The possibility of developing a complete graph invariant computable in polynomial time remains an open question. Consequently, creating efficient algorithms to verify non-isomorphism, including heuristic approaches, i...The possibility of developing a complete graph invariant computable in polynomial time remains an open question. Consequently, creating efficient algorithms to verify non-isomorphism, including heuristic approaches, is essential. Effective implementation of these heuristics necessitates both the adaptation of existing graph invariants and the invention of novel ones, which continues to be a relevant challenge. Numerous current invariants are capable of distinguishing a significant number of graphs rapidly in real-time scenarios. In this study, we present an invariant tailored for tournaments, a specific class of directed graphs. Tournaments are particularly intriguing because the count of distinct tournaments for a given number of vertices aligns with that of undirected graphs of the same size. The introduced invariant evaluates all possible tournament subsets derived from the original digraph that share the identical arc set. For each subset tournament, standard rankings are computed and aggregated to produce the final vertex scores, which serve as the new invariant. Our analysis indicates that this newly proposed invariant diverges from the most straightforward tournament invariant, which typically assigns scores to each participant. Preliminary computational tests demonstrate that the minimal correlation between the sequences generated by these two invariants occurs at a vertex count of 15.展开更多
Background:Recent years have witnessed the rapid rise of TikTok,a short-video social platform,which has sparked concerns about its potential for misuse and addiction.TikTok addiction has been associated with various p...Background:Recent years have witnessed the rapid rise of TikTok,a short-video social platform,which has sparked concerns about its potential for misuse and addiction.TikTok addiction has been associated with various psychological and social issues.This study aims to explore the mediating role of social ostracism in the relationship between the Dark Triad(Machiavellianism,Psychopathy,and Narcissism)and TikTok addiction.Methods:Data were collected from 425 Chinese college students through convenience sampling,using three validated scales:the Dirty Dozen,the Social Ostracism Scale,and the Bergen Social Media Addiction Scale.Structural Equation Modeling(SEM)with AMOS 24 revealed significant patterns.Results:Narcissism had direct positive effects on both social ostracism(β0.115,p 0.01)and TikTok addiction(β0.223,p 0.05),while Psychopathy only had a direct positive effect=<=<on social ostracism(β0.147,p 0.05).Contrary to expectations,Machiavellianism did not show significant direct=<effects on either social ostracism(βp 0.05)or TikTok addiction(β0.135,p 0.05).Mediation analysis=-0.031,>=>confirmed that social ostracism acted as a positive mediator,amplifying the effects of Psychopathy(β0.049,p 0.05)=<and Narcissism(β0.052,p 0.01)on TikTok addiction.In other words,higher levels of Psychopathy and Narcissism=<were linked to greater experiences of social ostracism,which in turn were linked to higher levels of TikTok addiction.Conclusion:These findings suggest an important role for social ostracism in linking Narcissism and Psychopathy to TikTok addiction.Addressing social ostracism and these dark personality traits through targeted interventions may be important in reducing TikTok addiction risks among individuals with such traits.展开更多
目的探讨Force Triad能量平台中血管结扎闭合系统（结扎束）在阴式子宫全切术（Transvaginal total hysterectomy,TVH）中的应用价值。方法 2013年4~12月住院患者60例,随机分成观察组（ligasuren血管闭合系统组）与对照组（传统手术组）...目的探讨Force Triad能量平台中血管结扎闭合系统（结扎束）在阴式子宫全切术（Transvaginal total hysterectomy,TVH）中的应用价值。方法 2013年4~12月住院患者60例,随机分成观察组（ligasuren血管闭合系统组）与对照组（传统手术组）,比较两组间在手术时间、术中出血量、术后排气时间、术后发热时间、术后离床活动时间以及平均住院天数等情况。结果观察组手术时间、术中出血量、术后离床活动时间及平均住院时间明显少于开腹手术组（P〈0.05）,差异有统计学意义;术后排气时间、术后发热时间差异均无显著性（P〉0.05）。结论 Ligasuren血管闭合系统在阴式子宫全切手术的应用方面有一定的优势,可以更有效地闭合血管,减少出血量及缩短手术时间,减少术后并发症等优点,值得推广。展开更多
