Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,...Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.展开更多
Americans have always been proud of their democratic system. Since the end of World War Ⅱ, the United States has even used its democratic system as a template to “democratize” some other countries. However, in rece...Americans have always been proud of their democratic system. Since the end of World War Ⅱ, the United States has even used its democratic system as a template to “democratize” some other countries. However, in recent years, the domestic democratic chaos in the United States has intensified, causing widespread doubts about the American political system and its democratic model.展开更多
BACKGROUND Mediastinal lymph nodes(MLNs)can be enlarged due to various benign or malignant causes.Endoscopic ultrasound(EUS)is often employed for the acquisition of tissue specimens of the enlarged MLN(EMLN).AIM To de...BACKGROUND Mediastinal lymph nodes(MLNs)can be enlarged due to various benign or malignant causes.Endoscopic ultrasound(EUS)is often employed for the acquisition of tissue specimens of the enlarged MLN(EMLN).AIM To determine the causes,document the symptoms,and determine factors predicting good yield of EUS-guided EMLN biopsy.METHODS All patients having EMLN(>10 mm)on thoracic imaging and referred for EUSguided biopsy were included in this retrospective observational study.Adequacy of the tissue specimen was assessed by the endoscopist with macroscopic on-site evaluation(MOSE)and then sent to a histopathologist for final diagnosis.Analysis for factors predicting good biopsy yield was then performed.RESULTS Of the total 243 patients with EMLN,131(53.9%)were males.The mean age was 47.6(±14.7)and range 14-86 years.Commonest causes of EMLN were tuberculosis 82(33.7%),anthracosis 53(21.8%),neoplastic disease 43(17.7%)and sarcoidosis 14(5.8%).Among the 43 patients with neoplastic diseases:40 had metastatic disease(breast 9,lung 7,pancreatobiliary 6,esophagus 5,kidney 5,hepatocellular 2,neuroendocrine 2,gastrointestinal stromal 1,undetermined 3)and 3 had primary malignancies(lymphoproliferative disorder 2,Kaposi sarcoma 1).Chest related clinical symptoms were absent in more than half the patients with tuberculosis 51/82(62.2%),anthracosis 31/53(58.5%)and neoplastic disease 28/43(65.1%).Factors associated with good biopsy yield were:Subcarinal location of MLN(P=0.026),MLN size>12 mm(P<0.0001),use of fine-needle biopsy(vs fine-needle aspiration)(P=0.049)and satisfactory MOSE(P<0.0001)on univariate analysis;while MLN size>12 mm(P=0.005)and satisfactory MOSE(P<0.0001)on multivariate analysis.CONCLUSION Tuberculosis,anthracosis and metastatic disease were the commonest causes of EMLN.More than half the cases with EMLN had no chest-related symptoms.Large MLN size and satisfactory MOSE observation predicted a good biopsy yield.展开更多
Based on the monitoring data of air quality and conventional meteorological data in Shaoyang City,a severe pollution weather process in Shaoyang from December 25,2023 to January 1,2024 was analyzed from the aspects of...Based on the monitoring data of air quality and conventional meteorological data in Shaoyang City,a severe pollution weather process in Shaoyang from December 25,2023 to January 1,2024 was analyzed from the aspects of changes in pollutant concentration,circulation background,and changes in various meteorological elements.The results show that this severe pollution weather process was a compound pollution process caused by accumulation of local pollutants and transportation of external pollutants,during which the primary pollutant was PM_(2.5).During the accumulation stage,the ground was controlled by a uniform pressure field,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the wind on the ground was from the northeast,which was conducive to the input of upstream pollution clusters into the city.Pollutant concentration was inversely correlated with daily average sea-level pressure,and positively correlated with daily average temperature.Wind speed and direction were closely related to PM_(2.5)concentration.During the accumulation stage,the ground was mainly dominated by weak winds,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the continuous northeastward wind continuously transported upstream pollutants to Shaoyang area.Local pollutants accumulated in the previous stable weather process and the terrain led to the outbreak of local pollution.展开更多
Based on abnormalities in tear film structure and dynamics,dry eye syndrome is primarily classified into five types:aqueous-deficient,mucin-deficient,evaporative/lipid-deficient,tear dynamics disorder,and mixed type.T...Based on abnormalities in tear film structure and dynamics,dry eye syndrome is primarily classified into five types:aqueous-deficient,mucin-deficient,evaporative/lipid-deficient,tear dynamics disorder,and mixed type.The disease has diverse triggers,commonly including:lacrimal gland dysfunction;meibomian gland dysfunction accelerating tear evaporation;reduced blinking due to prolonged electronic device use;contact lens wear interfering with the tear film;medication side effects;environmental factors;hormonal fluctuations;certain ophthalmic surgeries,for example,LASIK.Treatment requires targeting specific pathogenic mechanisms,with the core focus on controlling inflammation,restoring tear film stability,and improving related gland function.展开更多
Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,s...Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.展开更多
A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting....A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting. Furthermore, it was observed that the earlier being sown, the greater the rate of premature bolting when being sown prior to middle August. The rate of premature bolting observed in seedlings sown on August 8 was recorded at 35.6%. It was noted that as the age of the seedlings increased, the rate of premature bolting correspondingly increased. There were notable differences in the tolerance of various cultivars to elevated temperatures and prolonged sunlight exposure. For instance, cultivars such as Zhangjie 1 and Sichuan Shaguodi, which exhibit greater heat resistance, did not demonstrate premature bolting when sown in early August. The prolonged exposure to elevated temperatures, drought conditions, and extended periods of sunlight during the seedling stage of Huarong large leaf mustard, coupled with delayed irrigation and transplantation, contributed to the occurrence of premature bolting. The Huarong large leaf mustard, when been sown from late August to early September and transplanted at the appropriate time, exhibited normal growth and development, with no instances of premature bolting observed. It is advisable to select heat-resistant varieties, such as Zhangjie 1, prior to middle August. Huarong large leaf mustard should be sown in early to middle September. Additionally, it is essential to ensure centralized production and timely release of seeds, prompt transplantation and harvesting, and enhance the management of pests and diseases.展开更多
Cloudy-rainy weather for several days in 2007 was featured with the longest duration and the most serious extent of injury since the time from which there was meteorology observation record in Shandong.The causes of t...Cloudy-rainy weather for several days in 2007 was featured with the longest duration and the most serious extent of injury since the time from which there was meteorology observation record in Shandong.The causes of this process were analyzed in this article in terms of general circulation,character of physical quantity and tropical cyclone.The result showed that the precipitation process was a long wave adjustment process and it took place during the transformation process of general circulation turning from the zonal to the radial.During the cloudy-rainy weather process,the Ural mountain ridge and the Western Pacific subtropical high were more abnormally strong and in the further north than that in any other years.The tropical cyclone in the south of the subtropical cyclone activity was more frequent.There was more shortwave in middle latitudes of Asian.The cold air masses Siberia went down south.The cold air masses joined with the current of air in the Lower Yellow River.This led to the lasting cloudy-rainy weather for several days in Shandong.展开更多
Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Gastroenterologists and other involved clinicians are generally assiste...Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Gastroenterologists and other involved clinicians are generally assisted by international guidelines in its management.However,NVUGIB due to peptic ulcer disease only is mainly addressed by current guidelines,with upper gastrointestinal endoscopy being recommended as the gold standard modality for both diagnosis and treatment.Conversely,the management of rare and extraordinary rare causes of NVUGIB is not covered by current guidelines.Given they are frequently lifethreatening conditions,all the involved clinicians,that is emergency physicians,diagnostic and interventional radiologists,surgeons,in addition obviously to gastroenterologists,should be aware of and familiar with their management.Indeed,they typically require a prompt diagnosis and treatment,engaging a dedicated,patient-tailored,multidisciplinary team approach.The aim of our review was to extensively summarize the current evidence with regard to the management of rare and extraordinary rare causes of NVUGIB.展开更多
After the illustration of the development of quadrangle courtyards,the paper has analyzed the emergence of square architectural form and the formation of axial symmetrical pattern with the hall in the front and room a...After the illustration of the development of quadrangle courtyards,the paper has analyzed the emergence of square architectural form and the formation of axial symmetrical pattern with the hall in the front and room at the back and with wing rooms on the left and right side.It has analyzed the formation,development,climax,damage and inheritance of quadrangle courtyard,and considered that it could manifest Chinese traditional humanistic idea and aesthetic idea,and is in possession of profound cultural connotation and regional feature.On this basis,causes for quadrangle courtyards have been studied.The primary cause at the initial stage lies in human body structure theory and the perfection of quadrangle courtyards at later stage depends on ethic order theory.展开更多
