Three experiments of static state storage method, low-temperature and constant-pressure storage method and low-temperature and constant-pressure storage method were carried out to investigate which method was best in ...Three experiments of static state storage method, low-temperature and constant-pressure storage method and low-temperature and constant-pressure storage method were carried out to investigate which method was best in gas hydrate. The relationships of hydrate rate, capacity and liquid temperature versus time were derived and three results were contrasted. The experimental results show lowtemperature and constant-pressure method is better than the other two methods because it's operation period is shorter and storage capacity is larger than the other two. Low-temperature and constant-pressure method is the best method. So new method will be new research objective.展开更多
AIM: To establish a scoring system for predicting the incidence of postoperative complications and mortality in general surgery based on the physiological and operative severity score for the enumeration of mortality ...AIM: To establish a scoring system for predicting the incidence of postoperative complications and mortality in general surgery based on the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM), and to evaluate its efficacy. METHODS: Eighty-four patients with postoperative complications or death and 172 patients without postoperative complications, who underwent surgery in our department during the previous 2 years, were retrospectively analyzed by logistic regression. Fifteen indexes were investigated including age, cardiovascular function, respiratory function, blood test results, endocrine function, central nervous system function, hepatic function, renal function, nutritional status, extent of operative trauma, and course of anesthesia. Modified POSSUM (M-POSSUM) was developed using significant risk factors with its efficacy evaluated. RESULTS: The significant risk factors were found to be age, cardiovascular function, respiratory function, hepatic function, renal function, blood test results, endocrine function, nutritional status, duration of operation, intraoperative blood loss, and course of anesthesia. These factors were all included in the scoring system. There were significant differences in the scores between the patients with and without postoperative complications, between the patients died and survived with complications, and between the patients died and survived without complications. The receiver operating characteristic curves showed that the M-POSSUM could accurately predict postoperative complications and mortality.CONCLUSION: M-POSSUM correlates well with postoperative complications and mortality, and is more accurate than POSSUM.展开更多
Introduction: Perioperative hypothermia in cardiac surgery is associated with adverse outcome. The aim of this investigation was to study whether an underbody forced-air warming blanket during coronary artery bypass g...Introduction: Perioperative hypothermia in cardiac surgery is associated with adverse outcome. The aim of this investigation was to study whether an underbody forced-air warming blanket during coronary artery bypass graft surgery with normothermic cardiopulmonary bypass can prevent postoperative hypothermia. Methods: After Medical Ethics Committee approval, 60 low-risk cardiac surgery patients at random were assigned into a group that received standard thermal care management (control group n = 30) and a group that received the underbody forced-air warming system plus the standard thermal care (intervention group n = 30). Results: The temperature after-drop from the end of cardiopulmonary bypass to arrival in the ICU was less in the intervention group versus control group (0.4°C ± 0.3°C vs 0.6°C ± 0.4°C;P = 0.027). Out of the intervention group, 27 patients arrived in the ICU with a bladder temperature ? 36°C (90%) as compared to 14 patients (46.7%) from the control group (P < 0.001). The peripheral temperature was significantly higher in the intervention group as compared to the control group (P < 0.001). Conclusions: A full underbody forced-air warming blanket prevents postoperative hypothermia in normothermic coronary artery bypass graft surgery patients.展开更多
In this paper, a modified Newton type iterative method is considered for ap- proximately solving ill-posed nonlinear operator equations involving m-accretive mappings in Banach space. Convergence rate of the method is...In this paper, a modified Newton type iterative method is considered for ap- proximately solving ill-posed nonlinear operator equations involving m-accretive mappings in Banach space. Convergence rate of the method is obtained based on an a priori choice of the regularization parameter. Our analysis is not based on the sequential continuity of the normalized duality mapping.展开更多
The convergence of several Galerkin-Petrov methods, including polynomial collocation and analytic element collocation methods of Toeplitz operators on Dirichlet space, is established. In particular, it is shown that s...The convergence of several Galerkin-Petrov methods, including polynomial collocation and analytic element collocation methods of Toeplitz operators on Dirichlet space, is established. In particular, it is shown that such methods converge if the basis and test function own certain circular symmetry.展开更多
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna...Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed.展开更多
In this paper we develop two multilevel iteration methods for solving linear systems resulting from the Galerkin method and Tikhonov regularization for linear ill-posed problems. The two algorithms and their convergen...In this paper we develop two multilevel iteration methods for solving linear systems resulting from the Galerkin method and Tikhonov regularization for linear ill-posed problems. The two algorithms and their convergence analyses are presented in an abstract framework.展开更多
