Azvudine for the Treatment of COVID-19 in Pre-Existing Cardiovascular Diseases: A Single-Center, Real-World Experience.

COVID-19 can lead to adverse outcomes in patients with pre-existing diseases. Azvudine has been approved for treating COVID-19 in China, but the real-world data is limited. It is aimed to investigate the efficacy of Azvudine in patients with COVID-19 and pre-existing cardiovascular diseases. Patients with confirmed COVID-19 and pre-existing cardiovascular diseases are retrospectively enrolled. The primary outcome is all-cause death during hospitalization. Overall, 351 patients are included, with a median age of 74 years, and 44% are female. 212 (60.6%) patients are severe cases. Azvudine is used in 106 (30.2%) patients and not in 245 (69.8%). 72 patients died during hospitalization. After multivariate adjustment, patients who received Azvudine a lower risk of all-cause death (hazard ratio: 0.431; 95% confidence interval: 0.252-0.738; p = 0.002) than controls. Azvudine therapy is also associated with lower risks of shock and acute kidney injury. For sensitivity analysis in the propensity score-matched cohort (n = 90 for each group), there is also a significant difference in all-cause death between the two groups (hazard ratio: 0.189; 95% confidence interval: 0.071-0.498; p < 0.001). This study indicated that Azvudine therapy is associated with better outcomes in COVID-19 patients with pre-existing cardiovascular diseases.

LITAF Promotes Atherosclerotic Plaque Formation by Stimulating the NF-κB Inflammatory Pathway.

OBJECTIVE: Lipopolysaccharide-induced tumor necrosis factor-α factor (LITAF) protein is a newly discovered inflammatory protein. This study aims to study the role of LITAF in the formation of atherosclerosis. METHODS: A total of 10 C57BL/6J mice and 10 C57BL/6J mice with knockout of LITAF gene (C57BL/6J-LITAF-) were divided into two groups: the control group and the LITAF-/- group. The animals were accommodated for 16 weeks and then euthanized with their hearts and aortas isolated thereafter. Next, the roots of the mouse aorta were cryosectioned and stained with Oil Red O staining and immunohistochemical staining (CD68, α-SMA, and Masson), respectively. The area of Oil Red O staining and the proportion of positive expression after immunohistochemical staining were then compared between the control and LITAF-/- groups. At the same time, the blood of mice was collected for the extraction of proteins and RNA. The proteins and RNA were used to detect the expression of major molecules of the NF-κB inflammatory pathway in mice in the control group and the LITAF-/- group by Western blotting and RT-PCR. RESULTS: Oil Red O staining of the aortic root sections of the mice in each group revealed that the area of atherosclerotic plaques in the LITAF-/- group was substantially lower than that in the control group (P<0.05). Moreover, immunohistochemical staining determined that the expression level of α-SMA and CD68 in the LITAF-/- group was significantly lower than that in the control group, whereas the results were reversed following Masson staining (P<0.05). The expression levels of P65 and caspase 3 were significantly lower in the LITAF-/- group than in the control group (P<0.05), whereas the expression level of IκB was higher in the LITAF-/- group. CONCLUSION: LITAF might participate in the formation of atherosclerotic plaque through the NF-κB pathway and play a promoting role in the formation of atherosclerosis.

Research progress on coupling artificial intelligence and eco-environmental models.

Artificial intelligence (AI) has been widely used in the eco-environment field, but with shortcomings in revealing the laws of natural science, such as insufficient generalization ability and poor interpretability. In order to overcome these shortages and tap into complementary advantages, coupling AI and eco-environmental models containing physical mechanism has been a new research method with fast development in recent years. We introduced the classifications of AI used in eco-environmental field, outlined its applications, and mainly illustrated the progresses, status and inadequacies for the coupling research. Based on all the summaries, we proposed a new coupling method of physical mechanism and AI for reconstructing mechanism processes, followed by analyses of theoretical significance of partial parameters, feasibility of better generalization and interpretability, as well as prospection of imitating physical mechanism. At the end of the review, we discussed the trend of the coupling method of AI and eco-environment models.