A survey of zoological literature affirmed the wide occurrence of Fibonacci numbers in the organization of acellular and prokaryotic life forms as well as in some eukaryotic protistans and in the embryonic development...A survey of zoological literature affirmed the wide occurrence of Fibonacci numbers in the organization of acellular and prokaryotic life forms as well as in some eukaryotic protistans and in the embryonic development and adult forms of many living and fossil remains of metazoan animals. A detailed comparative analysis of the axial skeleton of a fossil fish and humans revealed a new rule of the “nested triad” of bones organized along the proximal to distal axis of limb appendages. This growth pattern and its ubiquity among living vertebrates appear to underlie a profound rule of pattern formation that is dictated in part by the genetics and epigenetic mechanisms of stem cell clonal development.展开更多
By means of Lax triads we reconstruct isospectral and nonisospectral scalar modified Kadomtsev–Petviashvili(mKP) hierarchies. In this approach the argument y is treated as an independent variable which is independent...By means of Lax triads we reconstruct isospectral and nonisospectral scalar modified Kadomtsev–Petviashvili(mKP) hierarchies. In this approach the argument y is treated as an independent variable which is independent of time parameters {t_1, t_2,...}. Consequently, the isospectral and nonisospectral scalar mKP flows can have clear zero curvature representations, which enables us to handle investigation of symmetries of the scalar isospectral mKP hierarchy as freely as for(1+1)-dimensional systems. As a result, we obtain Lie algebraic structures of the scalar mKP flows and construct symmetries for the scalar isospectral mKP hierarchy.展开更多
Taking the Big Bang as an established fact, the question inevitably arises about what exactly caused it, in what environment could it have happened and what happened before it. The developed approach allows us to shed...Taking the Big Bang as an established fact, the question inevitably arises about what exactly caused it, in what environment could it have happened and what happened before it. The developed approach allows us to shed light on many raised questions and to establish what universal laws and structures formed what happened before the Big Bang, to understand its cause and the dynamic processes that led to it. This required a radical revision of many views, giving them a new meaning and content. This approach has led to a consistent and conceptually new understanding of these phenomena, which allowed correctly formulate questions to which there are still no clear answers. Based on this formulation of the problem, we came to new ideas about the nature of Dark energy, Dark matter and the region of their birth, formulated and described the mechanism of the formation of worlds and their hierarchy on the other side of the Big Bang and the mechanism of this explosion itself. The Primary Parent Particle was introduced into the concept, which was the basis of everything and is the carrier of the fundamental Primary space introduced by us, which had at least two phase states. This particle consists of Beginnings united in the form of Borromeo rings. This made it possible to calculate the structure and primary spectrum of elementary particles that arose on the other side of the Big Bang, the mechanisms of their formation and the resulting fundamental interactions that lead to the existence of vortices before the Big Bang;the mechanisms of the birth of multiple universes and much more are also considered. The concept of the “cosmic genetic code" is introduced, the characteristics and mechanism of its formation before the Big Bang are presented.展开更多
以往人们多认为QT间期延长是药源性尖端扭转性室性心动过速(TdP)的重要机制。但是QT间期延长并不都能引发TdP,而TdP的发生也并不都伴随着QT间期延长,甚至在一些QT间期缩短的情况下,也有恶性室性心律失常的发生。因此近年来有学者提出TR...以往人们多认为QT间期延长是药源性尖端扭转性室性心动过速(TdP)的重要机制。但是QT间期延长并不都能引发TdP,而TdP的发生也并不都伴随着QT间期延长,甚至在一些QT间期缩短的情况下,也有恶性室性心律失常的发生。因此近年来有学者提出TRIaD的概念,其为心肌细胞动作电位三角形化(triangulation)、逆向频率依赖性(reverse use dependency)、不稳定性(instability)以及离散(dispersion)等指标的合称。越来越多的研究证明,TRIaD指标的变化是药源性TdP发生的共同基质;药物应用后表现出动作电位三角形化、逆向频率依赖性、不稳定性、离散增加等反应,无论有无QT间期的延长,均易发生室性心律失常,包括TdP。反之,即使QT间期延长,致心律失常作用也很小。展开更多
