The control equations of gas concentration field in gob areas with a known velocity field are partial differential equations with variable coefficients,whose traditional mathematical calculation methods are very compl...The control equations of gas concentration field in gob areas with a known velocity field are partial differential equations with variable coefficients,whose traditional mathematical calculation methods are very complex.A numerical simulation method can be used to calculate the gas concentration field,but it also needs considerable amounts of computer resources and the relations of gas concentration at different points of the gob area are undefined.Based on the model of stream tubes,the conservation equations of mass and gas components within the stream tube are used to deduce the equations of a gas concentration field in a gob area with a known velocity field.This method of calculation of a gas concentration field is applied in a gob area with a U-type ventilation working face,which suggests that this new method has the virtue of exact calculations is simple to operate and has a clear physical interpretation.展开更多
Background Differentiated thyroid cancer （DTC） is a common primary cancer for spinal metastases （SM）.The treatments for DTC spinal metastases （SM） have evolved from simple surgery and radiotherapy to a multidisc...Background Differentiated thyroid cancer （DTC） is a common primary cancer for spinal metastases （SM）.The treatments for DTC spinal metastases （SM） have evolved from simple surgery and radiotherapy to a multidisciplinary comprehensive therapeutic strategy of combined spinal surgery,general surgery,radiotherapy,nuclear medicine and endocrinology.The purpose of this study was to discuss the efficacy and prognosis associated with different surgical treatments of SM patients with DTC.Methods A total of 21 consecutive patients with SM of DTC that were treated between 1999 and 2013 were studied.Biopsy was routinely performed to achieve the pathological diagnosis before treatment.Three patients underwent total spondylectomy intralesionally or piecemeally,and 18 had curettage.Postoperative recurrence and survival times were analyzed by the Kaplan-Meier methods.Results Nineteen patients （90％） had an average of 42.7 months （range,7-170 months） follow-up.The median visual analogue scale for pain reduced from 5 points to 1 point （P ＜0.01）,and the median Karnofsky performance score increased from 70 to 90 points after surgery （P ＜0.01）.Seventeen patients with neurological deficits attained improvements after surgeries,of at least one level according to the Frankel classification （P ＜0.01）.Eight patients with curettage had recurrence.Four patients died of DTC,12 patients lived with disease,and three patients were disease-free.No significant effects on postoperative recurrence or survival were observed between surgery combined with conservative treatment,total spondylectomy,the number of bone metastases and visceral metastasis.Conclusions DTC-SM have a relatively favorable prognosis,and curettage and stabilization can effectively relieve the pain and improve the quality of life and neurological status of the patients.For patients with Tomita scores of ＜3,total spondylectomy may have better clinical outcomes.Comprehensive therapeutic strategies including surgery,radioiodine,external beam radiation therapy and embolization should be considered for most patients.展开更多
Background Aneurysmal bone cyst （ABC） is a benign lesion with the potential to be locally aggressive.The optimal treatment of cervical spine lesions remains controversial.This retrospective study was designed to eva...Background Aneurysmal bone cyst （ABC） is a benign lesion with the potential to be locally aggressive.The optimal treatment of cervical spine lesions remains controversial.This retrospective study was designed to evaluate the different treatments for primary ABCs of the cervical spine.Methods This series included eight men and six women diagnosed between 2002 and 2012.A retrospective review of the hospital charts,operating room reports,office charts,and radiographs was performed.The data collected included patient age,sex,radiological features,pathology,treatment method,outcomes,and complications from biopsies and treatments.The mean age at diagnosis was 17.5 years old with a range of 6-35 years.All patients had experienced local pain for a mean of 7.3 months （range,0.5-18.0 months）,and three patients had neurological deficits （one with radiculopathy and two with myelopathy）.The Frankel classification before treatment was E in 12 cases,D in one case,and C in one case.Results Four patients received radiotherapy alone.Ten patients underwent surgery,including five total spondyiectomies,two local resections,and three curettages.Three patients received preoperative selective arterial embolization,and four received adjuvant radiotherapy.The mean follow-up time was 44.5 months （range 12-96 months）,and no recurrence was identified.Three patients with neurological deficits achieved complete recovery,as noted at the final follow-up examination.One patient received radiotherapy without appropriate immobilization as prescribed and developed C1-C2 subluxation with severe spinal cord compression but without myelopathy.He refused further treatment.Conclusions The results can be achieved by different treatments （surgical resection/curettage,selective arterial embolization,and radiotherapy） for ABC of the cervical spine.Reconstruction of stability is also important for the treatment of cervical ABC.展开更多
基金Financial support for this work,provided by the Doctor Startup Foundation of Xi'an University of Science & Technology
文摘The control equations of gas concentration field in gob areas with a known velocity field are partial differential equations with variable coefficients,whose traditional mathematical calculation methods are very complex.A numerical simulation method can be used to calculate the gas concentration field,but it also needs considerable amounts of computer resources and the relations of gas concentration at different points of the gob area are undefined.Based on the model of stream tubes,the conservation equations of mass and gas components within the stream tube are used to deduce the equations of a gas concentration field in a gob area with a known velocity field.This method of calculation of a gas concentration field is applied in a gob area with a U-type ventilation working face,which suggests that this new method has the virtue of exact calculations is simple to operate and has a clear physical interpretation.
