At 11:00 am on August 5, 2017, Cangyuan Washan Airport experienced low cloud and low visibility weather, accompanied by aircraft turbulence, which affected the normal operation of flights, which was closely related to...At 11:00 am on August 5, 2017, Cangyuan Washan Airport experienced low cloud and low visibility weather, accompanied by aircraft turbulence, which affected the normal operation of flights, which was closely related to the meteorological conditions at that time. Using the hourly reanalysis data of the European Centre for Medium-range Weather Forecast (ECMWF) Reanalysis 5 (ERA5), including Geopotential height, temperature, precipitation, wind field, specific humidity, vorticity and other elements, with a spatial resolution of 0.25° × 0.25°, this paper focuses on the horizontal distribution and vertical configuration of various physical quantities before and after the occurrence of low cloud and low visibility weather at the airport. The results indicate that the main influencing system of this low cloud and low visibility weather is the westward tropical depression. Before the occurrence of low cloud and low visibility weather, low-level water vapor converges and is accompanied by precipitation. The temperature decreases with precipitation, the near-surface wind direction changes, and the wind speed decreases.展开更多
Near infrared spectroscopy(NIRS),coupled with principal component analysis and wavelength selection techniques,has been sed to develop a robust and reliable reduced-spectrum classifi-cation model for determining the g...Near infrared spectroscopy(NIRS),coupled with principal component analysis and wavelength selection techniques,has been sed to develop a robust and reliable reduced-spectrum classifi-cation model for determining the geographical origins of Nanfeng mandarins.The application of the changeable size moving window principal component analysis(CSMWPCA)provided a notably improved lassification model,with correct classification rates of 92.00%,100.00%,90.00%,100.00%,100.00%,100.00%and 100.00%for Fujian,Guangxi,Hunan,Baishe,Baofeng,Qiawan,Sanxi samples,respectively,as well as,a total dassification rate of 97.52%in the wavelength range from 1007 to 1296 nm.To test and apply the proposed method,the procedure was applied to the analysis of 59 samples in an independent test set.Good identification results(correct rate of 96.61%)were also received.The improvement achieved by the application of CSMWPCA method was particularly remarkable when taking the low complexities of the final model(290 variables)into account.The results of the study showed the great potential of NIRS as a fast,nondestructive and environmentally acceptable method for the rapid and reliable determination for geographical classifcation of Nanfeng mandarins.展开更多
[Objectives]To evaluate the impacts of the elemental sulfur(S 0)and micro-algae(MA)co-fertilization on saline-alkaline soil of sunflower field in the Hetao Irrigation District(HID).[Methods]The greenhouse pot experime...[Objectives]To evaluate the impacts of the elemental sulfur(S 0)and micro-algae(MA)co-fertilization on saline-alkaline soil of sunflower field in the Hetao Irrigation District(HID).[Methods]The greenhouse pot experiment was conducted with four treatments:control(CK),single S 0 fertilization(S),single MA fertilization(A),and S 0 and MA co-fertilization(SA)for comparing the selected soil properties and sunflower plant heights and weights in different treatments.[Results]The results showed that the mean soil organic matter(SOM)under the SA(25.08 g/kg)was significantly higher than that for the CK(20.59 g/kg),S(22.47 g/kg),and A(22.95 g/kg).The mean pH under the SA(7.75)was significantly lower than that for the CK(8.14),S(7.82),and A(7.96).The mean soil exchangeable Na+concentration under the SA was significantly lower than that for the S.The mean soil electrical conductivity(EC)under the SA was 9.76%lower than that for the S.The means of Cl-(1.22 g/kg)and SO 2-4(1.90 g/kg)in soil under the SA were lower than that for the S(1.30,2.06 g/kg)and A(1.31,1.97 g/kg),respectively.For plant height 3 at the late stage of plant growth,the mean plant height 3 under the SA(89.00 cm)was higher than that of the CK(69.60 cm)and A(74.33 cm).The total weights of the fresh sunflower heads,fresh stems,and dry seeds under the SA were higher than that for the CK,S,and A.[Conclusions]In conclusion,the S 0 and MA co-fertilization had positive effects on improving saline-alkaline soils,the soil under the S 0 and MA co-fertilization could be better conditions for promoting sunflower growth than that for the S,Z,and CK,and thereby the S 0 and MA co-fertilization could be a new idea to improve saline-alkaline soil in the cold and arid regions.展开更多