AIM: To evaluate the expression of fragile histidine triad (FHIT) gene protein, product of a candidate tumor suppressor, and to investigate the relationship between FHIT, cell apoptosis and proliferation, and patholog...AIM: To evaluate the expression of fragile histidine triad (FHIT) gene protein, product of a candidate tumor suppressor, and to investigate the relationship between FHIT, cell apoptosis and proliferation, and pathological features of primary hepatocellular carcinoma (HCC). METHODS: Forty-seven HCC and ten normal liver specimens were collected during surgical operation between 2001 and 2003. FHIT and proliferating cell nuclear antigen (PCNA) expression were detected by immunohistochemistry, and apoptotic level was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay on the tissue sections. RESULTS: All normal liver tissues showed a strong expression of FHIT, whereas 28 of 47 (59.6%) carcinomas showed a significant loss or absence of FHIT expression (P= 0.001). The proportion of reduced FHIT expression in those carcinomas at stages Ⅲ-Ⅳ (70.6%) and in those with extrahepatic metastasis (86.7%) showed an increasing trend compared with those at stages HI (30.8%, P= 0.013) and those without metastasis (46.9%, P = 0.010) respectively. Apoptotic incidence in advanced TNM stage carcinoma and those with positive FHIT expression was higher than that in early stage carcinoma (P=0.030) and in those with negative FHIT expression (P=0.044) respectively. The proliferating potential of hepatocellular carcinoma was associated with FHIT expression (P= 0.016) and the aggressive feature (P = 0.019). Kaplan-Meier analysis demonstrated that the survival time of these 47 patients correlated with TNM stage, FHIT expression and metastasis. CONCLUSION: There is marked loss or absence of FHIT expression, as well as abnormal apoptosis-prdiferation balance in HCC. FHIT may play an important role in carcinogenesis and development of HCC.展开更多
Besides obvious benefits,the Three Gorges Dam＇s construction resulted in new pollution scenarios with the potentials to threaten the Three Gorges Reservoir（TGR） ecosystem.In order to record organic contamination,to...Besides obvious benefits,the Three Gorges Dam＇s construction resulted in new pollution scenarios with the potentials to threaten the Three Gorges Reservoir（TGR） ecosystem.In order to record organic contamination,to find links to ecotoxicological impacts and to serve as reference for ensuing monitoring,several sites in the TGR area were screened applying the triad approach with additional lines-of-evidence as a holistic assessment method.Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011 and 2012 to determine organic pollution levels,mutagenic potentials and genotoxic impacts.Two regional hot-spots near the cities of Chongqing and Kaixian were identified and further investigated in 2013.Only polycyclic aromatic hydrocarbons（PAHs） could be detected in sediments in 2011（165-1653 ng/g）,emphasizing their roles as key pollutants of the area.Their ubiquity was confirmed at Chongqing（150-433 ng/g） and Kaixian（127-590 ng/g） in2013.Concentrations were comparable to other major Chinese and German rivers.However,the immense sediment influx suggested a deposition of 216-636 kg PAH/day（0.2-0.6 mg PAH/（m2·day））,indicating an ecotoxicological risk.PAH source analysis highlighted primary impacts of combustion sources on the more industrialized upper TGR section,whereas petrogenic sources dominated the mid-low section.Furthermore,sediment extracts from several sites exhibited significant activities of frameshift promutagens in the Ames fluctuation assay.Additionally,significant genotoxic impairments in erythrocytes of P.vachellii were detected（Chongqing/Kaixian）,demonstrating the relevance of genotoxicity as animportant mode of action in the TGR＇s fish.PAHs,their derivatives and non-target compounds are considered as main causative agents.展开更多
AIM: To examine the aberrant expression of fragile histidine triad (FHIT) gene and protein in gastric cancer, and to evaluate the role of FHIT gene and the relationship between FHIT gene and EBV infection in gastric c...AIM: To examine the aberrant expression of fragile histidine triad (FHIT) gene and protein in gastric cancer, and to evaluate the role of FHIT gene and the relationship between FHIT gene and EBV infection in gastric carcinogenesis. METHODS: FHIT transcripts were detected by nested RT-PCR in 30 cases of gastric cancer and their products were sequenced.FHIT protein was detected by Western blot. EBV infection was detected by PCR method in 50 cases of gastric cancer. RESULTS: The wild type transcripts were detected in all 30 matched normal tissues of gastric cancer.Aberrant transcripts were found in 11/30 (36.7%) gastric cancerous tissues. Sequencing analysis of the aberrant fragments found an RT-PCR product missing exons 5-7 in one case of gastric cancer, and another product missing exons 4-7. Four of ten (40.0%) cases of primary gastric cancer showed absent or decreased expression of FHIT protein as compared with their matched normal tissues.EBV was detected in 5/50 (10%) gastric cancers,among which 4/5 (80%) had aberrant transcripts of FHIT gene. CONCLUSION: Loss of FHIT gene or FHIT protein plays an important role in carcinogenesis,development and progression of gastric cancer.EBV infection might influence carcinogenesis of gastric cancer by inducing the abnormality of FHIT gene.展开更多
