Bionic microfluidics is garnering increasing attention due to the superior fluidic performance enabled by biomimetic microstructures.Inspired by the unique structures of young pumpkin stems,we fabricate helicoidally p...Bionic microfluidics is garnering increasing attention due to the superior fluidic performance enabled by biomimetic microstructures.Inspired by the unique structures of young pumpkin stems,we fabricate helicoidally patterned microchannels with precisely controlled morphologies using the projection micro-stereolithography(PμSL)-based 3D printing technique.Our helicoidally patterned microchannels achieve approximately twice the liquid lifting height compared to similarly sized smooth microchannels.This improvement is attributed to the enhanced capillary force.The additional meniscus formed between the helicoidally patterned microstructures significantly contributes to the increased capillary effects.Furthermore,the underlying mechanisms of fluidic performance in helicoidally patterned microchannels are theorized using a newly developed equation,which is also employed to optimize the geometric parameters and fluidic performance of the biomimetic helicoidal microchannels.Additionally,our biomimetic helicoidally patterned microchannels facilitate a significant step-lifting phenomenon,mimicking tall trees'transpiration.The fluidic performance of our biomimetic helicoidally patterned microchannels show promise for applications in enhanced liquid lifting,step-lifting,clean-water production,and others.展开更多
To eliminate distortion caused by vertical drift and illusory slopes in atomic force microscopy(AFM)imaging,a lifting-wavelet-based iterative thresholding correction method is proposed in this paper.This method achiev...To eliminate distortion caused by vertical drift and illusory slopes in atomic force microscopy(AFM)imaging,a lifting-wavelet-based iterative thresholding correction method is proposed in this paper.This method achieves high-quality AFM imaging via line-by-line corrections for each distorted profile along the fast axis.The key to this line-by-line correction is to accurately simulate the profile distortion of each scanning row.Therefore,a data preprocessing approach is first developed to roughly filter out most of the height data that impairs the accuracy of distortion modeling.This process is implemented through an internal double-screening mechanism.A line-fitting method is adopted to preliminarily screen out the obvious specimens.Lifting wavelet analysis is then carried out to identify the base parts that are mistakenly filtered out as specimens so as to preserve most of the base profiles and provide a good basis for further distortion modeling.Next,an iterative thresholding algorithm is developed to precisely simulate the profile distortion.By utilizing the roughly screened base profile,the optimal threshold,which is used to screen out the pure bases suitable for distortion modeling,is determined through iteration with a specified error rule.On this basis,the profile distortion is accurately modeled through line fitting on the finely screened base data,and the correction is implemented by subtracting the modeling result from the distorted profile.Finally,the effectiveness of the proposed method is verified through experiments and applications.展开更多
BACKGROUND Among the rapidly developing single-incision laparoscopic cholecystectomy(LC)techniques,transumbilical single-incision LC is increasingly replacing the traditional LC,with advantages of minimal invasion,sli...BACKGROUND Among the rapidly developing single-incision laparoscopic cholecystectomy(LC)techniques,transumbilical single-incision LC is increasingly replacing the traditional LC,with advantages of minimal invasion,slight postoperative pain,faster recovery.Despite the advantages mentioned above,the currently available specialized single-port laparoscopic instruments are hindered by high costs and limited applications,challenging their widespread use in medical facilities.AIM To design a two-point lifting/retracting(TPLR)technique for transumbilical single-port LC(TUSPLC)based on the anatomical features of the Calot's triangle(or cystohepatic triangle)and investigate its surgical feasibility.METHODS The clinical data of 103 patients who underwent TUSPLC utilizing the TPLR technique in the Department of Hepatobiliary Surgery at our hospital between June 2023 and June 2024 were retrospectively analyzed.The patient cohort included 82 cases of cholelithiasis,11 cases of gallbladder polyps,6 cases of concurrent gallstones and polyps,and 4 cases of gallbladder adenomyomatosis.RESULTS All the surgical procedures were conducted using standard laparoscopic instruments.Surgery was successful in 98(95.14%)patients using the TPLR method,which effectively exposed the Calot's triangle during surgery.The operative time ranged from 35 to 70 minutes,with an average of 42.4±26.8 minutes.In 3 cases,an additional operative port was required below the xiphoid process,and 2 cases were converted to conventional three-port LC.No complications such as abdominal pain,fever,bile leakage,hemorrhage,or incisional infection were noted postoperatively.No discernible surgical scars were observed at the 2-week postoperative reexamination.Additionally,a 3-month follow-up period revealed no complications.CONCLUSION The TPLR technique,developed based on the anatomical features of the Calot's triangle,facilitates exposure of the Calot's triangle during surgery.It is a simple,safe,feasible,and cost-effective method,and a promising approach for single-port LC.展开更多
