying crack is primarily caused by drying stress,and the reasonable methods for determining drying stress are sparse.In this study,the initiation and propagation of cracks during wood discs drying were simulated using the extended finite element method(XFEM).The distribution of drying stress and displacement was analyzed at different crack conditions based on the simulation results.This study aimed to solve the problem of the limitation of drying stress testing methods and provide a new idea for the study of wood drying stress.The numerical simulation results are found in good agreement with the experimental results,thus corroborating the feasibility of XFEM in modeling drying crack of wood discs.The stress concentration was observed at the crack tip region,while a minor stress was presented in the region of crack passing through,indicating that the crack formation process was also a process of releasing drying stress.Further,more energy was required to form double cracks in comparison with the single crack mode.
