AIM: To evaluate the efficacy and safety of active removal of silicone oil with low and high viscosity through a 23-gauge transconjunctival cannula using an external vacuum pump.METHODS: This study was conducted as a ...AIM: To evaluate the efficacy and safety of active removal of silicone oil with low and high viscosity through a 23-gauge transconjunctival cannula using an external vacuum pump.METHODS: This study was conducted as a prospective, interventional case series. A total of 22 eyes of 21 patients [1000 centistokes(c St): 17 eyes, 5700 c St:5 eyes] were included in this study. All patients underwent active silicone oil removal via the entire lumen of a 23-gauge microcannula with suction pressure of a650-700 mm Hg vacuum using an external vacuum pump. A tubing adaptor from the Total Plus Pak誖(Alcon,Fort Worth, USA) was used to join the microcannula and silicone vacuum tube connected to an external vacuum pump. Main outcome measures were mean removal time,changes of intraocular pressure(IOP) and visual acuity,and intraoperative and postoperative complications.RESULTS: Mean removal time(min) was 1.49±0.43 for1000 c St and 7. 12 ± 1. 27 for 5700 c St. The IOP was18.57±7.48 mm Hg at baseline, 11.68 ±4.55 mm Hg at day1 postoperatively(P <0.001), and 15.95±4.92, 16.82±3.81,17.41 ±3.50, and 17.09 ±3.01 mm Hg after one week, one month, three months, and six months, respectively. All patients showed improved or stabilized visual acuity.There was no occurrence of intraoperative or postoperative complications during the follow up period.CONCLUSION: This technique for active removal of silicone oil through a 23-gauge cannula using an external vacuum pump is fast, effective, and safe as well as economical for silicone oil with both low and high viscosity in all eyes with pseudophakia, aphakia, or phakia.展开更多
Based on the numerical solution of the time-dependent Dirac equation,we propose a method to observe in real time the ac Stark shift of a vacuum driven by an ultra-intense laser field.By overlapping the ultra-intense p...Based on the numerical solution of the time-dependent Dirac equation,we propose a method to observe in real time the ac Stark shift of a vacuum driven by an ultra-intense laser field.By overlapping the ultra-intense pump pulse with another zeptosecond probe pulse whose photon energy is smaller than 2mc^(2),electron–positron pair creation can be controlled by tuning the time delay between the pump and probe pulses.Since the pair creation rate depends sensitively on the instantaneous vacuum potential,one can reconstruct the ac Stark shift of the vacuum potential according to the time-delay-dependent pair creation rate.展开更多
Centrifugal pumps are widely used in the metallurgy,coal,and building sectors.In order to study the hydraulic characteristics of a closed impeller centrifugal pump during its shutdown in the so-called power frequency ...Centrifugal pumps are widely used in the metallurgy,coal,and building sectors.In order to study the hydraulic characteristics of a closed impeller centrifugal pump during its shutdown in the so-called power frequency and frequency conversion modes,experiments were carried to determine the characteristic evolution of parameters such as speed,inlet and outlet pressure,head,flow rate and shaft power.A quasi-steady-state method was also used to further investigate these transient behaviors.The results show that,compared to the power frequency input,the performance parameter curves for the frequency conversion input are less volatile and smoother.The characteristic time is longer and the response to shutdown is slower.The quasi-steady-state theoretical head-flow curves match the experimental head-flow curves more closely at low flow rates when the frequency conversion input is considered.Moreover,in this case,the similarity law predicts the hydraulic performance more accurately.展开更多
Objective: To evaluate the effect of external fixation combined with vacuum sealing drainage on the trauma degree and bone metabolism in patients with open tibiofibula fracture. Methods:A total of 116 patients with op...Objective: To evaluate the effect of external fixation combined with vacuum sealing drainage on the trauma degree and bone metabolism in patients with open tibiofibula fracture. Methods:A total of 116 patients with open tibiofibula fracture who received surgical treatment in Luzhou People's Hospital between February 2015 and January 2017 were divided into control group (n=58) and study group (n=58) by random number table. Control group received debridement + external fixation, and study group received debridement + external fixation +vacuum sealing drainage. The differences in the levels of trauma indexes and bone metabolism indexes were compared between the two groups before and after treatment. Results: Before surgery, there was no statistically significant difference in serum levels of trauma indexes and bone metabolism indexes between the two groups. 1 week after surgery, serum acute phase protein Tf level of study group was higher than that of control group whereas CER, Hp and CRP levels were lower than those of control group;stress indexes NE and Cor levels were lower than those of control group;bone metabolism indexes P1NP, BGP and BALP levels were higher than those of control group whereas β-CTX level was lower than that of control group. Conclusion: External fixation combined with vacuum sealing drainage can effectively reduce fracture trauma and promote fracture end healing in patients with open tibiofibula fracture.展开更多