[Identifying Relationship Between Nutrient Contents in Road-Deposited Sediment and Urban Basic Elements Based on Kernel Density Estimation].

Understanding the spatial connection between urban basic elements and pollutants in road-deposited sediment (RDS) is beneficial to the quantitative explanation of source areas and the precise management of urban nonpoint source pollution. The objective of this study was to explore the spatial connection between urban basic elements and nutrient contents in RDS, using Hanyang district of Wuhan city as a case study area. Total nitrogen (TN), total phosphorus (TP), exchangeable phosphorus (Ex-P), aluminum-bound phosphorus (Al-P), iron-bound phosphorus (Fe-P), occluded phosphorus (Oc-P), apatite phosphorus (Ca-P), detrital apatite phosphorus (De-P), and organophosphorus (Or-P) were chosen as representative pollutants, using the kernel density of the road network and seven groups of points of interest to represent the spatial distribution of urban basic elements. Through correlation analysis, the relationship between urban basic elements and nutrient contents in RDS was examined. The results showed that nutrient contents in RDS from Hanyang varied significantly with location. Specifically, Al-P, Oc-P, and Or-P had greater spatial variability in contrast with that of Ex-P and Fe-P, and the spatial variabilities of Ca-P and De-P both varied considerably with the particle size of the RDS. All types of urban basic elements and nutrient contents in RDS were correlated to different extents. Ex-P, Al-P, Oc-P, and Or-P were negatively correlated with the kernel density of most urban basic elements, whereas TN, TP, Fe-P, Ca-P, and De-P showed a positive correlation with the kernel density of most urban basic elements. TN, Al-P, Fe-P, Ca-P, and Or-P appeared to have much stronger correlation with the kernel density of urban basic elements compared to other selected pollutants, whereas the extent of correlation between them was influenced by the particle size of the RDS. In general, the correlation between nutrient contents in RDS and the kernel density of urban basic elements was more significant when the particle size of the RDS was under 450 µm and more robust when the particle size of the RDS was under 150 µm.

[Output Characteristics of Nitrogen and Phosphorus from Non-Point Source Pollution of Typical Land Use in A Micro-Watershed in Hilly Red Soil Region].

Scientific identification of runoff output characteristics of different land use patterns is the premise of controlling non-point source pollution in watersheds. The hydrology and output process of non-point source pollutants of forest, planting, and construction land with different rainfall characteristics were observed using a micro-watershed in a low mountain and hilly region of Southern China. The results showed that land use affected the hydrological characteristics and water quality processes of runoff. The characteristics of runoff generation time and cumulative rainfall under typical rainfall conditions were as follows:construction land(9 min, 2.0 mm), planting land(35 min, 11.4 mm), and forest land(108 min, 24 mm). There were significant differences in the three land use types in the pollution output process characteristics, such as pollutant concentration of total suspended matter(TSS), total nitrogen(TN) and phosphorus(TP), their components, N/P ratio change, and output intensity. Under typical rainfall, different land use types had similar pollution output stages, the mass concentrations of TSS, TN, and TP in the initial runoff were high, and then gradually stabilized. In addition, the first 30 min of the flow generation process contributed to the TSS, TN, and TP loads within the 23%-43% range. At the annual scale, there were significant differences between the contribution rate of each land use type to TN and TP load and ratio per unit area; the highest contribution to total pollution load was planting land(57% and 45%), while the highest in pollution load per unit area was construction land(9.50-12.50). The results also showed that the distribution of key non-point source areas had different spatial and temporal dynamics, which was comprehensively determined by the land use types in catchment units, the characteristics of annual rainfall, among other factors. With the increase in rainfall, the main contribution non-point source pollution in the micro-watershed changed from construction land to planting land. Targeted ecological interception strategies should be implemented based on the distribution characteristics of key source areas and characteristics of underlying surface runoff production process.

