Negative air ions are natural components of the air we breathe Forests are the main continuous natural source of negative air ions （NAI）. The spatio-temporal patterns of negative air ions were explored in Shanghai, ...Negative air ions are natural components of the air we breathe Forests are the main continuous natural source of negative air ions （NAI）. The spatio-temporal patterns of negative air ions were explored in Shanghai, based on monthly monitoring in 15 parks from March 2009 to February 2010. In each park, sampling sites were selected in forests and open spaces. The annual variation in negative air ion concentrations （NAIC） showed peak values from June to October and minimum values from December to January. NAIC were highest in summer and autumn, intermediate in spring, and lowest in winter. During spring and summer, NAIC in open spaces were significantly higher in rural areas than those in suburban areas. However, there were no significant differences in NAIC at forest sites among seasons. For open spaces, total suspended particles （TSP） were the dominant determining factor of NAIC in sum- mer, and air temperature and air humidity were the dominant determining factors of NAIC in spring, which were tightly correlated with Shanghai＇s ongoing urbanization and its impacts on the environment. R is suggested that urbanization could induce variation in NAIC along the urban-rural gradient, but that may not change the temporal variation pattern. Fur- thermore, the effects of urbanization on NAIC were limited in non-vegetated or less-vegetated sites, such as open spaces, but not in well-vegetated areas, such as urban forests. Therefore, we suggest that urban greening, especially urban forest, has significant resistance to theeffect of urbanization on NAIC.展开更多
The positive and negative terrains(P-N terrains) widely distributed across China's Loess Plateau constitute the dual structure characteristic of loess landforms. Analysis of loess P-N terrains at the watershed sca...The positive and negative terrains(P-N terrains) widely distributed across China's Loess Plateau constitute the dual structure characteristic of loess landforms. Analysis of loess P-N terrains at the watershed scale can serve to elucidate the structural characteristics and spatial patterns of P-N terrains, which benefits a better understanding of watershed evolution and suitable scales for loess landform research. The Two-Term Local Quadrat Variance Analysis(TTLQV) is calculated as the average of the square of the difference between the block totals of all possible adjacent pairs of block size, which can be used to detect both the scale and the intensity of landscape patches(e.g., plant/animal communities and gully networks). In this study, we determined the latitudinal and longitudinal spatial scale of P-N terrain patterns within 104 uniformly distributed watersheds in our target soil and water conservation region. The results showed that TTLQV is very effective for examining the scale of P-N terrain patterns. There were apparently three types of P-N terrain pattern in latitudinal direction(i.e., Loess Tableland type, Loess Hill type, and Transitional Form between Sand and Loess type), whereas there were both lower and higher values for P-N terrain pattern scales in all loess landforms in the longitudinal direction. The P-N terrain pattern alsoclearly presented anisotropy, suggesting that gully networks in the main direction were well-developed while others were relatively undeveloped. In addition, the relationships between the first scales and controlling factors(i.e., gully density, nibble degree, watershed area, mean watershed slope, NDVI, precipitation, loess thickness, and loess landforms) revealed that the first scales are primarily controlled by watershed area and loess landforms. This may indicate that the current spatial pattern of P-N terrains is characterized by internal force. In selecting suitable study areas in China' Loess Plateau, it is crucial to understand four control variables: the spatial scale of the P-N terrain pattern, the watershed area, the main direction of the watershed, and the loess landforms.展开更多
A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid ...A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid two phase flow and particulate mechanics in the standpipe,a method for predicting the pressure of the air passing through the recycle chamber and the pressure drop through the loop seal slit in these systems is also presented.The predicted pressure profile along the negative pressure gradient from the proposed model exhibits a good agreement with the experimental data.The experimental data show that the gas flow in the standpipe is always upward in the negative pressure gradients,while the direction ofthe superficial gas velocity through the recycle chamber of the loop seal does not affect the pressure drop in standpipe.It increases with an increasing negative pressure gradient.展开更多
