BACKGROUND Rectal prolapse arises from benign etiology.When symptoms of internal intussusception mirror those of rectal prolapse,a misdiagnosis is possible,especially under limited clinical presentation.It is crucial ...BACKGROUND Rectal prolapse arises from benign etiology.When symptoms of internal intussusception mirror those of rectal prolapse,a misdiagnosis is possible,especially under limited clinical presentation.It is crucial to recognize and differentiate rectal prolapse from internal intussusception because the two diagnoses have different prognoses.Here,we describe a case of adult sigmoid intussusception presenting as rectal prolapse.CASE SUMMARY A 64-year-old woman with no known medical history visited a gastrointestinal outpatient department due to hard bloody stool defecation for 1 wk followed by constipation for 3 d.Colonoscopy revealed a huge polypoid ulcerated tumor at the sigmoid colon with lumen stenosis.The patient was admitted due to postprocedural dull abdominal pain.Due to failed colonoscopy reduction and stent insertion,the patient underwent sigmoid colon resection with primary end-to-end anastomosis,with the transverse colostomy pathological report showing adenocarcinoma,pT3N0M0.She recovered well from the operation and was discharged with regular outpatient clinic follow-up.CONCLUSION Presentation and manifestation of sigmoid intussusception may resemble that of rectal prolapse,necessitating careful observation due to distinct prognostic implications.展开更多
相比燃油拖拉机,电动拖拉机具有节能高效、绿色清洁的优点。分布式驱动电动拖拉机结构简单、控制维度多,能进一步提高电动拖拉机的工作效率和作业精度。但是电机检测转速噪声导致轮毂电机速度波动严重,复杂路面及多种作业工况下进一步...相比燃油拖拉机,电动拖拉机具有节能高效、绿色清洁的优点。分布式驱动电动拖拉机结构简单、控制维度多,能进一步提高电动拖拉机的工作效率和作业精度。但是电机检测转速噪声导致轮毂电机速度波动严重,复杂路面及多种作业工况下进一步加剧了上述问题,严重降低了拖拉机的作业质量。针对上述问题,该研究提出一种基于sigmoid滤波器的线性自抗扰控制(linear active disturbance rejection control,LADRC)以提高轮毂电机的转速稳定性和抗扰动能力。该控制策略在传统LADRC的基础上引入sigmoid滤波器至扩张状态观测器(extended state observer,ESO),根据输入噪声信号误差变化改变滤波器带宽,以抑制观测误差中的中高频干扰信号,同时避免滤波器积分环节对轮毂电机速度跟踪快速性的影响,具有较快的收敛性。搭建试验平台对所提出控制策略进行试验验证,结果表明:与传统LADRC策略相比,本文所提控制策略在变速和变载工况下的转速脉动分别减小了32%和41.67%,iq电流脉动分别减小了6.25%和4.17%,可在快速、准确跟踪给定转速的同时,大幅提高轮毂电机驱动系统的噪声抑制性能,为复杂环境下电动拖拉机高精度作业提供技术参考。展开更多
Objective: Tinnitus-a common clinical symptom-can be categorized into pulsatile tinnitus(PT) and non-PT. Among these, PT is usually associated with sigmoid sinus symptoms, such as sigmoid sinus wall defect or divertic...Objective: Tinnitus-a common clinical symptom-can be categorized into pulsatile tinnitus(PT) and non-PT. Among these, PT is usually associated with sigmoid sinus symptoms, such as sigmoid sinus wall defect or diverticulum, for which various surgical treatments are available. We have discussed the clinical efficacy of surgery for sigmoid sinus-associated PT via the transmastoid approach in this study.Methods: We conducted a retrospective review of 4 patients who underwent surgery for sigmoid sinusassociated PT via the transmastoid approach at Nanjing Drum Tower Hospital from January to December2020. Of these, 2 patients had sigmoid sinus wall defect and 2 had sigmoid sinus diverticulum. Postoperative tinnitus grading and surgical efficacy were determined.Results: After surgery, PT dissolved in 3 patients, while tinnitus significantly decreased in 1 patient.During the follow-up period of 12-18 months, none of the 4 patients showed complications related to increased intracranial pressure or venous sinus thrombosis, and tinnitus symptoms disappeared in 3patients without recurrence, although 1 patient occasionally developed tinnitus. Postoperative thin-slice CTA of the temporal bone indicated that the sigmoid sinus bone wall defect or diverticulum was completely repaired with a thick soft tissue coverage.Conclusion: Surgical repair of sigmoid sinus-associated PT via the transmastoid approach deserves clinical promotion as it exhibited better efficiency while being relatively less invasive.展开更多
Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the ro...Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the rolling reduction rate of a conventionally rolled sample(at room temperature)is 33.8%,which can be increased to 41.5%by pulsed current-assisted rolling,enabling the formation of an ultra-thin strip with a size of 67.3μm in only one rolling pass.After three passes of pulsed current-assisted rolling,the thickness of the ultra-thin strip can be further reduced to 51.7μm.To clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip,ultra-thin strips with nearly the same thickness reduction were analyzed.It was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment,reducing the density of stacking faults,inhibiting martensitic phase transformation,and shortening the total length of grain boundaries.As a result,the ductility of ultra-thin strips can be effectively restored to approximately 16.3%while maintaining a high tensile strength of 1118 MPa.Therefore,pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility.展开更多
BACKGROUND Schwannomas are uncommon tumors originating from Schwann cells,forming the neural sheath.They account for approximately 2%-6%of all mesenchymal tumors and are most commonly identified in peripheral nerve tr...BACKGROUND Schwannomas are uncommon tumors originating from Schwann cells,forming the neural sheath.They account for approximately 2%-6%of all mesenchymal tumors and are most commonly identified in peripheral nerve trunks,with rarity in the gastrointestinal tract.Among gastrointestinal locations,the stomach harbors the majority of nerve sheath tumors,while such occurrences in the sigmoid colon are exceptionally infrequent.CASE SUMMARY This study presented a clinical case involving a 60-year-old female patient who,during colonoscopy,was diagnosed with a submucosal lesion that was later identified as a nerve sheath tumor.The patient underwent surgical resection,and the diagnosis was confirmed through immunohistochemistry.This study highlighted an exceptionally uncommon occurrence of a nerve sheath tumor in the sigmoid colon,which was effectively managed within our department.Additionally,a comprehensive review of relevant studies was conducted.CONCLUSION The preoperative diagnosis of nerve sheath tumors poses challenges,as the definitive diagnosis still relies on pathology and immunohistochemistry.Although categorized as benign,these tumors have the potential to demonstrate malignant behavior.Consequently,the optimal treatment approach entails the complete surgical excision of the tumor,ensuring the absence of residual lesions at the margins.展开更多
BACKGROUND Aggressive fibromatosis(AF),also known as desmoid tumor or desmoid-type fibromatosis,is a rare soft tissue neoplasm that can occur in almost any part of the body.Although it is a benign disease,AF is aggres...BACKGROUND Aggressive fibromatosis(AF),also known as desmoid tumor or desmoid-type fibromatosis,is a rare soft tissue neoplasm that can occur in almost any part of the body.Although it is a benign disease,AF is aggressive and infiltrative and has a high recurrence rate after surgery.Common sites for intra-abdominal AF are the small bowel mesentery,retroperitoneum,and pelvis.AF in the colon is extremely rare.CASE SUMMARY Here,we report the first case of sigmoid colon AF,which was accidentally discovered in a 27-year-old woman during laparoscopic myomectomy.Computed tomography confirmed a slightly enhanced mass in the sigmoid colon.Subsequent colonoscopy did not reveal a mass in the colonic lumen,but a suspected external compress was found in the sigmoid colon.Surgical disease involving a gastrointestinal stromal tumor was suspected.The patient underwent laparoscopic exploration,and sigmoidectomy with a negative margin was performed to excise the mass.Postoperative immunohistochemistry revealed that the mass was an AF.The patient recovered well and was recurrence-free at the 30-month follow-up without adjuvant therapy.CONCLUSION AF should be considered in the differential diagnosis of subepithelial colon masses.Radical resection alone can achieve good outcomes.展开更多