As the environmental problems become increasingly serious,distributed electrical propulsion systems with higher aerodynamic efficiency and lower pollution emission have received extensive attention in recent years.The...As the environmental problems become increasingly serious,distributed electrical propulsion systems with higher aerodynamic efficiency and lower pollution emission have received extensive attention in recent years.The distributed electrical propulsion usually employs the new aero-propulsion integrated configuration.A simulation strategy for internal and external flow coupling based on the combination of lifting line theory and body force method is proposed.The lifting line theory and body force method as source term are embedded into the Navier-Stokes formulation.The lift and drag characteristics of the aero-propulsion coupling configuration are simulated.The results indicate that the coupling configuration has the most obvious lift augmentation at 12°angle of attack,which can provide an 11.11%increase in lift for the airfoil.At 0°angle of attack,the pressure difference on the lip parts provides the thrust component,which results in a lower drag coefficient.Additionally,the failure impact of a ducted fan at the middle or edge on aerodynamics is investigated.For the two failure conditions,the lift of the coupling configuration is decreased significantly by 27.85%and 26.14%respectively,and the lip thrust is decreased by 70.74%and 56.48%respectively.展开更多
Objective To compare the difference of clinical efficacy between acupuncture of lifting and pressing manipulation and conventional acupuncture in motor function recovery of hemiplegic upper limb after stroke, so as to...Objective To compare the difference of clinical efficacy between acupuncture of lifting and pressing manipulation and conventional acupuncture in motor function recovery of hemiplegic upper limb after stroke, so as to provide referential support for clinical application. Method Fifty-nine patients with upper limb hemiplegia after stroke were selected and divided into group A （conventional acupuncture ± lifting and pressing manipulation, 30 cases} and group B （conventional acupuncture, 29 cases} according to random number table method. Upper limb motor function and activity of daily living of patients in the two groups were scored before and after treatment, and the results were analyzed and compared. Results The score of upper limb FugI-Meyer motor function of patients was 22.4 ± 2.83 and 32.97 ± 2.92 before and after treatment in group A, and was 19.89 ± 3.13 and 26.62 ± 3.31 before and after treatment in group B, and the difference between the two groups before and after treatment was significant （P〈0.01}. The score of Barthel index of patients was 60.67 ± 4.65 and 73.00 ± 3.82 before and after treatment in group A, and was 50.52 ± 5.15 and 60.17 ± 4.89 before and after treatment in group B, and the difference between the two groups before and after treatment was not statistcally significant {P〉0.05）. Conclusion Lifting and pressing manipulation combined with conventional acupuncture can better improve upper limb motor function of upper limb paralysis of patients after stroke.展开更多
A newnumerical method based on vector form intrinsic finite element（VFIFE） is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking...A newnumerical method based on vector form intrinsic finite element（VFIFE） is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking the steel gallery between the integrated building and the attached building of Nanjing M obile Communication Buildings for example, the static analysis was carried out and the corresponding results were compared with the results achieved by the traditional finite element method. Then, according to the characteristics of dynamic construction of steel structure integral lifting, the tension cable element was employed to simulate the behavior of dynamic construction. The VFIFE method avoids the iterative solution of the stiffness matrix and the singularity problems. Therefore, it is simple to simulate the complete process of steel structure lifting construction.Finally, by using the VFIFE, the displacement and internal force time history curves of the steel structures under different lifting speeds are obtained. The results show that the lifting speed has influence on the lifting force, the internal force, and the displacement of the structure. In the case of normal lifting speed, the dynamic magnification factor of 1. 5 is safe and reasonable for practical application.展开更多
The current morphological wavelet technologies utilize a fixed filter or a linear decomposition algorithm, which cannot cope with the sudden changes, such as impulses or edges in a signal effectively. This paper pre- ...The current morphological wavelet technologies utilize a fixed filter or a linear decomposition algorithm, which cannot cope with the sudden changes, such as impulses or edges in a signal effectively. This paper pre- sents a novel signal processing scheme, adaptive morpho- logical update lifting wavelet （AMULW）, for rolling element bearing fault detection. In contrast with the widely used morphological wavelet, the filters in AMULW are no longer fixed. Instead, the AMULW adaptively uses a morphological dilation-erosion filter or an average filter as the update lifting filter to modify the approximation signal. Moreover, the nonlinear morphological filter is utilized to substitute the traditional linear filter in AMULW. The effectiveness of the proposed AMULW is evaluated using a simulated vibration signal and experimental vibration sig- nals collected from a bearing test rig. Results show that the proposed method has a superior performance in extracting fault features of defective roiling element bearings.展开更多