[Influence of Impervious Surface Roughness on Accumulation and Erosion of Urban Non-Point Source Particles].

At present, there are few reports about how impervious surface microstructure characteristics affect the runoff output process of street dust. Based on field observations of 12 rainfall events, this study quantified the microstructure characteristics of impervious surfaces by structural depth (roughness) and analyzed the correlation between roughness and accumulation characteristics of street dust on sunny days as well as scouring characteristics in rainy days. The results show that the roughness of the underlying surface notably affects dust accumulation on sunny days and scouring in rainy days. The correlation between roughness and street dust accumulation (r=0.664, P<0.01) was enhanced on sunny days, and the correlation between roughness and street dust erosion (r=0.527, P<0.01) was enhanced by rainfall. The correlation of street dust accumulation and roughness of each particle size segment increased as particle size increased (0.529 ≤ r<0.757), and the correlation between street dust scouring amount and roughness decreased as particle size increased (0.603 > R > 0.209). By establishing the linear regression model of roughness and rainfall, the cumulative pollution load of TSS in rainfall runoff can be well predicted. The effects of roughness and rainfall on the cumulative load of grain sizes<20 µm and >250 µm are significant. These results elucidate the role of roughness and rainfall analysis in predicting surface runoff pollution load characteristics, which can provide new information for predicting and evaluating urban non-point source pollution.

Prevalence and Antibiotic Resistance Characteristics of Extraintestinal Pathogenic Escherichia coli among Healthy Chickens from Farms and Live Poultry Markets in China.

Chicken products and chickens with colibacillosis are often reported to be a suspected source of extraintestinal pathogenic Escherichia coli (ExPEC) causing several diseases in humans. Such pathogens in healthy chickens can also contaminate chicken carcasses at the slaughter and then are transmitted to humans via food supply; however, reports about the ExPEC in healthy chickens are still rare. In this study, we determined the prevalence and characteristics of ExPEC isolates in healthy chickens in China. A total of 926 E. coli isolates from seven layer farms (371 isolates), one white-feather broiler farm (78 isolates) and 17 live poultry markets (477 isolates from yellow-feather broilers) in 10 cities in China, were isolated and analyzed for antibiotic resistance phenotypes and genotypes. The molecular detection of ExPEC among these healthy chicken E. coli isolates was performed by PCRs, and the serogroups and antibiotic resistance characteristics of ExPEC were also analyzed. Pulsed-field gel electrophoresis (PFGE) and Multilocus sequence typing (MLST) were used to analyze the genetic relatedness of these ExPEC isolates. We found that the resistance rate for each of the 15 antimicrobials tested among E. coli from white-feather broilers was significantly higher than that from brown-egg layers and that from yellow-feather broilers in live poultry markets (p < 0.05). A total of 22 of the 926 E. coli isolates (2.4%) from healthy chickens were qualified as ExPEC, and the detection rate (7.7%, 6/78) of ExPEC among white-feather broilers was significantly higher than that (1.6%, 6/371) from brown-egg layers and that (2.1%, 10/477) from yellow-feather broilers (p < 0.05). PFGE and MLST analysis indicated that clonal dissemination of these ExPEC isolates was unlikely. Serogroup O78 was the most predominant type among the six serogroups identified in this study, and all the six serogroups had been frequently reported in human ExPEC isolates in many countries. All the 22 ExPEC isolates were multidrug-resistant (MDR) and the resistance rates to ampicillin (100%) and sulfamethoxazole-trimethoprim (100%) were the highest, followed by tetracycline (95.5%) and doxycycline (90.9%). blaCTX-M was found in 15 of the 22 ExPEC isolates including 10 harboring additional fosfomycin resistance gene fosA3. Notably, plasmid-borne colistin resistance gene mcr-1 was identified in six ExPEC isolates in this study. Worryingly, two ExPEC isolates were found to carry both mcr-1 and blaNDM, compromising both the efficacies of carbapenems and colistin. The presence of ExPEC isolates in healthy chickens, especially those carrying mcr-1 and/or blaNDM, is alarming and will pose a threat to the health of consumers. To our knowledge, this is the first report of mcr-1-positive ExPEC isolates harboring blaNDM from healthy chickens.