The <strong><em>purpose</em></strong> of this research was to ascertain causes of Restocking Delays in a Distributor Company of Airtel Airtime (<em>AA</em>) that give justification ...The <strong><em>purpose</em></strong> of this research was to ascertain causes of Restocking Delays in a Distributor Company of Airtel Airtime (<em>AA</em>) that give justification for benefits of using Real Time Inventory Tracking (<em>R.T.I.T</em>) in an attempt to mitigate Restocking Delays. From a study out at the Private Marketing and Trading Services (<em>PMTS</em>) an Authorized Distributor of Airtel Products undertaken in 2017 evidenced by Airtime scratch card and Electronic, <strong><em>E-Recharge</em></strong> Airtime among other forms to encourage <em>R.T.I.T</em> among other products in Telecom Companies and other Business Enterprises. The research comprises of the following areas among which included a detailed focus on a <strong><em>Qualitative</em></strong> and <strong><em>Quantitative approach</em></strong> in obtaining different <strong><em>categories</em></strong> of Restocking Delays in form of <strong><em>Themes</em></strong> and <strong><em>Sub Themes</em></strong> encountered in the Distribution Supply Chain (<em>SC</em>) of <em>AA</em> that is contained in this paper. This research continues to capture an in-depth explanation of the <strong><em>Managerial</em></strong> and <strong><em>Operational</em></strong> causes of restocking delays in respect to <em>AA</em>. Similarly, fast consumer products and services other than <em>AA</em> require a solution to <strong><em>Restocking Delays</em></strong> through implementation of Real Time Inventory Tracking Model (<em>R.T.I.T.M</em>) of <em>AA</em> among Distributor Companies (<em>DCs</em>). This paper also elaborated on Literature, Methodology and Findings obtained from the study. The <strong><em>results</em></strong> were obtained from <strong><em>regression analysis</em></strong> by using the Statistical Package for Social Sciences (<em>SPSS</em>) that showed a higher significance of <strong><em>Stock Turnover Period</em></strong> and<strong><em> Airtime Denomination</em></strong> as a contributor to Restocking Delays whereas <strong><em>Messages from Airtel</em></strong> Head office to the Distributor had a non-significant contribution to restocking Delays as in Figure 9. The research recommends a Model for <em>R.T.I.T</em> in Telecom Distribution <em>SC</em> of <em>AA </em>and Omnichannel Inventory Management (<em>OIM</em>) as a significant contributor to timely reliable inventory restocking and promotes higher sales among <em>DCs</em> and retailers through minimized Restocking Delays. It shows that the forces of Demand and Supply change over time with different tastes and preferences of customers. The imbalance in <em>AA</em> stock levels changes at given times due to unforeseen forces of consumer demand experienced by <em>DCs</em>, explained by the “<strong><em>Bullwhip Effect</em></strong>” due to information distortion in the Supply Chain (<em>SC</em>).展开更多
Walt·Whitman was one of the famous poets in American literary field. He is remembered by his masterpiece-Leaves of Grass, which composes a lot of his democratic ideas. His democratic poems and his writing styles ...Walt·Whitman was one of the famous poets in American literary field. He is remembered by his masterpiece-Leaves of Grass, which composes a lot of his democratic ideas. His democratic poems and his writing styles have their historical background which helped form his democratic ideas.展开更多
Theodore Dreiser’s novel Sister Carrie is the representative of studying the disillusionment of the American Dream.Since the publication of Sister Carrie,there have been many critics who commented on this work,and it...Theodore Dreiser’s novel Sister Carrie is the representative of studying the disillusionment of the American Dream.Since the publication of Sister Carrie,there have been many critics who commented on this work,and its main character Sister Carrie is a controversial person.Dreiser was criticized by critics and readers because he didn’t give any comment on her degener ation.This thesis tries to analyze the causes of this tragedy.In the end,the paper draws the conclusion:the American Dream looks beautiful,but to some extent it is not reliable,just like the foam of soap.It only gives people an illusion.So Carrie’s tragedy is in evitable.展开更多
The main causes of the vocational college students' oral fossilization summarized in the thesis are as follows:negative transfer of the native language,overgeneralization,communication strategies blockage.