<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> In India approximately 20% of the patients with brea...<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> In India approximately 20% of the patients with breast cancer are triple receptor negative. Owing to the aggressive nature and shorter disease-free survival judicious follow up and identification of failure pattern will benefit the patient. Similar studies have been conducted among non-Hispanic population and in China. This study aims to identify failure pattern in radically treated breast cancer patients who are triple receptor negative among Indian population. </span><b><span style="font-family:Verdana;">Methods</span></b><span style="font-family:Verdana;">: This prospective observational study was conducted in the Department of Radiation Oncology, a tertiary cancer centre in Kerala, India. The objective was to record the pattern of recurrence among triple negative breast cancer patients who completed their planned radical treatment. 171 patients with triple negative breast cancer were included in the study. Patients who completed the planned radical treatment were kept under regular follow up. Details of clinical examination and investigations during the follow up were recorded periodically. </span><b><span style="font-family:Verdana;">Results</span></b><span style="font-family:Verdana;">: Out of 171 patients 30 patients had </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">recurrence of disease. Median age of the population was 53 years. Among the 30 patients who had </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">recurrence, 16 patients (53%) had systemic relapse and 14 patients (47%) had locoregional relapse. Lung was found to be the most common site of distant metastasis (37%). Ipsilateral chest wall was found to be the most common site of locoregional relapse (50%). 6 months disease free survival was found to be 91.8%</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">and 1-year disease free survival was found to be 70.2%. </span><b><span style="font-family:Verdana;">Conclusion</span></b><span style="font-family:Verdana;">: Among radically treated triple negative breast cancers relapses, systemic recurrence was more than locoregional recurrences.</span></span></span></span>展开更多
Background: Triple negative breast cancer (TNBC) tends to present aggressively with rapid progression and poor survival. Methods: We retrospectively reviewed patients’ files to define TNBC patients’ characteristics,...Background: Triple negative breast cancer (TNBC) tends to present aggressively with rapid progression and poor survival. Methods: We retrospectively reviewed patients’ files to define TNBC patients’ characteristics, predictive and prognostic factors, pattern of recurrence and survival. Results: 965 cases were identified. 147 patients (15.2%) were TNBC. 71.1% patients were premenopausal. T2, T3, T4 tumors represented 46.1%, 32% and 14.1%, respectively. N0, N1, N2, N3 disease represented 18.5%, 50.9%, 27.8% and 2.8%, respectively. Stages II, III & IV constituted 34.1%, 44.2% and 15.5%, respectively. 31.5% patients received neoadjuvant chemotherapy with 17.7% complete pathological response. 19.5%, 35.9%, 44.6% patients had unknown, ≤20 and >20 Ki67, respectively. Among non-metastatic patients (n = 108), 21.3% patients developed relapse with median time to relapse of 11 months. 78.3% of them had visceral (88.3% lung) metastasis, 13% bone metastasis, 21.7% brain metastasis and 13% LRR. There is significantly high risk of relapse in patients with large tumor size [T4: 66.75%, T3: 22.9%, T2: 16.7%, T1: 0% (p = 0.002)], positive LNs [N3: 100%, N2: 37.9%, N1: 15.1%, N0: 4.3% (p 0.001)] and Ki67 [>20: 31.6% versus 10.8% for Ki67 ≤ 20 (P = 0.007)]. Multivariate analysis revealed only T4 and N2-3 were significantly associated with high probability for relapse (P = 0.022 & 0.038). The 3-year DFS and OS were 73.2% and 75% respectively. For metastatic patients (n = 20), the m PFS was 7 months and m OS 1.5 years. Conclusion: Our data confirms the aggressive nature of TNBC with significant risk of relapse for patients with large tumor and positive lymph nodes. Maintenance metronomic capecitabine, neoadjuvant/adjuvant immunotherapy could be beneficial for non-metastatic patients. Lungs and brain were the most common sites of distant failure with poor survival that necessitates administration of molecular biomarkers (BRCA mutations, PD-L1 expression and microsatellite instability) for patients’ selection for novel targeted therapy.展开更多