BACKGROUND Bariatric surgery is one of the most effective ways to treat morbid obesity,and postoperative nausea and vomiting(PONV)is one of the common complications after bariatric surgery.At present,the mechanism of ...BACKGROUND Bariatric surgery is one of the most effective ways to treat morbid obesity,and postoperative nausea and vomiting(PONV)is one of the common complications after bariatric surgery.At present,the mechanism of the high incidence of PONV after weight-loss surgery has not been clearly explained,and this study aims to investigate the effect of surgical position on PONV in patients undergoing bariatric surgery.AIM To explore the effect of the operative position during bariatric surgery on PONV.METHODS Data from obese patients,who underwent laparoscopic sleeve gastrectomy(LSG)in the authors’hospital between June 2020 and February 2022 were divided into 2 groups and retrospectively analyzed.Multivariable logistic regression analysis and the t-test were used to study the influence of operative position on PONV.RESULTS There were 15 cases of PONV in the supine split-leg group(incidence rate,50%)and 11 in the supine group(incidence rate,36.7%)(P=0.297).The mean operative duration in the supine split-leg group was 168.23±46.24 minutes and 140.60±32.256 minutes in the supine group(P<0.05).Multivariate analysis revealed that operative position was not an independent risk factor for PONV(odds ratio=1.192,95%confidence interval:0.376-3.778,P=0.766).CONCLUSION Operative position during LSG may affect PONV;however,the difference in the incidence of PONV was not statistically significant.Operative position should be carefully considered for obese patients before surgery.展开更多
Objective:While a rushed operation can omit essential procedures,prolonged operative time results in higher morbidity.Nevertheless,the optimal operative time range remains uncertain.This study aimed to estimate the id...Objective:While a rushed operation can omit essential procedures,prolonged operative time results in higher morbidity.Nevertheless,the optimal operative time range remains uncertain.This study aimed to estimate the ideal operative time range and evaluate its applicability in laparoscopic cancer surgery.Methods:A prospectively collected multicenter database of 397 patients who underwent laparoscopic distal gastrectomy were retrospectively reviewed.The ideal operative time range was statistically calculated by separately analyzing the operative time of uneventful surgeries.Finally,intraoperative and postoperative outcomes were compared among the shorter,ideal,and longer operative time groups.Results:The statistically calculated ideal operative time was 135.4-165.4 min.The longer operative time(LOT)group had a lower rate of uneventful,perfect surgery than the ideal or shorter operative time(IOT/SOT)group(2.8%vs.8.8%and 2.2%vs.13.4%,all P<0.05).Longer operative time increased bleeding,postoperative morbidities,and delayed diet and discharge(all P<0.05).Particularly,an uneventful,perfect surgery could not be achieved when the operative time exceeded 240 min.Regardless of ideal time range,SOT group achieved the highest percentage of uneventful surgery(13.4%),which was possible by surgeon's ability to retrieve a higher number of lymph nodes and perform≥150 gastrectomies annually.Conclusions:Operative time longer than the ideal time range(especially≥240 min)should be avoided.If the essential operative procedure were faithfully conducted without compromising oncological safety,an operative time shorter than the ideal range leaded to a better prognosis.Efforts to minimize operative time should be attempted with sufficient surgical experience.展开更多
The operating room is a unique environment where surgery exposes patients to non-physiological changes that can compromise lung mechanics.Therefore,raising clinicians’awareness of the potential risk of ventilator-ind...The operating room is a unique environment where surgery exposes patients to non-physiological changes that can compromise lung mechanics.Therefore,raising clinicians’awareness of the potential risk of ventilator-induced lung injury(VILI)is mandatory.Driving pressure is a useful tool for reducing lung complications in patients with acute respiratory distress syndrome and those undergoing elective surgery.Driving pressure has been most extensively studied in the context of single-lung ventilation during thoracic surgery.However,the awareness of association of VILI risk and patient positioning(prone,beach-chair,parkbench)and type of surgery must be raised.展开更多
BACKGROUND As one of the major abdominal operations,pancreaticoduodenectomy(PD)involves many organs.The operation is complex,and the scope of the operation is large,which can cause significant trauma in patients.The o...BACKGROUND As one of the major abdominal operations,pancreaticoduodenectomy(PD)involves many organs.The operation is complex,and the scope of the operation is large,which can cause significant trauma in patients.The operation has a high rate of complications.Pancreatic leakage is the main complication after PD.When pancreatic leakage occurs after PD,it can often lead to abdominal bleeding and infection,threatening the lives of patients.One study found that pancreatic leakage was affected by many factors including the choice of pancreaticojejunostomy method which can be well controlled.AIM To investigate the choice of operative methods for pancreaticojejunostomy and to conduct a multivariate study of pancreatic leakage in PD.METHODS A total of 420 patients undergoing PD in our hospital from January 2014 to March 2019 were enrolled and divided into group A(n=198)and group B(n=222)according to the pancreatointestinal anastomosis method adopted during the operation.Duct-to-mucosa pancreatojejunostomy was performed in group A and bundled pancreaticojejunostomy was performed in group B.The operation time,intraoperative blood loss,and pancreatic leakage of the two groups were assessed.The occurrence of pancreatic leakage after the operation in different patients was analyzed.RESULTS The differences in operative time and intraoperative bleeding between groups A and B were not significant(P>0.05).In group A,the time of pancreatojejunostomy was 26.03±4.40 min and pancreatic duct diameter was 3.90±1.10 mm.These measurements were significantly higher than those in group B(P<0.05).The differences in the occurrence of pancreatic leakage,abdominal infection,abdominal hemorrhage and gastric retention between group A and group B were not significant(P>0.05).The rates of pancreatic leakage in patients with preoperative albumin<30 g/L,preoperative jaundice time≥8 wk,and pancreatic duct diameter<3 mm,were 23.33%,33.96%,and 19.01%,respectively.These were significantly higher than those in patients with preoperative albumin≥30 g/L,preoperative jaundice time<8 wk,and pancreatic duct diameter≥3 cm(P<0.05).Logistic regression analysis showed that preoperative albumin<30 g/L,preoperative jaundice time≥8 wk,and pancreatic duct diameter<3 mm were risk factors for pancreatic leakage after PD(odds ratio=2.038,2.416 and 2.670,P<0.05).CONCLUSION The pancreatointestinal anastomosis method during PD has no significant effect on the occurrence of pancreatic leakage.The main risk factors for pancreatic leakage include preoperative albumin,preoperative jaundice time,and pancreatic duct diameter.展开更多