文摘BACKGROUND Rectal prolapse arises from benign etiology.When symptoms of internal intussusception mirror those of rectal prolapse,a misdiagnosis is possible,especially under limited clinical presentation.It is crucial to recognize and differentiate rectal prolapse from internal intussusception because the two diagnoses have different prognoses.Here,we describe a case of adult sigmoid intussusception presenting as rectal prolapse.CASE SUMMARY A 64-year-old woman with no known medical history visited a gastrointestinal outpatient department due to hard bloody stool defecation for 1 wk followed by constipation for 3 d.Colonoscopy revealed a huge polypoid ulcerated tumor at the sigmoid colon with lumen stenosis.The patient was admitted due to postprocedural dull abdominal pain.Due to failed colonoscopy reduction and stent insertion,the patient underwent sigmoid colon resection with primary end-to-end anastomosis,with the transverse colostomy pathological report showing adenocarcinoma,pT3N0M0.She recovered well from the operation and was discharged with regular outpatient clinic follow-up.CONCLUSION Presentation and manifestation of sigmoid intussusception may resemble that of rectal prolapse,necessitating careful observation due to distinct prognostic implications.
文摘相比燃油拖拉机,电动拖拉机具有节能高效、绿色清洁的优点。分布式驱动电动拖拉机结构简单、控制维度多,能进一步提高电动拖拉机的工作效率和作业精度。但是电机检测转速噪声导致轮毂电机速度波动严重,复杂路面及多种作业工况下进一步加剧了上述问题,严重降低了拖拉机的作业质量。针对上述问题,该研究提出一种基于sigmoid滤波器的线性自抗扰控制(linear active disturbance rejection control,LADRC)以提高轮毂电机的转速稳定性和抗扰动能力。该控制策略在传统LADRC的基础上引入sigmoid滤波器至扩张状态观测器(extended state observer,ESO),根据输入噪声信号误差变化改变滤波器带宽,以抑制观测误差中的中高频干扰信号,同时避免滤波器积分环节对轮毂电机速度跟踪快速性的影响,具有较快的收敛性。搭建试验平台对所提出控制策略进行试验验证,结果表明:与传统LADRC策略相比,本文所提控制策略在变速和变载工况下的转速脉动分别减小了32%和41.67%,iq电流脉动分别减小了6.25%和4.17%,可在快速、准确跟踪给定转速的同时,大幅提高轮毂电机驱动系统的噪声抑制性能,为复杂环境下电动拖拉机高精度作业提供技术参考。
基金This study was supported by the National Natural Science Foundation of China(Nos.81870721)the Major Program of National Natural Science Foundation of China(Nos.82192862).
文摘Objective: Tinnitus-a common clinical symptom-can be categorized into pulsatile tinnitus(PT) and non-PT. Among these, PT is usually associated with sigmoid sinus symptoms, such as sigmoid sinus wall defect or diverticulum, for which various surgical treatments are available. We have discussed the clinical efficacy of surgery for sigmoid sinus-associated PT via the transmastoid approach in this study.Methods: We conducted a retrospective review of 4 patients who underwent surgery for sigmoid sinusassociated PT via the transmastoid approach at Nanjing Drum Tower Hospital from January to December2020. Of these, 2 patients had sigmoid sinus wall defect and 2 had sigmoid sinus diverticulum. Postoperative tinnitus grading and surgical efficacy were determined.Results: After surgery, PT dissolved in 3 patients, while tinnitus significantly decreased in 1 patient.During the follow-up period of 12-18 months, none of the 4 patients showed complications related to increased intracranial pressure or venous sinus thrombosis, and tinnitus symptoms disappeared in 3patients without recurrence, although 1 patient occasionally developed tinnitus. Postoperative thin-slice CTA of the temporal bone indicated that the sigmoid sinus bone wall defect or diverticulum was completely repaired with a thick soft tissue coverage.Conclusion: Surgical repair of sigmoid sinus-associated PT via the transmastoid approach deserves clinical promotion as it exhibited better efficiency while being relatively less invasive.