Conspecific negative density dependence(CNDD)is a potentially important mechanism in maintaining species diversity.While previous evidence showed habitat heterogeneity and species’dispersal modes affect the strength ...Conspecific negative density dependence(CNDD)is a potentially important mechanism in maintaining species diversity.While previous evidence showed habitat heterogeneity and species’dispersal modes affect the strength of CNDD at early life stages of trees(e.g.,seedlings),it remains unclear how they affect the strength of CNDD at later life stages.We examined the degree of spatial aggregation between saplings and trees for species dispersed by wind and gravity in four topographic habitats within a 25-ha temperate forest dynamic plot in the Qinling Mountains of central China.We used the replicated spatial point pattern(RSPP)analysis and bivariate paircorrelation function(PCF)to detect the spatial distribution of saplings around trees at two scales,15 and 50 m,respectively.Although the signal was not apparent across the whole study region(or 25-ha),it is distinct on isolated areas with specific characteristics,suggesting that these characteristics could be important factors in CNDD.Further,we found that the gravity-dispersed tree species experienced CNDD across habitats,while for wind-dispersed species CNDD was found in gully,terrace and low-ridge habitats.Our study suggests that neglecting the habitat heterogeneity and dispersal mode can distort the signal of CNDD and community assembly in temperate forests.展开更多
Since the students are influenced by Chinese thinking pattern,they apply Chinese linguistic knowledge in English writ-ing.This paper analyzes the influence of the negative transfer of mother tongue in English writing ...Since the students are influenced by Chinese thinking pattern,they apply Chinese linguistic knowledge in English writ-ing.This paper analyzes the influence of the negative transfer of mother tongue in English writing from the levels of lexis,syntaxand discourse.The aim is to pursue some efficient methods of the improvement of college English writing.展开更多
Background: Coagulase negative Staphylococci (CoNS) are normal inhabitants of the skin and mucous membranes and thus have been dismissed for a long time as culture contaminants even if they have been isolated from ste...Background: Coagulase negative Staphylococci (CoNS) are normal inhabitants of the skin and mucous membranes and thus have been dismissed for a long time as culture contaminants even if they have been isolated from sterile specimens. The risk factors for CoNS infections include patients who are immunocompromised, implanted with foreign bodies or with indwelling devices. The aim of this study was to determine the antimicrobial susceptibility patterns and presence of mecA gene in methicillin resistant CoNS isolated in a teaching and referral hospital in Kenya. Methodology: This was a cross sectional retrospective study. Archived isolates were sub-cultured on 5% sheep blood agar. Speciation and antimicrobial susceptibility patterns were performed by Vitek2 technique. The presence of mecA gene was determined by (PCR). Results: A total of seven species were identified with Staphylococcus epidermidis having the highest percentage at 45.4% and Staphylococcus warneri with the lowest at 2.6%. High resistance to antibiotics that were tested was observed regardless of the source of the isolate. MecA gene was found in 90% of the isolates. Conclusion: Coagulase negative Staphylococci exhibited high levels of resistance generally. Most of the isolates carried the mecA gene. Despite some of the isolates being resistant to Cefoxitin, the mecA gene was not found. There is a possibility that methicillin resistance in these isolates is mediated using a different mechanism.展开更多
Somatic mutations accumulate with age in human tissues.Clonal amplifi-cation of some mutations causes cancers and other diseases.However,it is unclear if random mutation accumulation affects cellular function without ...Somatic mutations accumulate with age in human tissues.Clonal amplifi-cation of some mutations causes cancers and other diseases.However,it is unclear if random mutation accumulation affects cellular function without clonal amplification.We tested this in cell culture,avoiding the lim-itation that mutation accumulation in vivo leads to cancer.展开更多
