BACKGROUND The optimal approach for managing hepatic hemangioma is controversial.AIM To evaluate a clinical grading system for management of hepatic hemangioma based on our 17-year of single institution experience.MET...BACKGROUND The optimal approach for managing hepatic hemangioma is controversial.AIM To evaluate a clinical grading system for management of hepatic hemangioma based on our 17-year of single institution experience.METHODS A clinical grading system was retrospectively applied to 1171 patients with hepatic hemangioma from January 2002 to December 2018.Patients were classified into four groups based on the clinical grading system and treatment:(1)Observation group with score<4(Obs score<4);(2)Surgical group with score<4(Sur score<4);(3)Observation group with score≥4(Obs score≥4);and(4)Surgical group with score≥4(Sur score≥4).The clinico-pathological index and outcomes were evaluated.RESULTS There were significantly fewer symptomatic patients in surgical groups(Sur score≥4 vs Obs score≥4,P<0.001;Sur score<4 vs Obs score<4,χ^(2)=8.60,P=0.004;Sur score≥4 vs Obs score<4,P<0.001).The patients in Sur score≥4 had a lower rate of in need for intervention and total patients with adverse event than in Obs score≥4(P<0.001;P<0.001).Nevertheless,there was no significant difference in need for intervention and total patients with adverse event between the Sur score<4 and Obs score<4(P>0.05;χ^(2)=1.68,P>0.05).CONCLUSION This clinical grading system appeared as a practical tool for hepatic hemangioma.Surgery can be suggested for patients with a score≥4.For those with<4,follow-up should be proposed.展开更多
AIM: To evaluate the reliability and accuracy of threedimensional(3D) reconstruction for liver resection in patients with hepatic alveolar echinococcosis(HAE).METHODS: One-hundred and six consecutive patients with HAE...AIM: To evaluate the reliability and accuracy of threedimensional(3D) reconstruction for liver resection in patients with hepatic alveolar echinococcosis(HAE).METHODS: One-hundred and six consecutive patients with HAE underwent hepatectomy at our hospital between May 2011 and January 2015. Fifty-nine patients underwent preoperative 3D reconstruction and "virtual" 3D liver resection before surgery(Group A). Another 47 patients used conventional imaging methods for preoperative assessment(Group B). Outcomes of hepatectomy were compared between the two groups.RESULTS: There was no significant difference in preoperative data between the two groups. Compared with patients in Group B, those in Group A had a significantly shorter operation time(227.1 ± 51.4 vs 304.6 ± 88.1 min; P < 0.05), less intraoperative blood loss(308.1 ± 135.4 vs 458.1 ± 175.4 m L; P < 0.05), and lower requirement for intraoperative blood transfusion(186.4 ± 169.6 vs 289.4 ± 199.2 m L; P < 0.05). Estimated resection liver volumes in bothgroups had good correlation with actual graft weight(Group A: r = 0.978; Group B: r = 0.960). There was a significant higher serum level of albumin in Group A(26.3 ± 5.9 vs 22.6 ± 4.3 g/L, P < 0.05). Other postoperative laboratory parameters(serum levels of aminotransferase and bilirubin; prothrombin time) and duration of postoperative hospital stay were similar. Sixteen complications occurred in Group A and 19 in Group B. All patients were followed for 3-46(mean, 17.3) mo. There was no recurrence of lesions in Group A, but two recurrences in Group B. There were three deaths: two from cerebrovascular accident, and one from car accident.CONCLUSION: 3D reconstruction provides comprehensive and precise anatomical information for the liver. It also improves the chance of success and reduces the risk of hepatectomy in HAE.展开更多
Background: The University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are the two most frequently used liver graft preservation fluids. The present study aimed to compare their efficacy i...Background: The University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are the two most frequently used liver graft preservation fluids. The present study aimed to compare their efficacy in end-stage hepatic alveolar echinococcosis patients who underwent ex-situ liver resection and autotransplantation (ELRA). Methods: A total of 81 patients received ELRA from August 2010 to March 2018. They were allocated into UW ( n = 48) and HTK groups ( n = 33) based on the type of solutions used. Demographic and operational data were retrospectively analyzed. Primary outcomes included 90-day mortality, incidence of early graft loss, primary dysfunction, and postoperative complications. Results: Demographic and operational characteristics were similarly distributed in the two groups. No statistically significant differences were observed with regard to 90-day mortality (12.77% vs. 12.12%) and early graft loss rate (8.51% vs. 9.09%) between the two groups. Patients in the UW and HTK groups showed a primary dysfunction rate of 27.66% and 27.27%, respectively. The UW group exhibited a higher incidence tendency of biliary complications, albeit with no statistical significance. Conclusions: This is the largest cohort study comparing the efficacy of the UW and HTK organ-preserving solutions in end-stage hepatic alveolar echinococcosis patients in ELRA settings. UW and HTK solutions presented similar efficacy and safety. A randomized clinical trial with larger scale is needed for further investigation in future clinical applications.展开更多
