The shear behavior is regarded as the dominant property of rock joints and is dramatically affected by the joint surface roughness.To date,the effect of surface roughness on the shear behavior of rock joints under sta...The shear behavior is regarded as the dominant property of rock joints and is dramatically affected by the joint surface roughness.To date,the effect of surface roughness on the shear behavior of rock joints under static or cyclic loading conditions has been extensively studied,but such effect under impact loading conditions keeps unclear.To address this issue,a series of impact shear tests was performed using a novel-designed dynamic experimental system combined with the digital image correlation(DIC)technique.The dynamic shear strength,deformability and failure mode of the jointed specimens with various joint roughness coefficients(JRC)are comprehensively analyzed.Results show that the shear strength and shear displacement characteristics of the rock joint under the impact loading keep consistent with those under static loading conditions.However,the temporal variations of shear stress,slip displacement and normal displacement under the impact loading conditions show obviously different behaviors.An elastic rebound of the slip displacement occurs during the impact shearing and its value increases with increasing joint roughness.Two identifiable stages(i.e.compression and dilation)are observed in the normal displacement curves for the rougher rock joints,whereas the joints with small roughness only manifest normal compression displacement.Besides,as the roughness increases,the maximum compression tends to decrease,while the maximum dilation gradually increases.More-over,the microstructural analysis based on scanning electron microscope(SEM)suggests that the roughness significantly affects the characteristics of the shear fractured zone enclosing the joint surface.展开更多
Jointed rock specimens with a natural replicated joint surface oriented at a mean dip angle of 60were prepared,and a series of cyclic triaxial tests was performed at different confining pressures and cyclic deviatoric...Jointed rock specimens with a natural replicated joint surface oriented at a mean dip angle of 60were prepared,and a series of cyclic triaxial tests was performed at different confining pressures and cyclic deviatoric stress amplitudes.The samples were subjected to 10,000 loading-unloading cycles with a frequency of 8 Hz.At each level of confining pressure,the applied cyclic deviatoric stress amplitude was increased incrementally until excessive deformation of the jointed rock specimen was observed.Analysis of the test results indicated that there existed a critical cyclic deviatoric stress amplitude(i.e.critical dynamic deviatoric stress)beyond which the jointed rock specimens yielded.The measured critical dynamic deviatoric stress was less than the corresponding static deviatoric stress.At cyclic deviatoric stress amplitudes less than the critical dynamic deviatoric stress,minor cumulative residual axial strains were observed,resulting in hysteretic damping.However,for cyclic deviatoric stresses beyond the critical dynamic deviatoric stress,the plastic strains increased promptly,and the resilient moduli degraded rapidly during the initial loading cycles.Cyclic triaxial test results showed that at higher confining pressures,the ultimate residual axial strain attained by the jointed rock specimen decreased,the steadystate dissipated energy density and steady-state damping ratio per load cycle decreased,while steadystate resilient moduli increased.展开更多
