AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early endoscopy.METHODS:Retrospective data collection from four referral centers,all of which had a formal out-...AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early endoscopy.METHODS:Retrospective data collection from four referral centers,all of which had a formal out-of-hours emergency endoscopy service,even at weekends.A total of 388 patients with bleeding peptic ulcers who were admitted via the emergency room between January 2007 and December 2009 were enrolled.Analyzed parameters included time from patients' arrival until endoscopy,mortality,rebleeding,need for surgery and length of hospital stay.RESULTS:The weekday and weekend admission groups comprised 326 and 62 patients,respectively.There were no significant differences in baseline characteristics between the two groups,except for younger age in the weekend group.Most patients (97%) had undergone early endoscopy,which resulted in a low mortality rate regardless of point of presentation (1.8% overall vs 1.6% on the weekend).The only outcome that was worse in the weekend group was a higher rate of rebleeding (12% vs 21%,P = 0.030).However,multivariate analysis revealed nighttime admission and a high Rockall score (≥ 6) as significant independent risk factors for rebleeding,rather than weekend admission.CONCLUSION:Early endoscopy for peptic ulcer bleeding can prevent the weekend effect,and nighttime admission was identified as a novel risk factor for rebleeding,namely the nighttime effect.展开更多
AIM To compare mortality and time-to-surgery of patients admitted with hip fracture to our teaching hospital on weekdays vs weekends. METHODS Data was prospectively collected and retrospectively analysed for 816 hip f...AIM To compare mortality and time-to-surgery of patients admitted with hip fracture to our teaching hospital on weekdays vs weekends. METHODS Data was prospectively collected and retrospectively analysed for 816 hip fracture patients. Multivariate logistic regression was carried out on 3 binary outcomes(timeto-surgery < 36 h; 30-d mortality; 120-d mortality), using the explanatory variables time-of-admission; age; gender; American Society of Anesthesiologist(ASA) grade; abbreviated mental test score(AMTS); fracture type; accommodation admitted from; walking ability outdoors; accompaniment outdoors and season. RESULTS Baseline characteristics were not statistically different between those admitted on weekdays vs weekends. Weekend admission was not associated with an increased time-to-surgery(P = 0.975), 30-d mortality(P = 0.842) or 120-d mortality(P = 0.425). Gender(P = 0.028), ASA grade(P < 0.001), AMTS(P = 0.041) and accompaniment outdoors(P = 0.033) were significant covariates for 30-d mortality. Furthermore, age(P < 0.001),gender(P = 0.011), ASA grade(P < 0.001), AMTS(P < 0.001) and accompaniment outdoors(P = 0.033) all significantly influenced mortality at 120 d. ASA(P < 0.001) and season(P = 0.014) had significant effect on the odds of undergoing surgery in under 36 h.CONCLUSION Weekend admission was not associated with increased time-to-surgery or mortality in hip fracture patients. Demographic factors affect mortality in accordance with previous published reports.展开更多
Background Data regarding the influence of weekends and Chinese national holiday's admission on the outcomes of patients with ST-elevated myocardial infarction (STEMI) is lacking. This study sought to investigate t...Background Data regarding the influence of weekends and Chinese national holiday's admission on the outcomes of patients with ST-elevated myocardial infarction (STEMI) is lacking. This study sought to investigate the effect of Chinese national holidays and weekend admission on outcomes in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI). Methods Patients pre- senting with STEMI within 12 h of symptom onset who underwent PPCI were retrospectively enrolled. The primary outcome of in-hospital mortality and major adverse cardiovascular events in patients presenting Chinese national holiday's and weekends versus weekdays was evaluated. Results A total of 441 STEMI patients were enrolled in this study. Of these, 129 (29.3%) patients were admitted during Chinese national holidays and weekends and 312 (70.7%) during weekdays. Patients admitted during holidays and weekends were more likely to present with Killip class Ⅲ-Ⅳ. Patients