Background: The habitat features of breeding territory have important adaptive significance for the survival and reproduction of territory holders.The Chinese Grouse(Tetrastes sewerzowi) is a rare and endemic species ...Background: The habitat features of breeding territory have important adaptive significance for the survival and reproduction of territory holders.The Chinese Grouse(Tetrastes sewerzowi) is a rare and endemic species with rela?tively small distribution range and decreasing population trend.It is important to elucidate breeding territory habitat requirements of the Chinese Grouse for habitat management and conservation actions.Methods: Using radio?telemetry and field observations,we determined the core areas of 65 breeding territories of males.Two to three samples were selected in each core breeding territory as used sites and compared with nearby sites with no grouse occurrence using logistic regression.Results: Our model showed a high accuracy in prediction of core breeding territory used by males,which preferred stands with more small deciduous trees(0.5 m ≤ height < 5 m),more small willow trees(Salix spp.,0.5 m infl≤ height < 5 m),greater willow cover,and greater herb cover.The number of small willow trees had the great?estuence on males' core breeding territory selection.Dense shrubs were also chosen compared with unused sites Tall conifer trees was an important determinant in the distribution of Chinese Grouse at the landscape scale,and was relatively important in the univariate model,but not included in our final multivariable model.Conclusions: Male Chinese Grouse established territories at sites with abundant food resources.At the landscape scale,the Chinese Grouse occurred in alpine conifer forest.At the territory scale,small willow trees had the most important effect on males' core breeding territory selection.We suggest that the forest gaps in dense conifer for?est are important for improving the occurrence of willows and facilitating breeding territory establishment for the Chinese Grouse.展开更多
Background:Incubating birds must balance the conflict between thermal needs of the developing embryos and their self?maintenance needs for energy.The Chinese Grouse (Tetrastes sewerzowi) lives in high mountain conifer...Background:Incubating birds must balance the conflict between thermal needs of the developing embryos and their self?maintenance needs for energy.The Chinese Grouse (Tetrastes sewerzowi) lives in high mountain conifer forests and faces energy stress,cold environment,and predation pressure.Females might adjust incubation rhythm to adapt to these constraints. Methods:Two methods were used to investigate egg laying and incubation pattern of the Chinese Grouse;25 nests were monitored by data loggers and 12 nests by infrared video cameras. Results:Female Chinese Grouses usually laid an egg every 2 days.The incubation period was 28-31 days. Overall incubation constancy for Chinese Grouse was 93%. The females took 5.0 recesses per day and 34% of all 1696 recesses were taken in the crepuscular period. The average recess duration was 20.3 min. Females took more and shorter recesses in the latter part of incubation.The females who allocated more time to foraging had a higher reproductive success. Conclusions:Probably due to its high egg/body mass ratio,the Chinese Grouse has a long laying interval of 49 h. We suggest that,due to energy stress,females have relatively more recesses and they increase the number of recesses as incubation progresses.To compensate for the embryos'thermal needs, they extend the incubation period and shorten the recess duration in this cold environment.展开更多
Background: The species–area relationship is one of the best documented patterns in community ecology.Factors influencing species–area relationship are still not well understood.Since the proposal of the equilibrium...Background: The species–area relationship is one of the best documented patterns in community ecology.Factors influencing species–area relationship are still not well understood.Since the proposal of the equilibrium theory of island biogeography, many studies have tested the effects of area and isolation, estimating effects of disturbance and patch age were scarce and should also be important bearing.Methods: We investigated summer waterbird species richness in 38 post?mining subsidence lakes in Huainan and Fuyang, Anhui, China, May 25–June 12, 2016.We examined the effects of lake area, isolation(distance to natural water bodies), aquaculture disturbance, lake age and lake state(still sinking or not sinking) on summer waterbird species richness with multivariable linear regression method and model selection method.Results: Our results from multivariable linear regression and model selection were consistent, which showed that species