China＇s economy has undergone rapid transition and industrial restructuring. The term ＂urban industry＂ describes a particular type of industry within Chinese cities experiencing restructuring. Given the high percen...China＇s economy has undergone rapid transition and industrial restructuring. The term ＂urban industry＂ describes a particular type of industry within Chinese cities experiencing restructuring. Given the high percentage of industrial firms that have either closed or relo- cated from city centres to the urban fringe and beyond, emergent global cities such as Shanghai, are implementing strategies for local economic and urban development, which involve urban industrial upgrading numerous firms in the city centre and urban fringe. This study aims to analyze the location patterns of seven urban industrial sectors within the Shanghai urban region using 2008 micro-geography data. To avoid Modifiable Areal Unit Problem （MAUP） issue, four distance-based measures including nearest neighbourhood analysis, Kernel density estimation, K-function and co-location quotient have been exten- sively applied to analyze and compare the concentration and co-location between the seven sectors. The results reveal disparate patterns varying with distance and interesting co-location as well. The results are as follows： the city centre and the urban fringe have the highest intensity of urban industrial firms, but the zones with 20-30 km from the city centre is a watershed for most categories; the degree of concentration varies with distance, weaker at shorter distance, increasing up to the maximum distance of 30 km and then decreasing until 50 km; for all urban industries, there are three types of patterns, mixture of clustered, random and dispersed distribution at a varied range of distances. Consequently, this paper argues that the location pattern of urban industry reflects the stage-specific industrial restructuring and spatial transformation, conditioned by sustainability objectives.展开更多
Microtopography may affect the distribution of forests through its effect on rain redistribution and soil water distribution on the semi-arid Loess Plateau,China.In this study,we investigated the characteristics of mi...Microtopography may affect the distribution of forests through its effect on rain redistribution and soil water distribution on the semi-arid Loess Plateau,China.In this study,we investigated the characteristics of microtopography on two shady slopes（slope A,5 hm2,uniform slope;slope B,5 hm2,microtopography slope） and surveyed the height,the diameter at breast height and the location（x,y coordinates） of all selected individual trees（Robinia pseudoacacia Linn.,Pyrus betulifolia Bunge,Populus hopeiensis Hu ＆ Chow,Armeniaca sibirica Lam.,Populus simonii Carr.and Ulmus pumila Linn.） on slope A and slope B in the watersheds of Wuqi county,Shaanxi province.Subsequently,the effects of microtopography on the spatial pattern of forest stands were analyzed using Ripley＇s K（r） function.The results showed that：（1） The maximal aggregation radiuses of the tree species on the uniform slope（slope A） were larger than 40 m,whereas those of the tree species on the microtopography slope（slope B） were smaller than 30 m.（2） On slope B,the spatial association of R.pseudoacacia with P.betulifolia,A.sibirica,P.simonii and U.pumila varied from being strongly negative to positive at microtopography scales.The spatial association of Populus hopeiensis Hu ＆ Chow with U.pumila also varied from being strongly negative to positive at microtopography scales.However,there was no spatial association between P.betulifolia and P.hopeiensis,P.betulifolia and A.sibirica,P.betulifolia and P.simonii,P.betulifolia and U.pumila,P.hopeiensis and A.sibirica,P.hopeiensis and P.simonii,A.sibirica and P.simonii,A.sibirica and U.pumila,and P.simonii and U.pumila.On slope A,the spatial association between tree species were strongly negative.The results suggest that microtopography may shape tree distribution patterns on the semi-arid Loess Plateau.展开更多
This paper reports a cell trapping and patterning method using dielectric-pattern-assisted negative dielectrophoresis (dnDEP) that can achieve high-density cell arrays and complicated cell patterns.The dnDEP device co...This paper reports a cell trapping and patterning method using dielectric-pattern-assisted negative dielectrophoresis (dnDEP) that can achieve high-density cell arrays and complicated cell patterns.The dnDEP device consists of two planar metal electrodes and a patterned dielectric layer sandwiched in-between.The dielectric patterns generate non-uniform electric fields when an ac voltage is applied on the two electrodes,and the interaction of polarizable cells and the non-uniform electric fields imposes negative DEP forces on the cells,pushing them to the patterns in the dielectric layer.Using this dnDEP device,human lymphoma cells were successfully patterned in high-density microwell arrays and stellate structures.Thanks to the three-dimensional configuration and the small distance between the electrodes,cell trapping and patterning can be implemented with a voltage of 10 V.This dnDEP device has the advantages of simple configuration,low actuating voltage,and the compatibility with high conductivity physiological media for cell culturing.展开更多
基金supported by the National Natural Science Foundation of China(No.40971041)
