Brightness is an important parameter for 3rd generation light source. Correcting the emittance coupling is a realistic way to increase brightness without any additional equipment in a machine under operation. The main...Brightness is an important parameter for 3rd generation light source. Correcting the emittance coupling is a realistic way to increase brightness without any additional equipment in a machine under operation. The main sources of emittance coupling are betatron coupling and vertical dispersion. At the SSRF storage ring, tune split and LOCO are used to measure the respective betatron and emittance coupling. Both of these sources can be corrected by skew quadrupoles. By measuring the skew quadrupole-coupling response matrix, betatron coupling can be changed from 0.014% to 2%. But the vertical dispersion changes at the same time. LOCO can find the suitable setting to correct simultaneously the betatron coupling and vertical dispersion. The emittance coupling can be reduced to 0.17% by this method. More simulations show the potential for smaller emittance coupling if more skew quadrupoles are employed.展开更多
In this paper, we present numerically and experimentally the linear beam-optics distortion in the SSRF storage ring and the correction of optics by using a number of quadrupole magnets installed in the storage ring. T...In this paper, we present numerically and experimentally the linear beam-optics distortion in the SSRF storage ring and the correction of optics by using a number of quadrupole magnets installed in the storage ring. The measured orbit-response matrices were fitted to the model-response matrices to obtain the β and the dispersion functions in the storage ring. By readjusting the currents of quadrupole-magnet power supplies, we were able to successfully restore the optics parameters to values very close to the design ones, with rms deviations around 1%. This periodicity restoration is verified with the β function measurement.展开更多
Estimation and correction of the optics errors in an operational storage ring is always vital to achieve the design performance. To achieve this task, the most suitable and widely used technique, called linear optics ...Estimation and correction of the optics errors in an operational storage ring is always vital to achieve the design performance. To achieve this task, the most suitable and widely used technique, called linear optics from closed orbit（LOCO） is used in almost all storage ring based synchrotron radiation sources. In this technique, based on the response matrix fit, errors in the quadrupole strengths, beam position monitor（BPM） gains, orbit corrector calibration factors etc. can be obtained. For correction of the optics, suitable changes in the quadrupole strengths can be applied through the driving currents of the quadrupole power supplies to achieve the desired optics. The LOCO code has been used at the Indus-2 storage ring for the first time. The estimation of linear beam optics errors and their correction to minimize the distortion of linear beam dynamical parameters by using the installed number of quadrupole power supplies is discussed. After the optics correction, the performance of the storage ring is improved in terms of better beam injection/accumulation, reduced beam loss during energy ramping, and improvement in beam lifetime. It is also useful in controlling the leakage in the orbit bump required for machine studies or for commissioning of new beamlines.展开更多
Anatomic location/size and number of lesions,inadequate volume of future liver remnant,or poor coexisting premorbid conditions preclude surgery in the majority of patients with hepatocellular carcinoma(HCC).Liver tran...Anatomic location/size and number of lesions,inadequate volume of future liver remnant,or poor coexisting premorbid conditions preclude surgery in the majority of patients with hepatocellular carcinoma(HCC).Liver transplantation can cure some patients with poor liver function,but few patients are eligible because of scarcity of donors.Without specific anti-cancer treatment,the prognosis of HCC is poor.Various locoregional therapies are used to treat patients who are not candidates for surgery,and have emerged as tools for palliation,tumor downstaging,and bridging therapy prior to liver transplantation.Currently,local ablative therapy even competes with partial hepatectomy and liver transplantation as a primary treatment for small HCC.HCC is well suited to treatment with loco-regional therapy because it has a tendency to stay within the liver,with distant metastasis generally occurring late in the course of disease.This suggests that an effective local-regional therapy can have a great impact on HCC patients who are not candidates for surgical treatment.Loco-regional therapy can further be justified because patients with HCC usually die of liver failure consequent to intrahepatic growth resulting in liver tissue destruction,rather than extrahepatic metastases.展开更多