基金This work was supported by the fund of the National Natural Science Foundation of China(51974196)Major Program of National Natural Science Foundation of China(U22A20188)+1 种基金Science and Technology Innovation Teams of Shanxi Province(202304051001025)Central Government Guides the Special Fund Projects of Local Scientific and Technological Development(YDZX20191400002149).
文摘Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the rolling reduction rate of a conventionally rolled sample(at room temperature)is 33.8%,which can be increased to 41.5%by pulsed current-assisted rolling,enabling the formation of an ultra-thin strip with a size of 67.3μm in only one rolling pass.After three passes of pulsed current-assisted rolling,the thickness of the ultra-thin strip can be further reduced to 51.7μm.To clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip,ultra-thin strips with nearly the same thickness reduction were analyzed.It was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment,reducing the density of stacking faults,inhibiting martensitic phase transformation,and shortening the total length of grain boundaries.As a result,the ductility of ultra-thin strips can be effectively restored to approximately 16.3%while maintaining a high tensile strength of 1118 MPa.Therefore,pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility.
文摘BACKGROUND Schwannomas are uncommon tumors originating from Schwann cells,forming the neural sheath.They account for approximately 2%-6%of all mesenchymal tumors and are most commonly identified in peripheral nerve trunks,with rarity in the gastrointestinal tract.Among gastrointestinal locations,the stomach harbors the majority of nerve sheath tumors,while such occurrences in the sigmoid colon are exceptionally infrequent.CASE SUMMARY This study presented a clinical case involving a 60-year-old female patient who,during colonoscopy,was diagnosed with a submucosal lesion that was later identified as a nerve sheath tumor.The patient underwent surgical resection,and the diagnosis was confirmed through immunohistochemistry.This study highlighted an exceptionally uncommon occurrence of a nerve sheath tumor in the sigmoid colon,which was effectively managed within our department.Additionally,a comprehensive review of relevant studies was conducted.CONCLUSION The preoperative diagnosis of nerve sheath tumors poses challenges,as the definitive diagnosis still relies on pathology and immunohistochemistry.Although categorized as benign,these tumors have the potential to demonstrate malignant behavior.Consequently,the optimal treatment approach entails the complete surgical excision of the tumor,ensuring the absence of residual lesions at the margins.
基金Supported by Hangzhou Health Science and Technology Program,No.A20210271.
文摘BACKGROUND Aggressive fibromatosis(AF),also known as desmoid tumor or desmoid-type fibromatosis,is a rare soft tissue neoplasm that can occur in almost any part of the body.Although it is a benign disease,AF is aggressive and infiltrative and has a high recurrence rate after surgery.Common sites for intra-abdominal AF are the small bowel mesentery,retroperitoneum,and pelvis.AF in the colon is extremely rare.CASE SUMMARY Here,we report the first case of sigmoid colon AF,which was accidentally discovered in a 27-year-old woman during laparoscopic myomectomy.Computed tomography confirmed a slightly enhanced mass in the sigmoid colon.Subsequent colonoscopy did not reveal a mass in the colonic lumen,but a suspected external compress was found in the sigmoid colon.Surgical disease involving a gastrointestinal stromal tumor was suspected.The patient underwent laparoscopic exploration,and sigmoidectomy with a negative margin was performed to excise the mass.Postoperative immunohistochemistry revealed that the mass was an AF.The patient recovered well and was recurrence-free at the 30-month follow-up without adjuvant therapy.CONCLUSION AF should be considered in the differential diagnosis of subepithelial colon masses.Radical resection alone can achieve good outcomes.
