As oil and gas exploration moves into deeper waters,marine risers are subjected to increasingly complex service conditions,including vessel motions,ocean currents,seabed-soil interactions,and internal flow effects.Thi...As oil and gas exploration moves into deeper waters,marine risers are subjected to increasingly complex service conditions,including vessel motions,ocean currents,seabed-soil interactions,and internal flow effects.This work establishes a dynamic behavior model of steel catenary risers(SCRs)with varying curvatures subjected to internal flow and external currents and considers the effects of pipe-soil interactions on the curvature profile.The governing equation is solved via the generalized integral transform technique(GITT),which yields a semi-analytical solution of a high-order nonlinear partial differential equation.Parametric studies are then performed to analyze the effects of varying curvature on the vibration frequency and amplitude of SCRs.The vibration frequency and amplitude increase with the touchdown angle and hang-off angle,although the effect of the hang-off angle is negligible.Additionally,as the curvature increases along the centerline axis,the position of the maximum amplitude of the SCR moves upward.展开更多
BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of cor...BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.展开更多
Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decada...Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decadalscale compound heatwavedrought events remain debated.Here,using reconstructions and simulations from the Community Earth System Model Last Millennium Ensemble,we demonstrate that,over the last millennium,decadal droughts on the MP occurred under both warm and cold conditions,differing from recent compound heatwavedrought events.We found that by examining temperature changes during these drought periods,the distinct influences of external forcings and internal variability can be simply and effectively distinguished.Specifically,colddry events were primarily driven by volcanic eruptions that weakened the East Asian summer monsoon and midlatitude westerlies,reducing moisture transport to the MP.In contrast,warmdry events were predominantly induced by internal variability,notably the negative phase of the Atlantic Multidecadal Oscillation and the expansion of the Barents Sea ice extent.The recent extreme compound event was probably influenced by the combined effects of anthropogenic forcings and internal variability.These findings deepen our understanding of how external forcings and internal variability affect decadal drought events on the MP and highlight that recent compound events are unprecedented in the context of the last millennium.展开更多
BACKGROUND Postoperative pancreatic fistula(POPF)is the most frequent cause of morbimortality after pancreaticoduodenectomy,but the best technique to use to prevent its development is unclear.The choice of drainage me...BACKGROUND Postoperative pancreatic fistula(POPF)is the most frequent cause of morbimortality after pancreaticoduodenectomy,but the best technique to use to prevent its development is unclear.The choice of drainage method external duct stent(EDS),internal duct stent(IDS),or non-ductal stent(NDS)is also controversial.AIM To compare the three groups(EDS,IDS and NDS),analyzing the patient characteristics,perioperative examinations and survival.METHODS Patients who underwent pancreaticoduodenectomy and pancreaticojejunostomy between 2012 and 2020,were divided into the EDS,IDS and NDS groups.RESULTS Of the 244 patients included,129 were in the EDS group,71 in the IDS group,and 44 in the NDS group.Except for preoperative pancreatitis in the NDS patients,comorbidities were similar among the groups.Patients in the NDS group had a high caliber of the Wirsung duct and frequently presented with a hard pancreas(P<0.001).A lower rate of grade C POPF was observed in the EDS(1.6%)compared to the NDS(9.1%)and IDS group(14.1%)(P=0.009).The groups showed similar findings for delayed gastric emptying,postoperative hemorrhage,reoperation,and 5-year survivals.Ninety-day mortality rate was significantly higher in the IDS group(5.6%)compared to the EDS(1.6%)and NDS(4.5%)groups(P=0.046).Multivariate analysis showed that the use of EDS was a protective factor for grade B/C POPF(P=0.034),and 90-day mortality(P=0.018).Additionally,a Wirsung duct diameter<3 mm was the only risk factor for grade B/C POPF(P=0.001),and 90-day mortality(P=0.031).CONCLUSION The use of the EDS was a protective factor for grade B/C POPF and 90-day mortality,and the Wirsung duct<3 mm was a risk factor for grade B/C POPF and 90-day mortality.展开更多
In the domain of gas adsorption and separation,microporous materials have garnered considerable attention due to their elevated specific surface area and pore structure[1].And the dissolution of gases in liquids is li...In the domain of gas adsorption and separation,microporous materials have garnered considerable attention due to their elevated specific surface area and pore structure[1].And the dissolution of gases in liquids is limited by unstable liquid-phase pores and weak gas-liquid interactions,which leads to low solubility.However,conventional microporous materials are predominantly solid-state,which complicates their direct adsorption and separation application in liquid environments.展开更多