AIM To evaluate the long-term effectiveness and late toxicities of paclitaxel(PTX) plus cisplatin(DDP) with concurrent radiotherapy for locally advanced esophageal squamous cancer.METHODS Between 2008 and 2011, 76 pat...AIM To evaluate the long-term effectiveness and late toxicities of paclitaxel(PTX) plus cisplatin(DDP) with concurrent radiotherapy for locally advanced esophageal squamous cancer.METHODS Between 2008 and 2011, 76 patients were enrolled in a phase Ⅱ study on the treatment of loco-regionally advanced esophageal cancer with radiotherapy(68.4 Gy/44 fractions or 61.2 Gy/34 fractions) combined with 4-cycle chemotherapy consisting of DDP(25 mg/m^2 per day for 3 d) and PTX(175 mg/m^2 for 3 h). The primary endpoints were overall survival and progression-free survival, and the secondary endpoints were toxicity and the treatment failure pattern.RESULTS A total of 76 patients were enrolled in this study, of whom 63.2% finished the whole regimen. The 5-year survival rates for the per-protocol population and intent-to-treat population were 25.4% and 26.4%, respectively, and the median survival rates were 23.7 mo and 28.5 mo, respectively. Grade 3 or 4 late toxicity was observed in only one patient(heart failure). In log-rank analysis, the pretreatment stage(stage Ⅱ + Ⅲ: 36.1 mo vs stage Ⅳ: 14.9 mo) and the completed cycle(1-3 cycles: 16.1 mo vs 4 cycles: 35.5 mo) were significant prognostic factors(P = 0.037 < 0.05 and P = 0.013 < 0.05).CONCLUSION Radiotherapy combined with chemotherapy consisting of PTX and DDP is a safe and effective definitive treatment for loco-regionally advanced esophageal squamous cancer.展开更多
The most common malignancy of biliary tract is gallbladder cancer(GBC) which is the third most common cancer in gastrointestinal tract. It is a lethal disease for most patients in spite of growing awareness and improv...The most common malignancy of biliary tract is gallbladder cancer(GBC) which is the third most common cancer in gastrointestinal tract. It is a lethal disease for most patients in spite of growing awareness and improved diagnostic techniques. GBC has a verypoor prognosis and the 5 year survival rate is < 10%. Although etiology of the carcinoma of the gallbladder is still obscure, various factors have been implicated, cholelithiasis being the most frequent. The incidence of GBC worldwide is based on the gender, geography and ethnicity which suggest that both genetic and environmental factors can cause GBC. The major route of spread of gallbladder cancer(GC) is locoregional rather than distant. It spreads by lymphatic, vascular, neural, intraperitoneal, and intraductal routes. Sonography is usually the most common imaging test to evaluate symptoms of biliary tract disease including suspected GC. With recent advances in imaging modalities like multi-detector computed tomography(CT) scanners, magnetic resonance imaging-positron emission tomography/CT diagnosis of gallbladder cancer has improved. Studies have also targeted molecular and genetic pathways. Treatment options have included extended and radical surgeries and adjuvant chemotherapy. This review article deals in detail with important aspects of carcinoma gallbladder and its manifestations and challenges. Role of various imaging modalities in characterization and accurate staging has been discussed. The loco-regional spread of this aggressive malignancy is dealt explicitly.展开更多
Hepatocellular carcinoma(HCC) is the fifth most common malignancy and the third cause of tumor associated deaths worldwide. HCC incidence rates are increasing in many parts of the world including developing and develo...Hepatocellular carcinoma(HCC) is the fifth most common malignancy and the third cause of tumor associated deaths worldwide. HCC incidence rates are increasing in many parts of the world including developing and developed countries. Potentially curative treatments for HCC are resection and liver transplantation, but these are only suitable for patients with small tumors, meeting strict pre-defined criteria, or well-compensated liver disease. Early diagnosis of HCCcan be achieved by surveillance of at-risk populations. For patients with non-resectable disease treatments modalities include loco-ablative and systemic therapies. In this review we focus on treatment options in HCC and their allocation. Although significant research is in progress, to this date, the results are unsatisfactory with limited long-term survival. In the fight against this deadly disease, there is still a long way to go.展开更多