richness was positively related with lake area and negatively related with isolation.Aquaculture disturbance negatively influenced species richness.Highest species richness were found in lakes under intermediate intensity of aquaculture activities with area less than 100 ha and lakes under low intensity of aquaculture activities with area greater than 100 ha.Lake age and lake state had no significant effects on species richness.Conclusions: Species richness was most related with lake area, aquaculture disturbance, and isolation, with lake area had a positive effect, while aquaculture activities and isolation had a negative effect.What's more, aquaculture activi?ties significantly changed the slope of species–area relationship and might impede us finding a relationship between species richness and lake age.展开更多
Background:China is facing challenges of the shifting presentation of tuberculosis(TB)from younger to elderly due to an ageing population,longer life expectancy and reactivation disease.However,the burden of elderly T...Background:China is facing challenges of the shifting presentation of tuberculosis(TB)from younger to elderly due to an ageing population,longer life expectancy and reactivation disease.However,the burden of elderly TB and influence factors are not yet clear.To fill the gap,we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China.Methods:In this cohort established in 2013 through a prevalence survey conducted in selected sites,a total of 34076 elderlies without TB were enrolled into two-year follow-up.We used both active and passive case findings to find out all TB patients among them.The person-year(PY)incidence rates for both bacteriologically positive TB and active TB were calculated.Cox proportional regression model was performed to test effect of risk factors,and the population attributable fraction(PAF)of each risk factor contributing to incident TB among elderlies was calculated.Results:Over the two-year follow-up period,a total of 215 incident active TB were identified,62 of which were bacteriologically positive.The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100000 PY(95%CI:417.4–546.2 per 100000 PY)and 138.9 per 100000 PY(95%CI:104.4–173.5 per 100000 PY),respectively.Incident cases detected by active case finding were significantly higher(P<0.001).Male,non-Han nationality,previously treated TB,ex/current smoker and body mass index(BMI)<18.5 presented as independent predictors for developing TB disease.For developing bacteriologically positive TB,the biggest contribution was from self-reported ex or current smoker(18.06%).And,for developing active TB,the biggest contribution was from non-Han nationality(35.40%),followed by male(26.80%)and age at 75 years and above(10.85%).Conclusions:Ageing population in China had a high TB incidence rate and risk to develop TB disease,implying that National TB Program(NTP)needs to prioritize for elderly.Active case finding should be applied capture more active TB cases among this particular population,especially for male,non-Han nationality,and those with identified risk factors.展开更多
Nest survival is a vital component of breeding success,and affects population dynamics,as the loss of nests is the main cause of reproductive failure in birds.To identify key factors for the conservation of Chinese gr...Nest survival is a vital component of breeding success,and affects population dynamics,as the loss of nests is the main cause of reproductive failure in birds.To identify key factors for the conservation of Chinese grouse Tetrastes sewerzowi,we tested the effects of nest concealment,nest age,nesting season,and habitat edge on nest daily survival rate(DSR)of Chinese grouse using 54 nests found at Lianhuashan Nature Reserve,Gansu,China,2009-2012.Moreover,we controlled for the effect of research activity by testing the effect of nest checks on DSR.Overall,mammal predation caused 93%of nest failures.DSR was 0.986±0.0038 in the constant model and the probability of a nest with a full clutch of 6 eggs surviving the entire 40-day nesting period was 0.526±0.090.DSR decreased with nest age and nesting season(from 19 May to 3 July).Mammals instead of avian predators being responsible for most nest failures suggest that nest sites might be selected to avoid visual avian predators,but not olfactory mammalian predators,and the decreasing trend of DSR with nest age and nesting season could attribute to an additive exposure effect.Moreover,nest checks conducted by investigators significantly lowered nest DSR,especially during the late period of nesting season and for older nests.Mammalian predators might locate the nest site by following the investigator's odor.Based on our results,we suggest that the late incubation stage is a particularly vulnerable period for nest survival of Chinese grouse and those researchers should adjust their activities around nests to balance the need of acquiring accurate data and decreasing nest predation risk.展开更多