Salvia miltiorrhiza Bunge(S.miltiorrhiza),a perennial plant of the genus Salvia,is widely used in traditional folklore medicine.Previous chemical research on this plant contains diterpenoid quinones,phenolic acids,pol...Salvia miltiorrhiza Bunge(S.miltiorrhiza),a perennial plant of the genus Salvia,is widely used in traditional folklore medicine.Previous chemical research on this plant contains diterpenoid quinones,phenolic acids,polysaccharides and other compounds.The pharmacological investigation of S.miltiorrhiza has shown that it has various pharmacological activities,such as cardiovascular system protection,anti-inflammatory,anti-oxidant,anti-tumor,liver protection,and neuroprotection activities.This research tends to give an overview of the main chemical constituents and pharmacological effects of S.miltiorrhiza,aiming to reveal its potential value and provide reference for its further development.展开更多
Viburnum dilatatum(jiami in Chinese),belonging to the Caprifollaceae family,is widely distributed in Japan and China.Phytochemical investigations of Viburnum dilatatum(V.dilatatum)have resulted in the isolation of tri...Viburnum dilatatum(jiami in Chinese),belonging to the Caprifollaceae family,is widely distributed in Japan and China.Phytochemical investigations of Viburnum dilatatum(V.dilatatum)have resulted in the isolation of triterpenoids,phenolic glycosides essential oil,norisoprenoids,etc.Research results have shown that the chemical constituents of V.dilatatum possess various pharmacological activities,including antihyperglycemic,antioxidant activity and antiulcer effects.This study reviewed the chemical constituents and pharmacological activities of V.dilatatum to provide practical and useful information for further research and development of this plant.展开更多
A simple composite Sr_(1-x)Nd_(x)MnO_(3)(x=0,0.05,0.1,0.15,0.2) nano powders were successfully prepared by the sol-gel method as a light-weight broadband electromagnetic wave absorber.The effect of Nd^(3+)doping on th...A simple composite Sr_(1-x)Nd_(x)MnO_(3)(x=0,0.05,0.1,0.15,0.2) nano powders were successfully prepared by the sol-gel method as a light-weight broadband electromagnetic wave absorber.The effect of Nd^(3+)doping on the structure,microstructure and properties of SrMnO_(3) was investigated.It is found that with the doping of Nd^(3+),the space group of the SrMnO_(3) changes from p63/mmc to pm3m,and the crystalline shape starts to change from hexagonal to cubic crystalline.Scanning electron microscopy(SEM) and Brunauer-Emmett-Teller(BET) tests confirm that the particle sizes of the sample decrease and the specific surface area increases,which are attributed to the inhibition of grain growth after Nd^(3+)is doped.X-ray photoelectron spectroscopy(XPS) shows that after Nd^(3+)doping,the content of oxygen vacancy increases,and Mn^(4+) converts to Mn^(3+).Due to the defects of the materials,the polarization effect is enhanced,thus,the dielectric and magnetic properties of the doped samples are improved.The maximum reflection loss of the Sr_(0.85)Nd_(0.15)MnO_(3) is-33.41 dB at 7.84 GHz for a thickness of 2.4 mm,while Sr_(0.9)Nd_(0.1)MnO_(3) has the best bandwidth performance at 2.32 GHz with a reflection loss below-10dB.展开更多
Objective:This study aimed to observe the efficacy and safety of traditional Chinese medicine therapy in patients with positive antibody responses to severe acute respiratory syndrome coronavirus 2.Methods:A retrospec...Objective:This study aimed to observe the efficacy and safety of traditional Chinese medicine therapy in patients with positive antibody responses to severe acute respiratory syndrome coronavirus 2.Methods:A retrospective observation was conducted on 25 patients with positive antibody responses but negative nucleic acid testing results who received Anshouxinshen therapy.The changes in symptoms,infective indicators,and safety were recorded.Results:Following treatment,the positive IgM responses of 18 patients