admitted during holidays and weekends experienced a significantly longer door-to-baUoon time, symptom onset-to-door time as well as symptom onset-to-balloon time. The in-hospital mortality between patients presenting holidays and weekends versus weekdays was comparable. However, patients admitted during holidays and weekends have a signitieantly higher rate of in-hospital major adverse cardiovascular events. Multivariate analysis demonstrated that holidays and weekends admission was independ- ently associated with adverse outcomes. Conclusions In China, STEMI patients undergoing PPCI during national holidays and weekends have worse in-hospital outcomes compared to those admitted during weekdays. These findings suggest that continuous efforts should be undertaken to enhance the Chinese healthcare system and to ensure that comparable outcomes are achieved for all STEMI patients regardless of time of presentation.展开更多
BACKGROUND The care discrepancy for patients presenting to a hospital on the weekend relative to the work week is well documented.With respect to hip fractures,however,there is no consensus about the presence of a so-...BACKGROUND The care discrepancy for patients presenting to a hospital on the weekend relative to the work week is well documented.With respect to hip fractures,however,there is no consensus about the presence of a so-called“weekend effect”.This study sought to determine the effects,if any,of weekend admission on care of geriatric hip fractures admitted to a large tertiary care hospital.It was hypothesized that geriatric hip fracture patients admitted on a weekend would have longer times to medical optimization and surgery and increased complication and mortality rates relative to those admitted on a weekday.AIM To determine if weekend admission of geriatric hip fractures is associated with poor outcome measures and surgical delay.METHODS A retrospective chart review of operative geriatric hip fractures treated from 2015-2017 at a large tertiary care hospital was conducted.Two cohorts were compared:patients who arrived at the emergency department on a weekend,and those that arrived at the emergency department on a weekday.Primary outcome measures included mortality rate,complication rate,transfusion rate,and length of stay.Secondary outcome measures included time from emergency department arrival to surgery,time from emergency department arrival to medical optimization,and time from medical optimization to surgery.RESULTS There were no statistically significant differences in length of stay(P=0.2734),transfusion rate(P=0.9325),or mortality rate(P=0.3460)between the weekend and weekday cohorts.Complication rate was higher in patients who presented on a weekend compared to patients who presented on a weekday(13.3%vs 8.3%;P=0.044).Time from emergency department arrival to medical optimization(22.7 h vs 20.0 h;P=0.0015),time from medical optimization to surgery(13.9 h vs 10.8 h;P=0.0172),and time from emergency department arrival to surgery(42.7 h vs 32.5 h;P<0.0001)were all significantly longer in patients who presented to the hospital on a weekend compared to patients who presented to the hospital on a weekday.CONCLUSION This study provided insight into the“weekend effect”for geriatric hip fractures and found that day of presentation has a clinically significant impact on delivered care.展开更多
Based on questionnaire survey and cross--tabulation analysis, the authors discussed relationships between emissiveness and socio--economic elements ofShanghainese in their weekend trips, including emissivenesses of di...Based on questionnaire survey and cross--tabulation analysis, the authors discussed relationships between emissiveness and socio--economic elements ofShanghainese in their weekend trips, including emissivenesses of different age group,income per month, occupations, education and family structure. Visiting rates ofrecreationists to destinations demonstrated different levels even being under a same emissiveness. In the second part of the paper, the authors described three differentspatial scales of destination choice behavior of Shanghainese to tourist sites fromwhich situated in urban area, to which located in suburb area and in neighboringprovinces. The authors also observed the perceptive evaluation of Shanghainese tothose sites they had visited or would visit in the future. Some proposals abollt sustainable urban tourism development were put forward at the end of this paper.展开更多