文摘BACKGROUND The optimal approach for managing hepatic hemangioma is controversial.AIM To evaluate a clinical grading system for management of hepatic hemangioma based on our 17-year of single institution experience.METHODS A clinical grading system was retrospectively applied to 1171 patients with hepatic hemangioma from January 2002 to December 2018.Patients were classified into four groups based on the clinical grading system and treatment:(1)Observation group with score<4(Obs score<4);(2)Surgical group with score<4(Sur score<4);(3)Observation group with score≥4(Obs score≥4);and(4)Surgical group with score≥4(Sur score≥4).The clinico-pathological index and outcomes were evaluated.RESULTS There were significantly fewer symptomatic patients in surgical groups(Sur score≥4 vs Obs score≥4,P<0.001;Sur score<4 vs Obs score<4,χ^(2)=8.60,P=0.004;Sur score≥4 vs Obs score<4,P<0.001).The patients in Sur score≥4 had a lower rate of in need for intervention and total patients with adverse event than in Obs score≥4(P<0.001;P<0.001).Nevertheless,there was no significant difference in need for intervention and total patients with adverse event between the Sur score<4 and Obs score<4(P>0.05;χ^(2)=1.68,P>0.05).CONCLUSION This clinical grading system appeared as a practical tool for hepatic hemangioma.Surgery can be suggested for patients with a score≥4.For those with<4,follow-up should be proposed.
基金Supported by National Natural Science Foundation of China,No.81160201 and No.U1303222
文摘AIM: To evaluate the reliability and accuracy of threedimensional(3D) reconstruction for liver resection in patients with hepatic alveolar echinococcosis(HAE).METHODS: One-hundred and six consecutive patients with HAE underwent hepatectomy at our hospital between May 2011 and January 2015. Fifty-nine patients underwent preoperative 3D reconstruction and "virtual" 3D liver resection before surgery(Group A). Another 47 patients used conventional imaging methods for preoperative assessment(Group B). Outcomes of hepatectomy were compared between the two groups.RESULTS: There was no significant difference in preoperative data between the two groups. Compared with patients in Group B, those in Group A had a significantly shorter operation time(227.1 ± 51.4 vs 304.6 ± 88.1 min; P < 0.05), less intraoperative blood loss(308.1 ± 135.4 vs 458.1 ± 175.4 m L; P < 0.05), and lower requirement for intraoperative blood transfusion(186.4 ± 169.6 vs 289.4 ± 199.2 m L; P < 0.05). Estimated resection liver volumes in bothgroups had good correlation with actual graft weight(Group A: r = 0.978; Group B: r = 0.960). There was a significant higher serum level of albumin in Group A(26.3 ± 5.9 vs 22.6 ± 4.3 g/L, P < 0.05). Other postoperative laboratory parameters(serum levels of aminotransferase and bilirubin; prothrombin time) and duration of postoperative hospital stay were similar. Sixteen complications occurred in Group A and 19 in Group B. All patients were followed for 3-46(mean, 17.3) mo. There was no recurrence of lesions in Group A, but two recurrences in Group B. There were three deaths: two from cerebrovascular accident, and one from car accident.CONCLUSION: 3D reconstruction provides comprehensive and precise anatomical information for the liver. It also improves the chance of success and reduces the risk of hepatectomy in HAE.
基金supported by grants from Xinjiang Uyghur Autonomous Region Key Laboratory Open Research Program(No.2018D03002)the National Natural Science Foundation of China(No.81560329)+1 种基金Xinjiang Uyghur Autonomous Region Key Scientific Research Program(No.201430123–2)State Key Laboratory of Pathogenesis,Prevention,Treatment of High Incidence Diseases in Central Asia Fund(No.SKL-HIDCA-2017-Y2)
文摘Background: The University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solutions are the two most frequently used liver graft preservation fluids. The present study aimed to compare their efficacy in end-stage hepatic alveolar echinococcosis patients who underwent ex-situ liver resection and autotransplantation (ELRA). Methods: A total of 81 patients received ELRA from August 2010 to March 2018. They were allocated into UW ( n = 48) and HTK groups ( n = 33) based on the type of solutions used. Demographic and operational data were retrospectively analyzed. Primary outcomes included 90-day mortality, incidence of early graft loss, primary dysfunction, and postoperative complications. Results: Demographic and operational characteristics were similarly distributed in the two groups. No statistically significant differences were observed with regard to 90-day mortality (12.77% vs. 12.12%) and early graft loss rate (8.51% vs. 9.09%) between the two groups. Patients in the UW and HTK groups showed a primary dysfunction rate of 27.66% and 27.27%, respectively. The UW group exhibited a higher incidence tendency of biliary complications, albeit with no statistical significance. Conclusions: This is the largest cohort study comparing the efficacy of the UW and HTK organ-preserving solutions in end-stage hepatic alveolar echinococcosis patients in ELRA settings. UW and HTK solutions presented similar efficacy and safety. A randomized clinical trial with larger scale is needed for further investigation in future clinical applications.