文摘Background Differentiated thyroid cancer （DTC） is a common primary cancer for spinal metastases （SM）.The treatments for DTC spinal metastases （SM） have evolved from simple surgery and radiotherapy to a multidisciplinary comprehensive therapeutic strategy of combined spinal surgery,general surgery,radiotherapy,nuclear medicine and endocrinology.The purpose of this study was to discuss the efficacy and prognosis associated with different surgical treatments of SM patients with DTC.Methods A total of 21 consecutive patients with SM of DTC that were treated between 1999 and 2013 were studied.Biopsy was routinely performed to achieve the pathological diagnosis before treatment.Three patients underwent total spondylectomy intralesionally or piecemeally,and 18 had curettage.Postoperative recurrence and survival times were analyzed by the Kaplan-Meier methods.Results Nineteen patients （90％） had an average of 42.7 months （range,7-170 months） follow-up.The median visual analogue scale for pain reduced from 5 points to 1 point （P ＜0.01）,and the median Karnofsky performance score increased from 70 to 90 points after surgery （P ＜0.01）.Seventeen patients with neurological deficits attained improvements after surgeries,of at least one level according to the Frankel classification （P ＜0.01）.Eight patients with curettage had recurrence.Four patients died of DTC,12 patients lived with disease,and three patients were disease-free.No significant effects on postoperative recurrence or survival were observed between surgery combined with conservative treatment,total spondylectomy,the number of bone metastases and visceral metastasis.Conclusions DTC-SM have a relatively favorable prognosis,and curettage and stabilization can effectively relieve the pain and improve the quality of life and neurological status of the patients.For patients with Tomita scores of ＜3,total spondylectomy may have better clinical outcomes.Comprehensive therapeutic strategies including surgery,radioiodine,external beam radiation therapy and embolization should be considered for most patients.
文摘Background Aneurysmal bone cyst （ABC） is a benign lesion with the potential to be locally aggressive.The optimal treatment of cervical spine lesions remains controversial.This retrospective study was designed to evaluate the different treatments for primary ABCs of the cervical spine.Methods This series included eight men and six women diagnosed between 2002 and 2012.A retrospective review of the hospital charts,operating room reports,office charts,and radiographs was performed.The data collected included patient age,sex,radiological features,pathology,treatment method,outcomes,and complications from biopsies and treatments.The mean age at diagnosis was 17.5 years old with a range of 6-35 years.All patients had experienced local pain for a mean of 7.3 months （range,0.5-18.0 months）,and three patients had neurological deficits （one with radiculopathy and two with myelopathy）.The Frankel classification before treatment was E in 12 cases,D in one case,and C in one case.Results Four patients received radiotherapy alone.Ten patients underwent surgery,including five total spondyiectomies,two local resections,and three curettages.Three patients received preoperative selective arterial embolization,and four received adjuvant radiotherapy.The mean follow-up time was 44.5 months （range 12-96 months）,and no recurrence was identified.Three patients with neurological deficits achieved complete recovery,as noted at the final follow-up examination.One patient received radiotherapy without appropriate immobilization as prescribed and developed C1-C2 subluxation with severe spinal cord compression but without myelopathy.He refused further treatment.Conclusions The results can be achieved by different treatments （surgical resection/curettage,selective arterial embolization,and radiotherapy） for ABC of the cervical spine.Reconstruction of stability is also important for the treatment of cervical ABC.