Giant hiatal hernia（GHH） comprises 5% of hiatal hernia and is associated with significant complications.The traditional operative procedure,no matter transthoracic or transabdomen repair of giant hiatal hernia,is ch...Giant hiatal hernia（GHH） comprises 5% of hiatal hernia and is associated with significant complications.The traditional operative procedure,no matter transthoracic or transabdomen repair of giant hiatal hernia,is characteristic of more invasion and more complications.Although laparoscopic repair as a minimally invasive surgery is accepted,a part of patients can not tolerate pneumoperitoneum because of combination with cardiopulmonary diseases or severe posterior mediastinal and neck emphesema during operation.The aim of this article was to analyze our experience in gasless laparoscopic repair with abdominal wall lifting to treat the giant hiatal hernia.We performed a retrospective review of patients undergoing gasless laparoscopic repair of GHH with abdominal wall lifting from 2012 to 2015 at our institution.The GHH was defined as greater than one-third of the stomach in the chest.Gasless laparoscopic repair of GHH with abdominal wall lifting was attempted in 27 patients.Mean age was 67 years.The results showed that there were no conversions to open surgery and no intraoperative deaths.The mean duration of operation was 100 min（range：90–130 min）.One-side pleura was injured in 4 cases（14.8%）.The mean postoperative length of stay was 4 days（range：3–7 days）.Median follow-up was 26 months（range：6–38 months）.Transient dysphagia for solid food occurred in three patients（11.1%）,and this symptom disappeared within three months.There was one patient with recurrent hiatal hernia who was reoperated on.Two patients still complained of heartburn three months after surgery.Neither reoperation nor endoscopic treatment due to signs of postoperative esophageal stenosis was required in any patient.Totally,satisfactory outcome was reported in 88.9% patients.It was concluded that the gasless laparoscopic approach with abdominal wall lifting to the repair of GHH is feasible,safe,and effective for the patients who cannot tolerate the pneumoperitoneum.展开更多
基金supported by National Natural Science Foundation of China through Grant Nos.52495000,52332012 and 52176093partially supported by Beijing Huiyangdao Health Technology Co.,Ltd。
文摘Bionic microfluidics is garnering increasing attention due to the superior fluidic performance enabled by biomimetic microstructures.Inspired by the unique structures of young pumpkin stems,we fabricate helicoidally patterned microchannels with precisely controlled morphologies using the projection micro-stereolithography(PμSL)-based 3D printing technique.Our helicoidally patterned microchannels achieve approximately twice the liquid lifting height compared to similarly sized smooth microchannels.This improvement is attributed to the enhanced capillary force.The additional meniscus formed between the helicoidally patterned microstructures significantly contributes to the increased capillary effects.Furthermore,the underlying mechanisms of fluidic performance in helicoidally patterned microchannels are theorized using a newly developed equation,which is also employed to optimize the geometric parameters and fluidic performance of the biomimetic helicoidal microchannels.Additionally,our biomimetic helicoidally patterned microchannels facilitate a significant step-lifting phenomenon,mimicking tall trees'transpiration.The fluidic performance of our biomimetic helicoidally patterned microchannels show promise for applications in enhanced liquid lifting,step-lifting,clean-water production,and others.
基金supported by the National Natural Science Foundation of China under Grant No.21933006.
文摘To eliminate distortion caused by vertical drift and illusory slopes in atomic force microscopy(AFM)imaging,a lifting-wavelet-based iterative thresholding correction method is proposed in this paper.This method achieves high-quality AFM imaging via line-by-line corrections for each distorted profile along the fast axis.The key to this line-by-line correction is to accurately simulate the profile distortion of each scanning row.Therefore,a data preprocessing approach is first developed to roughly filter out most of the height data that impairs the accuracy of distortion modeling.This process is implemented through an internal double-screening mechanism.A line-fitting method is adopted to preliminarily screen out the obvious specimens.Lifting wavelet analysis is then carried out to identify the base parts that are mistakenly filtered out as specimens so as to preserve most of the base profiles and provide a good basis for further distortion modeling.Next,an iterative thresholding algorithm is developed to precisely simulate the profile distortion.By utilizing the roughly screened base profile,the optimal threshold,which is used to screen out the pure bases suitable for distortion modeling,is determined through iteration with a specified error rule.On this basis,the profile distortion is accurately modeled through line fitting on the finely screened base data,and the correction is implemented by subtracting the modeling result from the distorted profile.Finally,the effectiveness of the proposed method is verified through experiments and applications.