Objective:To explore the application effect of video assessment method in clinical nurses’nursing operation skills.Method:To select 58 nurses who participated in the individual soldier standard in the children’s hos...Objective:To explore the application effect of video assessment method in clinical nurses’nursing operation skills.Method:To select 58 nurses who participated in the individual soldier standard in the children’s hospital in 2019 and 2020 as the research objects,among which the nurses who participated in the individual soldier standard in 2019 were the nurses who participated in the individual soldier standard in 2019 and 2020.A total of 29 people in the first batch were set as the control group,using traditional assessment methods.In 2020,the second batch of 29 nurses who participated in the individual soldier standard reached the experimental group.Using the video assessment method,there was no significant difference in general information between the two groups(P>0.05).After the assessment,the scores,coping with work pressure,and proactiveness of the two groups of research subjects were compared.Results:The experimental group’s nursing operation assessment scores,coping with work pressure,and proactiveness were significantly better than those of the control group,the difference was statistically significant(P<0.05).Conclusion:The application of the video assessment method improves the passing rate of nurses’operational skills examination,enhances nurses’initiative in learning,reduces examination pressure,and can be accurately,timely,and safely applied to clinical nursing work,which is worthy of study and promotion.展开更多
Objective:Clinical education plays a key role in preparing students for patient care.Laparoscopy is one of the most important minimally invasive surgeries(MISs)wherein surgical technologists are responsible for camera...Objective:Clinical education plays a key role in preparing students for patient care.Laparoscopy is one of the most important minimally invasive surgeries(MISs)wherein surgical technologists are responsible for camera navigation and assistant surgeons are responsible for peg transfer.Therefore,it is necessary to improve the attitude of the operating room students toward these skills during their study period.The present study was conducted to determine the effect of simulating training in the fundamentals of laparoscopic surgery(FLS)on the attitude of the operating room students.Methods:This interventional study was conducted on 28 operating room students of Iran University of Medical Sciences in 2019.The census sampling method was used.The data-collection tool included the“Intrinsic motivation inventory(IMI)questionnaire.”The educational intervention was carried out in theoretical(booklet design)and practical(simulation)sections.Data analysis was carried out using descriptive and inferential analyses including the paired t-test,Mann–Whitney U test,and independent t-test.The collected data were analyzed using R and SPSS software.P-value<0.05 was considered as the significant level.Results:The mean±SD of the participants'age was 22.93±2.14 years,and the majority of them were women(67.9%).There was a significant difference in the mean scores of students'attitudes toward the FLS before and after the educational intervention(P<0.001)in all dimensions(interest,perceived competence,perceived choice,and tension).There was also a significant correlation between gender and interest dimension(P=0.005).Conclusions:The results of the present study showed that simulating the training FLS curriculum positively affects students'attitudes.Therefore,the researchers suggest that for creating a positive attitude,increasing students'interest in laparoscopic surgery,and ensuring a more effective presence in the operating room,this training should be considered in the operating room curriculum.展开更多
The rapid development of digital education provides new opportunities and challenges for teaching model innovation.This study aims to explore the application of the BOPPPS(Bridge-in,Objective,Pre-assessment,Participat...The rapid development of digital education provides new opportunities and challenges for teaching model innovation.This study aims to explore the application of the BOPPPS(Bridge-in,Objective,Pre-assessment,Participatory learning,Post-assessment,Summary)teaching method in the development of a blended teaching model for the Operations Research course under the background of digital education.In response to the characteristics of the course and the needs of the student group,the teaching design is reconstructed with a student-centered approach,increasing practical teaching links,improving the assessment and evaluation system,and effectively implementing it in conjunction with digital educational technology.This teaching model has shown significant effectiveness in the context of digital education,providing valuable experience and insights for the innovation of the Operations Research course.展开更多
Concomitant with the advancement of contemporary medical technology,the significance of perioperative nursing has been increasingly accentuated,necessitating elevated standards for the pedagogy of perioperative nursin...Concomitant with the advancement of contemporary medical technology,the significance of perioperative nursing has been increasingly accentuated,necessitating elevated standards for the pedagogy of perioperative nursing.Presently,the PBL(problem-based learning)pedagogical approach,when integrated with CBL(case-based learning),has garnered considerable interest.An extensive literature review has been conducted to analyze the application of the PBL-CBL fusion in the education of perioperative nursing.Findings indicate that this integrative teaching methodology not only enhances students’theoretical knowledge,practical competencies,and collaborative skills but also contributes to the elevation of teaching quality.In conclusion,the PBL-CBL teaching approach holds immense potential for broader application in perioperative nursing education.Nevertheless,it is imperative to continually refine this combined pedagogical strategy to further enhance the caliber of perioperative nursing instruction and to cultivate a greater number of exceptional nursing professionals in the operating room setting.展开更多