AIM To examine the association between weekend alcohol consumption and the biochemical and histological alterations at two different concentrations of alcohol in both genders in rats.METHODS Wistar rats weighing 170-2...AIM To examine the association between weekend alcohol consumption and the biochemical and histological alterations at two different concentrations of alcohol in both genders in rats.METHODS Wistar rats weighing 170-200 g were divided into groups as follows:(1) Control groups; and(2) weekend alcohol-consumption group: 2 d/weekly per 12 wk, at two different concentrations:(1) Group of males or females with a consumption of a solution of alcohol at 40%; and(2) group of males or females with a consumption of a solution of alcohol at 5%. At the end of the experiment, serum and liver samples were obtained. The following enzymes and metabolites were determined in serum: Alanine Aminotransferase(ALT), Aspartate Aminotransferase(AST), Lactate Dehydrogenase, and Gamma-Glutamyltransferase, and glucose, triglycerides, cholesterol, bilirubin, and albumin. Liver samples from each group were employed to analyze morphological abnormalities by light microscopy.RESULTS In all of the weekend alcohol-consumption groups, AST activity presented a significant, 10-fold rise. Regarding ALT activity, the groups with weekend alcohol consumption presented a significant increase that was six times greater. Bilirubin levels increased significantly in both groups of females. We observed a significant increase in the parameters of fatty change and inflammation due to weekend alcohol consumption. Only the group of females that consumed alcohol at 40% presented slight hepatocel ular disorganization CONCLUSION The results obtained herein provide solid evidence that weekend alcohol consumption gives rise to liver damage, demonstrated by biochemical and histological alterations, first manifested acutely, and prolonged weekend alcohol consumption can cause greater, irreversible damage.展开更多
Imprecise or delayed care can reflect many factors, including straightforward difficulties in physician judgment and false negative tests. However, the movement toward decreasing physician work hours also leads to del...Imprecise or delayed care can reflect many factors, including straightforward difficulties in physician judgment and false negative tests. However, the movement toward decreasing physician work hours also leads to delays in care caused by inadequate staffing or inadequate communication between staffing, which must be addressed if quality of care is to remain high. The demonstration of delays in the management of anastomotic leaks over weekends or in association with false positive radiologic studies exemplifies this challenge.展开更多
AIM:To evaluate the"weekend effect"on outcomes in patient admitted on the weekend for upper gastrointestinal bleeding(UGIB).METHODS:A comprehensive search was performed(March 2014).Studies comparing weekend ...AIM:To evaluate the"weekend effect"on outcomes in patient admitted on the weekend for upper gastrointestinal bleeding(UGIB).METHODS:A comprehensive search was performed(March 2014).Studies comparing weekend and weekday endoscopy in patients with UGIB were included.All studies had at least 2 of 3 primary outcomes which included:mortality,need for surgery,time to endoscopy,endoscopy on admission day,and length of hospital stay.Three authors individually extracted data.Metaanalysis was performed using pooled estimates with odds ratio or mean difference by fixed and random effects models.RESULTS:Eleven studies met the inclusion criteria.Patients admitted with UGIB on the weekend exhibited a statistically significant increase in mortality(OR=1.13;95%CI:1.06-1.20;P<0.01),need for surgery(OR=2.46;95%CI:1.51-3.99;P<0.01),and time to endoscopy(MD 2.68;95%CI:0.17-5.20;P=0.04)as compared to patients admitted with UGIB on a weekday.Furthermore,patients with UGIB admitted on weekend experienced statistically significant less endoscopy on day of admission(OR=0.72;95%CI:0.62-0.85;P<0.01).No difference was noted between the two groups for length of hospital stay(MD-1.29;95%CI:-3.03-0.45;P=0.15).CONCLUSION:A weekend effect seems to be apparent in patients with UGIB with significantly poorer outcomes.展开更多