AIM To investigate the relation of two different mutations to the outcome of partial external biliary diversion(PEBD)in severe bile salt export pump(BSEP) deficiency.METHODS Mutations in the gene encoding BSEP leading...AIM To investigate the relation of two different mutations to the outcome of partial external biliary diversion(PEBD)in severe bile salt export pump(BSEP) deficiency.METHODS Mutations in the gene encoding BSEP leading to severe BSEP deficiency in two unrelated patients were identified by genomic sequencing. Native liver biopsies and transiently transfected human embryonic kidney(HEK) 293 cells expressing either wild-type or mutated BSEP were subjected to immunofluorescence analysis to assess BSEP transporter localization. Bile acid profiles of patient and control bile samples were generated by ultra-performance liquid chromatographytandem mass spectrometry. Wild-type and mutant BSEP transport of [~3H]-labeled taurocholate(TC) and taurochenodeoxycholate(TCDC) was assessed by vesicular transport assays.RESULTS A girl(at 2 mo) presented with pruritus, jaundice and elevated serum bile salts(BS). PEBD stabilized liver function and prevented liver transplantation. She was heterozygous for the BSEP deletion p.T919 del and the nonsense mutation p.R1235 X. At the age of 17 years relative amounts of conjugated BS in her bile were normal, while total BS were less than 3% as compared to controls. An unrelated boy(age 1.5 years) presenting with severe pruritus and elevated serum BS was heterozygous for the same nonsense and another missense mutation, p.G1032 R. PEBD failed to alleviate pruritus, eventually necessitating liver transplantation. BS concentration in bile was about 5% of controls. BS were mainly unconjugated with an unusual low amount of chenodeoxycholate derivatives(< 5%). The patients' native liver biopsies showed canalicular BSEP expression. Both BSEP p.T919 del and p.G1032 R were localized in the plasma membrane in HEK293 cells. In vitro transport assays showed drastic reduction of transport by both mutations. Using purified recombinant BSEP as quantifiable reference, per-molecule transport rates for TC and TCDC were determined to be 3 and 2 BS molecules per wild-type BSEP transporter per minute, respectively.CONCLUSION In summary, our findings suggest that residual function of BSEP as well as substrate specificity influence the therapeutic effectiveness of PEBD in progressive familial intrahepatic cholestasis type 2(PFIC-2).展开更多
Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the supe...Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.展开更多
High power optically pumped vertical-external-cavity surface-emitting lasers with front and end pump are reported. The gain chip consists of 15 repeats of In_(0.26)GaAs/GaAsP_(0.02) multiple quantum wells and 30 pairs...High power optically pumped vertical-external-cavity surface-emitting lasers with front and end pump are reported. The gain chip consists of 15 repeats of In_(0.26)GaAs/GaAsP_(0.02) multiple quantum wells and 30 pairs of Al_(0.2)GaAs/Al_(0.98)GaAs distributed Bragg reflectors. The maximum output power of 3 W, optical-to-optical conversion efficiency of 22.4%, and slope efficiency of 29.8% are obtained with 5-℃ heatsink temperature under the front pump,while the maximum output power of 1.1 W, optical-to-optical conversion efficiency of 23.2%, and slope efficiency of30.8% are reached with 5-℃ heatsink temperature under the end pump. Influences of thermal effects on the output power of the laser with front and end pump are discussed.展开更多
The motion of particles in different channel Brownian pumps can be described by Langevin equations,and the pumping capacity is a useful indicator to demonstrate the strength of a pump’s transportation ability.Via the...The motion of particles in different channel Brownian pumps can be described by Langevin equations,and the pumping capacity is a useful indicator to demonstrate the strength of a pump’s transportation ability.Via the simulation,there is always an optimal value of temperature and unbiased external force for different pumps which make the concentration ratio between the right tube and left tube derive its maximum and minimum in two asymmetric tubes respectively.Besides,the concentration ratio will keep 1 regardless of radius,temperature or magnitude of force in the tube in a symmetric tube.To obtain more information about pumping capacity,exploring the average probability current(APC) of tubes in different conditions is necessary.Results indicate that as the concentration ratio is 1,the change of the APC when x_(0)=0 is similar to that when x_(0)=π.Also,when the concentration ratio is more than 1,there are optimal values of temperature,radius and magnitude of force where the APC gains a maximum,and the maximum decreases as the concentration in the right tube increases when x_(0)=0.展开更多