We discuss the incomplete semi-iterative method (ISIM) for an approximate solution of a linear fixed point equations x=Tx+c with a bounded linear operator T acting on a complex Banach space X such that its resolvent h...We discuss the incomplete semi-iterative method (ISIM) for an approximate solution of a linear fixed point equations x=Tx+c with a bounded linear operator T acting on a complex Banach space X such that its resolvent has a pole of order k at the point 1. Sufficient conditions for the convergence of ISIM to a solution of x=Tx+c, where c belongs to the range space of R(I-T) k, are established. We show that the ISIM has an attractive feature that it is usually convergent even when the spectral radius of the operator T is greater than 1 and Ind 1T≥1. Applications in finite Markov chain is considered and illustrative examples are reported, showing the convergence rate of the ISIM is very high.展开更多
The Oral and maxillofacial region is one of the complex regions of the body considering the vast anatomical structures that are found in this region;head and neck surgery has potential for many complications, yet inad...The Oral and maxillofacial region is one of the complex regions of the body considering the vast anatomical structures that are found in this region;head and neck surgery has potential for many complications, yet inadequate information on occurrence of post-operative complications in oral and maxillofacial surgeries in our setting has been documented. The aim of this study was to determine the occurrence of common early post-operative complications after oral and maxillofacial surgery in relationship to the underlying systemic condition. A descriptive postoperative study was done whereby patients who underwent oral and maxillofacial surgery were included. The included patients were those who underwent surgery for different pathological conditions, trauma, developmental/congenital conditions and inflammatory conditions to mention few. Demographic data, complications developed within one week post operative, and underlying systemic comorbidities before and after surgery were documented and analysed. A total of 102 patients were included in the study. The mean age of participants was 30.00 ± 17.01 years with a range of 2 to 81 years. Majority 43.1% (n = 44) had benign tumors with a leading diagnosis of ameloblastoma. In general, the most common complications which were noted in the cases included Pain 98% (n = 100) and Post-operative Swelling 97.1% (n = 99). The presence of underlying systemic comorbid conditions has a significant role in occurrence of some severe complications. The occurrence of complications does increase the duration of stay in the hospital hence increasing cost of treatment for which bearers are both patients and the hospital.展开更多
We introduce multilevel augmentation methods for solving operator equations based on direct sum decompositions of the range space of the operator and the solution space of the operator equation and a matrix splitting ...We introduce multilevel augmentation methods for solving operator equations based on direct sum decompositions of the range space of the operator and the solution space of the operator equation and a matrix splitting scheme. We establish a general setting for the analysis of these methods, showing that the methods yield approximate solutions of the same convergence order as the best approximation from the subspace. These augmentation methods allow us to develop fast, accurate and stable nonconventional numerical algorithms for solving operator equations. In particular, for second kind equations, special splitting techniques are proposed to develop such algorithms. These algorithms are then applied to solve the linear systems resulting from matrix compression schemes using wavelet-like functions for solving Fredholm integral equations of the second kind. For this special case, a complete analysis for computational complexity and convergence order is presented. Numerical examples are included to demonstrate the efficiency and accuracy of the methods. In these examples we use the proposed augmentation method to solve large scale linear systems resulting from the recently developed wavelet Galerkin methods and fast collocation methods applied to integral equations of the secondkind. Our numerical results confirm that this augmentation method is particularly efficient for solving large scale linear systems induced from wavelet compression schemes.展开更多
This paper presents an elasto-viscoplastic consistent tangent operator (CTO) based boundary element formulation, and application for calculation of path-domain independentJ integrals (extension of the classicalJ integ...This paper presents an elasto-viscoplastic consistent tangent operator (CTO) based boundary element formulation, and application for calculation of path-domain independentJ integrals (extension of the classicalJ integrals) in nonlinear crack analysis. When viscoplastic deformation happens, the effective stresses around the crack tip in the nonlinear region is allowed to exceed the loading surface, and the pure plastic theory is not suitable for this situation. The concept of consistency employed in the solution of increment viscoplastic problem, plays a crucial role in preserving the quadratic rate asymptotic convergence of iteractive schemes based on Newton's method. Therefore, this paper investigates the viscoplastic crack problem, and presents an implicit viscoplastic algorithm using the CTO concept in a boundary element framework for path-domain independentJ integrals. Applications are presented with two numerical examples for viscoplastic crack problems andJ integrals.展开更多
An important problem in the eviluation of acupuncture has been the difficulty in defining and designingan appropriate control group.In order to examine our methodoly for a control group,patientswith one mandibular thi...An important problem in the eviluation of acupuncture has been the difficulty in defining and designingan appropriate control group.In order to examine our methodoly for a control group,patientswith one mandibular third molar extraction were randomly assigned to an acupuncture group or aplacebo acupuncture group.The following acupuncture points were used in which the needles werePlaced ipsilateral to the tooth extraction side:Hegu(LI4),Jiache(ST 6),Xiaguan(ST展开更多
基金supported by the National Natural Science Foundation of China(No.50176051)the State Key Development Program for Basic Research of China(No.2000026306).