It was a little windy last Saturday, so I went to fly a kite with my cousins in the morning.It was interesting. In the afternoon, I went to Fred’s house with some classmates. It was his11th birthday and he had a birt...It was a little windy last Saturday, so I went to fly a kite with my cousins in the morning.It was interesting. In the afternoon, I went to Fred’s house with some classmates. It was his11th birthday and he had a birthday party. On Sunday, I went to the forest with the girls in my neighbourhood.We made a.fire and cooked food on the fire.It was delicious What a nice weekend I had!展开更多
Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O_3) concentrations in Xujiahui are higher at week-ends than those on ...Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O_3) concentrations in Xujiahui are higher at week-ends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays. The possible chemical cause of ozone "weekend effect" is that NO_2/NO ratio increases at weekends by 25.61% compared with those on weekdays. In addition, because of an average 12.13% reduction in NOx (NO + NO_2) in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate. The rate of ozone production is a function of VOCs and NOx in the atmosphere. VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the "NOx-limited". The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone "weekend effect" in Xujiahui. Furthermore, combining with MICAPS cloud amount data, the fact that ozone "weekend effect" in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone "weekend effect" in Xujiahui of Shanghai.展开更多
文摘AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early endoscopy.METHODS:Retrospective data collection from four referral centers,all of which had a formal out-of-hours emergency endoscopy service,even at weekends.A total of 388 patients with bleeding peptic ulcers who were admitted via the emergency room between January 2007 and December 2009 were enrolled.Analyzed parameters included time from patients' arrival until endoscopy,mortality,rebleeding,need for surgery and length of hospital stay.RESULTS:The weekday and weekend admission groups comprised 326 and 62 patients,respectively.There were no significant differences in baseline characteristics between the two groups,except for younger age in the weekend group.Most patients (97%) had undergone early endoscopy,which resulted in a low mortality rate regardless of point of presentation (1.8% overall vs 1.6% on the weekend).The only outcome that was worse in the weekend group was a higher rate of rebleeding (12% vs 21%,P = 0.030).However,multivariate analysis revealed nighttime admission and a high Rockall score (≥ 6) as significant independent risk factors for rebleeding,rather than weekend admission.CONCLUSION:Early endoscopy for peptic ulcer bleeding can prevent the weekend effect,and nighttime admission was identified as a novel risk factor for rebleeding,namely the nighttime effect.
文摘AIM To compare mortality and time-to-surgery of patients admitted with hip fracture to our teaching hospital on weekdays vs weekends. METHODS Data was prospectively collected and retrospectively analysed for 816 hip fracture patients. Multivariate logistic regression was carried out on 3 binary outcomes(timeto-surgery < 36 h; 30-d mortality; 120-d mortality), using the explanatory variables time-of-admission; age; gender; American Society of Anesthesiologist(ASA) grade; abbreviated mental test score(AMTS); fracture type; accommodation admitted from; walking ability outdoors; accompaniment outdoors and season. RESULTS Baseline characteristics were not statistically different between those admitted on weekdays vs weekends. Weekend admission was not associated with an increased time-to-surgery(P = 0.975), 30-d mortality(P = 0.842) or 120-d mortality(P = 0.425). Gender(P = 0.028), ASA grade(P < 0.001), AMTS(P = 0.041) and accompaniment outdoors(P = 0.033) were significant covariates for 30-d mortality. Furthermore, age(P < 0.001),gender(P = 0.011), ASA grade(P < 0.001), AMTS(P < 0.001) and accompaniment outdoors(P = 0.033) all significantly influenced mortality at 120 d. ASA(P < 0.001) and season(P = 0.014) had significant effect on the odds of undergoing surgery in under 36 h.CONCLUSION Weekend admission was not associated with increased time-to-surgery or mortality in hip fracture patients. Demographic factors affect mortality in accordance with previous published reports.