文摘Negative air ions are natural components of the air we breathe Forests are the main continuous natural source of negative air ions （NAI）. The spatio-temporal patterns of negative air ions were explored in Shanghai, based on monthly monitoring in 15 parks from March 2009 to February 2010. In each park, sampling sites were selected in forests and open spaces. The annual variation in negative air ion concentrations （NAIC） showed peak values from June to October and minimum values from December to January. NAIC were highest in summer and autumn, intermediate in spring, and lowest in winter. During spring and summer, NAIC in open spaces were significantly higher in rural areas than those in suburban areas. However, there were no significant differences in NAIC at forest sites among seasons. For open spaces, total suspended particles （TSP） were the dominant determining factor of NAIC in sum- mer, and air temperature and air humidity were the dominant determining factors of NAIC in spring, which were tightly correlated with Shanghai＇s ongoing urbanization and its impacts on the environment. R is suggested that urbanization could induce variation in NAIC along the urban-rural gradient, but that may not change the temporal variation pattern. Fur- thermore, the effects of urbanization on NAIC were limited in non-vegetated or less-vegetated sites, such as open spaces, but not in well-vegetated areas, such as urban forests. Therefore, we suggest that urban greening, especially urban forest, has significant resistance to theeffect of urbanization on NAIC.
基金supported by the National Natural Science Foundation of China (NO. 41201464, 41371424)the Fundamental Research Funds for the Central Universities of China (GK201703042)
文摘The positive and negative terrains(P-N terrains) widely distributed across China's Loess Plateau constitute the dual structure characteristic of loess landforms. Analysis of loess P-N terrains at the watershed scale can serve to elucidate the structural characteristics and spatial patterns of P-N terrains, which benefits a better understanding of watershed evolution and suitable scales for loess landform research. The Two-Term Local Quadrat Variance Analysis(TTLQV) is calculated as the average of the square of the difference between the block totals of all possible adjacent pairs of block size, which can be used to detect both the scale and the intensity of landscape patches(e.g., plant/animal communities and gully networks). In this study, we determined the latitudinal and longitudinal spatial scale of P-N terrain patterns within 104 uniformly distributed watersheds in our target soil and water conservation region. The results showed that TTLQV is very effective for examining the scale of P-N terrain patterns. There were apparently three types of P-N terrain pattern in latitudinal direction(i.e., Loess Tableland type, Loess Hill type, and Transitional Form between Sand and Loess type), whereas there were both lower and higher values for P-N terrain pattern scales in all loess landforms in the longitudinal direction. The P-N terrain pattern alsoclearly presented anisotropy, suggesting that gully networks in the main direction were well-developed while others were relatively undeveloped. In addition, the relationships between the first scales and controlling factors(i.e., gully density, nibble degree, watershed area, mean watershed slope, NDVI, precipitation, loess thickness, and loess landforms) revealed that the first scales are primarily controlled by watershed area and loess landforms. This may indicate that the current spatial pattern of P-N terrains is characterized by internal force. In selecting suitable study areas in China' Loess Plateau, it is crucial to understand four control variables: the spatial scale of the P-N terrain pattern, the watershed area, the main direction of the watershed, and the loess landforms.
文摘A series of experiments on a solid feed system was performed to investigate the effect of negative pressure gradient on the gas-solid flow pattern and hydrodynamic characteristics.Based on the non-fluidized gas-solid two phase flow and particulate mechanics in the standpipe,a method for predicting the pressure of the air passing through the recycle chamber and the pressure drop through the loop seal slit in these systems is also presented.The predicted pressure profile along the negative pressure gradient from the proposed model exhibits a good agreement with the experimental data.The experimental data show that the gas flow in the standpipe is always upward in the negative pressure gradients,while the direction ofthe superficial gas velocity through the recycle chamber of the loop seal does not affect the pressure drop in standpipe.It increases with an increasing negative pressure gradient.