VFDs （variable frequency drives） are an integral part of many industrial plants and stations. Reliable operation and maintenance of these drives is vital to ensure sustained plant operation and availability. Underst...VFDs （variable frequency drives） are an integral part of many industrial plants and stations. Reliable operation and maintenance of these drives is vital to ensure sustained plant operation and availability. Understanding of the principles of operation of VFD systems as well as knowledge about their required operating environment is necessary for all operating personnel. Many times the operating personnel do not get involved with different technical issues until a complete failure has occurred. Hence, the awareness of the most dominant failure causes has a significant impact on assisting operators to avoid catastrophic failures and tremendous economic losses due to VFD shutdown. Proper plant design, accurate monitoring and data logging, following manufacturer preventive maintenance schedule, and choosing qualified team of operators can be the key to an efficient operation and a long lifetime for any VFD system. In this paper, we have analyzed the electrical and non-electrical causes of VFD failures based on a case study of a typical medium voltage VFD pumping station. Finally, recommendations are given from field analysis and observations.展开更多
This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years. It is shown that observed climate change in China bears a strong similarity with the global aver...This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years. It is shown that observed climate change in China bears a strong similarity with the global average. The country-averaged annual mean surface air temperature has increased by 1.1℃ over the past 50 years and 0.5-0.8℃ over the past 100 years, slightly higher than the global temperature increase for the same periods. Northern China and winter have experienced the greatest increases in surface air temperature. Although no significant trend has been found in country-averaged annual precipitation, interdecadal variability and obvious trends on regional scales are detectable, with northwestern China and the mid and lower Yangtze River basin having undergone an obvious increase, and North China a severe drought. Some analyses show that frequency and magnitude of extreme weather and climate events have also undergone significant changes in the past 50 years or so. Studies of the causes of regional climate change through the use of climate models and consideration of various forcings, show that the warming of the last 50 years could possibly be attributed to an increased atmospheric concentration of greenhouse gases, while the temperature change of the first half of the 20th century may be due to solar activity, volcanic eruptions and sea surface temperature change. A significant decline in sunshine duration and solar radiation at the surface in eastern China has been attributed to the increased emission of pollutants. Projections of future climate by models of the NCC （National Climate Center, China Meteorological Administration） and the IAP （Institute of Atmospheric Physics, Chinese Academy of Sciences）, as well as 40 models developed overseas, indicate a potential significant warming in China in the 21st century, with the largest warming set to occur in winter months and in northern China. Under varied emission scenarios, the country-averaged annual mean temperature is projected to increase by 1.5 2.1℃ by 2020, 2.3 3.3℃ by 2050, and by 3.9-6.0℃ by 2100, in comparison to the 30-year average of 1961-1990. Most models project a 10% 12% increase in annual precipitation in China by 2100, with the trend being particularly evident in Northeast and Northwest China, but with parts of central China probably undergoing a drying trend. Large uncertainty exists in the projection of precipitation, and further studies are needed. Furthermore, anthropogenic climate change will probably lead to a weaker winter monsoon and a stronger summer monsoon in eastern Asia.展开更多
Approximately 10%-15% of couples are infertile, and a male factor is involved in almost half of these cases. This observation is due in part to defects in spermatogenesis, and the underlying causes, including genetic ...Approximately 10%-15% of couples are infertile, and a male factor is involved in almost half of these cases. This observation is due in part to defects in spermatogenesis, and the underlying causes, including genetic abnormalities, remain largely unknown. Until recently, the only genetic tests used in the diagnosis of male infertility were aimed at detecting the presence of microdeletions of the long arm of the Y chromosome and/or chromosomal abnormalities. Various other single-gene or polygenic defects have been proposed to be involved in male fertility. However, their causative effects often remain unproven. The recent evolution in the development of whole-genome-based techniques and the large-scale analysis of mouse models might help in this process. Through knockout mouse models, at least 388 genes have been shown to be associated with spermatogenesis in mice. However, problems often arise when translating this information from mice to humans.展开更多
Chaohu Lake, located in the central Anhui Province, is one of the five largest fresh lakes in China. Now it is one of the three most eutrophication lakes in China. The deterioration of its water quality has influenced...Chaohu Lake, located in the central Anhui Province, is one of the five largest fresh lakes in China. Now it is one of the three most eutrophication lakes in China. The deterioration of its water quality has influenced the sustainable development of society, economy and environment of Hefei City, the capital of Anhui Province. A series of measures have been carried out to control its eutrophication, but it is still serious. On the basis of the lake water quality data from 1984 to 2003, the causes of the eutrophication of Chaohu Lake are analyzed. Studies indicated that the suitable natural conditions and human activities played a crucial role in the process of the eutrophication of Chaohu Lake. A great amount of industrial, agricultural and domestic sewage discharged into the lake is the main cause of eutrophication in the lake. Land use, soil erosion and shoreline collapse destroyed the watershed eco-environment and the terrestrial ecosystem of Chaohu Lake. And the building of Yuxi Gate extends the sluggish of the nutritious substance and speeds up the process of the eutrophication. From the view of systematic engineering and watershed ecology, a series of the countermeasures have been put forward to control the eutrophication.展开更多
基金supported by the China Geological Survey Project(Nos.DD20220864 and DD20243077).