became negative within one week,with an average time for antibody to become negative being 2 days.Of the seven patients with positive IgG responses,six became IgG-negative with an average time for antibody to become negative being 6.8 days.All symptoms of anxiety,insomnia,cough,fever,fatigue,and other symptoms improved 100%for all patients.After treatment,the lymphocyte count and lymphocyte ratio of patients significantly increased.No adverse reactions to Anshouxinshen therapy were reported.Conclusion:Anshouxinshen therapy is an effective treatment for patients with positive antibody responses to syndrome coronavirus 2,safely improving their immune functions.Early traditional Chinese medicine intervention can reduce the incidence of coronavirus disease 2019 and improve its cure rate,thereby promoting the prevention and control of coronavirus disease 2019.展开更多
BACKGROUND Gastric Helicobacter pylori(H.pylori)infection is related to chronic gastritis,gastroduodenal ulcer,and gastric malignancies;whether this infection is related to colorectal polyps and colorectal cancer(CRC)...BACKGROUND Gastric Helicobacter pylori(H.pylori)infection is related to chronic gastritis,gastroduodenal ulcer,and gastric malignancies;whether this infection is related to colorectal polyps and colorectal cancer(CRC),remains debatable.AIM To investigate the relationship between gastric H.pylori infection and the risk of colorectal polyps and CRC.METHODS We retrospectively analyzed 3872 patients with colorectal polyps who underwent colonoscopy and pathological diagnosis.We also analyzed 304 patients with primary CRC.The characteristics of these patients were compared with those of the control group,which included 2362 patients with the normal intestinal mucosa.All subjects completed a 14C-urea breath test,bidirectional gastrointestinal endoscopy,and a biopsy on the same day.Data on the number,size,location,and pathology of the polyps,the location,and pathology of the CRC,the detection of H.pylori,and the incidence of H.pylori-associated atrophic gastritis or intestinal metaplasia were obtained.A logistic regression model was used to analyze the relationship between gastric infection due to H.pylori,and the incidence of colorectal polyps and CRC.RESULTS The prevalence of H.pylori infection was higher in the multiple polyps group than in the solitary polyp group and the control group[95%confidence interval(CI)=1.02-1.31,P=0.03;95%CI:2.12-2.74,P<0.001].The patients with adenomatous polyps had a higher incidence of H.pylori infection than patients with non-adenomatous polyps[59.95%vs 51.75%,adjusted odds ratio(OR)=1.41,95%CI:1.24-1.60,P<0.01].Patients with H.pylori-associated atrophic gastritis or intestinal metaplasia were at high risk of CRC(adjusted OR=3.46,95%CI:2.63-4.55,P<0.01;adjusted OR=4.86,95%CI:3.22-7.34,P<0.01,respectively).The size and location of the polyps,the histopathological characteristics and the location of CRC were not related to H.pylori infection.CONCLUSION Our study demonstrates that the incidence of gastric H.pylori infection and H.pylori-associated atrophic gastritis or intestinal metaplasia elevates the risk of colorectal polyps and CRC.展开更多
BACKGROUND Colorectal cancer is a common malignant tumor of the digestive tract.The relationship between sentinel polyps(rectal polyps with proximal colon cancer)and proximal colon cancer has received extensive attent...BACKGROUND Colorectal cancer is a common malignant tumor of the digestive tract.The relationship between sentinel polyps(rectal polyps with proximal colon cancer)and proximal colon cancer has received extensive attention in recent years.However,there is still no clear conclusion regarding the relationship.AIM To investigate the clinical characteristics of sentinel polyps and their correlation with proximal colon cancer.METHODS A retrospective analysis of 2587 patients with rectal polyps from January 2006 to December 2017 was performed.According to whether or not proximal colon cancer was diagnosed,the patients were divided into either a sentinel polyp group(192 patients)or a pure rectal polyp group(2395 patients).The endoscopic features,clinicopathological features,therapeutic effects,and short-term prognosis were analyzed and compared between the two groups.RESULTS The mean age of patients in the sentinel polyp group was generally higher than that