Loco-regional treatments for hepatocellular carcinoma(HCC) are important alternatives to curative transplantation or resection.Among them,radiofrequency ablation(RFA) is accepted as the most popular technique showing ...Loco-regional treatments for hepatocellular carcinoma(HCC) are important alternatives to curative transplantation or resection.Among them,radiofrequency ablation(RFA) is accepted as the most popular technique showing excellent local tumor control and acceptable morbidity.The current role of RFA is well documented in the evidence-based practice guidelines of European Association of Study of Liver,American Association of Study of the Liver Disease and Japanese academic societies.Several randomized controlled trials have confirmed that RFA is superior to percutaneous ethanol injections in terms of local tumor control and survival.The overall survival after RFA is comparable to after surgical resection in a selected group of patients with smaller(< 3 cm) tumors.Currently,the clinical benefits of combined RFA with transarterial chemoembolization for intermediate stage HCC are increasingly being explored.Here we review the ongoing technical advancements of RFA and future potential.展开更多
Hepatocellular carcinoma(HCC) is a common, increasingly prevalent malignancy. For all but the smallest lesions, surgical removal of cancer via resection or liver transplantation(LT) is considered the most feasible pat...Hepatocellular carcinoma(HCC) is a common, increasingly prevalent malignancy. For all but the smallest lesions, surgical removal of cancer via resection or liver transplantation(LT) is considered the most feasible pathway to cure. Resection- even with favorable survival- is associated with a fairly high rate of recurrence, perhaps since most HCCs occur in the setting of cirrhosis. LT offers the advantage of removing not only the cancer but the diseased liver from which the cancer has arisen, and LT outperforms resection for survival with selected patients. Since time waiting for LT is time during which HCC can progress, locoregional therapy(LRT) is widely employed by transplant centers. The purpose of LRT is either to bridge patients to LT by preventing progression and waitlist dropout, or to downstage patients who slightly exceed standard eligibility criteria initially but can fall within it after treatment. Transarterial chemoembolization and radiofrequency ablation have been the most widely utilized LRTs to date, with favorable efficacy and safety as a bridge to LT(and for the former, as a downstaging modality). The list of potentially effective LRTs has expanded in recent years, and includes transarterial chemoembolization with drug-eluting beads, radioembolization and novel forms of extracorporal therapy. Herein we appraise the various LRT modalities for HCC, and their potential roles in specific clinical scenarios in patients awaiting LT.展开更多
文摘Brightness is an important parameter for 3rd generation light source. Correcting the emittance coupling is a realistic way to increase brightness without any additional equipment in a machine under operation. The main sources of emittance coupling are betatron coupling and vertical dispersion. At the SSRF storage ring, tune split and LOCO are used to measure the respective betatron and emittance coupling. Both of these sources can be corrected by skew quadrupoles. By measuring the skew quadrupole-coupling response matrix, betatron coupling can be changed from 0.014% to 2%. But the vertical dispersion changes at the same time. LOCO can find the suitable setting to correct simultaneously the betatron coupling and vertical dispersion. The emittance coupling can be reduced to 0.17% by this method. More simulations show the potential for smaller emittance coupling if more skew quadrupoles are employed.
文摘In this paper, we present numerically and experimentally the linear beam-optics distortion in the SSRF storage ring and the correction of optics by using a number of quadrupole magnets installed in the storage ring. The measured orbit-response matrices were fitted to the model-response matrices to obtain the β and the dispersion functions in the storage ring. By readjusting the currents of quadrupole-magnet power supplies, we were able to successfully restore the optics parameters to values very close to the design ones, with rms deviations around 1%. This periodicity restoration is verified with the β function measurement.