文摘Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.
文摘Americans have always been proud of their democratic system. Since the end of World War Ⅱ, the United States has even used its democratic system as a template to “democratize” some other countries. However, in recent years, the domestic democratic chaos in the United States has intensified, causing widespread doubts about the American political system and its democratic model.
文摘BACKGROUND Mediastinal lymph nodes(MLNs)can be enlarged due to various benign or malignant causes.Endoscopic ultrasound(EUS)is often employed for the acquisition of tissue specimens of the enlarged MLN(EMLN).AIM To determine the causes,document the symptoms,and determine factors predicting good yield of EUS-guided EMLN biopsy.METHODS All patients having EMLN(>10 mm)on thoracic imaging and referred for EUSguided biopsy were included in this retrospective observational study.Adequacy of the tissue specimen was assessed by the endoscopist with macroscopic on-site evaluation(MOSE)and then sent to a histopathologist for final diagnosis.Analysis for factors predicting good biopsy yield was then performed.RESULTS Of the total 243 patients with EMLN,131(53.9%)were males.The mean age was 47.6(±14.7)and range 14-86 years.Commonest causes of EMLN were tuberculosis 82(33.7%),anthracosis 53(21.8%),neoplastic disease 43(17.7%)and sarcoidosis 14(5.8%).Among the 43 patients with neoplastic diseases:40 had metastatic disease(breast 9,lung 7,pancreatobiliary 6,esophagus 5,kidney 5,hepatocellular 2,neuroendocrine 2,gastrointestinal stromal 1,undetermined 3)and 3 had primary malignancies(lymphoproliferative disorder 2,Kaposi sarcoma 1).Chest related clinical symptoms were absent in more than half the patients with tuberculosis 51/82(62.2%),anthracosis 31/53(58.5%)and neoplastic disease 28/43(65.1%).Factors associated with good biopsy yield were:Subcarinal location of MLN(P=0.026),MLN size>12 mm(P<0.0001),use of fine-needle biopsy(vs fine-needle aspiration)(P=0.049)and satisfactory MOSE(P<0.0001)on univariate analysis;while MLN size>12 mm(P=0.005)and satisfactory MOSE(P<0.0001)on multivariate analysis.CONCLUSION Tuberculosis,anthracosis and metastatic disease were the commonest causes of EMLN.More than half the cases with EMLN had no chest-related symptoms.Large MLN size and satisfactory MOSE observation predicted a good biopsy yield.
文摘Based on the monitoring data of air quality and conventional meteorological data in Shaoyang City,a severe pollution weather process in Shaoyang from December 25,2023 to January 1,2024 was analyzed from the aspects of changes in pollutant concentration,circulation background,and changes in various meteorological elements.The results show that this severe pollution weather process was a compound pollution process caused by accumulation of local pollutants and transportation of external pollutants,during which the primary pollutant was PM_(2.5).During the accumulation stage,the ground was controlled by a uniform pressure field,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the wind on the ground was from the northeast,which was conducive to the input of upstream pollution clusters into the city.Pollutant concentration was inversely correlated with daily average sea-level pressure,and positively correlated with daily average temperature.Wind speed and direction were closely related to PM_(2.5)concentration.During the accumulation stage,the ground was mainly dominated by weak winds,and the conditions of atmospheric diffusion were poor.During the outbreak stage,the continuous northeastward wind continuously transported upstream pollutants to Shaoyang area.Local pollutants accumulated in the previous stable weather process and the terrain led to the outbreak of local pollution.