文摘Three experiments of static state storage method, low-temperature and constant-pressure storage method and low-temperature and constant-pressure storage method were carried out to investigate which method was best in gas hydrate. The relationships of hydrate rate, capacity and liquid temperature versus time were derived and three results were contrasted. The experimental results show lowtemperature and constant-pressure method is better than the other two methods because it's operation period is shorter and storage capacity is larger than the other two. Low-temperature and constant-pressure method is the best method. So new method will be new research objective.
文摘AIM: To establish a scoring system for predicting the incidence of postoperative complications and mortality in general surgery based on the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM), and to evaluate its efficacy. METHODS: Eighty-four patients with postoperative complications or death and 172 patients without postoperative complications, who underwent surgery in our department during the previous 2 years, were retrospectively analyzed by logistic regression. Fifteen indexes were investigated including age, cardiovascular function, respiratory function, blood test results, endocrine function, central nervous system function, hepatic function, renal function, nutritional status, extent of operative trauma, and course of anesthesia. Modified POSSUM (M-POSSUM) was developed using significant risk factors with its efficacy evaluated. RESULTS: The significant risk factors were found to be age, cardiovascular function, respiratory function, hepatic function, renal function, blood test results, endocrine function, nutritional status, duration of operation, intraoperative blood loss, and course of anesthesia. These factors were all included in the scoring system. There were significant differences in the scores between the patients with and without postoperative complications, between the patients died and survived with complications, and between the patients died and survived without complications. The receiver operating characteristic curves showed that the M-POSSUM could accurately predict postoperative complications and mortality.CONCLUSION: M-POSSUM correlates well with postoperative complications and mortality, and is more accurate than POSSUM.
文摘Introduction: Perioperative hypothermia in cardiac surgery is associated with adverse outcome. The aim of this investigation was to study whether an underbody forced-air warming blanket during coronary artery bypass graft surgery with normothermic cardiopulmonary bypass can prevent postoperative hypothermia. Methods: After Medical Ethics Committee approval, 60 low-risk cardiac surgery patients at random were assigned into a group that received standard thermal care management (control group n = 30) and a group that received the underbody forced-air warming system plus the standard thermal care (intervention group n = 30). Results: The temperature after-drop from the end of cardiopulmonary bypass to arrival in the ICU was less in the intervention group versus control group (0.4°C ± 0.3°C vs 0.6°C ± 0.4°C;P = 0.027). Out of the intervention group, 27 patients arrived in the ICU with a bladder temperature ? 36°C (90%) as compared to 14 patients (46.7%) from the control group (P < 0.001). The peripheral temperature was significantly higher in the intervention group as compared to the control group (P < 0.001). Conclusions: A full underbody forced-air warming blanket prevents postoperative hypothermia in normothermic coronary artery bypass graft surgery patients.
文摘In this paper, a modified Newton type iterative method is considered for ap- proximately solving ill-posed nonlinear operator equations involving m-accretive mappings in Banach space. Convergence rate of the method is obtained based on an a priori choice of the regularization parameter. Our analysis is not based on the sequential continuity of the normalized duality mapping.
基金Supported by the National Natural Science Foundation of China (10371082)Chinese National Natural Science Foundation Committee Tianyuan Foundation (10526040)Guangzhou University Doctor Foundation (WXF-1001)
文摘The convergence of several Galerkin-Petrov methods, including polynomial collocation and analytic element collocation methods of Toeplitz operators on Dirichlet space, is established. In particular, it is shown that such methods converge if the basis and test function own certain circular symmetry.
文摘Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed.
基金The NSF(0611005)of Jiangxi Province and the SF(2007293)of Jiangxi Provincial Education Department.