文摘Background Data regarding the influence of weekends and Chinese national holiday's admission on the outcomes of patients with ST-elevated myocardial infarction (STEMI) is lacking. This study sought to investigate the effect of Chinese national holidays and weekend admission on outcomes in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI). Methods Patients pre- senting with STEMI within 12 h of symptom onset who underwent PPCI were retrospectively enrolled. The primary outcome of in-hospital mortality and major adverse cardiovascular events in patients presenting Chinese national holiday's and weekends versus weekdays was evaluated. Results A total of 441 STEMI patients were enrolled in this study. Of these, 129 (29.3%) patients were admitted during Chinese national holidays and weekends and 312 (70.7%) during weekdays. Patients admitted during holidays and weekends were more likely to present with Killip class Ⅲ-Ⅳ. Patients admitted during holidays and weekends experienced a significantly longer door-to-baUoon time, symptom onset-to-door time as well as symptom onset-to-balloon time. The in-hospital mortality between patients presenting holidays and weekends versus weekdays was comparable. However, patients admitted during holidays and weekends have a signitieantly higher rate of in-hospital major adverse cardiovascular events. Multivariate analysis demonstrated that holidays and weekends admission was independ- ently associated with adverse outcomes. Conclusions In China, STEMI patients undergoing PPCI during national holidays and weekends have worse in-hospital outcomes compared to those admitted during weekdays. These findings suggest that continuous efforts should be undertaken to enhance the Chinese healthcare system and to ensure that comparable outcomes are achieved for all STEMI patients regardless of time of presentation.
文摘BACKGROUND The care discrepancy for patients presenting to a hospital on the weekend relative to the work week is well documented.With respect to hip fractures,however,there is no consensus about the presence of a so-called“weekend effect”.This study sought to determine the effects,if any,of weekend admission on care of geriatric hip fractures admitted to a large tertiary care hospital.It was hypothesized that geriatric hip fracture patients admitted on a weekend would have longer times to medical optimization and surgery and increased complication and mortality rates relative to those admitted on a weekday.AIM To determine if weekend admission of geriatric hip fractures is associated with poor outcome measures and surgical delay.METHODS A retrospective chart review of operative geriatric hip fractures treated from 2015-2017 at a large tertiary care hospital was conducted.Two cohorts were compared:patients who arrived at the emergency department on a weekend,and those that arrived at the emergency department on a weekday.Primary outcome measures included mortality rate,complication rate,transfusion rate,and length of stay.Secondary outcome measures included time from emergency department arrival to surgery,time from emergency department arrival to medical optimization,and time from medical optimization to surgery.RESULTS There were no statistically significant differences in length of stay(P=0.2734),transfusion rate(P=0.9325),or mortality rate(P=0.3460)between the weekend and weekday cohorts.Complication rate was higher in patients who presented on a weekend compared to patients who presented on a weekday(13.3%vs 8.3%;P=0.044).Time from emergency department arrival to medical optimization(22.7 h vs 20.0 h;P=0.0015),time from medical optimization to surgery(13.9 h vs 10.8 h;P=0.0172),and time from emergency department arrival to surgery(42.7 h vs 32.5 h;P<0.0001)were all significantly longer in patients who presented to the hospital on a weekend compared to patients who presented to the hospital on a weekday.CONCLUSION This study provided insight into the“weekend effect”for geriatric hip fractures and found that day of presentation has a clinically significant impact on delivered care.
文摘Based on questionnaire survey and cross--tabulation analysis, the authors discussed relationships between emissiveness and socio--economic elements ofShanghainese in their weekend trips, including emissivenesses of different age group,income per month, occupations, education and family structure. Visiting rates ofrecreationists to destinations demonstrated different levels even being under a same emissiveness. In the second part of the paper, the authors described three differentspatial scales of destination choice behavior of Shanghainese to tourist sites fromwhich situated in urban area, to which located in suburb area and in neighboringprovinces. The authors also observed the perceptive evaluation of Shanghainese tothose sites they had visited or would visit in the future. Some proposals abollt sustainable urban tourism development were put forward at the end of this paper.