[Effect of Check Dam on Phosphorus Transport and Retention in the Qingshui River, in Zhangjiakou City].

The transport and retention of phosphorus is a key process in nutrient cycling in river ecosystems and one of the main indicators used to evaluate river health. To explore the effect of check dams on the transport and retention of phosphorus, water samples were collected from four representative monitoring sections of a check-dammed reach of the Qingshui River in Zhangjiakou City. Various forms of phosphorus and runoff process were monitored, and local real-time rainfall data were also collected. The results showed that:① The average concentration ratios of total phosphorus (TP), total dissolved phosphorus (TDP), total particulate phosphorus (TPP), and total suspended solids (TSS) downstream to upstream of the dam were 50%, 79%, 47%, and 58%, respectively, indicating that the check dam has a retention effect on phosphorus and sediment. ② During non-rainfall periods, TP, TDP, and TPP were retained in the check dam reach, while these forms of phosphorus were both retained and transported in the check dam reach during period of rainfall; the ratio of TP, TDP, and TPP retaining rainfall events to total rainfall events was 63.6%, 9%, and 81.8%, respectively, indicating that the transport-retention process was affected by the time interval, duration, and intensity of rainfall events. ③ When a single rainfall event or continuous event exceeded 56 mm, the retention effect of the check dam notably decreased.

[Transition of Particulate Pollutant in the Parcel-based Catchment of Sponge City].

Most sponge city constructions in China are carried out in urban parcel-based catchments, and the quality and quantity of surface runoff can be controlled by several low impact development (LID) facilities. However, there are few reports on the generation and control of urban diffuse pollution. In this study, two areas with different hardening rates were compared to analyze the load conditions during the accumulation-wash-off-transport process of particulate pollutants. The results showed that the road surface in the catchment was the main underlying surface that the particulate pollutants contributed to. The road dust accumulation in the medium hardening rate (61.1%) and high hardening rate (73.6%) plots accounted for 88.4% (2.22-12.51 g ·m-2) and 90.1% (4.99-33.43 g ·m-2) of the catchment area unit, respectively. The contribution to the suspended solids (SS) load of runoff was 91.7% (0.97-7.34 g ·m-2) and 90.5% (0.92-18.77 g ·m-2), respectively. The SS load of road runoff accounted for approximately 95.2% and 83.1%, respectively. The pollution load (SS) after treatment by the LID facilities was approximately 24.0% and 40.2% of the surface runoff, respectively. The particle size distribution of road dust during the accumulation and wash-off processes was>150 µm, while that in surface and output runoff was <50 µm. With the increase in the impervious area, the distribution of finer particles (<105 µm) in the process of accumulation and wash-off increased (24.4%, 106.4%), while the distribution of particles <50 µm in road runoff decreased (12.4%). The particle size distribution of the accumulated, washed dust, and the rain runoff on the roof were roughly similar to those on the road. However, compared to the particle size distribution of road dust, in the accumulation and wash-off processes, the coarser particles (>1000 µm) of the medium hardening rate plot and the particles of size 250-450 µm and <45 µm of the high hardening rate plot increased significantly (>1000 µm: 58.1%, 108.5%; 250-450 µm: 72.9%, 41.8%; <45 µm: 59.2%, 64.8%). The results revealed the entire distribution process (accumulation-wash-off-transport) of particulate pollutants and the effect of LID facilities on the total SS pollution load of the catchment, which can provide an important reference for the scientific assessment of the project performance of LID installation in urban parcel-based catchments.