文摘Based on abnormalities in tear film structure and dynamics,dry eye syndrome is primarily classified into five types:aqueous-deficient,mucin-deficient,evaporative/lipid-deficient,tear dynamics disorder,and mixed type.The disease has diverse triggers,commonly including:lacrimal gland dysfunction;meibomian gland dysfunction accelerating tear evaporation;reduced blinking due to prolonged electronic device use;contact lens wear interfering with the tear film;medication side effects;environmental factors;hormonal fluctuations;certain ophthalmic surgeries,for example,LASIK.Treatment requires targeting specific pathogenic mechanisms,with the core focus on controlling inflammation,restoring tear film stability,and improving related gland function.
文摘Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.
基金Supported by Key R&D Projects of Hunan Provincial Department of Science and Technology"Study on Key Modern Processing Techniques and Product Development of Huarong Mustard"(2023NK2039).
文摘A survey conducted on the premature bolting of Huarong large leaf mustard from 2018 to 2024 revealed that Huarong large leaf mustard sown in middle August was associated with a higher propensity for premature bolting. Furthermore, it was observed that the earlier being sown, the greater the rate of premature bolting when being sown prior to middle August. The rate of premature bolting observed in seedlings sown on August 8 was recorded at 35.6%. It was noted that as the age of the seedlings increased, the rate of premature bolting correspondingly increased. There were notable differences in the tolerance of various cultivars to elevated temperatures and prolonged sunlight exposure. For instance, cultivars such as Zhangjie 1 and Sichuan Shaguodi, which exhibit greater heat resistance, did not demonstrate premature bolting when sown in early August. The prolonged exposure to elevated temperatures, drought conditions, and extended periods of sunlight during the seedling stage of Huarong large leaf mustard, coupled with delayed irrigation and transplantation, contributed to the occurrence of premature bolting. The Huarong large leaf mustard, when been sown from late August to early September and transplanted at the appropriate time, exhibited normal growth and development, with no instances of premature bolting observed. It is advisable to select heat-resistant varieties, such as Zhangjie 1, prior to middle August. Huarong large leaf mustard should be sown in early to middle September. Additionally, it is essential to ensure centralized production and timely release of seeds, prompt transplantation and harvesting, and enhance the management of pests and diseases.
文摘Cloudy-rainy weather for several days in 2007 was featured with the longest duration and the most serious extent of injury since the time from which there was meteorology observation record in Shandong.The causes of this process were analyzed in this article in terms of general circulation,character of physical quantity and tropical cyclone.The result showed that the precipitation process was a long wave adjustment process and it took place during the transformation process of general circulation turning from the zonal to the radial.During the cloudy-rainy weather process,the Ural mountain ridge and the Western Pacific subtropical high were more abnormally strong and in the further north than that in any other years.The tropical cyclone in the south of the subtropical cyclone activity was more frequent.There was more shortwave in middle latitudes of Asian.The cold air masses Siberia went down south.The cold air masses joined with the current of air in the Lower Yellow River.This led to the lasting cloudy-rainy weather for several days in Shandong.
文摘Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Gastroenterologists and other involved clinicians are generally assisted by international guidelines in its management.However,NVUGIB due to peptic ulcer disease only is mainly addressed by current guidelines,with upper gastrointestinal endoscopy being recommended as the gold standard modality for both diagnosis and treatment.Conversely,the management of rare and extraordinary rare causes of NVUGIB is not covered by current guidelines.Given they are frequently lifethreatening conditions,all the involved clinicians,that is emergency physicians,diagnostic and interventional radiologists,surgeons,in addition obviously to gastroenterologists,should be aware of and familiar with their management.Indeed,they typically require a prompt diagnosis and treatment,engaging a dedicated,patient-tailored,multidisciplinary team approach.The aim of our review was to extensively summarize the current evidence with regard to the management of rare and extraordinary rare causes of NVUGIB.
文摘After the illustration of the development of quadrangle courtyards,the paper has analyzed the emergence of square architectural form and the formation of axial symmetrical pattern with the hall in the front and room at the back and with wing rooms on the left and right side.It has analyzed the formation,development,climax,damage and inheritance of quadrangle courtyard,and considered that it could manifest Chinese traditional humanistic idea and aesthetic idea,and is in possession of profound cultural connotation and regional feature.On this basis,causes for quadrangle courtyards have been studied.The primary cause at the initial stage lies in human body structure theory and the perfection of quadrangle courtyards at later stage depends on ethic order theory.
