BACKGROUND Rectal mucinous adenocarcinoma(MAC)is a rare pathological type of rectal can-cer with unique pathological features and a poor prognosis.It is difficult to diag-nose and treat early because of the lack of sp...BACKGROUND Rectal mucinous adenocarcinoma(MAC)is a rare pathological type of rectal can-cer with unique pathological features and a poor prognosis.It is difficult to diag-nose and treat early because of the lack of specific manifestations in some aspects of the disease.The common metastatic organs of rectal cancer are the liver and lung;however,rectal carcinoma with metastasis to subcutaneous soft tissue is a rare finding.CASE SUMMARY In this report,the clinical data,diagnosis and treatment process,and postope-rative pathological features of a patient with left waist subcutaneous soft tissue masses were retrospectively analyzed.The patient underwent surgical treatment after admission and recovered well after surgery.The final pathological diagnosis was rectal MAC with left waist subcutaneous soft tissue metastasis.CONCLUSION Subcutaneous soft tissue metastasis of rectal MAC is rare,and it can suggest that the tumor is disseminated,and it can appear even earlier than the primary ma-lignant tumor,which is occult and leads to a missed diagnosis and misdiagnosis clinically.When a subcutaneous soft tissue mass of unknown origin appears in a patient with rectal cancer,a ma-lignant tumor should be considered.展开更多
BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'prognosis.AIM To assess the occurrence and factors influencing gastroint...BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'prognosis.AIM To assess the occurrence and factors influencing gastrointestinal symptoms in patients with uremia undergoing hemodialysis.METHODS We retrospectively selected 98 patients with uremia who underwent regular hemo-dialysis treatment in the blood purification center of our hospital from December 2022 to December 2023.The gastrointestinal symptoms and scores of each dimension were evaluated using the Gastrointestinal Symptom Grading Scale(GSRS).Patients were divided into gastrointestinal symptoms and no gastrointestinal symptom groups according to whether they had gastrointestinal symptoms.The factors that may affect gastrointestinal symptoms were identified by single-factor analysis.Multiple logistic regression analysis was performed to identify independent risk factors for gastrointestinal symptoms.RESULTS Gastrointestinal symptoms included indigestion,constipation,reflux,diarrhea,abdominal pain,and eating disorders,and the total average GSRS score was 1.35±0.47.This study showed that age,number of tablets,dialysis time,glucocorticoid,parathyroid hormone(PTH),combined diabetes mellitus and C-reactive protein(CRP)were independent risk factors for gastrointestinal symptoms in patients with uremia undergoing hemodialysis,whereas body mass index(BMI),hemoglobin(Hb),and urea clearance index were independent protective factors(P<0.05).CONCLUSION Gastrointestinal symptoms are mostly mild in patients with uremia undergoing hemodialysis,most commonly including dyspepsia,eating disorders,and gastroesophageal reflux.The independent influencing factors mainly include the BMI,age,number of pills taken,dialysis time,urea clearance index,Hb,use of glucocorticoids,and thyroid hormone level.PTH,CRP,and diabetes are clinically related factors influencing the occurrence of gastrointestinal symptoms,and targeted prevention can be performed.展开更多
BACKGROUND We previously showed,using the Traditional Chinese Medicine System Pharmacology Database,that Gegen Qinlian decoction(GQD)had a direct antitumor effect,and was combined with programmed cell death protein(PD...BACKGROUND We previously showed,using the Traditional Chinese Medicine System Pharmacology Database,that Gegen Qinlian decoction(GQD)had a direct antitumor effect,and was combined with programmed cell death protein(PD)-1 inhibitors to treat microsatellite stable(MSS)tumor-bearing mice.However,the effect of GQD on patients with colorectal cancer(CRC)is not clear.AIM To determine the therapeutic mechanism of GQD in improving immune function,reducing inflammation and protecting intestinal barrier function.METHODS Seventy patients with CRC were included in this study:37 in the control group and 33 in the treatment group.The proportions of