文摘Estimation and correction of the optics errors in an operational storage ring is always vital to achieve the design performance. To achieve this task, the most suitable and widely used technique, called linear optics from closed orbit（LOCO） is used in almost all storage ring based synchrotron radiation sources. In this technique, based on the response matrix fit, errors in the quadrupole strengths, beam position monitor（BPM） gains, orbit corrector calibration factors etc. can be obtained. For correction of the optics, suitable changes in the quadrupole strengths can be applied through the driving currents of the quadrupole power supplies to achieve the desired optics. The LOCO code has been used at the Indus-2 storage ring for the first time. The estimation of linear beam optics errors and their correction to minimize the distortion of linear beam dynamical parameters by using the installed number of quadrupole power supplies is discussed. After the optics correction, the performance of the storage ring is improved in terms of better beam injection/accumulation, reduced beam loss during energy ramping, and improvement in beam lifetime. It is also useful in controlling the leakage in the orbit bump required for machine studies or for commissioning of new beamlines.
文摘Anatomic location/size and number of lesions,inadequate volume of future liver remnant,or poor coexisting premorbid conditions preclude surgery in the majority of patients with hepatocellular carcinoma(HCC).Liver transplantation can cure some patients with poor liver function,but few patients are eligible because of scarcity of donors.Without specific anti-cancer treatment,the prognosis of HCC is poor.Various locoregional therapies are used to treat patients who are not candidates for surgery,and have emerged as tools for palliation,tumor downstaging,and bridging therapy prior to liver transplantation.Currently,local ablative therapy even competes with partial hepatectomy and liver transplantation as a primary treatment for small HCC.HCC is well suited to treatment with loco-regional therapy because it has a tendency to stay within the liver,with distant metastasis generally occurring late in the course of disease.This suggests that an effective local-regional therapy can have a great impact on HCC patients who are not candidates for surgical treatment.Loco-regional therapy can further be justified because patients with HCC usually die of liver failure consequent to intrahepatic growth resulting in liver tissue destruction,rather than extrahepatic metastases.
基金Supported by National Natural Science Foundation of China,No.21172043 and No.21441010
文摘AIM To evaluate the long-term effectiveness and late toxicities of paclitaxel(PTX) plus cisplatin(DDP) with concurrent radiotherapy for locally advanced esophageal squamous cancer.METHODS Between 2008 and 2011, 76 patients were enrolled in a phase Ⅱ study on the treatment of loco-regionally advanced esophageal cancer with radiotherapy(68.4 Gy/44 fractions or 61.2 Gy/34 fractions) combined with 4-cycle chemotherapy consisting of DDP(25 mg/m^2 per day for 3 d) and PTX(175 mg/m^2 for 3 h). The primary endpoints were overall survival and progression-free survival, and the secondary endpoints were toxicity and the treatment failure pattern.RESULTS A total of 76 patients were enrolled in this study, of whom 63.2% finished the whole regimen. The 5-year survival rates for the per-protocol population and intent-to-treat population were 25.4% and 26.4%, respectively, and the median survival rates were 23.7 mo and 28.5 mo, respectively. Grade 3 or 4 late toxicity was observed in only one patient(heart failure). In log-rank analysis, the pretreatment stage(stage Ⅱ + Ⅲ: 36.1 mo vs stage Ⅳ: 14.9 mo) and the completed cycle(1-3 cycles: 16.1 mo vs 4 cycles: 35.5 mo) were significant prognostic factors(P = 0.037 < 0.05 and P = 0.013 < 0.05).CONCLUSION Radiotherapy combined with chemotherapy consisting of PTX and DDP is a safe and effective definitive treatment for loco-regionally advanced esophageal squamous cancer.
