目的:检测柚皮苷(Ng)对游离型和牙本质结合型胶原酶活性的影响。方法:用荧光定量法检测125、250、500μg/m L Ng对游离型胶原酶活性的影响。制备牙本质胶原样本24个,随机分为3组(n=8):去离子水处理组(空白组);500μg/m L Ng处理组,2 g/...目的:检测柚皮苷(Ng)对游离型和牙本质结合型胶原酶活性的影响。方法:用荧光定量法检测125、250、500μg/m L Ng对游离型胶原酶活性的影响。制备牙本质胶原样本24个,随机分为3组(n=8):去离子水处理组(空白组);500μg/m L Ng处理组,2 g/L氯已定处理组;各组分别处理10 min后,将牙本质胶原样本分别置于老化液中15 d,检测胶原的干重变化、羟脯氨酸释放量。另制备牙本质片6个,经100 g/L H3PO4处理60 s后,随机分为2组(n=3),实验组为500μg/m L Ng处理10 min;空白组不做任何处理,用原位明胶酶实验评估Ng对牙本质结合型胶原酶活性的影响。结果:500μg/m L Ng的酶抑制率(83.17%)高于125、250μg/L Ng;500μg/L Ng处理老化15 d后的牙本质胶原样本,其胶原干重丢失比例、羟脯氨酸释放量均显著低于空白组(P<0.05);原位明胶酶实验结果显示,500μg/m L Ng处理后的样本荧光释放量显著低于空白组(P<0.05)。结论:500μg/m L Ng对游离型和牙本质结合型胶原酶均有抑制作用。展开更多
This study examines the relationship between earnings quality and insider trading. Using downward earnings restatement firms to identify low-quality earnings, we find that insiders outsell non-earnings restatement fir...This study examines the relationship between earnings quality and insider trading. Using downward earnings restatement firms to identify low-quality earnings, we find that insiders outsell non-earnings restatement firms of their holdings over the period from two years before to one year after the beginning of the restatement period. In addition, the amounts of restatement are positively associated with the excess insider selling. We also provide evidence that excess insider selling predicts excessive earnings manipulations that eventually lead to GAAP （Generally Accepted Accounting Principles） violation. Some researchers argued that insider trading can be an efficient way of transferring insider information to the capital markets. Our evidence of intensive insider selling in the context of earnings restatements implies that insiders disregard their fiduciary duties to the shareholders during the periods of deteriorating financial performance.展开更多
This paper mainly explores the Australian Aboriginal-white relationship in two novels： The Secret River （2005） by non-Indigenous writer Kate Grenville, and Carpentaria （2006） by Indigenous novelist Alexis Wright,...This paper mainly explores the Australian Aboriginal-white relationship in two novels： The Secret River （2005） by non-Indigenous writer Kate Grenville, and Carpentaria （2006） by Indigenous novelist Alexis Wright, and compares the discursive strategies and narrative devices the authors have adopted to represent whiteness and Indigeneity, one from the European settlers＇ point of view, the other from the standpoint of an Aboriginal author. In The Secret River, Grenville resorts to the genre of historical novel as a way of reconciling the past. Though the novel challenges the racialised stereotypes of the Aboriginal people by adopting a double perspective （a reconfigured white perspective to refute the colonists＇ views）, the moral ambiguity of the settler identity is still complicit with the colonial discourse. On the other hand, Carpentaria rejects a narrow, essentialist categorization of the Aboriginal people and defamiliarises the concept of whiteness by foregrounding it in a critique rather than as the default norm. Set in a narrative related to the oral tradition, the novel brings Aboriginal cosmology into full play A comparison of the two novels provides a panoramic view of how the Aboriginal-white relationships are presented through the literary imaginary in Australia.展开更多
Let D be a digraph. We call D primitive if there exists a positive integer ksuch that for all ordered pairs of venices u, v V(D) (not necessarily distinct), there isa directed walk of length k from u to v. In 1982, ...Let D be a digraph. We call D primitive if there exists a positive integer ksuch that for all ordered pairs of venices u, v V(D) (not necessarily distinct), there isa directed walk of length k from u to v. In 1982, J.A.Ross posed two problems: (1) If Dis a primitive digraph on n vertices with girth s>1 and (D) = n+s(n-2), does Dcontain an elementary circuit of length n? (2) Let D be a strong digraph on n verticeswhich contains a loop and suppose D is not isomorphic to Bi,n for i=1, 2, n-1(see Figure 1), if (D) =2n-2, does D contain an elementary circuit of length n?In this paper, we have solved both completely and obtained the following results: (1)Suppose that D is a primitive digraph on n vertices with girth s>1 and exponentn+s (n-2). Then D is Hamiltonian. (2) Suppose that D is a primitive digraph on nvertices which contains a loop, and (D)=2n-2. Then D is Hamiltonian if and only if max {d(u,v))=(u, v)= 2}=2} =n-2.展开更多
Transcription factor TFIIA is controlled by complex regulatory networks including proteolysis by the protease Taspase 1, though the full impact of cleavage remains elusive. Here, we demonstrate that in contrast to the...Transcription factor TFIIA is controlled by complex regulatory networks including proteolysis by the protease Taspase 1, though the full impact of cleavage remains elusive. Here, we demonstrate that in contrast to the general assumption, de novo produced TFIIA is rapidly confined to the cytoplasm via an evolutionary conserved nuclear export signal （NES, amino acids ^21VINDVRDIFL^30）, interacting with the nuclear export receptor Exportin-1/chromosomal region maintenance 1 （Crml）. Chemical export inhibition or genetic inactivation of the NES not only promotes TFIIA＇s nuclear localization but also affects its transcrip- tional activity. Notably, Taspase 1 processing promotes TFIIA＇s nuclear accumulation by NES masking, and modulates its tran- scriptional activity. Moreover, TFIIA complex formation with the TATA box binding protein （TBP） is cooperatively enhanced by inhibition of proteolysis and nuclear export, leading to an increase of the ceil cycle inhibitor p16INK, which is counteracted by pre- vention of TBP binding. We here identified a novel mechanism how proteolysis and nuclear transport cooperatively fine-tune tran- scriptional programs.展开更多