文摘<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> In India approximately 20% of the patients with breast cancer are triple receptor negative. Owing to the aggressive nature and shorter disease-free survival judicious follow up and identification of failure pattern will benefit the patient. Similar studies have been conducted among non-Hispanic population and in China. This study aims to identify failure pattern in radically treated breast cancer patients who are triple receptor negative among Indian population. </span><b><span style="font-family:Verdana;">Methods</span></b><span style="font-family:Verdana;">: This prospective observational study was conducted in the Department of Radiation Oncology, a tertiary cancer centre in Kerala, India. The objective was to record the pattern of recurrence among triple negative breast cancer patients who completed their planned radical treatment. 171 patients with triple negative breast cancer were included in the study. Patients who completed the planned radical treatment were kept under regular follow up. Details of clinical examination and investigations during the follow up were recorded periodically. </span><b><span style="font-family:Verdana;">Results</span></b><span style="font-family:Verdana;">: Out of 171 patients 30 patients had </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">recurrence of disease. Median age of the population was 53 years. Among the 30 patients who had </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">recurrence, 16 patients (53%) had systemic relapse and 14 patients (47%) had locoregional relapse. Lung was found to be the most common site of distant metastasis (37%). Ipsilateral chest wall was found to be the most common site of locoregional relapse (50%). 6 months disease free survival was found to be 91.8%</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">and 1-year disease free survival was found to be 70.2%. </span><b><span style="font-family:Verdana;">Conclusion</span></b><span style="font-family:Verdana;">: Among radically treated triple negative breast cancers relapses, systemic recurrence was more than locoregional recurrences.</span></span></span></span>
文摘Background: Triple negative breast cancer (TNBC) tends to present aggressively with rapid progression and poor survival. Methods: We retrospectively reviewed patients’ files to define TNBC patients’ characteristics, predictive and prognostic factors, pattern of recurrence and survival. Results: 965 cases were identified. 147 patients (15.2%) were TNBC. 71.1% patients were premenopausal. T2, T3, T4 tumors represented 46.1%, 32% and 14.1%, respectively. N0, N1, N2, N3 disease represented 18.5%, 50.9%, 27.8% and 2.8%, respectively. Stages II, III & IV constituted 34.1%, 44.2% and 15.5%, respectively. 31.5% patients received neoadjuvant chemotherapy with 17.7% complete pathological response. 19.5%, 35.9%, 44.6% patients had unknown, ≤20 and >20 Ki67, respectively. Among non-metastatic patients (n = 108), 21.3% patients developed relapse with median time to relapse of 11 months. 78.3% of them had visceral (88.3% lung) metastasis, 13% bone metastasis, 21.7% brain metastasis and 13% LRR. There is significantly high risk of relapse in patients with large tumor size [T4: 66.75%, T3: 22.9%, T2: 16.7%, T1: 0% (p = 0.002)], positive LNs [N3: 100%, N2: 37.9%, N1: 15.1%, N0: 4.3% (p 0.001)] and Ki67 [>20: 31.6% versus 10.8% for Ki67 ≤ 20 (P = 0.007)]. Multivariate analysis revealed only T4 and N2-3 were significantly associated with high probability for relapse (P = 0.022 & 0.038). The 3-year DFS and OS were 73.2% and 75% respectively. For metastatic patients (n = 20), the m PFS was 7 months and m OS 1.5 years. Conclusion: Our data confirms the aggressive nature of TNBC with significant risk of relapse for patients with large tumor and positive lymph nodes. Maintenance metronomic capecitabine, neoadjuvant/adjuvant immunotherapy could be beneficial for non-metastatic patients. Lungs and brain were the most common sites of distant failure with poor survival that necessitates administration of molecular biomarkers (BRCA mutations, PD-L1 expression and microsatellite instability) for patients’ selection for novel targeted therapy.
基金Shihong Jia was financially supported by the National Natural Science Foundation of China(Grant No.32001120)the Fundamental Research Funds for the Central Universities(Grant No.31020200QD026)+1 种基金Qiulong Yin was supported by the National Natural Science Foundation of China(Grant No.32001171)Ying Luo was supported by the Innovation Capability Support Program of Shaanxi(Grant No.2022KRM090).