[Influence of Pervious/Impervious Pattern on Runoff and Pollution in Parcel-based Catchment].

Determining the influence of pervious/impervious underlying surface pattern (composition, position, proportion, etc.) on the generation capacity of surface runoff and pollution in the urban parcel-based catchment could aid in alleviating the urban waterlogging and control non-point source pollution significantly. Landscape metrics were used to analyze the relationship between the characteristics of pervious/impervious underlying surface pattern and total runoff (Q) and the cumulative load of dissolved pollutants (Ld) and particulate pollutants (Lp). The results showed that: ① For the metrics of fragmentation, the patch density (PD) was positively correlated with Q and Ld. and largest patch index (LPI) was negatively correlated with them. Especially, the PD exhibited a significantly positive correlation with Ld(r=0.59, P<0.05, calculated in COD). However, the LPI exhibited a significantly negative correlation with Ld (r=-0.60, P<0.05, calculated in COD). ② For the metrics of complexity, landscape shape index (LSI) was positively correlated with Q and Lp, and mean shape index (MSI) was negatively correlated with them. Especially, the LSI exhibited a significantly positive correlation with Lp (r=0.61, P<0.05, calculated in TP) significantly. However, the MSI exhibited a significantly negative correlation with Lp (r=-0.62, P<0.01, calculated in TP) significantly. ③ For the metrics of vergence, the split index (SPLIT) was positively correlated with Q and Ld, and the cohesion index (COHESION) was negatively correlated with them. The COHESION exhibited a significantly negative correlation with Ld(r=-0.59, P<0.05, calculated in COD), whereas the SPLIT exhibited a significantly positive correlation with Ld (r=0.6, P<0.05, calculated in COD). ④ In the planning on the distribution and pattern of pervious surface under small-scale catchment, it is suggested that the scattered small-regular patches should be transformed to large-irregular patches or patch group. The relationship of the fragmentation, complexity, and vergence of pervious/impervious surface, with the runoff generation, and pollution output in parcel-based catchment was analyzed, which provided a new method for rainfall runoff and pollution control by considering rational allocation of LID facilities in terms of its pattern characteristics (area, distance, shape, etc.).

[Pollutant Transport Analysis and Source Apportionment of the Entire Non-point Source Pollution Process in Combined Sewer Systems].

A comprehensive and scientific understanding of non-point source pollutant transport pathways and source apportionment in combined sewer systems is essential for managing and improving the urban water environment. This study analyzed build-up and wash-off processes of pollutants on road surfaces and in sewers within a catchment of combined sewer systems in a typical old district in Zhuhai. Besides, source apportionment of the entire urban non-point source pollution was investigated by using the mass conservation method. The outcomes revealed that the build-up load of road deposited sediments in the study area was (28.81±10.69) g·m-2. The average wash-off load of road deposited sediments during five different rainfall events was (19.27±10.90) g·m-2 and the wash-off percentage was (52.69±13.3)%. The event mean concentrations of suspended solids (SS) in road runoff were 52-109 mg·L-1, and the event mean concentrations of SS in sewer runoff were 68-158 mg·L-1. Source apportionment analysis showed that road runoff, domestic wastewater, and sewer sediments contributed 39%-72%, <20%, and 13%-56% to SS, respectively. The thickness of sewer sediments increased by 1-14 cm during light and moderate rains, and the thickness decreased by 7-17 cm during heavy rains. It was found that rainfall characteristics affected the contribution percentages of pollution sources. The contribution of pollution from road runoff, domestic sewage, and sewer sediments in combined sewer systems were 2%-52%, 9%-65%, and 8%-81%, respectively. The derived outcomes should be useful for developing recommendations to control non-point source pollution in combined sewer systems and improve urban receiving water quality in China.

Apatinib Plus Chemotherapy Shows Clinical Activity in Advanced NSCLC: A Retrospective Study.