文摘In this paper we develop two multilevel iteration methods for solving linear systems resulting from the Galerkin method and Tikhonov regularization for linear ill-posed problems. The two algorithms and their convergence analyses are presented in an abstract framework.
文摘BACKGROUND Bariatric surgery is one of the most effective ways to treat morbid obesity,and postoperative nausea and vomiting(PONV)is one of the common complications after bariatric surgery.At present,the mechanism of the high incidence of PONV after weight-loss surgery has not been clearly explained,and this study aims to investigate the effect of surgical position on PONV in patients undergoing bariatric surgery.AIM To explore the effect of the operative position during bariatric surgery on PONV.METHODS Data from obese patients,who underwent laparoscopic sleeve gastrectomy(LSG)in the authors’hospital between June 2020 and February 2022 were divided into 2 groups and retrospectively analyzed.Multivariable logistic regression analysis and the t-test were used to study the influence of operative position on PONV.RESULTS There were 15 cases of PONV in the supine split-leg group(incidence rate,50%)and 11 in the supine group(incidence rate,36.7%)(P=0.297).The mean operative duration in the supine split-leg group was 168.23±46.24 minutes and 140.60±32.256 minutes in the supine group(P<0.05).Multivariate analysis revealed that operative position was not an independent risk factor for PONV(odds ratio=1.192,95%confidence interval:0.376-3.778,P=0.766).CONCLUSION Operative position during LSG may affect PONV;however,the difference in the incidence of PONV was not statistically significant.Operative position should be carefully considered for obese patients before surgery.
文摘Objective:While a rushed operation can omit essential procedures,prolonged operative time results in higher morbidity.Nevertheless,the optimal operative time range remains uncertain.This study aimed to estimate the ideal operative time range and evaluate its applicability in laparoscopic cancer surgery.Methods:A prospectively collected multicenter database of 397 patients who underwent laparoscopic distal gastrectomy were retrospectively reviewed.The ideal operative time range was statistically calculated by separately analyzing the operative time of uneventful surgeries.Finally,intraoperative and postoperative outcomes were compared among the shorter,ideal,and longer operative time groups.Results:The statistically calculated ideal operative time was 135.4-165.4 min.The longer operative time(LOT)group had a lower rate of uneventful,perfect surgery than the ideal or shorter operative time(IOT/SOT)group(2.8%vs.8.8%and 2.2%vs.13.4%,all P<0.05).Longer operative time increased bleeding,postoperative morbidities,and delayed diet and discharge(all P<0.05).Particularly,an uneventful,perfect surgery could not be achieved when the operative time exceeded 240 min.Regardless of ideal time range,SOT group achieved the highest percentage of uneventful surgery(13.4%),which was possible by surgeon's ability to retrieve a higher number of lymph nodes and perform≥150 gastrectomies annually.Conclusions:Operative time longer than the ideal time range(especially≥240 min)should be avoided.If the essential operative procedure were faithfully conducted without compromising oncological safety,an operative time shorter than the ideal range leaded to a better prognosis.Efforts to minimize operative time should be attempted with sufficient surgical experience.
文摘The operating room is a unique environment where surgery exposes patients to non-physiological changes that can compromise lung mechanics.Therefore,raising clinicians’awareness of the potential risk of ventilator-induced lung injury(VILI)is mandatory.Driving pressure is a useful tool for reducing lung complications in patients with acute respiratory distress syndrome and those undergoing elective surgery.Driving pressure has been most extensively studied in the context of single-lung ventilation during thoracic surgery.However,the awareness of association of VILI risk and patient positioning(prone,beach-chair,parkbench)and type of surgery must be raised.
基金Scientific Research Programme for Health Commission of Jiangxi Province,No.20204269.
文摘BACKGROUND As one of the major abdominal operations,pancreaticoduodenectomy(PD)involves many organs.The operation is complex,and the scope of the operation is large,which can cause significant trauma in patients.The operation has a high rate of complications.Pancreatic leakage is the main complication after PD.When pancreatic leakage occurs after PD,it can often lead to abdominal bleeding and infection,threatening the lives of patients.One study found that pancreatic leakage was affected by many factors including the choice of pancreaticojejunostomy method which can be well controlled.AIM To investigate the choice of operative methods for pancreaticojejunostomy and to conduct a multivariate study of pancreatic leakage in PD.METHODS A total of 420 patients undergoing PD in our hospital from January 2014 to March 2019 were enrolled and divided into group A(n=198)and group B(n=222)according to the pancreatointestinal anastomosis method adopted during the operation.Duct-to-mucosa pancreatojejunostomy was performed in group A and bundled pancreaticojejunostomy was performed in group B.The operation time,intraoperative blood loss,and pancreatic leakage of the two groups were assessed.The occurrence of pancreatic leakage after the operation in different patients was analyzed.RESULTS The differences in operative time and intraoperative bleeding between groups A and B were not significant(P>0.05).In group A,the time of pancreatojejunostomy was 26.03±4.40 min and pancreatic duct diameter was 3.90±1.10 mm.These measurements were significantly higher than those in group B(P<0.05).The differences in the occurrence of pancreatic leakage,abdominal infection,abdominal hemorrhage and gastric retention between group A and group B were not significant(P>0.05).The rates of pancreatic leakage in patients with preoperative albumin<30 g/L,preoperative jaundice time≥8 wk,and pancreatic duct diameter<3 mm,were 23.33%,33.96%,and 19.01%,respectively.These were significantly higher than those in patients with preoperative albumin≥30 g/L,preoperative jaundice time<8 wk,and pancreatic duct diameter≥3 cm(P<0.05).Logistic regression analysis showed that preoperative albumin<30 g/L,preoperative jaundice time≥8 wk,and pancreatic duct diameter<3 mm were risk factors for pancreatic leakage after PD(odds ratio=2.038,2.416 and 2.670,P<0.05).CONCLUSION The pancreatointestinal anastomosis method during PD has no significant effect on the occurrence of pancreatic leakage.The main risk factors for pancreatic leakage include preoperative albumin,preoperative jaundice time,and pancreatic duct diameter.