文摘The most common malignancy of biliary tract is gallbladder cancer(GBC) which is the third most common cancer in gastrointestinal tract. It is a lethal disease for most patients in spite of growing awareness and improved diagnostic techniques. GBC has a verypoor prognosis and the 5 year survival rate is < 10%. Although etiology of the carcinoma of the gallbladder is still obscure, various factors have been implicated, cholelithiasis being the most frequent. The incidence of GBC worldwide is based on the gender, geography and ethnicity which suggest that both genetic and environmental factors can cause GBC. The major route of spread of gallbladder cancer(GC) is locoregional rather than distant. It spreads by lymphatic, vascular, neural, intraperitoneal, and intraductal routes. Sonography is usually the most common imaging test to evaluate symptoms of biliary tract disease including suspected GC. With recent advances in imaging modalities like multi-detector computed tomography(CT) scanners, magnetic resonance imaging-positron emission tomography/CT diagnosis of gallbladder cancer has improved. Studies have also targeted molecular and genetic pathways. Treatment options have included extended and radical surgeries and adjuvant chemotherapy. This review article deals in detail with important aspects of carcinoma gallbladder and its manifestations and challenges. Role of various imaging modalities in characterization and accurate staging has been discussed. The loco-regional spread of this aggressive malignancy is dealt explicitly.
文摘Hepatocellular carcinoma(HCC) is the fifth most common malignancy and the third cause of tumor associated deaths worldwide. HCC incidence rates are increasing in many parts of the world including developing and developed countries. Potentially curative treatments for HCC are resection and liver transplantation, but these are only suitable for patients with small tumors, meeting strict pre-defined criteria, or well-compensated liver disease. Early diagnosis of HCCcan be achieved by surveillance of at-risk populations. For patients with non-resectable disease treatments modalities include loco-ablative and systemic therapies. In this review we focus on treatment options in HCC and their allocation. Although significant research is in progress, to this date, the results are unsatisfactory with limited long-term survival. In the fight against this deadly disease, there is still a long way to go.
文摘Loco-regional treatments for hepatocellular carcinoma(HCC) are important alternatives to curative transplantation or resection.Among them,radiofrequency ablation(RFA) is accepted as the most popular technique showing excellent local tumor control and acceptable morbidity.The current role of RFA is well documented in the evidence-based practice guidelines of European Association of Study of Liver,American Association of Study of the Liver Disease and Japanese academic societies.Several randomized controlled trials have confirmed that RFA is superior to percutaneous ethanol injections in terms of local tumor control and survival.The overall survival after RFA is comparable to after surgical resection in a selected group of patients with smaller(< 3 cm) tumors.Currently,the clinical benefits of combined RFA with transarterial chemoembolization for intermediate stage HCC are increasingly being explored.Here we review the ongoing technical advancements of RFA and future potential.
文摘Hepatocellular carcinoma(HCC) is a common, increasingly prevalent malignancy. For all but the smallest lesions, surgical removal of cancer via resection or liver transplantation(LT) is considered the most feasible pathway to cure. Resection- even with favorable survival- is associated with a fairly high rate of recurrence, perhaps since most HCCs occur in the setting of cirrhosis. LT offers the advantage of removing not only the cancer but the diseased liver from which the cancer has arisen, and LT outperforms resection for survival with selected patients. Since time waiting for LT is time during which HCC can progress, locoregional therapy(LRT) is widely employed by transplant centers. The purpose of LRT is either to bridge patients to LT by preventing progression and waitlist dropout, or to downstage patients who slightly exceed standard eligibility criteria initially but can fall within it after treatment. Transarterial chemoembolization and radiofrequency ablation have been the most widely utilized LRTs to date, with favorable efficacy and safety as a bridge to LT(and for the former, as a downstaging modality). The list of potentially effective LRTs has expanded in recent years, and includes transarterial chemoembolization with drug-eluting beads, radioembolization and novel forms of extracorporal therapy. Herein we appraise the various LRT modalities for HCC, and their potential roles in specific clinical scenarios in patients awaiting LT.