Joint deformity and dysfunction are common and serious complications in the late stage of rheumatoid arthritis,which seriously affect the quality of life of patients.Traditional Chinese medicine(TCM)believes that join...Joint deformity and dysfunction are common and serious complications in the late stage of rheumatoid arthritis,which seriously affect the quality of life of patients.Traditional Chinese medicine(TCM)believes that joint deformity and dysfunction in some patients with rheumatoid arthritis are closely related to the apraxia of meridians and tendons due to enduring illness.Based on the theory of meridians and tendons circulation,using the local and nearby therapeutic effect of acupoints as the treatment method in clinical practice,we conducted penetration needling of Houxi,Baxie,Wailaogong as well as Ashi points of interphalangeal joints of both hands through bilateral Sanjian,and used the uniform reinforcing-reducing method to soothe tendons and meridians,thus effectively improving the dysfunction of deformed joints.展开更多
BACKGROUND Various surgical techniques have been developed to enhance the nose shapes of Asian patients.Silicone implant augmentation rhinoplasty is widely used because it is relatively easy to perform and often yield...BACKGROUND Various surgical techniques have been developed to enhance the nose shapes of Asian patients.Silicone implant augmentation rhinoplasty is widely used because it is relatively easy to perform and often yields satisfactory outcomes.However,this technique may lead to complications,including ischemia,necrosis,and over-augmentation.The most appropriate management of these complications,including infection,is immediate implant removal and revision surgery once the accompanying inflammation has healed.Occasionally,the patient may experience distress from nasal deformities during the intervention period.CASE SUMMARY Herein,we describe the case of a patient who underwent a secondary dorsal augmentation,with a folded dermofat graft harvested from the inguinal area and simultaneous implant removal,successfully preventing dimpling of the nasal deformity.CONCLUSION This surgical method can effectively manage implant-related complications following augmentation rhinoplasty using a silicone implant and provide satis-factory patient outcomes.展开更多
目的:比较类风湿性关节炎(rheumatoid arthritis,RA)前足畸形重建术第5跖骨头切除成形与不切除的临床疗效。方法:回顾性分析2015年5月至2019年1月收治的50例(76足)女性RA致前足中重度畸形患者,依据第5跖趾关节退变情况,行RA前足重建第5...目的:比较类风湿性关节炎(rheumatoid arthritis,RA)前足畸形重建术第5跖骨头切除成形与不切除的临床疗效。方法:回顾性分析2015年5月至2019年1月收治的50例(76足)女性RA致前足中重度畸形患者,依据第5跖趾关节退变情况,行RA前足重建第5跖骨头保留或切除术,分为第5跖骨头保留组(保留组)和第5跖骨头切除组(切除组)。保留组24例,年龄47~81(60.37±8.60)岁;病程13~22(19.00±3.06)年;身体质量指数(body mass index,BMI)21~28(23.53±2.47)kg·m-2;中度拇外翻畸形6例(6足),重度拇外翻畸形18例(30足);采用第1跖趾关节融合联合第2-4跖趾关节成形及第5跖趾关节清理术治疗。切除组26例,年龄30~80(58.53±13.70)岁;病程8~25(17.94±3.92)年;BMI为20~28(24.60±2.03)kg·m-2;中度拇外翻畸形4例(4足),重度拇外翻畸形22例(36足);采用第1跖趾关节融合联合2-5跖趾关节跖骨头切除成形术治疗。观察并比较两组手术时间、术后并发症情况,比较术前和末次随访时拇外翻角(hallux valgus angle,HVA),第1-2跖骨间角(intermetatarsal angles between the first and the second metatarsals,IMAFS),第1-5跖骨间角(intermetatarsal angles between the first and the fifth metatarsals,IMAFF)变化情况,并采用日本足踝外科协会(Japanese Society for Surgery of Foot,JSSF)评价临床疗效。结果:50例均获得随访,切除组随访时间为14~46(25.30±8.83)个月;保留组随访时间为12~48(24.30±11.12)个月,两组随访时间比较,差异无统计学意义(P>0.05)。两组手术时间、术后并发症比较,差异无统计学意义(P>0.05)。切除组JSSF评分、HVA、IMAFS、IMAFF分别由术前的(45.09±3.35)分、(38.90±13.67)°、(12.88±1.72)°、(32.50±2.99)°改善至末次随访时的(81.60±3.27)分、(15.40±0.96)°、(9.06±2.27)°、(22.20±1.98)°(P<0.05);保留组分别由(47.09±3.96)分、(43.30±12.65)°、(13.99±3.13)°、(33.20±6.14)°改善至(83.10±3.66)分、(15.20±1.54)°、(8.99±1.02)°、(24.70±1.88)°。两组间术前及末次随访时JSSF评分、HVA、IMAFS、IMAFF比较,差异均无统计学意义(P>0.05)。末次随访时,两组JSSF评分中疼痛、畸形比较,差异有统计学意义(P<0.05)。结论:无论是类风湿前足重建术还是前足重建第5跖趾关节清理术,术后临床疗效及影像学结果均明显改善。对比类风湿前足重建术,类风湿前足重建第5跖趾关节清理术治疗类风湿前足中重度畸形,疼痛改善明显,但畸形改善较差。对于类风湿引起的前足中重度畸形,第5跖趾头关节面轻中度退变畸形的患者可考虑使用。展开更多
基金We acknowledge the funding support from the National Natural Science Foundation of China(Grant Nos.51879135 and 51879184)the Natural Sciences and Engineering Research Council of Canada(NSERC)through the Discovery Grant No.72031326.