文摘Objective:To explore the application effect of video assessment method in clinical nurses’nursing operation skills.Method:To select 58 nurses who participated in the individual soldier standard in the children’s hospital in 2019 and 2020 as the research objects,among which the nurses who participated in the individual soldier standard in 2019 were the nurses who participated in the individual soldier standard in 2019 and 2020.A total of 29 people in the first batch were set as the control group,using traditional assessment methods.In 2020,the second batch of 29 nurses who participated in the individual soldier standard reached the experimental group.Using the video assessment method,there was no significant difference in general information between the two groups(P>0.05).After the assessment,the scores,coping with work pressure,and proactiveness of the two groups of research subjects were compared.Results:The experimental group’s nursing operation assessment scores,coping with work pressure,and proactiveness were significantly better than those of the control group,the difference was statistically significant(P<0.05).Conclusion:The application of the video assessment method improves the passing rate of nurses’operational skills examination,enhances nurses’initiative in learning,reduces examination pressure,and can be accurately,timely,and safely applied to clinical nursing work,which is worthy of study and promotion.
基金supported by the Iran University of Medical Science。
文摘Objective:Clinical education plays a key role in preparing students for patient care.Laparoscopy is one of the most important minimally invasive surgeries(MISs)wherein surgical technologists are responsible for camera navigation and assistant surgeons are responsible for peg transfer.Therefore,it is necessary to improve the attitude of the operating room students toward these skills during their study period.The present study was conducted to determine the effect of simulating training in the fundamentals of laparoscopic surgery(FLS)on the attitude of the operating room students.Methods:This interventional study was conducted on 28 operating room students of Iran University of Medical Sciences in 2019.The census sampling method was used.The data-collection tool included the“Intrinsic motivation inventory(IMI)questionnaire.”The educational intervention was carried out in theoretical(booklet design)and practical(simulation)sections.Data analysis was carried out using descriptive and inferential analyses including the paired t-test,Mann–Whitney U test,and independent t-test.The collected data were analyzed using R and SPSS software.P-value<0.05 was considered as the significant level.Results:The mean±SD of the participants'age was 22.93±2.14 years,and the majority of them were women(67.9%).There was a significant difference in the mean scores of students'attitudes toward the FLS before and after the educational intervention(P<0.001)in all dimensions(interest,perceived competence,perceived choice,and tension).There was also a significant correlation between gender and interest dimension(P=0.005).Conclusions:The results of the present study showed that simulating the training FLS curriculum positively affects students'attitudes.Therefore,the researchers suggest that for creating a positive attitude,increasing students'interest in laparoscopic surgery,and ensuring a more effective presence in the operating room,this training should be considered in the operating room curriculum.
文摘The rapid development of digital education provides new opportunities and challenges for teaching model innovation.This study aims to explore the application of the BOPPPS(Bridge-in,Objective,Pre-assessment,Participatory learning,Post-assessment,Summary)teaching method in the development of a blended teaching model for the Operations Research course under the background of digital education.In response to the characteristics of the course and the needs of the student group,the teaching design is reconstructed with a student-centered approach,increasing practical teaching links,improving the assessment and evaluation system,and effectively implementing it in conjunction with digital educational technology.This teaching model has shown significant effectiveness in the context of digital education,providing valuable experience and insights for the innovation of the Operations Research course.
文摘Concomitant with the advancement of contemporary medical technology,the significance of perioperative nursing has been increasingly accentuated,necessitating elevated standards for the pedagogy of perioperative nursing.Presently,the PBL(problem-based learning)pedagogical approach,when integrated with CBL(case-based learning),has garnered considerable interest.An extensive literature review has been conducted to analyze the application of the PBL-CBL fusion in the education of perioperative nursing.Findings indicate that this integrative teaching methodology not only enhances students’theoretical knowledge,practical competencies,and collaborative skills but also contributes to the elevation of teaching quality.In conclusion,the PBL-CBL teaching approach holds immense potential for broader application in perioperative nursing education.Nevertheless,it is imperative to continually refine this combined pedagogical strategy to further enhance the caliber of perioperative nursing instruction and to cultivate a greater number of exceptional nursing professionals in the operating room setting.