of the pure rectal polyp group,and the positivity rates of anemia,stool occult blood,and tumor markers of the sentinel polyp group were also significantly higher than those in the rectal polyp group(χ^2=90.56,P<0.01;χ^2=70.30,P<0.01;χ^2=92.80,P<0.01).The majority of the patients in the sentinel polyp group had multiple polyps,large polyps,adenomatous polyps,or sessile polyps(χ^2=195.96,P<0.01;χ^2=460.46,P<0.01;χ^2=94.69,P<0.01;χ^2=48.01,P<0.01).Most of the proximal colon cancers were Duke’s A and B stages in the sentinel polyp group.In the pure rectal polyp group,2203 patients underwent endoscopic treatment,and all of the patients were cured and discharged.In the sentinel polyp group,65 patients underwent radical operation,and 61 patients received endoscopic submucosal dissection or endoscopic mucosal resection.Additionally,21 patients were lost to follow-up after 6-12 mo,and the loss rate was 10.94%.A total of 63.16%of patients experienced remission without tumor recurrence or metastasis,33.33%of patients experienced tumors regression or improved symptoms,and the other 3.51%of the patients died.CONCLUSION If there are multiple,sessile,and adenomatous rectal polyps with a maximum diameter>1 cm,the possibility of the carcinogenesis of the polyps or of the proximal colon should be monitored closely.These patients should be followed in the short-term and should undergo a whole-colon examination.展开更多
Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeabil...Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeability,which will lead to the distortion of the petroleum resources reserves assessment.Therefore,the hollow glass microspheres/epoxy resin(HGM/EP)composites were innovatively proposed as temperature preserved materials for in-situ temperature-preserved coring(ITP-Coring),and the physical,mechanical,and temperature preserved properties were evaluated.The results indicated that:As the HGM content increased,the density and mechanical properties of the composites gradually decreased,while the water absorption was deficient without hydrostatic pressure.For composites with 50 vol%HGM,when the hydrostatic pressure reached 60 MPa,the water absorption was above 30.19%,and the physical and mechanical properties of composites were weakened.When the hydrostatic pressure was lower than 40 MPa,the mechanical properties and thermal conductivity of composites were almost unchanged.Therefore,the composites with 50 vol%HGM can be used for ITPCoring operations in deep environments with the highest hydrostatic pressure of 40 MPa.Finally,to further understand the temperature preserved performance of composites in practical applications,the temperature preserved properties were measured.An unsteady-state heat transfer model was established based on the test results,then the theoretical change of the core temperature during the coring process was obtained.The above tests results can provide a research basis for deep rock in-situ temperature preserved corer and support accurate assessment of deep petroleum reserves.展开更多
文摘At 11:00 am on August 5, 2017, Cangyuan Washan Airport experienced low cloud and low visibility weather, accompanied by aircraft turbulence, which affected the normal operation of flights, which was closely related to the meteorological conditions at that time. Using the hourly reanalysis data of the European Centre for Medium-range Weather Forecast (ECMWF) Reanalysis 5 (ERA5), including Geopotential height, temperature, precipitation, wind field, specific humidity, vorticity and other elements, with a spatial resolution of 0.25° × 0.25°, this paper focuses on the horizontal distribution and vertical configuration of various physical quantities before and after the occurrence of low cloud and low visibility weather at the airport. The results indicate that the main influencing system of this low cloud and low visibility weather is the westward tropical depression. Before the occurrence of low cloud and low visibility weather, low-level water vapor converges and is accompanied by precipitation. The temperature decreases with precipitation, the near-surface wind direction changes, and the wind speed decreases.
基金supported by General Administration of Quality Supervision,Inspection and Quarantine of the People's Republic of China (2012IK169)National Natural Science Youth Foundation of China (21205053).