文摘The shear behavior is regarded as the dominant property of rock joints and is dramatically affected by the joint surface roughness.To date,the effect of surface roughness on the shear behavior of rock joints under static or cyclic loading conditions has been extensively studied,but such effect under impact loading conditions keeps unclear.To address this issue,a series of impact shear tests was performed using a novel-designed dynamic experimental system combined with the digital image correlation(DIC)technique.The dynamic shear strength,deformability and failure mode of the jointed specimens with various joint roughness coefficients(JRC)are comprehensively analyzed.Results show that the shear strength and shear displacement characteristics of the rock joint under the impact loading keep consistent with those under static loading conditions.However,the temporal variations of shear stress,slip displacement and normal displacement under the impact loading conditions show obviously different behaviors.An elastic rebound of the slip displacement occurs during the impact shearing and its value increases with increasing joint roughness.Two identifiable stages(i.e.compression and dilation)are observed in the normal displacement curves for the rougher rock joints,whereas the joints with small roughness only manifest normal compression displacement.Besides,as the roughness increases,the maximum compression tends to decrease,while the maximum dilation gradually increases.More-over,the microstructural analysis based on scanning electron microscope(SEM)suggests that the roughness significantly affects the characteristics of the shear fractured zone enclosing the joint surface.
文摘Jointed rock specimens with a natural replicated joint surface oriented at a mean dip angle of 60were prepared,and a series of cyclic triaxial tests was performed at different confining pressures and cyclic deviatoric stress amplitudes.The samples were subjected to 10,000 loading-unloading cycles with a frequency of 8 Hz.At each level of confining pressure,the applied cyclic deviatoric stress amplitude was increased incrementally until excessive deformation of the jointed rock specimen was observed.Analysis of the test results indicated that there existed a critical cyclic deviatoric stress amplitude(i.e.critical dynamic deviatoric stress)beyond which the jointed rock specimens yielded.The measured critical dynamic deviatoric stress was less than the corresponding static deviatoric stress.At cyclic deviatoric stress amplitudes less than the critical dynamic deviatoric stress,minor cumulative residual axial strains were observed,resulting in hysteretic damping.However,for cyclic deviatoric stresses beyond the critical dynamic deviatoric stress,the plastic strains increased promptly,and the resilient moduli degraded rapidly during the initial loading cycles.Cyclic triaxial test results showed that at higher confining pressures,the ultimate residual axial strain attained by the jointed rock specimen decreased,the steadystate dissipated energy density and steady-state damping ratio per load cycle decreased,while steadystate resilient moduli increased.
基金Supported by National Natural Science Foundation of China(82205105).
文摘Joint deformity and dysfunction are common and serious complications in the late stage of rheumatoid arthritis,which seriously affect the quality of life of patients.Traditional Chinese medicine(TCM)believes that joint deformity and dysfunction in some patients with rheumatoid arthritis are closely related to the apraxia of meridians and tendons due to enduring illness.Based on the theory of meridians and tendons circulation,using the local and nearby therapeutic effect of acupoints as the treatment method in clinical practice,we conducted penetration needling of Houxi,Baxie,Wailaogong as well as Ashi points of interphalangeal joints of both hands through bilateral Sanjian,and used the uniform reinforcing-reducing method to soothe tendons and meridians,thus effectively improving the dysfunction of deformed joints.