Apatinib is an oral TKI with antiangiogenic properties, and it is currently approved for the treatment of advanced gastric cancer in China. This agent has also been tested in other human solid tumors, including non-small cell lung cancer (NSCLC). Since the combination of chemotherapy and an antiangiogenic agent has been shown to be a feasible strategy in NSCLC, it is conceivable that a similar approach combining apatinib with chemotherapy may yield clinical activity. With this in mind, we investigated the efficiency of apatinib in combination with pemetrexed or docetaxel in advanced NSCLC. We treated a total of 20 patients with metastatic NSCLC adenocarcinoma with apatinib in combination with either pemetrexed or docetaxel from January 2016 to March 2017. The performance status of these patients was 0 or 1. All of these patients had been previously treated with two or more lines of treatment and had experienced disease progression prior to study enrollment. The overall objective response rate (ORR) was 30%, with 6 patients who had partial response (PR), 10 patients who had stable disease (SD), and 4 patients who had progressive disease (PD). The main adverse events were skin rash, hypertension, palmar-plantar erythrodysesthesia syndrome, diarrhea, and fatigue. Nearly 30% of patients required interruption of treatment as a result of toxicity. Our study demonstrated that apatinib combined with systemic cytotoxic chemotherapy has clinical efficacy in patients with disease-refractory metastatic NSCLC and provides evidence for further studies investigating apatinib-based combination regimens.

[Evaluation of Effect of Urban Non-point Source Pollution Control on Porous Asphalt-Bio-retention Combined Roads].

Different combinations of low impact development (LID) technologies can be applied for control of urban non-point source pollution. There are currently few evaluations of urban non-point source pollution and pollution load reduction based on a combination of porous asphalt and bio-retention. Taking Shenzhen International Low Carbon City as an example, road-deposited sediments were collected prior to and after rainfall events. Runoff was monitored under six typical rainfall events, from porous asphalt and the inlet/outlet of bio-retention. Through analysis of changes in the process of "build-up-wash-off-transport" of pollutant loads, the average build-up of road-deposited sediments in the study area was found to be (15.80±3.79) g·m-2; the mass percentage of road-deposited sediments (size>250 µm) was approximately 65.14%. The average wash-off percentage of six different intensity rainfall events was 17.15%, and road-deposited sediments (size<105 µm) were carried by 62.71%-74.94%. The average pollution loads of surface runoff pollutants SS, TN, and TP were 2.02, 0.025, and 0.0013 g·m-2, respectively. The removal rates of SS, TN, and TP through porous asphalt under infiltration and filtration were 70.26%, 46.29%, and 19.27%, respectively. The secondary purification removal rates of runoff water in bio-retention were 85.25%, 20.22%, and 70.27%, respectively. Pollutant loads into Dingshan River totaled 0.08, 0.011, and 0.0003 g·m-2, representing 4.05%, 43.47%, and 24.39% of runoff. The combination thus had a significant effect on runoff purification. Through quantitative research on the formation of non-point source pollution, this paper provides a scientific basis for estimating pollution loads of urban non-point source pollution and evaluating the performance of LID projects. It makes suggestions for the popularization and application of LID and sponge city design in China.

[Net anthropogenic nitrogen input to Huaihe River Basin, China during 1990-2010].

Social economy in Huaihe River Basin had undergone enormous changes during 1990-2010. The grain yield had increased by 58%, from 64.14 million tons to 101.21 million tons, and the urbanization rate had increased by 22%, from 13% to 35%. Assessing the negative impacts of these high intensive human activities caused by rapid social development on terrestrial ecosystem would serve as a scientific basis for quantitative management of regional ecology. This paper estimated the spatial and temporal distribution of net anthropogenic nitrogen input (NANI) in Huaihe River Basin during 1990-2010. The results showed that there was an increasing trend in NANI in the period of 1990-2001, and after that this trend was slower. The NANI increased from approximately 17232 kg N · km(-2) · a(-1) in 1990 to a peak of 28771 kg N · km(-2) · a(-1) in 2003, and then declined to 26415 kg N · km(-2) · a(-1) in 2010. Chemical fertilizer and atmospheric deposition were the largest two sources of NANI, followed by food & feed import and biological nitrogen. Contributions from both chemical fertilizer and atmospheric deposition had been increasing continuously, respectively from 64% and 16% in 1990 to 77% and 19%. Our findings implied that the shift from fertilizer-supported agriculture and fossil fuel-supported industry to sci-tech lead economic development is urgently needed.