文摘The <strong><em>purpose</em></strong> of this research was to ascertain causes of Restocking Delays in a Distributor Company of Airtel Airtime (<em>AA</em>) that give justification for benefits of using Real Time Inventory Tracking (<em>R.T.I.T</em>) in an attempt to mitigate Restocking Delays. From a study out at the Private Marketing and Trading Services (<em>PMTS</em>) an Authorized Distributor of Airtel Products undertaken in 2017 evidenced by Airtime scratch card and Electronic, <strong><em>E-Recharge</em></strong> Airtime among other forms to encourage <em>R.T.I.T</em> among other products in Telecom Companies and other Business Enterprises. The research comprises of the following areas among which included a detailed focus on a <strong><em>Qualitative</em></strong> and <strong><em>Quantitative approach</em></strong> in obtaining different <strong><em>categories</em></strong> of Restocking Delays in form of <strong><em>Themes</em></strong> and <strong><em>Sub Themes</em></strong> encountered in the Distribution Supply Chain (<em>SC</em>) of <em>AA</em> that is contained in this paper. This research continues to capture an in-depth explanation of the <strong><em>Managerial</em></strong> and <strong><em>Operational</em></strong> causes of restocking delays in respect to <em>AA</em>. Similarly, fast consumer products and services other than <em>AA</em> require a solution to <strong><em>Restocking Delays</em></strong> through implementation of Real Time Inventory Tracking Model (<em>R.T.I.T.M</em>) of <em>AA</em> among Distributor Companies (<em>DCs</em>). This paper also elaborated on Literature, Methodology and Findings obtained from the study. The <strong><em>results</em></strong> were obtained from <strong><em>regression analysis</em></strong> by using the Statistical Package for Social Sciences (<em>SPSS</em>) that showed a higher significance of <strong><em>Stock Turnover Period</em></strong> and<strong><em> Airtime Denomination</em></strong> as a contributor to Restocking Delays whereas <strong><em>Messages from Airtel</em></strong> Head office to the Distributor had a non-significant contribution to restocking Delays as in Figure 9. The research recommends a Model for <em>R.T.I.T</em> in Telecom Distribution <em>SC</em> of <em>AA </em>and Omnichannel Inventory Management (<em>OIM</em>) as a significant contributor to timely reliable inventory restocking and promotes higher sales among <em>DCs</em> and retailers through minimized Restocking Delays. It shows that the forces of Demand and Supply change over time with different tastes and preferences of customers. The imbalance in <em>AA</em> stock levels changes at given times due to unforeseen forces of consumer demand experienced by <em>DCs</em>, explained by the “<strong><em>Bullwhip Effect</em></strong>” due to information distortion in the Supply Chain (<em>SC</em>).
文摘Walt·Whitman was one of the famous poets in American literary field. He is remembered by his masterpiece-Leaves of Grass, which composes a lot of his democratic ideas. His democratic poems and his writing styles have their historical background which helped form his democratic ideas.
文摘Theodore Dreiser’s novel Sister Carrie is the representative of studying the disillusionment of the American Dream.Since the publication of Sister Carrie,there have been many critics who commented on this work,and its main character Sister Carrie is a controversial person.Dreiser was criticized by critics and readers because he didn’t give any comment on her degener ation.This thesis tries to analyze the causes of this tragedy.In the end,the paper draws the conclusion:the American Dream looks beautiful,but to some extent it is not reliable,just like the foam of soap.It only gives people an illusion.So Carrie’s tragedy is in evitable.
文摘The main causes of the vocational college students' oral fossilization summarized in the thesis are as follows:negative transfer of the native language,overgeneralization,communication strategies blockage.
文摘VFDs （variable frequency drives） are an integral part of many industrial plants and stations. Reliable operation and maintenance of these drives is vital to ensure sustained plant operation and availability. Understanding of the principles of operation of VFD systems as well as knowledge about their required operating environment is necessary for all operating personnel. Many times the operating personnel do not get involved with different technical issues until a complete failure has occurred. Hence, the awareness of the most dominant failure causes has a significant impact on assisting operators to avoid catastrophic failures and tremendous economic losses due to VFD shutdown. Proper plant design, accurate monitoring and data logging, following manufacturer preventive maintenance schedule, and choosing qualified team of operators can be the key to an efficient operation and a long lifetime for any VFD system. In this paper, we have analyzed the electrical and non-electrical causes of VFD failures based on a case study of a typical medium voltage VFD pumping station. Finally, recommendations are given from field analysis and observations.