AIM： To detect the expression of fragile histidine triad （FHIT） in normal colorectal tissue, colorectal adenoma and colorectal cancer （CRC） tissue, and to analyze its relationship with the clinicopathological fea...AIM： To detect the expression of fragile histidine triad （FHIT） in normal colorectal tissue, colorectal adenoma and colorectal cancer （CRC） tissue, and to analyze its relationship with the clinicopathological features of CRC, and apoptosis-associatecl proteins （Bcl-2, Bax, survivin） and apoptosis in colorectal cancer. METHODS： FHIT mRNA analysis was performed by nested reverse transcription-polymerase chain reaction （RT-PCR） assay. Tissue microarray （TMA） was established to detect the expression of FHIT, Bcl-2, Bax and survivin genes in 80 CRC tissue specimens, 16 colorectal adenoma tissue specimens and 16 hemorrhoid （PPH） tissue specimens during the same period of time as the control. Citrate-microwave-SP was used as immunohistochemical method. The relationship between clinicopathological factors, such as differentiation grades and 5-year survival rate was observed. TUNEL assay was used to detect the apoptosis index in 80 CRC tissue specimens. RESULTS： Ten out of 26 （38.5%） CRC tissue specimens expressed aberrant FHIT transcripts, none of the aberrant FHIT transcripts was observed in the matchednormal tissue and colorectal adenoma tissue by nested RT-PCR assay. The positive rate of FHIT gene expression in normal colorectal tissue, colorectal adenoma and carcinoma tissue was 93.75%, 68.75% and 46.25%, respectively. Clinicopathological analysis of patients showed that the decreased FHIT gene expression was not associated with age, sex, serum CEA levels, tumor site and size, histological classification. However, the expression of FHIT was correlated with differentiation grades, pathological stages, lymph node metastases and 5-year survival rate after operation. The positive rate of apoptosis-associated proteins （Bax, Bcl-2 and survivin） in CRC tissue was 72.50%, 51.25% and 77.50%, respectively. The expression of these apoptosisassociated proteins in CRC tissue was correlated with the expression of FHIT. The mean apoptosis index in FHIT negative tumors was significantly lower than that in FHIT- positive tumors （5.41 ± 0.23 vs 0.56 ± 0.10, P 〈 0.01）. CONCLUSION： The FHIT gene plays an important role in the regulation of apoptosis and decreased FHIT expression plays a key role in the initiation and progression of colorectal carcinoma.展开更多
文摘The possibility of developing a complete graph invariant computable in polynomial time remains an open question. Consequently, creating efficient algorithms to verify non-isomorphism, including heuristic approaches, is essential. Effective implementation of these heuristics necessitates both the adaptation of existing graph invariants and the invention of novel ones, which continues to be a relevant challenge. Numerous current invariants are capable of distinguishing a significant number of graphs rapidly in real-time scenarios. In this study, we present an invariant tailored for tournaments, a specific class of directed graphs. Tournaments are particularly intriguing because the count of distinct tournaments for a given number of vertices aligns with that of undirected graphs of the same size. The introduced invariant evaluates all possible tournament subsets derived from the original digraph that share the identical arc set. For each subset tournament, standard rankings are computed and aggregated to produce the final vertex scores, which serve as the new invariant. Our analysis indicates that this newly proposed invariant diverges from the most straightforward tournament invariant, which typically assigns scores to each participant. Preliminary computational tests demonstrate that the minimal correlation between the sequences generated by these two invariants occurs at a vertex count of 15.
基金reported in this paper represents a contribution to“Research Project on the Construction of Smart Teaching Capabilities in New Era Mingde College English(Grant No.2022YB0099)”at Henan Provincial Department of Education.
