In the last few decades, the eutrophication of lakes has been a serious issue in the middle and lower reaches of the Yangtze River watershed. To explore the relationship between lake systems and ...anthropogenic activities, sediments were collected from the Shuanglong reservoir in the Dianchi watershed in Southwest China. Total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), and the carbon isotopic ratio (
δ
13
C) were analyzed in sediment cores to reconstruct the effects of natural succession and human activities on the past lacustrine environmental conditions. A reliable chronology of the sediment core was established by using the
210
Pb dating technique, which indicated that the age span of the 70-cm sediment core is from the years 1871 to 2011. Above – 31 cm depth in the core, TN, TP, TOC, C/N, and
δ
13
C increased significantly, indicating that eutrophication has occurred since the 1980s. By combining the indicators of
δ
13
C and C/N, it was shown that terrestrial and lacustrine components were the main sources of organic matter (OM) in the reservoir, which was mostly controlled by terrestrial C
3
plants and algae. Since the 1980s, increased sewage discharge, fish aquaculture, fertilizer application, population, and economic strength have sped up the eutrophication process, and the eutrophication was further intensified in 2001.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, the concentrations of seven heavy metals (Cr, Ni, Cu, Zn, As, Hg, and Pb) and Pb isotope in a sediment core from the Shuanglong reservoir, Southwestern China, were investigated. Based ...on the constant rate of supply (CRS) model, the age span of a 60 cm sediment sample was determined to range from the years 1944 to 2015. Combined with chronology and heavy metal content, the evolution of the sources and pollution levels of heavy metals showed a changing trend composed of various stages. The sources of heavy metals transitioned from natural origins in 1944–1964 to industrial origins in 1965–2004. The subsequent reduction in heavy metal content was mainly due to the vigorous implementation of environmental protection policies from 2005 to 2012. In recent years (2013–2015), the heavy metal content has increased due to frequent human activity. Principal component analysis (PCA), correlation analysis, and the coefficient of variation (CV) analysis indicated that Cr, Ni, Cu, Zn, and As were derived from natural processes, Pb mainly came from automobile manufacturing, and Hg was mainly from industrial sources. The values of the geo-accumulation index (Ig), single pollution index (Pi), and single potential ecological risk index (Er) showed that the contamination of Hg and Pb was slight to moderate. Moreover, the values of the potential ecological risk index (RI), pollution load index (PLI), and Nemerow index (PN) indicated that the Shuanglong reservoir is under low ecological risk.
Lake sediment records the evolution process of the interaction between human and nature. It is important to master the lacustrine sedimentation rate for the ecological environment assessment of ...catchment. A 60-cm sediment core was collected in the Da River Reservoir during 2019 to analyze radionuclides (
210
Pb and
137
Cs) massic activities, grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and metals (Mn, Cu, Al, and Pb) mass fractions to reconstruct the response of sedimentation rate to environmental evolution. The environmental changes in the small catchment were classified into the following three stages through cluster analysis (CA) for geochemical parameters in the sediment core: phase I (1881–1985), phase II (1987–1999), and phase III (2000–2018). The average depth sedimentation rates (ADSRs) of the three stages were 0.33, 0.90, and 1.50 cm/year, respectively. The sedimentation rates increased from the bottom to the surface layer, indicating that the exogenous inputs into the reservoir have been occurring. The sediment deposition in phase III was strongly disturbed by the environmental changes (such as warmer climate and intensified land use). Therefore, sedimentation rates showed a rapid increase. Both Pearson correlation analysis and redundancy analysis (RDA) showed that sedimentation rates were positively correlated with climatic factors, particle size, nutrients and metals mass fractions, elemental ratios, and socioeconomic parameters. Sedimentation rates show high sensitivity to anthropogenic activities and climatic change, which can be used to reconstruct the environmental evolution process at a small catchment scale.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, the concentrations of seven heavy metals (Cr, Ni, Cu, Zn, As, Hg, and Pb) and Pb isotope in a sediment core from the Shuanglong reservoir, Southwestern China, were investigated. Based ...on the constant rate of supply (CRS) model, the age span of a 60 cm sediment sample was determined to range from the years 1944 to 2015. Combined with chronology and heavy metal content, the evolution of the sources and pollution levels of heavy metals showed a changing trend composed of various stages. The sources of heavy metals transitioned from natural origins in 1944-1964 to industrial origins in 1965-2004. The subsequent reduction in heavy metal content was mainly due to the vigorous implementation of environmental protection policies from 2005 to 2012. In recent years (2013-2015), the heavy metal content has increased due to frequent human activity. Principal component analysis (PC A), correlation analysis, and the coefficient of variation (CV) analysis indicated that Cr, Ni, Cu, Zn, and As were derived from natural processes, Pb mainly came from automobile manufacturing, and Hg was mainly from industrial sources. The values of the geo-accumulation index (Ig), single pollution index (Pi), and single potential ecological risk index (Er) showed that the contamination of Hg and Pb was slight to moderate. Moreover, the values of the potential ecological risk index (RI), pollution load index (PIT), and Nemerow index (P^) indicated that the Shuanglong reservoir is under low ecological risk. Keywords: typical water-supply reservoir; heavy metals; sediment sources; pollution evaluation
This paper introduces the study of multi-robot coordinated collision avoidance and task collaboration in a multi-robot system considering the localization uncertainty. Use MATLAB simulation and use ...the Voronoi-based method to change the uncertainty of the robot's position in a specific working environment and compare the performance of the robot and the effect of avoiding collisions. An effective solution is also considered for the deadlock problem in motion planning. It is feasible and secure to use the Voronoi-based method to avoid collisions and complete tasks under the localization uncertainty.