文摘AIM: To evaluate the efficacy and safety of active removal of silicone oil with low and high viscosity through a 23-gauge transconjunctival cannula using an external vacuum pump.METHODS: This study was conducted as a prospective, interventional case series. A total of 22 eyes of 21 patients [1000 centistokes(c St): 17 eyes, 5700 c St:5 eyes] were included in this study. All patients underwent active silicone oil removal via the entire lumen of a 23-gauge microcannula with suction pressure of a650-700 mm Hg vacuum using an external vacuum pump. A tubing adaptor from the Total Plus Pak誖(Alcon,Fort Worth, USA) was used to join the microcannula and silicone vacuum tube connected to an external vacuum pump. Main outcome measures were mean removal time,changes of intraocular pressure(IOP) and visual acuity,and intraoperative and postoperative complications.RESULTS: Mean removal time(min) was 1.49±0.43 for1000 c St and 7. 12 ± 1. 27 for 5700 c St. The IOP was18.57±7.48 mm Hg at baseline, 11.68 ±4.55 mm Hg at day1 postoperatively(P <0.001), and 15.95±4.92, 16.82±3.81,17.41 ±3.50, and 17.09 ±3.01 mm Hg after one week, one month, three months, and six months, respectively. All patients showed improved or stabilized visual acuity.There was no occurrence of intraoperative or postoperative complications during the follow up period.CONCLUSION: This technique for active removal of silicone oil through a 23-gauge cannula using an external vacuum pump is fast, effective, and safe as well as economical for silicone oil with both low and high viscosity in all eyes with pseudophakia, aphakia, or phakia.
基金supported by the National Natural Science Foundation of China(Grant Nos.12304341 and 11974419)the National Key R&D Program of China(Grant Nos.2021YFA1601700 and 2018YFA0404802)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA25051000).
文摘Based on the numerical solution of the time-dependent Dirac equation,we propose a method to observe in real time the ac Stark shift of a vacuum driven by an ultra-intense laser field.By overlapping the ultra-intense pump pulse with another zeptosecond probe pulse whose photon energy is smaller than 2mc^(2),electron–positron pair creation can be controlled by tuning the time delay between the pump and probe pulses.Since the pair creation rate depends sensitively on the instantaneous vacuum potential,one can reconstruct the ac Stark shift of the vacuum potential according to the time-delay-dependent pair creation rate.
基金supported by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(Grant No.2022C03170)Science and Technology Project of Quzhou(Grant No.2022K98)Hunan Province Key Field R&D Plan Project(Grant No.2022GK2068).
文摘Centrifugal pumps are widely used in the metallurgy,coal,and building sectors.In order to study the hydraulic characteristics of a closed impeller centrifugal pump during its shutdown in the so-called power frequency and frequency conversion modes,experiments were carried to determine the characteristic evolution of parameters such as speed,inlet and outlet pressure,head,flow rate and shaft power.A quasi-steady-state method was also used to further investigate these transient behaviors.The results show that,compared to the power frequency input,the performance parameter curves for the frequency conversion input are less volatile and smoother.The characteristic time is longer and the response to shutdown is slower.The quasi-steady-state theoretical head-flow curves match the experimental head-flow curves more closely at low flow rates when the frequency conversion input is considered.Moreover,in this case,the similarity law predicts the hydraulic performance more accurately.
文摘Objective: To evaluate the effect of external fixation combined with vacuum sealing drainage on the trauma degree and bone metabolism in patients with open tibiofibula fracture. Methods:A total of 116 patients with open tibiofibula fracture who received surgical treatment in Luzhou People's Hospital between February 2015 and January 2017 were divided into control group (n=58) and study group (n=58) by random number table. Control group received debridement + external fixation, and study group received debridement + external fixation +vacuum sealing drainage. The differences in the levels of trauma indexes and bone metabolism indexes were compared between the two groups before and after treatment. Results: Before surgery, there was no statistically significant difference in serum levels of trauma indexes and bone metabolism indexes between the two groups. 1 week after surgery, serum acute phase protein Tf level of study group was higher than that of control group whereas CER, Hp and CRP levels were lower than those of control group;stress indexes NE and Cor levels were lower than those of control group;bone metabolism indexes P1NP, BGP and BALP levels were higher than those of control group whereas β-CTX level was lower than that of control group. Conclusion: External fixation combined with vacuum sealing drainage can effectively reduce fracture trauma and promote fracture end healing in patients with open tibiofibula fracture.