CD4+T,CD8+T,natural killer(NK),NKT and T regulatory cells were measured by flow cytometry.Levels of the cytokines tumor necrosis factor(TNF)-α,interferon(IFN)-γ,interleukin(IL)-2,IL-6,IL-10 and serotonin(5-hydroxytryptamine;5-HT)in serum were assessed by enzyme-linked immunosorbent assay(ELISA).The expression of zonula occludens(ZO)-1,occludin,nuclear factor(NF)-κB and TNF-αin tumor and normal tissues was measured by immunohistochemistry.The composition of gut microbiota from patients in the treatment group was assessed using 16S rDNA analysis.RESULTS There were no adverse events in the treatment group.The proportion of CD4+T cells and NKT cells in the post-treatment group was significantly higher than that in the pre-treatment and control groups(P<0.05).The level of TNF-αin the posttreatment group was significantly lower than that in the pre-treatment and control groups(P<0.05).The concentration of 5-HT in the post-treatment group was significantly lower than that in the pre-treatment group(P<0.05).The expression of ZO-1 and occludin in tumor tissues in the treatment group was significantly higher than that in the control group(P<0.05).The expression of ZO-1 in normal tissues of the treatment group was significantly higher than that in the control group(P=0.010).Compared with the control group,expression of NF-κB and TNF-αin tumor tissues of the treatment group was significantly decreased(P<0.05).Compared with the pre-treatment group,GQD decreased the relative abundance of Megamonas and Veillonella.In addition,GQD increased the relative abundance of Bacteroides,Akkermansia and Prevotella.CONCLUSION GQD enhances immunity and protects intestinal barrier function in patients with CRC by regulating the composition of gut microbiota.展开更多
Cross-ply unidirectional laminates made of ultra-high molecular weight polyethylene fibers are widely used as components of bullet-proof vests.To simulate the delamination process of the material under penetration,we ...Cross-ply unidirectional laminates made of ultra-high molecular weight polyethylene fibers are widely used as components of bullet-proof vests.To simulate the delamination process of the material under penetration,we constructed a numerical mechanical model,which was validated by tests using 7.6239 mm rifle bullets penetrating laminates of different thicknesses.The results show that the delamination region is essentially diamond-shaped.The simulated delamination region is in good agreement with the experimental data.It is found that the delamination region increases with the compression modulus along the fiber direction.The delamination region increases when the shear strength between the fabric layers decreases;However,it is little influenced by the normal strength.The delamination region of the front face of the laminate is little influenced by the failure strain of the material and the initial velocity of the bullet.The delamination region of the back face increases with the failure strain and decreases with the initial velocity.展开更多
AIM: To explore hemodynamics and vasoactive substance levels during renal vein congestion that occurs in the anhepatic phase of liver transplantation.METHODS: New Zealand rabbits received ligation of the hepatic pedic...AIM: To explore hemodynamics and vasoactive substance levels during renal vein congestion that occurs in the anhepatic phase of liver transplantation.METHODS: New Zealand rabbits received ligation of the hepatic pedicle, supra-hepatic vena cava and infrahepatic vena cava [anhepatic phase group(APH); n = 8], the renal veins(RVL; n = 8), renal veins and hepatic pedicle [with the inferior vena cava left open)(RVHP; n = 8)], or a sham operation(SOP; n = 8). Hemodynamic parameters(systolic, diastolic, and mean arterial blood pressures) and the levels of serum bradykinin(BK) and angiotensin Ⅱ(ANGII) were measured at baseline(0 min), and 10 min, 20 min, 30 min, and 45 min after the surgery. Correlation analyses were performed to evaluate the associations between hemodynamic parameters and levels of vasoactive substances.RESULTS:All experimental groups(APH,RVL,and RVHP)showed significant decreases in hemodynamic parameters(systolic,diastolic,and mean arterial blood pressures)compared to baseline levels,as well as compared to the SOP controls(P<0.05 for all).In contrast,BK levels were significantly