The authors have studied the motion mechanism of the magnetic fluid in a reciprocating seal gap,on the basis of which the authors obtain an anti pressure formula of the reciprocating shaft magnetic fluid seal from gen...The authors have studied the motion mechanism of the magnetic fluid in a reciprocating seal gap,on the basis of which the authors obtain an anti pressure formula of the reciprocating shaft magnetic fluid seal from general Navier Stokes equation.In order to verify the correctness of the anti pressure formula,the authors have calculated the magnetic field distribution of seal structure and have gotten the maximum still anti pressure.Finally,the authors have verified the influence of speed and stroke on the seal anti pressure.展开更多
With the emergence of the new digital platforms, a diversified number of approaches and providers cannot damage too much a rather crowded info sphere. What may come as a general challenge is the "performance" amateu...With the emergence of the new digital platforms, a diversified number of approaches and providers cannot damage too much a rather crowded info sphere. What may come as a general challenge is the "performance" amateurs who have the devices, the will but not the skills to become reliable communicators. Good training and an expanded concern for the accuracy of messages should distinguish between fact and fiction, and between information and opinion. The smart phone, the iPod, the lap top, or the tablet has expanded the means of communication. They have also diversified the types of messages circulated. The traditional main stream media outlets are facing a mounting competition from the social networks populated with the folk journalists, albeit, and non-professionals. Basic training of all those willing to come into the communication ring and regulations may concern not only the professionals but also the amateurs, and it may be ways to get over what seems to be a deadlock.展开更多
An important part of human communication--verbal abuse--shows signs of specifically national features. So far the Russian language of law is sadly lacking a few terms necessary in legal procedures concerning cases of ...An important part of human communication--verbal abuse--shows signs of specifically national features. So far the Russian language of law is sadly lacking a few terms necessary in legal procedures concerning cases of human rights violation. The "Westernization" of Russian collectivist mentality makes the solution of the problem still more urgent.展开更多
The suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muf...The suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muffler affects the operation of the compressor owing to gas pressure drop, which causes volumetric and energetic efficiency loss due to the gas specific volume augmentation. Therefore, there is a compromise between sound attenuation and pressure drop increase, which has to be taken into account by compressor designers. In this work, it presents a numerical solution to the flow through a suction muffler in order to analyze the pressure field and point out the main contributions to the overall pressure drop of the flow. A commercial CFD (computational fluid dynamics) code was used to perform the numerical simulations and the results were validated by using experimental data. After analyzing the pressure field, the geometry of the muffler was modified intending to decrease the flow pressure drop. The geometric modification produced a 28% reduction on the overall pressure drop, without influencing the sound attenuation.展开更多
α-secretase and β-secretase are known to compete for amyloid precursor protein (APP) processing and thus play a vital role in Alzheimer's disease pathogenesis. A disintegrin and metaUoproteinase 10 (ADAM10) and...α-secretase and β-secretase are known to compete for amyloid precursor protein (APP) processing and thus play a vital role in Alzheimer's disease pathogenesis. A disintegrin and metaUoproteinase 10 (ADAM10) and β-site APP cleaving enzyme 1 (BACE1) mediate the major activities of α-secretase and β-secretase in brain and share various common substrates. However, whether they function separately or together is poorly understood. Here, we show that ADAM10 and BACE1 co-localize in the neurites of mouse primary neurons. Co-immunoprecipitation and fluorescence resonance energy transfer analysis revealed that ADAM10 and BACE1 interact with each other under both endogenous and exogenous conditions. In addition, we found that ADAMIO enhances the proteolysis of neural cell adhesion molecule close homolog of L1 (CHL1) by BACE1. Further studies found that ADAM10-BACE1 interaction interfering peptide LT52 attenuates the regulation of ADAM10 on BACEl-mediated cleavage of CHL1. Our data indicate that ADAM10-BACE1 interaction regulates the proteolysis of some specific substrates and may play a potential role in brain function.展开更多