文摘BACKGROUND Among the rapidly developing single-incision laparoscopic cholecystectomy(LC)techniques,transumbilical single-incision LC is increasingly replacing the traditional LC,with advantages of minimal invasion,slight postoperative pain,faster recovery.Despite the advantages mentioned above,the currently available specialized single-port laparoscopic instruments are hindered by high costs and limited applications,challenging their widespread use in medical facilities.AIM To design a two-point lifting/retracting(TPLR)technique for transumbilical single-port LC(TUSPLC)based on the anatomical features of the Calot's triangle(or cystohepatic triangle)and investigate its surgical feasibility.METHODS The clinical data of 103 patients who underwent TUSPLC utilizing the TPLR technique in the Department of Hepatobiliary Surgery at our hospital between June 2023 and June 2024 were retrospectively analyzed.The patient cohort included 82 cases of cholelithiasis,11 cases of gallbladder polyps,6 cases of concurrent gallstones and polyps,and 4 cases of gallbladder adenomyomatosis.RESULTS All the surgical procedures were conducted using standard laparoscopic instruments.Surgery was successful in 98(95.14%)patients using the TPLR method,which effectively exposed the Calot's triangle during surgery.The operative time ranged from 35 to 70 minutes,with an average of 42.4±26.8 minutes.In 3 cases,an additional operative port was required below the xiphoid process,and 2 cases were converted to conventional three-port LC.No complications such as abdominal pain,fever,bile leakage,hemorrhage,or incisional infection were noted postoperatively.No discernible surgical scars were observed at the 2-week postoperative reexamination.Additionally,a 3-month follow-up period revealed no complications.CONCLUSION The TPLR technique,developed based on the anatomical features of the Calot's triangle,facilitates exposure of the Calot's triangle during surgery.It is a simple,safe,feasible,and cost-effective method,and a promising approach for single-port LC.
基金the funding support from the Taihang Laboratory,China(No.D2024-1-0201).
文摘As the environmental problems become increasingly serious,distributed electrical propulsion systems with higher aerodynamic efficiency and lower pollution emission have received extensive attention in recent years.The distributed electrical propulsion usually employs the new aero-propulsion integrated configuration.A simulation strategy for internal and external flow coupling based on the combination of lifting line theory and body force method is proposed.The lifting line theory and body force method as source term are embedded into the Navier-Stokes formulation.The lift and drag characteristics of the aero-propulsion coupling configuration are simulated.The results indicate that the coupling configuration has the most obvious lift augmentation at 12°angle of attack,which can provide an 11.11%increase in lift for the airfoil.At 0°angle of attack,the pressure difference on the lip parts provides the thrust component,which results in a lower drag coefficient.Additionally,the failure impact of a ducted fan at the middle or edge on aerodynamics is investigated.For the two failure conditions,the lift of the coupling configuration is decreased significantly by 27.85%and 26.14%respectively,and the lip thrust is decreased by 70.74%and 56.48%respectively.
文摘Objective To compare the difference of clinical efficacy between acupuncture of lifting and pressing manipulation and conventional acupuncture in motor function recovery of hemiplegic upper limb after stroke, so as to provide referential support for clinical application. Method Fifty-nine patients with upper limb hemiplegia after stroke were selected and divided into group A （conventional acupuncture ± lifting and pressing manipulation, 30 cases} and group B （conventional acupuncture, 29 cases} according to random number table method. Upper limb motor function and activity of daily living of patients in the two groups were scored before and after treatment, and the results were analyzed and compared. Results The score of upper limb FugI-Meyer motor function of patients was 22.4 ± 2.83 and 32.97 ± 2.92 before and after treatment in group A, and was 19.89 ± 3.13 and 26.62 ± 3.31 before and after treatment in group B, and the difference between the two groups before and after treatment was significant （P〈0.01}. The score of Barthel index of patients was 60.67 ± 4.65 and 73.00 ± 3.82 before and after treatment in group A, and was 50.52 ± 5.15 and 60.17 ± 4.89 before and after treatment in group B, and the difference between the two groups before and after treatment was not statistcally significant {P〉0.05）. Conclusion Lifting and pressing manipulation combined with conventional acupuncture can better improve upper limb motor function of upper limb paralysis of patients after stroke.