increased compared to baseline in the APH,RVL,and RVHP groups at all time points measured(P<0.05 for all),whereas no change was observed in the SOP controls.There were no significant differences among the experimental groups for any measure at any time point.Further analyses revealed that systolic,diastolic,and mean arterial blood pressures were all negatively correlated with BK levels,and positively correlated with ANGII levels in the APH,RVL,and RVHP groups(P<0.05 for all).CONCLUSION:In the anhepatic phase of orthotopic liver transplantation,renal vein congestion significantly impacts hemodynamic parameters,which correlate with serum BK and ANGII levels.展开更多
This study investigates and quantifies some possible sources affecting the position of impact points of small caliber spin-stabilized projectiles(such as 12.7 mm bullets).A comparative experiment utilizing the control...This study investigates and quantifies some possible sources affecting the position of impact points of small caliber spin-stabilized projectiles(such as 12.7 mm bullets).A comparative experiment utilizing the control variable method was designed to figure out the influence of tiny eccentric centroids on the projectiles.The study critically analyzes data obtained from characteristic parameter measurements and precision trials.It also combines Sobol’s algorithm with an artificial intelligence algorithmdAdaptive Neuro-Fuzzy Inference Systems(ANFIS)ein order to conduct global sensitivity analysis and determine which parameters were most influential.The results indicate that the impact points of projectiles with an entry angle of 0°deflected to the left to that of projectiles with an entry angle of 90°.The difference of the mean coordinates of impact points was about 12.61 cm at a target range of 200 m.Variance analysis indicated that the entry angleei.e.the initial position of mass eccentricityehad a notable influence.After global sensitivity analysis,the significance of the effect of mass eccentricity was confirmed again and the most influential factors were determined to be the axial moment and transverse moment of inertia(Izz Iyy),the mass of a projectile(m),the distance between nose and center of mass along the symmetry axis for a projectile(Lm),and the eccentric distance of the centroid(Lr).The results imply that the control scheme by means of modifying mass center(moving mass or mass eccentricity)is promising for designing small-caliber spin-stabilized projectiles.展开更多
OBJECTIVE Hepatocyte growth factor (HGF) expression is closely related to the progression and poor prognosis of colorectal cancer patients. In this study, we investigated the effects on proliferation and migration o...OBJECTIVE Hepatocyte growth factor (HGF) expression is closely related to the progression and poor prognosis of colorectal cancer patients. In this study, we investigated the effects on proliferation and migration of the human colon carcinoma cell line SW620 by silencing HGF expression. METHODS HGF was silenced using specific HGF a/f3 siRNA. The proliferation, migration, cell cycle and ultrastructure of SW620 cells were examined. RESULTS The transfection efficiency was 70%-80%. The expression rate of HGF in the experimental group was significantly lower than that in the negative and blank control groups (P 〈 0.05). The proliferation inhibition rate in the experimental group at 24, 48, 72 and 96 h after transfection was 14.2%, 50.2%, 39.5% and 23.2%, respectively. The migratory ability of cells in the experimental group was significantly inhibited compared with that in the negative control or blank control groups (58.2% vs. 2.1% or 0%, P 〈 0.05). CONCLUSION The application of RNA interference to silence the expression of HGF in the colon carcinoma cell line SW620 effectively inhibits the proliferation and migration of tumor cells.展开更多
Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial defor...Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial deformation of a cartridge,considering the radial constraint of the closed end at the bottom of the cartridge.Owing to the influence of the closed end,the bottom of a cartridge does not establish complete contact with the chamber.Owing to strain concentration in the non-contact area,this area is more amenable to the occurrence of cartridge rupture.This theory predicts the location of the fracture more accurately than the traditional theory.The maximum axial deformation of a cartridge comprises bending and friction deformation.The maximum strain at the bottom of the cartridge increased by 135%owing to the introduction of bending strain caused by the closed end.The strain distribution of a cartridge was measured using digital image correlation technology,and the measured result was consistent with the predicted results of the bending deformation theory and rupture case.The effects of wall thickness,radial clearance,friction coefficient,and axial clearance on the axial deformation of the cylinder were studied.Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation;furthermore,lubrication and reduction in axial clearance reduce frictional deformation,which in turn reduce cartridge rupture.展开更多
The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were co...The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber.A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations.The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated.The effects of the angle between the cartridge and chamber,the cartridge case material,and the intermal impact pressure on the predicted headspace value were also analyzed.The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model.The internal impact pressure,pressure change rate,and cartridge material were all found to affect the predicted headspace.展开更多
BACKGROUND Insertion of a catheter into the bladder is a rare complication of peritoneal dialysis(PD),and is mainly related to surgical injury.This paper reports a case of bladder perforation that was caused by percut...BACKGROUND Insertion of a catheter into the bladder is a rare complication of peritoneal dialysis(PD),and is mainly related to surgical injury.This paper reports a case of bladder perforation that was caused by percutaneous PD catheterization.CASE SUMMARY A 64-year-old man underwent percutaneous PD catheterization for end-stage renal disease.On the second day after the operation,urgent urination and gross hematuria occurred.Urinalysis showed the presence of red and white blood cells.Empirical anti-infective treatment was given.On the third day after the operation,urgent urination occurred during PD perfusion.Ultrasound showed that the PD catheter was located in the bladder,and subsequent computed tomography(CT)showed that the PD catheter moved through the anterior wall into the bladder.The PD catheter was withdrawn from the bladder and catheterization was retained.Repeat CT on the fourth day after the operation showed that the PD catheter was removed from the bladder,but there was poor catheter function.The PD catheter was removed and the patient was changed to hemodialysis.CT cystography showed that the bladder healed well and the patient was discharged 14 d after the operation.CONCLUSION Bladder perforation injury should be considered and treated timeously in case of bladder irritation during and after percutaneous PD catheterization.The use of Doppler ultrasound and other related technologies may reduce the incidence of such complications.展开更多
文摘BACKGROUND Rectal mucinous adenocarcinoma(MAC)is a rare pathological type of rectal can-cer with unique pathological features and a poor prognosis.It is difficult to diag-nose and treat early because of the lack of specific manifestations in some aspects of the disease.The common metastatic organs of rectal cancer are the liver and lung;however,rectal carcinoma with metastasis to subcutaneous soft tissue is a rare finding.CASE SUMMARY In this report,the clinical data,diagnosis and treatment process,and postope-rative pathological features of a patient with left waist subcutaneous soft tissue masses were retrospectively analyzed.The patient underwent surgical treatment after admission and recovered well after surgery.The final pathological diagnosis was rectal MAC with left waist subcutaneous soft tissue metastasis.CONCLUSION Subcutaneous soft tissue metastasis of rectal MAC is rare,and it can suggest that the tumor is disseminated,and it can appear even earlier than the primary ma-lignant tumor,which is occult and leads to a missed diagnosis and misdiagnosis clinically.When a subcutaneous soft tissue mass of unknown origin appears in a patient with rectal cancer,a ma-lignant tumor should be considered.