[Responses of riverine nitrogen export to net anthropogenic nitrogen inputs: a review].

Nitrogen (N) inputs caused by human activities potentially influences the aquatic environment. However, researches on N pollution in China are mainly discussed from the microscopic point of view, i. e. field experiment. Watershed-scale diagnosis of N pollution has just started, leading to ambiguous identification of ecological problems, pollution issues and pollution potential at watershed scale. In this paper, relationships between net anthropogenic N inputs (NANI) and riverine N flux (RNF) and factors influencing these relationships at watershed scale had been investigated. This would help diagnose ecological and environmental problems at watershed scale, understand the roles of natural climate and human activities in affecting N fluxes, and ultimately provide both theoretical and practical insights into environmental management decisions.

[Characteristics of heavy metal contamination in street dusts along the urban-rural gradient around Beijing].

Road-deposited sediment (RDS) is an important carrier of the diffused pollution. This study analyzed the influences of the urban-suburban-rural gradient (central urban, urban village, central suburban county, rural town, and rural village areas) on the content and chemical fractions of heavy metals. The concentrations of five heavy metals (Cr, Cu, Ni, Pb, and Zn) in RDS in the central urban area were the highest, and the lowest concentrations appeared in the rural village area. The mass of RDS per unit area were opposite to the metals concentrations in distribution. The proportion of weak acid extractable Ni, Pb, and Zn in RDS was higher than that of Cr and Cu. The contribution of heavy metals in smaller grain size (32.4% - 62.4%) was greater than that in coarser grain size (22.9% - 49.6%). It will be helpful to reduce the RDS pollution for runoff and apply appropriate strategies for controlling runoff pollution from RDS according to RDS and its contribution to heavy metal pollution along the urban-rural gradient.

[Migration and transformation of heavy metals in street dusts with different particle sizes during urban runoff].

The heavy metal pollution in runoff caused by street dust washoff has been an increasingly prominent problem in the context of rapid urbanization in China. Based on measurement of heavy metal contents in street dusts with different particle sizes and an experiment of street dust washoff using simulated rainfall, we analyzed the role of particle size of street dust in heavy metal pollution, and the variation in geometrical forms of heavy metals during street dust washoff. Our results showed that the heavy metal concentration decreased from "static" street dust to "dynamic" runoff particulate in the same diameter particles. Heavy metals in street dust were dissolved and extracted during washoff. The average loss proportion of the five metals (Cr, Cu, Ni, Pb, Zn) were 24.3%, 56.8%, 34.3%, 22.8%, 27.3%, respectively. The loss proportion increased with the decrease of the particle size of street dust. Proportion of extracted form dust was higher in street than that in washoff samples, which suggested some dissolved loss in water. In washoff samples, dissolved metals of waterphase did not have significant changes; however, heavy metals with particle state in waterphase reduced rapidly during runoff. Meanwhile, heavy metals of solid-phase particle reduced during runoff. Street dust with small particle size had higher loss rate during runoff. The variation rate of street dust loss among different particle sizes varied from 4.6% to 62.1%. Street dust with smaller particle size had higher migration ability in runoff, which was more risky to urban water pollution.

Analysis of Na(+)/Ca (2+) exchanger (NCX) function and current in murine cardiac myocytes during heart failure.