基金Supported by the German -Research Foun-dation-through the Clin-ical Research Group KFO217“Hepatobiliary tran-sport an-d liver diseases”the Collaborative Research Cen-tre 974“Commun-ication-an-d Systemic Relevan-ce in-Liver Damage an-d Regen-eration-”
文摘AIM To investigate the relation of two different mutations to the outcome of partial external biliary diversion(PEBD)in severe bile salt export pump(BSEP) deficiency.METHODS Mutations in the gene encoding BSEP leading to severe BSEP deficiency in two unrelated patients were identified by genomic sequencing. Native liver biopsies and transiently transfected human embryonic kidney(HEK) 293 cells expressing either wild-type or mutated BSEP were subjected to immunofluorescence analysis to assess BSEP transporter localization. Bile acid profiles of patient and control bile samples were generated by ultra-performance liquid chromatographytandem mass spectrometry. Wild-type and mutant BSEP transport of [~3H]-labeled taurocholate(TC) and taurochenodeoxycholate(TCDC) was assessed by vesicular transport assays.RESULTS A girl(at 2 mo) presented with pruritus, jaundice and elevated serum bile salts(BS). PEBD stabilized liver function and prevented liver transplantation. She was heterozygous for the BSEP deletion p.T919 del and the nonsense mutation p.R1235 X. At the age of 17 years relative amounts of conjugated BS in her bile were normal, while total BS were less than 3% as compared to controls. An unrelated boy(age 1.5 years) presenting with severe pruritus and elevated serum BS was heterozygous for the same nonsense and another missense mutation, p.G1032 R. PEBD failed to alleviate pruritus, eventually necessitating liver transplantation. BS concentration in bile was about 5% of controls. BS were mainly unconjugated with an unusual low amount of chenodeoxycholate derivatives(< 5%). The patients' native liver biopsies showed canalicular BSEP expression. Both BSEP p.T919 del and p.G1032 R were localized in the plasma membrane in HEK293 cells. In vitro transport assays showed drastic reduction of transport by both mutations. Using purified recombinant BSEP as quantifiable reference, per-molecule transport rates for TC and TCDC were determined to be 3 and 2 BS molecules per wild-type BSEP transporter per minute, respectively.CONCLUSION In summary, our findings suggest that residual function of BSEP as well as substrate specificity influence the therapeutic effectiveness of PEBD in progressive familial intrahepatic cholestasis type 2(PFIC-2).
基金The National Natural Science Foundation of China ( No. 50476022 )Ministries and Commissions of Science and Technology of Shanghai Government (No. 03DZ 14014)
文摘Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.
基金Project supported by the Chongqing Research Program of Basic Research and Frontier Technology(Grant No.cstc2015jcyj BX0098)the National Natural Science Foundation of China(Grant No.61575011)the Foundation for the Creative Research Groups of Higher Education of Chongqing(Grant No.CXTDX201601016)
文摘High power optically pumped vertical-external-cavity surface-emitting lasers with front and end pump are reported. The gain chip consists of 15 repeats of In_(0.26)GaAs/GaAsP_(0.02) multiple quantum wells and 30 pairs of Al_(0.2)GaAs/Al_(0.98)GaAs distributed Bragg reflectors. The maximum output power of 3 W, optical-to-optical conversion efficiency of 22.4%, and slope efficiency of 29.8% are obtained with 5-℃ heatsink temperature under the front pump,while the maximum output power of 1.1 W, optical-to-optical conversion efficiency of 23.2%, and slope efficiency of30.8% are reached with 5-℃ heatsink temperature under the end pump. Influences of thermal effects on the output power of the laser with front and end pump are discussed.
基金National Natural Science Foundation of China (No. 61975058)Blue Shield Technology Project,China (No. LD20170209)。
文摘The motion of particles in different channel Brownian pumps can be described by Langevin equations,and the pumping capacity is a useful indicator to demonstrate the strength of a pump’s transportation ability.Via the simulation,there is always an optimal value of temperature and unbiased external force for different pumps which make the concentration ratio between the right tube and left tube derive its maximum and minimum in two asymmetric tubes respectively.Besides,the concentration ratio will keep 1 regardless of radius,temperature or magnitude of force in the tube in a symmetric tube.To obtain more information about pumping capacity,exploring the average probability current(APC) of tubes in different conditions is necessary.Results indicate that as the concentration ratio is 1,the change of the APC when x_(0)=0 is similar to that when x_(0)=π.Also,when the concentration ratio is more than 1,there are optimal values of temperature,radius and magnitude of force where the APC gains a maximum,and the maximum decreases as the concentration in the right tube increases when x_(0)=0.