文摘BACKGROUND Gastrointestinal symptoms are common in patients with uremia undergoing hemodialysis,and these symptoms seriously affect patients'prognosis.AIM To assess the occurrence and factors influencing gastrointestinal symptoms in patients with uremia undergoing hemodialysis.METHODS We retrospectively selected 98 patients with uremia who underwent regular hemo-dialysis treatment in the blood purification center of our hospital from December 2022 to December 2023.The gastrointestinal symptoms and scores of each dimension were evaluated using the Gastrointestinal Symptom Grading Scale(GSRS).Patients were divided into gastrointestinal symptoms and no gastrointestinal symptom groups according to whether they had gastrointestinal symptoms.The factors that may affect gastrointestinal symptoms were identified by single-factor analysis.Multiple logistic regression analysis was performed to identify independent risk factors for gastrointestinal symptoms.RESULTS Gastrointestinal symptoms included indigestion,constipation,reflux,diarrhea,abdominal pain,and eating disorders,and the total average GSRS score was 1.35±0.47.This study showed that age,number of tablets,dialysis time,glucocorticoid,parathyroid hormone(PTH),combined diabetes mellitus and C-reactive protein(CRP)were independent risk factors for gastrointestinal symptoms in patients with uremia undergoing hemodialysis,whereas body mass index(BMI),hemoglobin(Hb),and urea clearance index were independent protective factors(P<0.05).CONCLUSION Gastrointestinal symptoms are mostly mild in patients with uremia undergoing hemodialysis,most commonly including dyspepsia,eating disorders,and gastroesophageal reflux.The independent influencing factors mainly include the BMI,age,number of pills taken,dialysis time,urea clearance index,Hb,use of glucocorticoids,and thyroid hormone level.PTH,CRP,and diabetes are clinically related factors influencing the occurrence of gastrointestinal symptoms,and targeted prevention can be performed.
基金The study was reviewed and approved by the Fourth Hospital of Hebei Medical University Institutional Review Board(Approval No.2019082).
文摘BACKGROUND We previously showed,using the Traditional Chinese Medicine System Pharmacology Database,that Gegen Qinlian decoction(GQD)had a direct antitumor effect,and was combined with programmed cell death protein(PD)-1 inhibitors to treat microsatellite stable(MSS)tumor-bearing mice.However,the effect of GQD on patients with colorectal cancer(CRC)is not clear.AIM To determine the therapeutic mechanism of GQD in improving immune function,reducing inflammation and protecting intestinal barrier function.METHODS Seventy patients with CRC were included in this study:37 in the control group and 33 in the treatment group.The proportions of CD4+T,CD8+T,natural killer(NK),NKT and T regulatory cells were measured by flow cytometry.Levels of the cytokines tumor necrosis factor(TNF)-α,interferon(IFN)-γ,interleukin(IL)-2,IL-6,IL-10 and serotonin(5-hydroxytryptamine;5-HT)in serum were assessed by enzyme-linked immunosorbent assay(ELISA).The expression of zonula occludens(ZO)-1,occludin,nuclear factor(NF)-κB and TNF-αin tumor and normal tissues was measured by immunohistochemistry.The composition of gut microbiota from patients in the treatment group was assessed using 16S rDNA analysis.RESULTS There were no adverse events in the treatment group.The proportion of CD4+T cells and NKT cells in the post-treatment group was significantly higher than that in the pre-treatment and control groups(P<0.05).The level of TNF-αin the posttreatment group was significantly lower than that in the pre-treatment and control groups(P<0.05).The concentration of 5-HT in the post-treatment group was significantly lower than that in the pre-treatment group(P<0.05).The expression of ZO-1 and occludin in tumor tissues in the treatment group was significantly higher than that in the control group(P<0.05).The expression of ZO-1 in normal tissues of the treatment group was significantly higher than that in the control group(P=0.010).Compared with the control group,expression of NF-κB and TNF-αin tumor tissues of the treatment group was significantly decreased(P<0.05).Compared with the pre-treatment group,GQD decreased the relative abundance of Megamonas and Veillonella.In addition,GQD increased the relative abundance of Bacteroides,Akkermansia and Prevotella.CONCLUSION GQD enhances immunity and protects intestinal barrier function in patients with CRC by regulating the composition of gut microbiota.
基金the Research Foundation for Advanced Talents of Jiangsu University(15JDG038)the Foundation of National Laboratory(601010417)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJB130003).