Background Bladder cancer is the ninth most common cancer in the world; fewer than 15％ of transitional-cell carcinoma patients survive 2 years if left untreated.Although radical cystectomy is the ...standard treatment of choice,much of them relapse and the necessity of adjuvant chemotherapy is still under debate.The aim of the study was to evaluate the efficacy of adjuvant intraarterial chemotherapy （IAC） with gemcitabine and cisplatin （GC） on locally advanced bladder cancer.Methods This is a retrospective study on 60 patients with locally advanced bladder carcinoma who underwent radical cystectomy between May 2000 and June 2011.Patients were studied in two groups based on IAC and followed up for up to 5 years.Results Among 60 patients,there were 25 patients who underwent IAC （GC） after radical cystectomy （the IAC group） and 35 patients who underwent radical cystectomy alone （the control group）.Although not significant,the relapse rates were slightly reduced in the IAC group than in the control group.Patients with IAC had a reduction in mortality compared with patients without IAC over 5 years.Specifically,IAC significantly reduced about 82％ of mortality within the first year （hazard ratio=0.18,95％ Cl 0.03-0.97,P=-0.04）.Additionally,IAC was well tolerated and safe.The most common adverse effect was transient myelosuppression （10/25,40％）,which was resolved by various medical treatments.Conclusions Compared with radical cystectomy alone,radical cystectomy in combination with adjuvant IAC moderately but significantly reduces 1-year mortality.Our preliminary data showed only marginal benefit for the early survival.However,a randomized clinical study is needed to determine the long-term survival benefit.
Infective endocarditis due to Streptococcus gordonii: a case report WANG Xiaolin, ZHAO Gangde, LIN Lanyi, ZHOU Huijuan, FANG Yuehua, SHENG Zike, CAI Wei, XIE Qing, DING Yezhou, TAO Rong, WANG Hui
Zhenduanxue Lilun yu Shijian,
10/2022, Volume:
21, Issue:
5
Journal Article
Open access
Infective endocarditis (IE) is a rare but life-threatening disease. Invasive dental treatment (IDT) can produce temporary bacteremia, so they are considered as potential risk factors for IE. The ...physicians should pay attention to the possibility of IE, when patients have fever of unknown origin after IDT. Streptococcus gordonii is one of the common colonization bacteria in periodontal environment. A case of infective endocarditis caused by Streptococcus gordon after tooth extraction was reported. This case suggests an important link between IE and IDT.
Brucellosis, a zoonotic disease, was made statutorily notifiable in China in 1955. We analyzed the incidence and spatial-temporal distribution of human brucellosis during 1955-2014 in China using ...notifiable surveillance data: aggregated data for 1955-2003 and individual case data for 2004-2014. A total of 513,034 brucellosis cases were recorded, of which 99.3% were reported in northern China during 1955-2014, and 69.1% (258, 462/374, 141) occurred during February-July in 1990-2014. Incidence remained high during 1955-1978 (interquartile range 0.42-1.0 cases/100,000 residents), then decreased dramatically in 1979-1994. However, brucellosis has reemerged since 1995 (interquartile range 0.11-0.23 in 1995-2003 and 1.48-2.89 in 2004-2014); the historical high occurred in 2014, and the affected area expanded from northern pastureland provinces to the adjacent grassland and agricultural areas, then to southern coastal and southwestern areas. Control strategies in China should be adjusted to account for these changes by adopting a One Health approach.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dengue has been a notifiable disease in China since 1 September 1989. Cases have been reported each year during the past 25 years of dramatic socio-economic changes in China, and reached a historical ...high in 2014. This study describes the changing epidemiology of dengue in China during this period, to identify high-risk areas and seasons and to inform dengue prevention and control activities.
We describe the incidence and distribution of dengue in mainland China using notifiable surveillance data from 1990-2014, which includes classification of imported and indigenous cases from 2005-2014.
From 1990-2014, 69,321 cases of dengue including 11 deaths were reported in mainland China, equating to 2.2 cases per one million residents. The highest number was recorded in 2014 (47,056 cases). The number of provinces affected has increased, from a median of three provinces per year (range: 1 to 5 provinces) during 1990-2000 to a median of 14.5 provinces per year (range: 5 to 26 provinces) during 2001-2014. During 2005-2014, imported cases were reported almost every month and 28 provinces (90.3%) were affected. However, 99.8% of indigenous cases occurred between July and November. The regions reporting indigenous cases have expanded from the coastal provinces of southern China and provinces adjacent to Southeast Asia to the central part of China. Dengue virus serotypes 1, 2, 3, and 4 were all detected from 2009-2014.
In China, the area affected by dengue has expanded since 2000 and the incidence has increased steadily since 2012, for both imported and indigenous dengue. Surveillance and control strategies should be adjusted to account for these changes, and further research should explore the drivers of these trends.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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