文摘目的:检测柚皮苷(Ng)对游离型和牙本质结合型胶原酶活性的影响。方法:用荧光定量法检测125、250、500μg/m L Ng对游离型胶原酶活性的影响。制备牙本质胶原样本24个,随机分为3组(n=8):去离子水处理组(空白组);500μg/m L Ng处理组,2 g/L氯已定处理组;各组分别处理10 min后,将牙本质胶原样本分别置于老化液中15 d,检测胶原的干重变化、羟脯氨酸释放量。另制备牙本质片6个,经100 g/L H3PO4处理60 s后,随机分为2组(n=3),实验组为500μg/m L Ng处理10 min;空白组不做任何处理,用原位明胶酶实验评估Ng对牙本质结合型胶原酶活性的影响。结果:500μg/m L Ng的酶抑制率(83.17%)高于125、250μg/L Ng;500μg/L Ng处理老化15 d后的牙本质胶原样本,其胶原干重丢失比例、羟脯氨酸释放量均显著低于空白组(P<0.05);原位明胶酶实验结果显示,500μg/m L Ng处理后的样本荧光释放量显著低于空白组(P<0.05)。结论:500μg/m L Ng对游离型和牙本质结合型胶原酶均有抑制作用。
文摘This study examines the relationship between earnings quality and insider trading. Using downward earnings restatement firms to identify low-quality earnings, we find that insiders outsell non-earnings restatement firms of their holdings over the period from two years before to one year after the beginning of the restatement period. In addition, the amounts of restatement are positively associated with the excess insider selling. We also provide evidence that excess insider selling predicts excessive earnings manipulations that eventually lead to GAAP （Generally Accepted Accounting Principles） violation. Some researchers argued that insider trading can be an efficient way of transferring insider information to the capital markets. Our evidence of intensive insider selling in the context of earnings restatements implies that insiders disregard their fiduciary duties to the shareholders during the periods of deteriorating financial performance.
文摘This paper mainly explores the Australian Aboriginal-white relationship in two novels： The Secret River （2005） by non-Indigenous writer Kate Grenville, and Carpentaria （2006） by Indigenous novelist Alexis Wright, and compares the discursive strategies and narrative devices the authors have adopted to represent whiteness and Indigeneity, one from the European settlers＇ point of view, the other from the standpoint of an Aboriginal author. In The Secret River, Grenville resorts to the genre of historical novel as a way of reconciling the past. Though the novel challenges the racialised stereotypes of the Aboriginal people by adopting a double perspective （a reconfigured white perspective to refute the colonists＇ views）, the moral ambiguity of the settler identity is still complicit with the colonial discourse. On the other hand, Carpentaria rejects a narrow, essentialist categorization of the Aboriginal people and defamiliarises the concept of whiteness by foregrounding it in a critique rather than as the default norm. Set in a narrative related to the oral tradition, the novel brings Aboriginal cosmology into full play A comparison of the two novels provides a panoramic view of how the Aboriginal-white relationships are presented through the literary imaginary in Australia.
文摘Let D be a digraph. We call D primitive if there exists a positive integer ksuch that for all ordered pairs of venices u, v V(D) (not necessarily distinct), there isa directed walk of length k from u to v. In 1982, J.A.Ross posed two problems: (1) If Dis a primitive digraph on n vertices with girth s>1 and (D) = n+s(n-2), does Dcontain an elementary circuit of length n? (2) Let D be a strong digraph on n verticeswhich contains a loop and suppose D is not isomorphic to Bi,n for i=1, 2, n-1(see Figure 1), if (D) =2n-2, does D contain an elementary circuit of length n?In this paper, we have solved both completely and obtained the following results: (1)Suppose that D is a primitive digraph on n vertices with girth s>1 and exponentn+s (n-2). Then D is Hamiltonian. (2) Suppose that D is a primitive digraph on nvertices which contains a loop, and (D)=2n-2. Then D is Hamiltonian if and only if max {d(u,v))=(u, v)= 2}=2} =n-2.
文摘Transcription factor TFIIA is controlled by complex regulatory networks including proteolysis by the protease Taspase 1, though the full impact of cleavage remains elusive. Here, we demonstrate that in contrast to the general assumption, de novo produced TFIIA is rapidly confined to the cytoplasm via an evolutionary conserved nuclear export signal （NES, amino acids ^21VINDVRDIFL^30）, interacting with the nuclear export receptor Exportin-1/chromosomal region maintenance 1 （Crml）. Chemical export inhibition or genetic inactivation of the NES not only promotes TFIIA＇s nuclear localization but also affects its transcrip- tional activity. Notably, Taspase 1 processing promotes TFIIA＇s nuclear accumulation by NES masking, and modulates its tran- scriptional activity. Moreover, TFIIA complex formation with the TATA box binding protein （TBP） is cooperatively enhanced by inhibition of proteolysis and nuclear export, leading to an increase of the ceil cycle inhibitor p16INK, which is counteracted by pre- vention of TBP binding. We here identified a novel mechanism how proteolysis and nuclear transport cooperatively fine-tune tran- scriptional programs.