文摘Cross-ply unidirectional laminates made of ultra-high molecular weight polyethylene fibers are widely used as components of bullet-proof vests.To simulate the delamination process of the material under penetration,we constructed a numerical mechanical model,which was validated by tests using 7.6239 mm rifle bullets penetrating laminates of different thicknesses.The results show that the delamination region is essentially diamond-shaped.The simulated delamination region is in good agreement with the experimental data.It is found that the delamination region increases with the compression modulus along the fiber direction.The delamination region increases when the shear strength between the fabric layers decreases;However,it is little influenced by the normal strength.The delamination region of the front face of the laminate is little influenced by the failure strain of the material and the initial velocity of the bullet.The delamination region of the back face increases with the failure strain and decreases with the initial velocity.
基金Supported by Natural Science Foundation of Gansu Province,China,No.3ZS051-A25-104Clinical Medicine Research Special Funds of Chinese Medical Association,China,No.14040360573
文摘AIM: To explore hemodynamics and vasoactive substance levels during renal vein congestion that occurs in the anhepatic phase of liver transplantation.METHODS: New Zealand rabbits received ligation of the hepatic pedicle, supra-hepatic vena cava and infrahepatic vena cava [anhepatic phase group(APH); n = 8], the renal veins(RVL; n = 8), renal veins and hepatic pedicle [with the inferior vena cava left open)(RVHP; n = 8)], or a sham operation(SOP; n = 8). Hemodynamic parameters(systolic, diastolic, and mean arterial blood pressures) and the levels of serum bradykinin(BK) and angiotensin Ⅱ(ANGII) were measured at baseline(0 min), and 10 min, 20 min, 30 min, and 45 min after the surgery. Correlation analyses were performed to evaluate the associations between hemodynamic parameters and levels of vasoactive substances.RESULTS:All experimental groups(APH,RVL,and RVHP)showed significant decreases in hemodynamic parameters(systolic,diastolic,and mean arterial blood pressures)compared to baseline levels,as well as compared to the SOP controls(P<0.05 for all).In contrast,BK levels were significantly increased compared to baseline in the APH,RVL,and RVHP groups at all time points measured(P<0.05 for all),whereas no change was observed in the SOP controls.There were no significant differences among the experimental groups for any measure at any time point.Further analyses revealed that systolic,diastolic,and mean arterial blood pressures were all negatively correlated with BK levels,and positively correlated with ANGII levels in the APH,RVL,and RVHP groups(P<0.05 for all).CONCLUSION:In the anhepatic phase of orthotopic liver transplantation,renal vein congestion significantly impacts hemodynamic parameters,which correlate with serum BK and ANGII levels.
基金supported by the Fundamental Research Funds for the Central Universities,China(grant no.30918012203)the Foundation of National Laboratory,China(grant no.JCKYS2019209C001)。
文摘This study investigates and quantifies some possible sources affecting the position of impact points of small caliber spin-stabilized projectiles(such as 12.7 mm bullets).A comparative experiment utilizing the control variable method was designed to figure out the influence of tiny eccentric centroids on the projectiles.The study critically analyzes data obtained from characteristic parameter measurements and precision trials.It also combines Sobol’s algorithm with an artificial intelligence algorithmdAdaptive Neuro-Fuzzy Inference Systems(ANFIS)ein order to conduct global sensitivity analysis and determine which parameters were most influential.The results indicate that the impact points of projectiles with an entry angle of 0°deflected to the left to that of projectiles with an entry angle of 90°.The difference of the mean coordinates of impact points was about 12.61 cm at a target range of 200 m.Variance analysis indicated that the entry angleei.e.the initial position of mass eccentricityehad a notable influence.After global sensitivity analysis,the significance of the effect of mass eccentricity was confirmed again and the most influential factors were determined to be the axial moment and transverse moment of inertia(Izz Iyy),the mass of a projectile(m),the distance between nose and center of mass along the symmetry axis for a projectile(Lm),and the eccentric distance of the centroid(Lr).The results imply that the control scheme by means of modifying mass center(moving mass or mass eccentricity)is promising for designing small-caliber spin-stabilized projectiles.
基金This work was supported by a grant from the Natural Science Foundation of Hebei Province of China (No.05547008D-3).