文摘Near infrared spectroscopy(NIRS),coupled with principal component analysis and wavelength selection techniques,has been sed to develop a robust and reliable reduced-spectrum classifi-cation model for determining the geographical origins of Nanfeng mandarins.The application of the changeable size moving window principal component analysis(CSMWPCA)provided a notably improved lassification model,with correct classification rates of 92.00%,100.00%,90.00%,100.00%,100.00%,100.00%and 100.00%for Fujian,Guangxi,Hunan,Baishe,Baofeng,Qiawan,Sanxi samples,respectively,as well as,a total dassification rate of 97.52%in the wavelength range from 1007 to 1296 nm.To test and apply the proposed method,the procedure was applied to the analysis of 59 samples in an independent test set.Good identification results(correct rate of 96.61%)were also received.The improvement achieved by the application of CSMWPCA method was particularly remarkable when taking the low complexities of the final model(290 variables)into account.The results of the study showed the great potential of NIRS as a fast,nondestructive and environmentally acceptable method for the rapid and reliable determination for geographical classifcation of Nanfeng mandarins.
基金Supported by“Bayannur Ecological Governance and Green Development Academician Expert Workstation Construction Project of Hetao College”Provided by the Inner Mongolia Autonomous Region Science and Technology Department“Investigation of Agricultural Soil Carbon Dioxide Emission and Soil Quality Improvement in the Hetao Irrigation District”Provided by the Inner Mongolia Science and Technology Program.
文摘[Objectives]To evaluate the impacts of the elemental sulfur(S 0)and micro-algae(MA)co-fertilization on saline-alkaline soil of sunflower field in the Hetao Irrigation District(HID).[Methods]The greenhouse pot experiment was conducted with four treatments:control(CK),single S 0 fertilization(S),single MA fertilization(A),and S 0 and MA co-fertilization(SA)for comparing the selected soil properties and sunflower plant heights and weights in different treatments.[Results]The results showed that the mean soil organic matter(SOM)under the SA(25.08 g/kg)was significantly higher than that for the CK(20.59 g/kg),S(22.47 g/kg),and A(22.95 g/kg).The mean pH under the SA(7.75)was significantly lower than that for the CK(8.14),S(7.82),and A(7.96).The mean soil exchangeable Na+concentration under the SA was significantly lower than that for the S.The mean soil electrical conductivity(EC)under the SA was 9.76%lower than that for the S.The means of Cl-(1.22 g/kg)and SO 2-4(1.90 g/kg)in soil under the SA were lower than that for the S(1.30,2.06 g/kg)and A(1.31,1.97 g/kg),respectively.For plant height 3 at the late stage of plant growth,the mean plant height 3 under the SA(89.00 cm)was higher than that of the CK(69.60 cm)and A(74.33 cm).The total weights of the fresh sunflower heads,fresh stems,and dry seeds under the SA were higher than that for the CK,S,and A.[Conclusions]In conclusion,the S 0 and MA co-fertilization had positive effects on improving saline-alkaline soils,the soil under the S 0 and MA co-fertilization could be better conditions for promoting sunflower growth than that for the S,Z,and CK,and thereby the S 0 and MA co-fertilization could be a new idea to improve saline-alkaline soil in the cold and arid regions.
文摘Salvia miltiorrhiza Bunge(S.miltiorrhiza),a perennial plant of the genus Salvia,is widely used in traditional folklore medicine.Previous chemical research on this plant contains diterpenoid quinones,phenolic acids,polysaccharides and other compounds.The pharmacological investigation of S.miltiorrhiza has shown that it has various pharmacological activities,such as cardiovascular system protection,anti-inflammatory,anti-oxidant,anti-tumor,liver protection,and neuroprotection activities.This research tends to give an overview of the main chemical constituents and pharmacological effects of S.miltiorrhiza,aiming to reveal its potential value and provide reference for its further development.
文摘Viburnum dilatatum(jiami in Chinese),belonging to the Caprifollaceae family,is widely distributed in Japan and China.Phytochemical investigations of Viburnum dilatatum(V.dilatatum)have resulted in the isolation of triterpenoids,phenolic glycosides essential oil,norisoprenoids,etc.Research results have shown that the chemical constituents of V.dilatatum possess various pharmacological activities,including antihyperglycemic,antioxidant activity and antiulcer effects.This study reviewed the chemical constituents and pharmacological activities of V.dilatatum to provide practical and useful information for further research and development of this plant.