基金The National Natural Science Foundation of China(No.51308105)
文摘A newnumerical method based on vector form intrinsic finite element（VFIFE） is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking the steel gallery between the integrated building and the attached building of Nanjing M obile Communication Buildings for example, the static analysis was carried out and the corresponding results were compared with the results achieved by the traditional finite element method. Then, according to the characteristics of dynamic construction of steel structure integral lifting, the tension cable element was employed to simulate the behavior of dynamic construction. The VFIFE method avoids the iterative solution of the stiffness matrix and the singularity problems. Therefore, it is simple to simulate the complete process of steel structure lifting construction.Finally, by using the VFIFE, the displacement and internal force time history curves of the steel structures under different lifting speeds are obtained. The results show that the lifting speed has influence on the lifting force, the internal force, and the displacement of the structure. In the case of normal lifting speed, the dynamic magnification factor of 1. 5 is safe and reasonable for practical application.
基金Supported by National Natural Science Foundation of China(51705431,51375078)Natural Sciences and Engineering Research Council of Canada(RGPIN-2015-04897)
文摘The current morphological wavelet technologies utilize a fixed filter or a linear decomposition algorithm, which cannot cope with the sudden changes, such as impulses or edges in a signal effectively. This paper pre- sents a novel signal processing scheme, adaptive morpho- logical update lifting wavelet （AMULW）, for rolling element bearing fault detection. In contrast with the widely used morphological wavelet, the filters in AMULW are no longer fixed. Instead, the AMULW adaptively uses a morphological dilation-erosion filter or an average filter as the update lifting filter to modify the approximation signal. Moreover, the nonlinear morphological filter is utilized to substitute the traditional linear filter in AMULW. The effectiveness of the proposed AMULW is evaluated using a simulated vibration signal and experimental vibration sig- nals collected from a bearing test rig. Results show that the proposed method has a superior performance in extracting fault features of defective roiling element bearings.
基金supported by a grant from the Beijing Municipal Science&Technology Commission(No.Z141107002514121)
文摘Giant hiatal hernia（GHH） comprises 5% of hiatal hernia and is associated with significant complications.The traditional operative procedure,no matter transthoracic or transabdomen repair of giant hiatal hernia,is characteristic of more invasion and more complications.Although laparoscopic repair as a minimally invasive surgery is accepted,a part of patients can not tolerate pneumoperitoneum because of combination with cardiopulmonary diseases or severe posterior mediastinal and neck emphesema during operation.The aim of this article was to analyze our experience in gasless laparoscopic repair with abdominal wall lifting to treat the giant hiatal hernia.We performed a retrospective review of patients undergoing gasless laparoscopic repair of GHH with abdominal wall lifting from 2012 to 2015 at our institution.The GHH was defined as greater than one-third of the stomach in the chest.Gasless laparoscopic repair of GHH with abdominal wall lifting was attempted in 27 patients.Mean age was 67 years.The results showed that there were no conversions to open surgery and no intraoperative deaths.The mean duration of operation was 100 min（range：90–130 min）.One-side pleura was injured in 4 cases（14.8%）.The mean postoperative length of stay was 4 days（range：3–7 days）.Median follow-up was 26 months（range：6–38 months）.Transient dysphagia for solid food occurred in three patients（11.1%）,and this symptom disappeared within three months.There was one patient with recurrent hiatal hernia who was reoperated on.Two patients still complained of heartburn three months after surgery.Neither reoperation nor endoscopic treatment due to signs of postoperative esophageal stenosis was required in any patient.Totally,satisfactory outcome was reported in 88.9% patients.It was concluded that the gasless laparoscopic approach with abdominal wall lifting to the repair of GHH is feasible,safe,and effective for the patients who cannot tolerate the pneumoperitoneum.
文摘在形式化地分析DWT(Discrete Wavelet Transform)Lifting分解的基础上,提出了分解集合的分级结构概念与技术,其克服了求解问题的高复杂性所带来的实际计算与搜索困难;进一步地,从数值稳定性及计算代价两方面研究了分解的评价问题,给出了两种实用的分解稳定性准则;最后,结合分级结构技术提出了最优分解算法.这些方法应用在JPEG2000框架下的图像压缩系统中得到了一些深刻结论,如发现了LTD(Long Then Danger)现象等,可以为压缩系统中小波变换的快速实现提供新的理论依据与实用算法.实验结果表明了上述方法在求解效率与灵活性、寻优速度以及适用范围等方面的优越性.