The pollen receptor kinases (PRK) are critical regulators of pollen tube growth. The Arabidopsis genome encodes eight PRK genes, of which six are highly expressed in pollen tubes. The potential functions of AtPRK1 thr...The pollen receptor kinases (PRK) are critical regulators of pollen tube growth. The Arabidopsis genome encodes eight PRK genes, of which six are highly expressed in pollen tubes. The potential functions of AtPRK1 through AtPRK5, but not of AtPRK6,in pollen growth were analyzed in tobacco. Herein, AtPRK6 was cloned, and its function was identified. AtPRK6 was expressed specifically in pollen tubes. A yeast two-hybrid screen of AtPRK6 against 14 Arabidopsis Rop guanine nucleotide exchange factors (RopGEFs) showed that AtPRK6 interacted with AtRopGEF8 and AtRopGEF12. These interactions were confirmed in Arabidopsis mesophyll protoplasts. The interactions between AtPRK6 and AtRopGEF8/12 were mediated by the C-termini of AtRopGEF8/12 and by the juxtamembrane and kinase domain of AtPRK6, but were not dependent on the kinase activity. In addition, transient overexpression of AtPRK6::GFP in Arabidopsis protoplasts revealed that AtPRK6 was localized to the plasma membrane. Tobacco pollen tubes overexpressing AtPRK6 exhibited shorter tubes with enlarged tips. This depolarized tube growth required the kinase domain of AtPRK6 and was not dependent on kinase activity. Taken together, the results show that AtPRK6,through its juxtamembrane and kinase domains (KD), interacts with AtRopGEF8/12 and plays crucial roles in polarized growth of pollen tubes.展开更多
The underlying kin structure of groups of animals may be glimpsed from patterns of spatial position or temporal as- sociation between individuals, and is presumed to facilitate inclusive fitness benefits. Such structu...The underlying kin structure of groups of animals may be glimpsed from patterns of spatial position or temporal as- sociation between individuals, and is presumed to facilitate inclusive fitness benefits. Such structure may be evident at a finer, behavioural, scale with individuals preferentially interacting with kin. We tested whether kin structure within groups of meerkats Suricata suricatta matched three forms of social interaction networks: grooming, dominance or foraging competitions. Networks of dominance interactions were positively related to networks of kinship, with close relatives engaging in dominance interactions with each other. This relationship persisted even after excluding the breeding dominant pair and when we restricted the kinship network to only include links between first order kin, which are most likely to be able to discern kin through simple rules of thumb. Conversely, we found no relationship between kinship networks and either grooming networks or networks of foraging competitions. This is surprising because a positive association between kin in a grooming network, or a negative association be- tween kin in a network of foraging competitions offers opportunities for inclusive fitness benefits. Indeed, the positive association between kin in a network of dominance interactions that we did detect does not offer clear inclusive fitness benefits to group members. We conclude that kin structure in behavioural interactions in meerkats may be driven by factors other than indirect fit- ness benefits, and that networks of cooperative behaviours such as grooming may be driven by direct benefits accruing to indi- viduals perhaps through mutualism or manipulation展开更多
基金National Natural Science F oundation of China(No.59705004)
文摘The authors have studied the motion mechanism of the magnetic fluid in a reciprocating seal gap,on the basis of which the authors obtain an anti pressure formula of the reciprocating shaft magnetic fluid seal from general Navier Stokes equation.In order to verify the correctness of the anti pressure formula,the authors have calculated the magnetic field distribution of seal structure and have gotten the maximum still anti pressure.Finally,the authors have verified the influence of speed and stroke on the seal anti pressure.
文摘With the emergence of the new digital platforms, a diversified number of approaches and providers cannot damage too much a rather crowded info sphere. What may come as a general challenge is the "performance" amateurs who have the devices, the will but not the skills to become reliable communicators. Good training and an expanded concern for the accuracy of messages should distinguish between fact and fiction, and between information and opinion. The smart phone, the iPod, the lap top, or the tablet has expanded the means of communication. They have also diversified the types of messages circulated. The traditional main stream media outlets are facing a mounting competition from the social networks populated with the folk journalists, albeit, and non-professionals. Basic training of all those willing to come into the communication ring and regulations may concern not only the professionals but also the amateurs, and it may be ways to get over what seems to be a deadlock.
文摘An important part of human communication--verbal abuse--shows signs of specifically national features. So far the Russian language of law is sadly lacking a few terms necessary in legal procedures concerning cases of human rights violation. The "Westernization" of Russian collectivist mentality makes the solution of the problem still more urgent.