基金Project supported by the National Natural Science Foundation of China(51861006)Guangxi Science and Technology Project(AD19110010)。
文摘A simple composite Sr_(1-x)Nd_(x)MnO_(3)(x=0,0.05,0.1,0.15,0.2) nano powders were successfully prepared by the sol-gel method as a light-weight broadband electromagnetic wave absorber.The effect of Nd^(3+)doping on the structure,microstructure and properties of SrMnO_(3) was investigated.It is found that with the doping of Nd^(3+),the space group of the SrMnO_(3) changes from p63/mmc to pm3m,and the crystalline shape starts to change from hexagonal to cubic crystalline.Scanning electron microscopy(SEM) and Brunauer-Emmett-Teller(BET) tests confirm that the particle sizes of the sample decrease and the specific surface area increases,which are attributed to the inhibition of grain growth after Nd^(3+)is doped.X-ray photoelectron spectroscopy(XPS) shows that after Nd^(3+)doping,the content of oxygen vacancy increases,and Mn^(4+) converts to Mn^(3+).Due to the defects of the materials,the polarization effect is enhanced,thus,the dielectric and magnetic properties of the doped samples are improved.The maximum reflection loss of the Sr_(0.85)Nd_(0.15)MnO_(3) is-33.41 dB at 7.84 GHz for a thickness of 2.4 mm,while Sr_(0.9)Nd_(0.1)MnO_(3) has the best bandwidth performance at 2.32 GHz with a reflection loss below-10dB.
文摘Objective:This study aimed to observe the efficacy and safety of traditional Chinese medicine therapy in patients with positive antibody responses to severe acute respiratory syndrome coronavirus 2.Methods:A retrospective observation was conducted on 25 patients with positive antibody responses but negative nucleic acid testing results who received Anshouxinshen therapy.The changes in symptoms,infective indicators,and safety were recorded.Results:Following treatment,the positive IgM responses of 18 patients became negative within one week,with an average time for antibody to become negative being 2 days.Of the seven patients with positive IgG responses,six became IgG-negative with an average time for antibody to become negative being 6.8 days.All symptoms of anxiety,insomnia,cough,fever,fatigue,and other symptoms improved 100%for all patients.After treatment,the lymphocyte count and lymphocyte ratio of patients significantly increased.No adverse reactions to Anshouxinshen therapy were reported.Conclusion:Anshouxinshen therapy is an effective treatment for patients with positive antibody responses to syndrome coronavirus 2,safely improving their immune functions.Early traditional Chinese medicine intervention can reduce the incidence of coronavirus disease 2019 and improve its cure rate,thereby promoting the prevention and control of coronavirus disease 2019.
基金financially supported by the Joint Fund for Nuclear Technology Innovation Sponsored by the National Natural Science Foundation of China and the China National Nuclear Corporation(No.U2067201)。
文摘BACKGROUND Gastric Helicobacter pylori(H.pylori)infection is related to chronic gastritis,gastroduodenal ulcer,and gastric malignancies;whether this infection is related to colorectal polyps and colorectal cancer(CRC),remains debatable.AIM To investigate the relationship between gastric H.pylori infection and the risk of colorectal polyps and CRC.METHODS We retrospectively analyzed 3872 patients with colorectal polyps who underwent colonoscopy and pathological diagnosis.We also analyzed 304 patients with primary CRC.The characteristics of these patients were compared with those of the control group,which included 2362 patients with the normal intestinal mucosa.All subjects completed a 14C-urea breath test,bidirectional gastrointestinal endoscopy,and a biopsy on the same day.Data on the number,size,location,and pathology of the polyps,the location,and pathology of the CRC,the detection of H.pylori,and the incidence of H.pylori-associated atrophic gastritis or intestinal metaplasia were obtained.A logistic regression model was used to analyze the relationship between gastric infection due to H.pylori,and the incidence of colorectal polyps and CRC.RESULTS The prevalence of H.pylori infection was higher in the multiple polyps group than in the solitary polyp group and the control group[95%confidence interval(CI)=1.02-1.31,P=0.03;95%CI:2.12-2.74,P<0.001].The patients with adenomatous polyps had a higher incidence of H.pylori infection than patients with non-adenomatous polyps[59.95%vs 51.75%,adjusted odds ratio(OR)=1.41,95%CI:1.24-1.60,P<0.01].Patients with H.pylori-associated atrophic gastritis or intestinal metaplasia were at high risk of CRC(adjusted OR=3.46,95%CI:2.63-4.55,P<0.01;adjusted OR=4.86,95%CI:3.22-7.34,P<0.01,respectively).The size and location of the polyps,the histopathological characteristics and the location of CRC were not related to H.pylori infection.CONCLUSION Our study demonstrates that the incidence of gastric H.pylori infection and H.pylori-associated atrophic gastritis or intestinal metaplasia elevates the risk of colorectal polyps and CRC.