基金supported by grants from the National Natural Science Foundation of China(NSFC,31520103903)
文摘Background: The habitat features of breeding territory have important adaptive significance for the survival and reproduction of territory holders.The Chinese Grouse(Tetrastes sewerzowi) is a rare and endemic species with rela?tively small distribution range and decreasing population trend.It is important to elucidate breeding territory habitat requirements of the Chinese Grouse for habitat management and conservation actions.Methods: Using radio?telemetry and field observations,we determined the core areas of 65 breeding territories of males.Two to three samples were selected in each core breeding territory as used sites and compared with nearby sites with no grouse occurrence using logistic regression.Results: Our model showed a high accuracy in prediction of core breeding territory used by males,which preferred stands with more small deciduous trees(0.5 m ≤ height < 5 m),more small willow trees(Salix spp.,0.5 m infl≤ height < 5 m),greater willow cover,and greater herb cover.The number of small willow trees had the great?estuence on males' core breeding territory selection.Dense shrubs were also chosen compared with unused sites Tall conifer trees was an important determinant in the distribution of Chinese Grouse at the landscape scale,and was relatively important in the univariate model,but not included in our final multivariable model.Conclusions: Male Chinese Grouse established territories at sites with abundant food resources.At the landscape scale,the Chinese Grouse occurred in alpine conifer forest.At the territory scale,small willow trees had the most important effect on males' core breeding territory selection.We suggest that the forest gaps in dense conifer for?est are important for improving the occurrence of willows and facilitating breeding territory establishment for the Chinese Grouse.
基金supported by grants of the National Natural Science Foundation of China(31520103903,31172099)CAS Innovation Program and Deutsche Forschungs-emeinschaft and World Pheasant Association
文摘Background:Incubating birds must balance the conflict between thermal needs of the developing embryos and their self?maintenance needs for energy.The Chinese Grouse (Tetrastes sewerzowi) lives in high mountain conifer forests and faces energy stress,cold environment,and predation pressure.Females might adjust incubation rhythm to adapt to these constraints. Methods:Two methods were used to investigate egg laying and incubation pattern of the Chinese Grouse;25 nests were monitored by data loggers and 12 nests by infrared video cameras. Results:Female Chinese Grouses usually laid an egg every 2 days.The incubation period was 28-31 days. Overall incubation constancy for Chinese Grouse was 93%. The females took 5.0 recesses per day and 34% of all 1696 recesses were taken in the crepuscular period. The average recess duration was 20.3 min. Females took more and shorter recesses in the latter part of incubation.The females who allocated more time to foraging had a higher reproductive success. Conclusions:Probably due to its high egg/body mass ratio,the Chinese Grouse has a long laying interval of 49 h. We suggest that,due to energy stress,females have relatively more recesses and they increase the number of recesses as incubation progresses.To compensate for the embryos'thermal needs, they extend the incubation period and shorten the recess duration in this cold environment.