文摘Background:Recent years have witnessed the rapid rise of TikTok,a short-video social platform,which has sparked concerns about its potential for misuse and addiction.TikTok addiction has been associated with various psychological and social issues.This study aims to explore the mediating role of social ostracism in the relationship between the Dark Triad(Machiavellianism,Psychopathy,and Narcissism)and TikTok addiction.Methods:Data were collected from 425 Chinese college students through convenience sampling,using three validated scales:the Dirty Dozen,the Social Ostracism Scale,and the Bergen Social Media Addiction Scale.Structural Equation Modeling(SEM)with AMOS 24 revealed significant patterns.Results:Narcissism had direct positive effects on both social ostracism(β0.115,p 0.01)and TikTok addiction(β0.223,p 0.05),while Psychopathy only had a direct positive effect=<=<on social ostracism(β0.147,p 0.05).Contrary to expectations,Machiavellianism did not show significant direct=<effects on either social ostracism(βp 0.05)or TikTok addiction(β0.135,p 0.05).Mediation analysis=-0.031,>=>confirmed that social ostracism acted as a positive mediator,amplifying the effects of Psychopathy(β0.049,p 0.05)=<and Narcissism(β0.052,p 0.01)on TikTok addiction.In other words,higher levels of Psychopathy and Narcissism=<were linked to greater experiences of social ostracism,which in turn were linked to higher levels of TikTok addiction.Conclusion:These findings suggest an important role for social ostracism in linking Narcissism and Psychopathy to TikTok addiction.Addressing social ostracism and these dark personality traits through targeted interventions may be important in reducing TikTok addiction risks among individuals with such traits.
文摘A survey of zoological literature affirmed the wide occurrence of Fibonacci numbers in the organization of acellular and prokaryotic life forms as well as in some eukaryotic protistans and in the embryonic development and adult forms of many living and fossil remains of metazoan animals. A detailed comparative analysis of the axial skeleton of a fossil fish and humans revealed a new rule of the “nested triad” of bones organized along the proximal to distal axis of limb appendages. This growth pattern and its ubiquity among living vertebrates appear to underlie a profound rule of pattern formation that is dictated in part by the genetics and epigenetic mechanisms of stem cell clonal development.
基金Supported by the National Natural Science Foundation of China under Grant No.11371241
文摘By means of Lax triads we reconstruct isospectral and nonisospectral scalar modified Kadomtsev–Petviashvili(mKP) hierarchies. In this approach the argument y is treated as an independent variable which is independent of time parameters {t_1, t_2,...}. Consequently, the isospectral and nonisospectral scalar mKP flows can have clear zero curvature representations, which enables us to handle investigation of symmetries of the scalar isospectral mKP hierarchy as freely as for(1+1)-dimensional systems. As a result, we obtain Lie algebraic structures of the scalar mKP flows and construct symmetries for the scalar isospectral mKP hierarchy.
文摘Taking the Big Bang as an established fact, the question inevitably arises about what exactly caused it, in what environment could it have happened and what happened before it. The developed approach allows us to shed light on many raised questions and to establish what universal laws and structures formed what happened before the Big Bang, to understand its cause and the dynamic processes that led to it. This required a radical revision of many views, giving them a new meaning and content. This approach has led to a consistent and conceptually new understanding of these phenomena, which allowed correctly formulate questions to which there are still no clear answers. Based on this formulation of the problem, we came to new ideas about the nature of Dark energy, Dark matter and the region of their birth, formulated and described the mechanism of the formation of worlds and their hierarchy on the other side of the Big Bang and the mechanism of this explosion itself. The Primary Parent Particle was introduced into the concept, which was the basis of everything and is the carrier of the fundamental Primary space introduced by us, which had at least two phase states. This particle consists of Beginnings united in the form of Borromeo rings. This made it possible to calculate the structure and primary spectrum of elementary particles that arose on the other side of the Big Bang, the mechanisms of their formation and the resulting fundamental interactions that lead to the existence of vortices before the Big Bang;the mechanisms of the birth of multiple universes and much more are also considered. The concept of the “cosmic genetic code" is introduced, the characteristics and mechanism of its formation before the Big Bang are presented.