文摘BACKGROUND Various surgical techniques have been developed to enhance the nose shapes of Asian patients.Silicone implant augmentation rhinoplasty is widely used because it is relatively easy to perform and often yields satisfactory outcomes.However,this technique may lead to complications,including ischemia,necrosis,and over-augmentation.The most appropriate management of these complications,including infection,is immediate implant removal and revision surgery once the accompanying inflammation has healed.Occasionally,the patient may experience distress from nasal deformities during the intervention period.CASE SUMMARY Herein,we describe the case of a patient who underwent a secondary dorsal augmentation,with a folded dermofat graft harvested from the inguinal area and simultaneous implant removal,successfully preventing dimpling of the nasal deformity.CONCLUSION This surgical method can effectively manage implant-related complications following augmentation rhinoplasty using a silicone implant and provide satis-factory patient outcomes.
文摘目的:比较类风湿性关节炎(rheumatoid arthritis,RA)前足畸形重建术第5跖骨头切除成形与不切除的临床疗效。方法:回顾性分析2015年5月至2019年1月收治的50例(76足)女性RA致前足中重度畸形患者,依据第5跖趾关节退变情况,行RA前足重建第5跖骨头保留或切除术,分为第5跖骨头保留组(保留组)和第5跖骨头切除组(切除组)。保留组24例,年龄47~81(60.37±8.60)岁;病程13~22(19.00±3.06)年;身体质量指数(body mass index,BMI)21~28(23.53±2.47)kg·m-2;中度拇外翻畸形6例(6足),重度拇外翻畸形18例(30足);采用第1跖趾关节融合联合第2-4跖趾关节成形及第5跖趾关节清理术治疗。切除组26例,年龄30~80(58.53±13.70)岁;病程8~25(17.94±3.92)年;BMI为20~28(24.60±2.03)kg·m-2;中度拇外翻畸形4例(4足),重度拇外翻畸形22例(36足);采用第1跖趾关节融合联合2-5跖趾关节跖骨头切除成形术治疗。观察并比较两组手术时间、术后并发症情况,比较术前和末次随访时拇外翻角(hallux valgus angle,HVA),第1-2跖骨间角(intermetatarsal angles between the first and the second metatarsals,IMAFS),第1-5跖骨间角(intermetatarsal angles between the first and the fifth metatarsals,IMAFF)变化情况,并采用日本足踝外科协会(Japanese Society for Surgery of Foot,JSSF)评价临床疗效。结果:50例均获得随访,切除组随访时间为14~46(25.30±8.83)个月;保留组随访时间为12~48(24.30±11.12)个月,两组随访时间比较,差异无统计学意义(P>0.05)。两组手术时间、术后并发症比较,差异无统计学意义(P>0.05)。切除组JSSF评分、HVA、IMAFS、IMAFF分别由术前的(45.09±3.35)分、(38.90±13.67)°、(12.88±1.72)°、(32.50±2.99)°改善至末次随访时的(81.60±3.27)分、(15.40±0.96)°、(9.06±2.27)°、(22.20±1.98)°(P<0.05);保留组分别由(47.09±3.96)分、(43.30±12.65)°、(13.99±3.13)°、(33.20±6.14)°改善至(83.10±3.66)分、(15.20±1.54)°、(8.99±1.02)°、(24.70±1.88)°。两组间术前及末次随访时JSSF评分、HVA、IMAFS、IMAFF比较,差异均无统计学意义(P>0.05)。末次随访时,两组JSSF评分中疼痛、畸形比较,差异有统计学意义(P<0.05)。结论:无论是类风湿前足重建术还是前足重建第5跖趾关节清理术,术后临床疗效及影像学结果均明显改善。对比类风湿前足重建术,类风湿前足重建第5跖趾关节清理术治疗类风湿前足中重度畸形,疼痛改善明显,但畸形改善较差。对于类风湿引起的前足中重度畸形,第5跖趾头关节面轻中度退变畸形的患者可考虑使用。