文摘Conspecific negative density dependence(CNDD)is a potentially important mechanism in maintaining species diversity.While previous evidence showed habitat heterogeneity and species’dispersal modes affect the strength of CNDD at early life stages of trees(e.g.,seedlings),it remains unclear how they affect the strength of CNDD at later life stages.We examined the degree of spatial aggregation between saplings and trees for species dispersed by wind and gravity in four topographic habitats within a 25-ha temperate forest dynamic plot in the Qinling Mountains of central China.We used the replicated spatial point pattern(RSPP)analysis and bivariate paircorrelation function(PCF)to detect the spatial distribution of saplings around trees at two scales,15 and 50 m,respectively.Although the signal was not apparent across the whole study region(or 25-ha),it is distinct on isolated areas with specific characteristics,suggesting that these characteristics could be important factors in CNDD.Further,we found that the gravity-dispersed tree species experienced CNDD across habitats,while for wind-dispersed species CNDD was found in gully,terrace and low-ridge habitats.Our study suggests that neglecting the habitat heterogeneity and dispersal mode can distort the signal of CNDD and community assembly in temperate forests.
文摘Since the students are influenced by Chinese thinking pattern,they apply Chinese linguistic knowledge in English writ-ing.This paper analyzes the influence of the negative transfer of mother tongue in English writing from the levels of lexis,syntaxand discourse.The aim is to pursue some efficient methods of the improvement of college English writing.
文摘Background: Coagulase negative Staphylococci (CoNS) are normal inhabitants of the skin and mucous membranes and thus have been dismissed for a long time as culture contaminants even if they have been isolated from sterile specimens. The risk factors for CoNS infections include patients who are immunocompromised, implanted with foreign bodies or with indwelling devices. The aim of this study was to determine the antimicrobial susceptibility patterns and presence of mecA gene in methicillin resistant CoNS isolated in a teaching and referral hospital in Kenya. Methodology: This was a cross sectional retrospective study. Archived isolates were sub-cultured on 5% sheep blood agar. Speciation and antimicrobial susceptibility patterns were performed by Vitek2 technique. The presence of mecA gene was determined by (PCR). Results: A total of seven species were identified with Staphylococcus epidermidis having the highest percentage at 45.4% and Staphylococcus warneri with the lowest at 2.6%. High resistance to antibiotics that were tested was observed regardless of the source of the isolate. MecA gene was found in 90% of the isolates. Conclusion: Coagulase negative Staphylococci exhibited high levels of resistance generally. Most of the isolates carried the mecA gene. Despite some of the isolates being resistant to Cefoxitin, the mecA gene was not found. There is a possibility that methicillin resistance in these isolates is mediated using a different mechanism.
基金supported by the American Federation for Aging Research(the Sagol Network GerOmic Award for Junior Faculty)the US National Institutes of Health(P01AG017242,P01 AG047200,P01 AI172501,P01HL132825,P01 HL160476,P30 AG038072,R00 AG056656,U01 ES029519,U01 HL145560,and U19 AG056278)+2 种基金the University of Minnesota(Fesler-Lampert Chair for Aging Studies)the Veteran’s Affairs Medical Center of Boston(36C24122N0769)the European Union’s Horizon 2020 Research and Innovation Programme(810115-DYNASNET).
文摘Somatic mutations accumulate with age in human tissues.Clonal amplifi-cation of some mutations causes cancers and other diseases.However,it is unclear if random mutation accumulation affects cellular function without clonal amplification.We tested this in cell culture,avoiding the lim-itation that mutation accumulation in vivo leads to cancer.