文摘This article summarizes the main results and findings of studies conducted by Chinese scientists in the past five years. It is shown that observed climate change in China bears a strong similarity with the global average. The country-averaged annual mean surface air temperature has increased by 1.1℃ over the past 50 years and 0.5-0.8℃ over the past 100 years, slightly higher than the global temperature increase for the same periods. Northern China and winter have experienced the greatest increases in surface air temperature. Although no significant trend has been found in country-averaged annual precipitation, interdecadal variability and obvious trends on regional scales are detectable, with northwestern China and the mid and lower Yangtze River basin having undergone an obvious increase, and North China a severe drought. Some analyses show that frequency and magnitude of extreme weather and climate events have also undergone significant changes in the past 50 years or so. Studies of the causes of regional climate change through the use of climate models and consideration of various forcings, show that the warming of the last 50 years could possibly be attributed to an increased atmospheric concentration of greenhouse gases, while the temperature change of the first half of the 20th century may be due to solar activity, volcanic eruptions and sea surface temperature change. A significant decline in sunshine duration and solar radiation at the surface in eastern China has been attributed to the increased emission of pollutants. Projections of future climate by models of the NCC （National Climate Center, China Meteorological Administration） and the IAP （Institute of Atmospheric Physics, Chinese Academy of Sciences）, as well as 40 models developed overseas, indicate a potential significant warming in China in the 21st century, with the largest warming set to occur in winter months and in northern China. Under varied emission scenarios, the country-averaged annual mean temperature is projected to increase by 1.5 2.1℃ by 2020, 2.3 3.3℃ by 2050, and by 3.9-6.0℃ by 2100, in comparison to the 30-year average of 1961-1990. Most models project a 10% 12% increase in annual precipitation in China by 2100, with the trend being particularly evident in Northeast and Northwest China, but with parts of central China probably undergoing a drying trend. Large uncertainty exists in the projection of precipitation, and further studies are needed. Furthermore, anthropogenic climate change will probably lead to a weaker winter monsoon and a stronger summer monsoon in eastern Asia.
文摘Approximately 10%-15% of couples are infertile, and a male factor is involved in almost half of these cases. This observation is due in part to defects in spermatogenesis, and the underlying causes, including genetic abnormalities, remain largely unknown. Until recently, the only genetic tests used in the diagnosis of male infertility were aimed at detecting the presence of microdeletions of the long arm of the Y chromosome and/or chromosomal abnormalities. Various other single-gene or polygenic defects have been proposed to be involved in male fertility. However, their causative effects often remain unproven. The recent evolution in the development of whole-genome-based techniques and the large-scale analysis of mouse models might help in this process. Through knockout mouse models, at least 388 genes have been shown to be associated with spermatogenesis in mice. However, problems often arise when translating this information from mice to humans.
基金U nderthe auspicesofthe cooperative projectbetw een G overnm entofChina and Japan (N o.JIC A G L:SCH EFY 98)
文摘Chaohu Lake, located in the central Anhui Province, is one of the five largest fresh lakes in China. Now it is one of the three most eutrophication lakes in China. The deterioration of its water quality has influenced the sustainable development of society, economy and environment of Hefei City, the capital of Anhui Province. A series of measures have been carried out to control its eutrophication, but it is still serious. On the basis of the lake water quality data from 1984 to 2003, the causes of the eutrophication of Chaohu Lake are analyzed. Studies indicated that the suitable natural conditions and human activities played a crucial role in the process of the eutrophication of Chaohu Lake. A great amount of industrial, agricultural and domestic sewage discharged into the lake is the main cause of eutrophication in the lake. Land use, soil erosion and shoreline collapse destroyed the watershed eco-environment and the terrestrial ecosystem of Chaohu Lake. And the building of Yuxi Gate extends the sluggish of the nutritious substance and speeds up the process of the eutrophication. From the view of systematic engineering and watershed ecology, a series of the countermeasures have been put forward to control the eutrophication.