文摘OBJECTIVE Hepatocyte growth factor (HGF) expression is closely related to the progression and poor prognosis of colorectal cancer patients. In this study, we investigated the effects on proliferation and migration of the human colon carcinoma cell line SW620 by silencing HGF expression. METHODS HGF was silenced using specific HGF a/f3 siRNA. The proliferation, migration, cell cycle and ultrastructure of SW620 cells were examined. RESULTS The transfection efficiency was 70%-80%. The expression rate of HGF in the experimental group was significantly lower than that in the negative and blank control groups (P 〈 0.05). The proliferation inhibition rate in the experimental group at 24, 48, 72 and 96 h after transfection was 14.2%, 50.2%, 39.5% and 23.2%, respectively. The migratory ability of cells in the experimental group was significantly inhibited compared with that in the negative control or blank control groups (58.2% vs. 2.1% or 0%, P 〈 0.05). CONCLUSION The application of RNA interference to silence the expression of HGF in the colon carcinoma cell line SW620 effectively inhibits the proliferation and migration of tumor cells.
基金The authors are grateful for the reviewers’instructive suggestions and careful proofreading.This work was supported by the Equipment Development Department of the Central Military Commission of China(grant nos.301090702)the Foundation of National Laboratory(grant nos.61426060102162606005 and JCKYS2019209C001).
文摘Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial deformation of a cartridge,considering the radial constraint of the closed end at the bottom of the cartridge.Owing to the influence of the closed end,the bottom of a cartridge does not establish complete contact with the chamber.Owing to strain concentration in the non-contact area,this area is more amenable to the occurrence of cartridge rupture.This theory predicts the location of the fracture more accurately than the traditional theory.The maximum axial deformation of a cartridge comprises bending and friction deformation.The maximum strain at the bottom of the cartridge increased by 135%owing to the introduction of bending strain caused by the closed end.The strain distribution of a cartridge was measured using digital image correlation technology,and the measured result was consistent with the predicted results of the bending deformation theory and rupture case.The effects of wall thickness,radial clearance,friction coefficient,and axial clearance on the axial deformation of the cylinder were studied.Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation;furthermore,lubrication and reduction in axial clearance reduce frictional deformation,which in turn reduce cartridge rupture.
基金supported by the National Natural Science Foundation of China(Grant Nos.11372137 and 11602025)Equipment Development Department of the Central Military Commission of China(Grant No.301030905)。
文摘The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber.A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations.The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated.The effects of the angle between the cartridge and chamber,the cartridge case material,and the intermal impact pressure on the predicted headspace value were also analyzed.The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model.The internal impact pressure,pressure change rate,and cartridge material were all found to affect the predicted headspace.
文摘BACKGROUND Insertion of a catheter into the bladder is a rare complication of peritoneal dialysis(PD),and is mainly related to surgical injury.This paper reports a case of bladder perforation that was caused by percutaneous PD catheterization.CASE SUMMARY A 64-year-old man underwent percutaneous PD catheterization for end-stage renal disease.On the second day after the operation,urgent urination and gross hematuria occurred.Urinalysis showed the presence of red and white blood cells.Empirical anti-infective treatment was given.On the third day after the operation,urgent urination occurred during PD perfusion.Ultrasound showed that the PD catheter was located in the bladder,and subsequent computed tomography(CT)showed that the PD catheter moved through the anterior wall into the bladder.The PD catheter was withdrawn from the bladder and catheterization was retained.Repeat CT on the fourth day after the operation showed that the PD catheter was removed from the bladder,but there was poor catheter function.The PD catheter was removed and the patient was changed to hemodialysis.CT cystography showed that the bladder healed well and the patient was discharged 14 d after the operation.CONCLUSION Bladder perforation injury should be considered and treated timeously in case of bladder irritation during and after percutaneous PD catheterization.The use of Doppler ultrasound and other related technologies may reduce the incidence of such complications.