基金Foundation： National Natural Science Foundation of China, No.41571124
文摘China＇s economy has undergone rapid transition and industrial restructuring. The term ＂urban industry＂ describes a particular type of industry within Chinese cities experiencing restructuring. Given the high percentage of industrial firms that have either closed or relo- cated from city centres to the urban fringe and beyond, emergent global cities such as Shanghai, are implementing strategies for local economic and urban development, which involve urban industrial upgrading numerous firms in the city centre and urban fringe. This study aims to analyze the location patterns of seven urban industrial sectors within the Shanghai urban region using 2008 micro-geography data. To avoid Modifiable Areal Unit Problem （MAUP） issue, four distance-based measures including nearest neighbourhood analysis, Kernel density estimation, K-function and co-location quotient have been exten- sively applied to analyze and compare the concentration and co-location between the seven sectors. The results reveal disparate patterns varying with distance and interesting co-location as well. The results are as follows： the city centre and the urban fringe have the highest intensity of urban industrial firms, but the zones with 20-30 km from the city centre is a watershed for most categories; the degree of concentration varies with distance, weaker at shorter distance, increasing up to the maximum distance of 30 km and then decreasing until 50 km; for all urban industries, there are three types of patterns, mixture of clustered, random and dispersed distribution at a varied range of distances. Consequently, this paper argues that the location pattern of urban industry reflects the stage-specific industrial restructuring and spatial transformation, conditioned by sustainability objectives.
基金financially supported by China National Scientific and Technical Innovation Research Project for 12~(th) Five Year Plan (2011BAD38B0601)the National Natural Science Foundation of China (41472313)the Natural Science Foundation of Shandong Province (ZR2011DM012,ZR2014DL002)
文摘Microtopography may affect the distribution of forests through its effect on rain redistribution and soil water distribution on the semi-arid Loess Plateau,China.In this study,we investigated the characteristics of microtopography on two shady slopes（slope A,5 hm2,uniform slope;slope B,5 hm2,microtopography slope） and surveyed the height,the diameter at breast height and the location（x,y coordinates） of all selected individual trees（Robinia pseudoacacia Linn.,Pyrus betulifolia Bunge,Populus hopeiensis Hu ＆ Chow,Armeniaca sibirica Lam.,Populus simonii Carr.and Ulmus pumila Linn.） on slope A and slope B in the watersheds of Wuqi county,Shaanxi province.Subsequently,the effects of microtopography on the spatial pattern of forest stands were analyzed using Ripley＇s K（r） function.The results showed that：（1） The maximal aggregation radiuses of the tree species on the uniform slope（slope A） were larger than 40 m,whereas those of the tree species on the microtopography slope（slope B） were smaller than 30 m.（2） On slope B,the spatial association of R.pseudoacacia with P.betulifolia,A.sibirica,P.simonii and U.pumila varied from being strongly negative to positive at microtopography scales.The spatial association of Populus hopeiensis Hu ＆ Chow with U.pumila also varied from being strongly negative to positive at microtopography scales.However,there was no spatial association between P.betulifolia and P.hopeiensis,P.betulifolia and A.sibirica,P.betulifolia and P.simonii,P.betulifolia and U.pumila,P.hopeiensis and A.sibirica,P.hopeiensis and P.simonii,A.sibirica and P.simonii,A.sibirica and U.pumila,and P.simonii and U.pumila.On slope A,the spatial association between tree species were strongly negative.The results suggest that microtopography may shape tree distribution patterns on the semi-arid Loess Plateau.
基金supported in part by the National Natural Science Foundation of China (Grant No. 60871006)
文摘This paper reports a cell trapping and patterning method using dielectric-pattern-assisted negative dielectrophoresis (dnDEP) that can achieve high-density cell arrays and complicated cell patterns.The dnDEP device consists of two planar metal electrodes and a patterned dielectric layer sandwiched in-between.The dielectric patterns generate non-uniform electric fields when an ac voltage is applied on the two electrodes,and the interaction of polarizable cells and the non-uniform electric fields imposes negative DEP forces on the cells,pushing them to the patterns in the dielectric layer.Using this dnDEP device,human lymphoma cells were successfully patterned in high-density microwell arrays and stellate structures.Thanks to the three-dimensional configuration and the small distance between the electrodes,cell trapping and patterning can be implemented with a voltage of 10 V.This dnDEP device has the advantages of simple configuration,low actuating voltage,and the compatibility with high conductivity physiological media for cell culturing.