文摘BACKGROUND Colorectal cancer is a common malignant tumor of the digestive tract.The relationship between sentinel polyps(rectal polyps with proximal colon cancer)and proximal colon cancer has received extensive attention in recent years.However,there is still no clear conclusion regarding the relationship.AIM To investigate the clinical characteristics of sentinel polyps and their correlation with proximal colon cancer.METHODS A retrospective analysis of 2587 patients with rectal polyps from January 2006 to December 2017 was performed.According to whether or not proximal colon cancer was diagnosed,the patients were divided into either a sentinel polyp group(192 patients)or a pure rectal polyp group(2395 patients).The endoscopic features,clinicopathological features,therapeutic effects,and short-term prognosis were analyzed and compared between the two groups.RESULTS The mean age of patients in the sentinel polyp group was generally higher than that of the pure rectal polyp group,and the positivity rates of anemia,stool occult blood,and tumor markers of the sentinel polyp group were also significantly higher than those in the rectal polyp group(χ^2=90.56,P<0.01;χ^2=70.30,P<0.01;χ^2=92.80,P<0.01).The majority of the patients in the sentinel polyp group had multiple polyps,large polyps,adenomatous polyps,or sessile polyps(χ^2=195.96,P<0.01;χ^2=460.46,P<0.01;χ^2=94.69,P<0.01;χ^2=48.01,P<0.01).Most of the proximal colon cancers were Duke’s A and B stages in the sentinel polyp group.In the pure rectal polyp group,2203 patients underwent endoscopic treatment,and all of the patients were cured and discharged.In the sentinel polyp group,65 patients underwent radical operation,and 61 patients received endoscopic submucosal dissection or endoscopic mucosal resection.Additionally,21 patients were lost to follow-up after 6-12 mo,and the loss rate was 10.94%.A total of 63.16%of patients experienced remission without tumor recurrence or metastasis,33.33%of patients experienced tumors regression or improved symptoms,and the other 3.51%of the patients died.CONCLUSION If there are multiple,sessile,and adenomatous rectal polyps with a maximum diameter>1 cm,the possibility of the carcinogenesis of the polyps or of the proximal colon should be monitored closely.These patients should be followed in the short-term and should undergo a whole-colon examination.
基金National Natural Science Foundation of China(grant number 51827901)funded by the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)Shenzhen Basic Research Program(General Program)(No.JCYJ20190808153416970)
文摘Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeability,which will lead to the distortion of the petroleum resources reserves assessment.Therefore,the hollow glass microspheres/epoxy resin(HGM/EP)composites were innovatively proposed as temperature preserved materials for in-situ temperature-preserved coring(ITP-Coring),and the physical,mechanical,and temperature preserved properties were evaluated.The results indicated that:As the HGM content increased,the density and mechanical properties of the composites gradually decreased,while the water absorption was deficient without hydrostatic pressure.For composites with 50 vol%HGM,when the hydrostatic pressure reached 60 MPa,the water absorption was above 30.19%,and the physical and mechanical properties of composites were weakened.When the hydrostatic pressure was lower than 40 MPa,the mechanical properties and thermal conductivity of composites were almost unchanged.Therefore,the composites with 50 vol%HGM can be used for ITPCoring operations in deep environments with the highest hydrostatic pressure of 40 MPa.Finally,to further understand the temperature preserved performance of composites in practical applications,the temperature preserved properties were measured.An unsteady-state heat transfer model was established based on the test results,then the theoretical change of the core temperature during the coring process was obtained.The above tests results can provide a research basis for deep rock in-situ temperature preserved corer and support accurate assessment of deep petroleum reserves.