基金supported by the National Natural Science Foundation of China(Grant No.31472020)
文摘Background: The species–area relationship is one of the best documented patterns in community ecology.Factors influencing species–area relationship are still not well understood.Since the proposal of the equilibrium theory of island biogeography, many studies have tested the effects of area and isolation, estimating effects of disturbance and patch age were scarce and should also be important bearing.Methods: We investigated summer waterbird species richness in 38 post?mining subsidence lakes in Huainan and Fuyang, Anhui, China, May 25–June 12, 2016.We examined the effects of lake area, isolation(distance to natural water bodies), aquaculture disturbance, lake age and lake state(still sinking or not sinking) on summer waterbird species richness with multivariable linear regression method and model selection method.Results: Our results from multivariable linear regression and model selection were consistent, which showed that species richness was positively related with lake area and negatively related with isolation.Aquaculture disturbance negatively influenced species richness.Highest species richness were found in lakes under intermediate intensity of aquaculture activities with area less than 100 ha and lakes under low intensity of aquaculture activities with area greater than 100 ha.Lake age and lake state had no significant effects on species richness.Conclusions: Species richness was most related with lake area, aquaculture disturbance, and isolation, with lake area had a positive effect, while aquaculture activities and isolation had a negative effect.What's more, aquaculture activi?ties significantly changed the slope of species–area relationship and might impede us finding a relationship between species richness and lake age.
基金This study was supported by The National Twelfth Five-year Mega-Scientific Projects of infectious diseases of China(grant No.:2013ZX10003004-001)the funder had no contribution to study design,data collection and analysis,result interpretation and paper writing.
文摘Background:China is facing challenges of the shifting presentation of tuberculosis(TB)from younger to elderly due to an ageing population,longer life expectancy and reactivation disease.However,the burden of elderly TB and influence factors are not yet clear.To fill the gap,we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China.Methods:In this cohort established in 2013 through a prevalence survey conducted in selected sites,a total of 34076 elderlies without TB were enrolled into two-year follow-up.We used both active and passive case findings to find out all TB patients among them.The person-year(PY)incidence rates for both bacteriologically positive TB and active TB were calculated.Cox proportional regression model was performed to test effect of risk factors,and the population attributable fraction(PAF)of each risk factor contributing to incident TB among elderlies was calculated.Results:Over the two-year follow-up period,a total of 215 incident active TB were identified,62 of which were bacteriologically positive.The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100000 PY(95%CI:417.4–546.2 per 100000 PY)and 138.9 per 100000 PY(95%CI:104.4–173.5 per 100000 PY),respectively.Incident cases detected by active case finding were significantly higher(P<0.001).Male,non-Han nationality,previously treated TB,ex/current smoker and body mass index(BMI)<18.5 presented as independent predictors for developing TB disease.For developing bacteriologically positive TB,the biggest contribution was from self-reported ex or current smoker(18.06%).And,for developing active TB,the biggest contribution was from non-Han nationality(35.40%),followed by male(26.80%)and age at 75 years and above(10.85%).Conclusions:Ageing population in China had a high TB incidence rate and risk to develop TB disease,implying that National TB Program(NTP)needs to prioritize for elderly.Active case finding should be applied capture more active TB cases among this particular population,especially for male,non-Han nationality,and those with identified risk factors.
基金This research is financially supported by the National Natural Science Foundation of China(Project 31520103903,31172099).
文摘Nest survival is a vital component of breeding success,and affects population dynamics,as the loss of nests is the main cause of reproductive failure in birds.To identify key factors for the conservation of Chinese grouse Tetrastes sewerzowi,we tested the effects of nest concealment,nest age,nesting season,and habitat edge on nest daily survival rate(DSR)of Chinese grouse using 54 nests found at Lianhuashan Nature Reserve,Gansu,China,2009-2012.Moreover,we controlled for the effect of research activity by testing the effect of nest checks on DSR.Overall,mammal predation caused 93%of nest failures.DSR was 0.986±0.0038 in the constant model and the probability of a nest with a full clutch of 6 eggs surviving the entire 40-day nesting period was 0.526±0.090.DSR decreased with nest age and nesting season(from 19 May to 3 July).Mammals instead of avian predators being responsible for most nest failures suggest that nest sites might be selected to avoid visual avian predators,but not olfactory mammalian predators,and the decreasing trend of DSR with nest age and nesting season could attribute to an additive exposure effect.Moreover,nest checks conducted by investigators significantly lowered nest DSR,especially during the late period of nesting season and for older nests.Mammalian predators might locate the nest site by following the investigator's odor.Based on our results,we suggest that the late incubation stage is a particularly vulnerable period for nest survival of Chinese grouse and those researchers should adjust their activities around nests to balance the need of acquiring accurate data and decreasing nest predation risk.