文摘以往人们多认为QT间期延长是药源性尖端扭转性室性心动过速(TdP)的重要机制。但是QT间期延长并不都能引发TdP,而TdP的发生也并不都伴随着QT间期延长,甚至在一些QT间期缩短的情况下,也有恶性室性心律失常的发生。因此近年来有学者提出TRIaD的概念,其为心肌细胞动作电位三角形化(triangulation)、逆向频率依赖性(reverse use dependency)、不稳定性(instability)以及离散(dispersion)等指标的合称。越来越多的研究证明,TRIaD指标的变化是药源性TdP发生的共同基质;药物应用后表现出动作电位三角形化、逆向频率依赖性、不稳定性、离散增加等反应,无论有无QT间期的延长,均易发生室性心律失常,包括TdP。反之,即使QT间期延长,致心律失常作用也很小。
文摘AIM: To evaluate the expression of fragile histidine triad (FHIT) gene protein, product of a candidate tumor suppressor, and to investigate the relationship between FHIT, cell apoptosis and proliferation, and pathological features of primary hepatocellular carcinoma (HCC). METHODS: Forty-seven HCC and ten normal liver specimens were collected during surgical operation between 2001 and 2003. FHIT and proliferating cell nuclear antigen (PCNA) expression were detected by immunohistochemistry, and apoptotic level was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay on the tissue sections. RESULTS: All normal liver tissues showed a strong expression of FHIT, whereas 28 of 47 (59.6%) carcinomas showed a significant loss or absence of FHIT expression (P= 0.001). The proportion of reduced FHIT expression in those carcinomas at stages Ⅲ-Ⅳ (70.6%) and in those with extrahepatic metastasis (86.7%) showed an increasing trend compared with those at stages HI (30.8%, P= 0.013) and those without metastasis (46.9%, P = 0.010) respectively. Apoptotic incidence in advanced TNM stage carcinoma and those with positive FHIT expression was higher than that in early stage carcinoma (P=0.030) and in those with negative FHIT expression (P=0.044) respectively. The proliferating potential of hepatocellular carcinoma was associated with FHIT expression (P= 0.016) and the aggressive feature (P = 0.019). Kaplan-Meier analysis demonstrated that the survival time of these 47 patients correlated with TNM stage, FHIT expression and metastasis. CONCLUSION: There is marked loss or absence of FHIT expression, as well as abnormal apoptosis-prdiferation balance in HCC. FHIT may play an important role in carcinogenesis and development of HCC.
基金the Tongji University, Shanghai, and the Chongqing University, Chongqing, as part of the MICROTOX project ("Transformation, Bioaccumulation and Toxicity of Organic Micropollutants in the Yangtze Three Gorges Reservoir" No. FKZ 02WT1141)+5 种基金the Sino-German joint environmental research program "Yangtze-Hydro - Sustainable Management of the Newly Created Ecosystem at the Three Gorges Dam" (No. FKZ 02WT Bergmann et al. (2011) www.yangtzeproject.de)part of the research cluster "Pollutants/Water/Sediment-Impacts of Transformation and Transportation Processes on the Yangtze Water Quality"supported by a cooperation project with Chinese colleagues also sponsored by the Federal Ministry of Education and Research, Germany (No. DLR FKZ 01DO12007)the Chinese 111 Program
文摘Besides obvious benefits,the Three Gorges Dam＇s construction resulted in new pollution scenarios with the potentials to threaten the Three Gorges Reservoir（TGR） ecosystem.In order to record organic contamination,to find links to ecotoxicological impacts and to serve as reference for ensuing monitoring,several sites in the TGR area were screened applying the triad approach with additional lines-of-evidence as a holistic assessment method.Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011 and 2012 to determine organic pollution levels,mutagenic potentials and genotoxic impacts.Two regional hot-spots near the cities of Chongqing and Kaixian were identified and further investigated in 2013.Only polycyclic aromatic hydrocarbons（PAHs） could be detected in sediments in 2011（165-1653 ng/g）,emphasizing their roles as key pollutants of the area.Their ubiquity was confirmed at Chongqing（150-433 ng/g） and Kaixian（127-590 ng/g） in2013.Concentrations were comparable to other major Chinese and German rivers.However,the immense sediment influx suggested a deposition of 216-636 kg PAH/day（0.2-0.6 mg PAH/（m2·day））,indicating an ecotoxicological risk.PAH source analysis highlighted primary impacts of combustion sources on the more industrialized upper TGR section,whereas petrogenic sources dominated the mid-low section.Furthermore,sediment extracts from several sites exhibited significant activities of frameshift promutagens in the Ames fluctuation assay.Additionally,significant genotoxic impairments in erythrocytes of P.vachellii were detected（Chongqing/Kaixian）,demonstrating the relevance of genotoxicity as animportant mode of action in the TGR＇s fish.PAHs,their derivatives and non-target compounds are considered as main causative agents.