文摘AIM To examine the association between weekend alcohol consumption and the biochemical and histological alterations at two different concentrations of alcohol in both genders in rats.METHODS Wistar rats weighing 170-200 g were divided into groups as follows:(1) Control groups; and(2) weekend alcohol-consumption group: 2 d/weekly per 12 wk, at two different concentrations:(1) Group of males or females with a consumption of a solution of alcohol at 40%; and(2) group of males or females with a consumption of a solution of alcohol at 5%. At the end of the experiment, serum and liver samples were obtained. The following enzymes and metabolites were determined in serum: Alanine Aminotransferase(ALT), Aspartate Aminotransferase(AST), Lactate Dehydrogenase, and Gamma-Glutamyltransferase, and glucose, triglycerides, cholesterol, bilirubin, and albumin. Liver samples from each group were employed to analyze morphological abnormalities by light microscopy.RESULTS In all of the weekend alcohol-consumption groups, AST activity presented a significant, 10-fold rise. Regarding ALT activity, the groups with weekend alcohol consumption presented a significant increase that was six times greater. Bilirubin levels increased significantly in both groups of females. We observed a significant increase in the parameters of fatty change and inflammation due to weekend alcohol consumption. Only the group of females that consumed alcohol at 40% presented slight hepatocel ular disorganization CONCLUSION The results obtained herein provide solid evidence that weekend alcohol consumption gives rise to liver damage, demonstrated by biochemical and histological alterations, first manifested acutely, and prolonged weekend alcohol consumption can cause greater, irreversible damage.
文摘Imprecise or delayed care can reflect many factors, including straightforward difficulties in physician judgment and false negative tests. However, the movement toward decreasing physician work hours also leads to delays in care caused by inadequate staffing or inadequate communication between staffing, which must be addressed if quality of care is to remain high. The demonstration of delays in the management of anastomotic leaks over weekends or in association with false positive radiologic studies exemplifies this challenge.
文摘AIM:To evaluate the"weekend effect"on outcomes in patient admitted on the weekend for upper gastrointestinal bleeding(UGIB).METHODS:A comprehensive search was performed(March 2014).Studies comparing weekend and weekday endoscopy in patients with UGIB were included.All studies had at least 2 of 3 primary outcomes which included:mortality,need for surgery,time to endoscopy,endoscopy on admission day,and length of hospital stay.Three authors individually extracted data.Metaanalysis was performed using pooled estimates with odds ratio or mean difference by fixed and random effects models.RESULTS:Eleven studies met the inclusion criteria.Patients admitted with UGIB on the weekend exhibited a statistically significant increase in mortality(OR=1.13;95%CI:1.06-1.20;P<0.01),need for surgery(OR=2.46;95%CI:1.51-3.99;P<0.01),and time to endoscopy(MD 2.68;95%CI:0.17-5.20;P=0.04)as compared to patients admitted with UGIB on a weekday.Furthermore,patients with UGIB admitted on weekend experienced statistically significant less endoscopy on day of admission(OR=0.72;95%CI:0.62-0.85;P<0.01).No difference was noted between the two groups for length of hospital stay(MD-1.29;95%CI:-3.03-0.45;P=0.15).CONCLUSION:A weekend effect seems to be apparent in patients with UGIB with significantly poorer outcomes.
文摘It was a little windy last Saturday, so I went to fly a kite with my cousins in the morning.It was interesting. In the afternoon, I went to Fred’s house with some classmates. It was his11th birthday and he had a birthday party. On Sunday, I went to the forest with the girls in my neighbourhood.We made a.fire and cooked food on the fire.It was delicious What a nice weekend I had!
基金the National Natural Science Foundation of China (Grant Nos. 40575060 and 40705046)the Special Research Project of China Meteorological Bureau
文摘Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O_3) concentrations in Xujiahui are higher at week-ends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays. The possible chemical cause of ozone "weekend effect" is that NO_2/NO ratio increases at weekends by 25.61% compared with those on weekdays. In addition, because of an average 12.13% reduction in NOx (NO + NO_2) in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate. The rate of ozone production is a function of VOCs and NOx in the atmosphere. VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the "NOx-limited". The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone "weekend effect" in Xujiahui. Furthermore, combining with MICAPS cloud amount data, the fact that ozone "weekend effect" in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone "weekend effect" in Xujiahui of Shanghai.