文摘The suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muffler affects the operation of the compressor owing to gas pressure drop, which causes volumetric and energetic efficiency loss due to the gas specific volume augmentation. Therefore, there is a compromise between sound attenuation and pressure drop increase, which has to be taken into account by compressor designers. In this work, it presents a numerical solution to the flow through a suction muffler in order to analyze the pressure field and point out the main contributions to the overall pressure drop of the flow. A commercial CFD (computational fluid dynamics) code was used to perform the numerical simulations and the results were validated by using experimental data. After analyzing the pressure field, the geometry of the muffler was modified intending to decrease the flow pressure drop. The geometric modification produced a 28% reduction on the overall pressure drop, without influencing the sound attenuation.
文摘α-secretase and β-secretase are known to compete for amyloid precursor protein (APP) processing and thus play a vital role in Alzheimer's disease pathogenesis. A disintegrin and metaUoproteinase 10 (ADAM10) and β-site APP cleaving enzyme 1 (BACE1) mediate the major activities of α-secretase and β-secretase in brain and share various common substrates. However, whether they function separately or together is poorly understood. Here, we show that ADAM10 and BACE1 co-localize in the neurites of mouse primary neurons. Co-immunoprecipitation and fluorescence resonance energy transfer analysis revealed that ADAM10 and BACE1 interact with each other under both endogenous and exogenous conditions. In addition, we found that ADAMIO enhances the proteolysis of neural cell adhesion molecule close homolog of L1 (CHL1) by BACE1. Further studies found that ADAM10-BACE1 interaction interfering peptide LT52 attenuates the regulation of ADAM10 on BACEl-mediated cleavage of CHL1. Our data indicate that ADAM10-BACE1 interaction regulates the proteolysis of some specific substrates and may play a potential role in brain function.
基金supported by the National Natural Science Foundation of China (31300247)
文摘The pollen receptor kinases (PRK) are critical regulators of pollen tube growth. The Arabidopsis genome encodes eight PRK genes, of which six are highly expressed in pollen tubes. The potential functions of AtPRK1 through AtPRK5, but not of AtPRK6,in pollen growth were analyzed in tobacco. Herein, AtPRK6 was cloned, and its function was identified. AtPRK6 was expressed specifically in pollen tubes. A yeast two-hybrid screen of AtPRK6 against 14 Arabidopsis Rop guanine nucleotide exchange factors (RopGEFs) showed that AtPRK6 interacted with AtRopGEF8 and AtRopGEF12. These interactions were confirmed in Arabidopsis mesophyll protoplasts. The interactions between AtPRK6 and AtRopGEF8/12 were mediated by the C-termini of AtRopGEF8/12 and by the juxtamembrane and kinase domain of AtPRK6, but were not dependent on the kinase activity. In addition, transient overexpression of AtPRK6::GFP in Arabidopsis protoplasts revealed that AtPRK6 was localized to the plasma membrane. Tobacco pollen tubes overexpressing AtPRK6 exhibited shorter tubes with enlarged tips. This depolarized tube growth required the kinase domain of AtPRK6 and was not dependent on kinase activity. Taken together, the results show that AtPRK6,through its juxtamembrane and kinase domains (KD), interacts with AtRopGEF8/12 and plays crucial roles in polarized growth of pollen tubes.
文摘The underlying kin structure of groups of animals may be glimpsed from patterns of spatial position or temporal as- sociation between individuals, and is presumed to facilitate inclusive fitness benefits. Such structure may be evident at a finer, behavioural, scale with individuals preferentially interacting with kin. We tested whether kin structure within groups of meerkats Suricata suricatta matched three forms of social interaction networks: grooming, dominance or foraging competitions. Networks of dominance interactions were positively related to networks of kinship, with close relatives engaging in dominance interactions with each other. This relationship persisted even after excluding the breeding dominant pair and when we restricted the kinship network to only include links between first order kin, which are most likely to be able to discern kin through simple rules of thumb. Conversely, we found no relationship between kinship networks and either grooming networks or networks of foraging competitions. This is surprising because a positive association between kin in a grooming network, or a negative association be- tween kin in a network of foraging competitions offers opportunities for inclusive fitness benefits. Indeed, the positive association between kin in a network of dominance interactions that we did detect does not offer clear inclusive fitness benefits to group members. We conclude that kin structure in behavioural interactions in meerkats may be driven by factors other than indirect fit- ness benefits, and that networks of cooperative behaviours such as grooming may be driven by direct benefits accruing to indi- viduals perhaps through mutualism or manipulation