Na(+)/Ca(2+) exchanger (NCX) plays important roles in cardiac electrical activity and calcium homeostasis. NCX current (I(NCX)) shows transmural gradient across left ventricle in many species. Previous studies demonstrated that NCX expression was increased and transmural gradient of I(NCX) was disrupted in failing heart, but the mechanisms underlying I(NCX) remodeling still remain unknown. In present study, we used patch clamp technique to record I(NCX) from subepicardial (EPI) myocytes and subendocardial (ENDO) myocytes isolated from sham operation (SO) mice and heart failure (HF) mice. Our results showed that I(NCX) was higher in normal EPI cells compared with that in ENDO, whatever for forward mode or reverse mode. In HF group, I(NCX) was significantly up-regulated, but EPI-ENDO difference was disrupted because of a more increase of I(NCX) in ENDO myocytes. In order to explore the molecular mechanism underlying remodeling of I(NCX) in failing heart, we detected the protein expression of NCX1 and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) by Western blot. We found that CaMKII activity was dramatically enhanced and parallel with the expression of NCX1 in failing heart. Our study demonstrated that transmural gradient of I(NCX) existed in murine left ventricle, and increased activity of CaMKII should account for I(NCX) remodeling in failing heart.

Protective effect of caffeine administration on myocardial ischemia/reperfusion injury in rats.

Many studies have examined the association between coffee consumption and risk of cardiovascular disease, but the results remain controversial. Caffeine is one of the main biologically active compounds of coffee. The aim of this study was to investigate the potential role of caffeine on myocardial ischemia/reperfusion (I/R) injury in the rats. We administered caffeine (25 mg/kg per day) or saline in rats for 4 weeks before myocardial ischemia/reperfusion operation. Compared with the sham group, caffeine treatment decreased ischemia-associated infarct size, serum creatine kinase, and lactate dehydrogenase 3-h reperfusion after 30-min ischemia. Myocardial neutrophil infiltration (assessed by myeloperoxidase activity) was significantly decreased compared with the control group. Meanwhile, caffeine reduced the myocardial apoptosis and suppressed the activation of caspase 3 during myocardial I/R. Importantly, we observed a strong poly(ADP-ribose) polymerase (PARP) activation during myocardial I/R, and caffeine administration inhibited PARP activation and attenuated the expression of PARP-related proinflammatory mediators such as inducible nitric oxide synthetase, IL-6, and TNF-α, all of which may be correlated with downregulated nuclear factor κB activity. We concluded that caffeine protected against myocardial I/R injury by inhibiting inflammation and apoptosis.

The mechanisms underlying ICa heterogeneity across murine left ventricle.

L-type calcium current (I(Ca)) plays a critical role in excitation-contraction coupling (ECC). Unlike transient outward K(+) current (I(to)), it is controversial whether I(Ca) transmural gradient exists in left ventricle. Although previous studies have shown some evidences for I(Ca) heterogeneity, the mechanism is still unknown. In this study, the authors recorded I(Ca) from epicardial (EPI) and endocardial (ENDO) myocytes isolated from murine left ventricle using patch-clamp technique. It was found that I(Ca) density was obviously larger in EPI than in ENDO (7.3 ± 0.3 pA/pF vs. 6.2 ± 0.2 pA/pF, at test potential of +10 mV, P < 0.05). The characteristics of I(Ca) showed no difference between these two regions except for the fast inactivation time constants (9.9 ± 0.9 ms in EPI vs. 13.5 ± 0.9 ms in ENDO, at test potential of +10 mV, P < 0.05). In addition, it was explored the molecular mechanism underlying I(Ca) transmural gradient by Western blot. The authors demonstrated that a higher activity of CaMKII in ENDO cells induced more nuclear translocation of p65, a component of nuclear factor-kappa B (NF-kB). Consequently, p65 in ENDO inhibited more transcription of Cav1.2, the main encoding gene for L-type calcium channels (LTCCs). These results reveal a difference in CaMKII/p65 signal pathway between EPI and ENDO that underlies this mechanism of I(Ca) heterogeneity in murine left ventricle.