基金Supported by the National Natural Science Foundation of China,No. 30371607
文摘AIM: To examine the aberrant expression of fragile histidine triad (FHIT) gene and protein in gastric cancer, and to evaluate the role of FHIT gene and the relationship between FHIT gene and EBV infection in gastric carcinogenesis. METHODS: FHIT transcripts were detected by nested RT-PCR in 30 cases of gastric cancer and their products were sequenced.FHIT protein was detected by Western blot. EBV infection was detected by PCR method in 50 cases of gastric cancer. RESULTS: The wild type transcripts were detected in all 30 matched normal tissues of gastric cancer.Aberrant transcripts were found in 11/30 (36.7%) gastric cancerous tissues. Sequencing analysis of the aberrant fragments found an RT-PCR product missing exons 5-7 in one case of gastric cancer, and another product missing exons 4-7. Four of ten (40.0%) cases of primary gastric cancer showed absent or decreased expression of FHIT protein as compared with their matched normal tissues.EBV was detected in 5/50 (10%) gastric cancers,among which 4/5 (80%) had aberrant transcripts of FHIT gene. CONCLUSION: Loss of FHIT gene or FHIT protein plays an important role in carcinogenesis,development and progression of gastric cancer.EBV infection might influence carcinogenesis of gastric cancer by inducing the abnormality of FHIT gene.
基金Supported by the Natural Science Foundation of Guangdong Province, No. 06020005
文摘AIM： To detect the expression of fragile histidine triad （FHIT） in normal colorectal tissue, colorectal adenoma and colorectal cancer （CRC） tissue, and to analyze its relationship with the clinicopathological features of CRC, and apoptosis-associatecl proteins （Bcl-2, Bax, survivin） and apoptosis in colorectal cancer. METHODS： FHIT mRNA analysis was performed by nested reverse transcription-polymerase chain reaction （RT-PCR） assay. Tissue microarray （TMA） was established to detect the expression of FHIT, Bcl-2, Bax and survivin genes in 80 CRC tissue specimens, 16 colorectal adenoma tissue specimens and 16 hemorrhoid （PPH） tissue specimens during the same period of time as the control. Citrate-microwave-SP was used as immunohistochemical method. The relationship between clinicopathological factors, such as differentiation grades and 5-year survival rate was observed. TUNEL assay was used to detect the apoptosis index in 80 CRC tissue specimens. RESULTS： Ten out of 26 （38.5%） CRC tissue specimens expressed aberrant FHIT transcripts, none of the aberrant FHIT transcripts was observed in the matchednormal tissue and colorectal adenoma tissue by nested RT-PCR assay. The positive rate of FHIT gene expression in normal colorectal tissue, colorectal adenoma and carcinoma tissue was 93.75%, 68.75% and 46.25%, respectively. Clinicopathological analysis of patients showed that the decreased FHIT gene expression was not associated with age, sex, serum CEA levels, tumor site and size, histological classification. However, the expression of FHIT was correlated with differentiation grades, pathological stages, lymph node metastases and 5-year survival rate after operation. The positive rate of apoptosis-associated proteins （Bax, Bcl-2 and survivin） in CRC tissue was 72.50%, 51.25% and 77.50%, respectively. The expression of these apoptosisassociated proteins in CRC tissue was correlated with the expression of FHIT. The mean apoptosis index in FHIT negative tumors was significantly lower than that in FHIT- positive tumors （5.41 ± 0.23 vs 0.56 ± 0.10, P 〈 0.01）. CONCLUSION： The FHIT gene plays an important role in the regulation of apoptosis and decreased FHIT expression plays a key role in the initiation and progression of colorectal carcinoma.