基金Project1 990 1 0 0 6 supported by National Natural Science Foundation of China,Doctoral Foundation of China,Chi-na Scholarship council and Laboratory of Computational Physics in Beijing of Chinathe second author is also supportedby the State Major Key
文摘We discuss the incomplete semi-iterative method (ISIM) for an approximate solution of a linear fixed point equations x=Tx+c with a bounded linear operator T acting on a complex Banach space X such that its resolvent has a pole of order k at the point 1. Sufficient conditions for the convergence of ISIM to a solution of x=Tx+c, where c belongs to the range space of R(I-T) k, are established. We show that the ISIM has an attractive feature that it is usually convergent even when the spectral radius of the operator T is greater than 1 and Ind 1T≥1. Applications in finite Markov chain is considered and illustrative examples are reported, showing the convergence rate of the ISIM is very high.
文摘The Oral and maxillofacial region is one of the complex regions of the body considering the vast anatomical structures that are found in this region;head and neck surgery has potential for many complications, yet inadequate information on occurrence of post-operative complications in oral and maxillofacial surgeries in our setting has been documented. The aim of this study was to determine the occurrence of common early post-operative complications after oral and maxillofacial surgery in relationship to the underlying systemic condition. A descriptive postoperative study was done whereby patients who underwent oral and maxillofacial surgery were included. The included patients were those who underwent surgery for different pathological conditions, trauma, developmental/congenital conditions and inflammatory conditions to mention few. Demographic data, complications developed within one week post operative, and underlying systemic comorbidities before and after surgery were documented and analysed. A total of 102 patients were included in the study. The mean age of participants was 30.00 ± 17.01 years with a range of 2 to 81 years. Majority 43.1% (n = 44) had benign tumors with a leading diagnosis of ameloblastoma. In general, the most common complications which were noted in the cases included Pain 98% (n = 100) and Post-operative Swelling 97.1% (n = 99). The presence of underlying systemic comorbid conditions has a significant role in occurrence of some severe complications. The occurrence of complications does increase the duration of stay in the hospital hence increasing cost of treatment for which bearers are both patients and the hospital.
基金Supported in part by the Natural Science Foundation of China under grants 10371137and 10201034Foundation of Doctoral Program of National Higher Education of China under under grant 20030558008Guangdong Provincial Natural Science Foundation of China u
文摘We introduce multilevel augmentation methods for solving operator equations based on direct sum decompositions of the range space of the operator and the solution space of the operator equation and a matrix splitting scheme. We establish a general setting for the analysis of these methods, showing that the methods yield approximate solutions of the same convergence order as the best approximation from the subspace. These augmentation methods allow us to develop fast, accurate and stable nonconventional numerical algorithms for solving operator equations. In particular, for second kind equations, special splitting techniques are proposed to develop such algorithms. These algorithms are then applied to solve the linear systems resulting from matrix compression schemes using wavelet-like functions for solving Fredholm integral equations of the second kind. For this special case, a complete analysis for computational complexity and convergence order is presented. Numerical examples are included to demonstrate the efficiency and accuracy of the methods. In these examples we use the proposed augmentation method to solve large scale linear systems resulting from the recently developed wavelet Galerkin methods and fast collocation methods applied to integral equations of the secondkind. Our numerical results confirm that this augmentation method is particularly efficient for solving large scale linear systems induced from wavelet compression schemes.
基金The project supported by National Natural Science Foundation of China(9713008)Zhejiang Natural Science Foundation Special Funds No. RC.9601
文摘This paper presents an elasto-viscoplastic consistent tangent operator (CTO) based boundary element formulation, and application for calculation of path-domain independentJ integrals (extension of the classicalJ integrals) in nonlinear crack analysis. When viscoplastic deformation happens, the effective stresses around the crack tip in the nonlinear region is allowed to exceed the loading surface, and the pure plastic theory is not suitable for this situation. The concept of consistency employed in the solution of increment viscoplastic problem, plays a crucial role in preserving the quadratic rate asymptotic convergence of iteractive schemes based on Newton's method. Therefore, this paper investigates the viscoplastic crack problem, and presents an implicit viscoplastic algorithm using the CTO concept in a boundary element framework for path-domain independentJ integrals. Applications are presented with two numerical examples for viscoplastic crack problems andJ integrals.
文摘An important problem in the eviluation of acupuncture has been the difficulty in defining and designingan appropriate control group.In order to examine our methodoly for a control group,patientswith one mandibular third molar extraction were randomly assigned to an acupuncture group or aplacebo acupuncture group.The following acupuncture points were used in which the needles werePlaced ipsilateral to the tooth extraction side:Hegu(LI4),Jiache(ST 6),Xiaguan(ST