OBJECTIVE:To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected,aiming to provide a theoretical ...OBJECTIVE:To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected,aiming to provide a theoretical basis for clinical diagnosis and treatment.METHODS:We retrospectively analyzed the data of patients who underwent electronic colonoscopy and were found to have colorectal polyps at the Gastrointestinal Endoscopy Center of Dongfang Hospital,Beijing University of Chinese Medicine,from January 1,2017,to December 31,2023.We also reviewed their lung CT results and used statistical software to analyze the recurrence,location,size,and pathology of colorectal polyps in relation to the presence,number,and size of pulmonary nodules.RESULTS:Both colorectal polyps and pulmonary nodules are more common in elderly males.Patients with recurrent colorectal polyps are more likely to have pulmonary nodules,which tend to be located in the left colon and are more likely to be adenomatous in nature;those without pulmonary nodules show no clear pattern in polyp distribution,with a tendency towards inflammatory and hyperplastic pathology;the data from this study suggests that the proportion of lung nodules larger than 0.5 cm in the recurrent group is higher than in the non-recurrent group,and the proportion of colorectal polyps larger than 1 cm in the recurrent group is also higher than in the non-recurrent group.CONCLUSION:There is a certain connection between the pathogenesis and treatment of colorectal polyps and pulmonary nodules.Cold,phlegm,dampness,blood stasis,and toxic coagulation are common pathogenic factors of the two diseases.Patients with larger colorectal polyps should be advised to undergo regular colonoscopy.Patients with recurrent polyps or those with left colon necrosis or cancer indicated by colonoscopy should be advised to complete lung related examinations to rule out the possibility of pulmonary nodules.展开更多
Artificial Intelligence(AI),as a strategic technology leading the new round of scientific and technological revolution and industrial transformation,is reshaping the global power dynamics.Major countries are accelerat...Artificial Intelligence(AI),as a strategic technology leading the new round of scientific and technological revolution and industrial transformation,is reshaping the global power dynamics.Major countries are accelerating their strategic deployment around technological innovation,standard-setting,and rule-building,making technology increasingly intertwined with geopolitics.Since the U.S.released Preparing for the Future of Artificial Intelligence in 2016,it has integrated AI into its national strategic system and continuously upgraded it,aiming to maintain its dominance in the global competition.Meanwhile,the internal and external tensions of the U.S.AI strategy have become increasingly prominent,profoundly influencing its global strategy and future trajectory.展开更多
This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for ...This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels.展开更多
Materialist dialectics holds that internal causes are the basis of change and the external causes are the condition of change, and that external causes become operative through internal causes. This law can be applied...Materialist dialectics holds that internal causes are the basis of change and the external causes are the condition of change, and that external causes become operative through internal causes. This law can be applied into SLA. The internal causes and external causes influence SLA greatly. This paper mainly discusses the factors involved in SLA process.展开更多
External and internal rectal prolapse with their affiliated rectocele and enterocele, are associated with debilitating symptoms such as obstructed defecation, pelvic pain and faecal incontinence. Since perineal proced...External and internal rectal prolapse with their affiliated rectocele and enterocele, are associated with debilitating symptoms such as obstructed defecation, pelvic pain and faecal incontinence. Since perineal procedures are associated with a higher recurrence rate, an abdominal approach is commonly preferred. Despite the description of greater than three hundred different procedures, thus far no clear superiority of one surgical technique has been demonstrated. Ventral mesh rectopexy(VMR) is a relatively new and promising technique to correct rectal prolapse. In contrast to the abdominal procedures of past decades, VMR avoids posterolateral rectal mobilisation and thereby minimizes the risk of postoperative constipation. Because of a perceived acceptable recurrence rate, good functional results and low mesh-related morbidity in the short to medium term, VMR has been popularized in the past decade. Laparoscopic or robotic-assisted VMR is now being progressively performed internationally and several articles and guidelines propose the procedure as the treatment of choice for rectal prolapse. In this article, an outline of the current status of laparoscopic and robotic ventral mesh rectopexy for the treatment of internal and external rectal prolapse is presented.展开更多
Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out.However,the nonlinear characteristics of gear systems under combined internal ...Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out.However,the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated.An eight-degree-of-freedom(8-DOF)nonlinear spur gear-rotor-bearing model,which contains backlash,transmission error,eccentricity,gravity and input/output torque,is established,and the coupled lateral-torsional vibration characteristics are studied.Based on the equations of motion,the coupled spur gear-rotor-bearing system(SGRBS)is investigated using the Runge-Kutta numerical method,and the effects of rotational speed,error fluctuation and load fluctuation on the dynamic responses are explored.The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion,quasi-periodic motion,chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations.Significantly,the changing rotational speed could effectively control the vibration of the system.Vibration level increases with the increasing error fluctuation.Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase,the chaotic motion may be restricted.The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.展开更多
Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the thr...Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the three, followed by August and December. The Tws differences among walls with different orientation were higher in April and December when the weather tends to be sunny, and lower in August with more cloudy days in the time. In April and August, Tws of E-wall was the highest, followed by S- and N-wall. But in December Tws of S-wall might be sometimes higher than E one. Diurnal range of internal Tws was usually smaller than that of the external, with also a time lag for the occurrence of its maximum and minimum. The results can serve as a basis for further research on building microclimate and urban architecture designs. It also gives suggestions for similar studies in other areas.展开更多
The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of gr...The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively.展开更多
Applying the multidimensional Lindstedt-Poincare （MDLP） method, we study the forced vibrations with internal resonance of a clamped-clamped pipe conveying fluid under ex- ternal periodic excitation. The frequency-am...Applying the multidimensional Lindstedt-Poincare （MDLP） method, we study the forced vibrations with internal resonance of a clamped-clamped pipe conveying fluid under ex- ternal periodic excitation. The frequency-amplitude response curves of the first-mode resonance with internal resonance are obtained and its characteristics are discussed; moreover, the motions of the first two modes are also analyzed in detail. The present results reveal rich and complex dynamic behaviors caused by internal resonance and that some of the internal resonances are de- cided by the excitation amplitude. The MDLP method is also proved to be a simple and efficient technique to deal with nonlinear dynamics.展开更多
BACKGROUND Reconstruction of the pelvic ring anatomy in unstable anterior pelvic ring injuries is a significant step to reduce the mortality rate associated with these injuries efficiently.There is a debate on using e...BACKGROUND Reconstruction of the pelvic ring anatomy in unstable anterior pelvic ring injuries is a significant step to reduce the mortality rate associated with these injuries efficiently.There is a debate on using either an anterior subcutaneous pelvis internal fixator(INFIX)or an anterior supra-acetabular external fixator(EXFIX)to manage an unstable anterior pelvic ring fracture.AIM To compare the functional and radiological outcomes and complications of INFIX vs EXFIX in managing unstable pelvic ring injuries.METHODS A prospective cohort study included 54 patients with unstable pelvic ring fractures.The patients were divided into two groups;the INFIX group,in which 30 cases were fixed by INFIX,and the EXFIX group,in which 24 patients were treated by EXFIX.The average age in the EXFIX group was 31.17 years(16-57 years),while in the INFIX group,it was 34.5 years(17-53 years).The study included 20(66.7%)males and 10(33.3%)females in the INFIX group and 10(41.7%)males and 14(58.3%)females in the EXFIX group.The radiological outcomes were evaluated using Matta and Tornetta's score,and the functional outcomes using the Majeed score.RESULTS The results revealed a statistically significant difference between both groups(P=0.013)regarding radiological outcomes,according to Matta and Tornetta's score in favor of the INFIX group.Sitting,standing,and walking abilities were measured at a 3-mo follow-up visit using Majeed score modules.It was significantly better among the INFIX group than the EXFIX group in all three modules.At the final follow-up,both groups had no statistically significant difference according to the Majeed score;92.35 in the INFIX group and 90.99 in the EXFIX group(P=0.513).A lower surgical site infection rate was noticed in the INFIX group(P=0.007).CONCLUSION Anterior subcutaneous pelvis INFIX is associated with better radiological outcomes and a lower infection rate than anterior supra-acetabular EXFIX in managing patients with unstable anterior pelvic ring fractures.展开更多
To study the redistribution of endothelin- 1 (ET- 1) receptors in two subcellular organelles , the sarcolemmal membrane and the light vesicle, of rat heart during the progression of sepsis. Methods. Sepsis was induced...To study the redistribution of endothelin- 1 (ET- 1) receptors in two subcellular organelles , the sarcolemmal membrane and the light vesicle, of rat heart during the progression of sepsis. Methods. Sepsis was induced by cecal ligation and puncture (CLP). ET1 receptor was assayed by using [125I]- ET1 binding. Marker enzyme activities, protein yield, and dry- to- wet weight ratio of cardiac membranes were measured. Results. Septic rat heart exhibited two distinct phases: an initial hyperdynamic phase( 9h after CLP; early stage of sepsis) followed by a hypodynamic (18h after CLP, late stage of sepsis) phase. [125I]- ET1 binding study showed that during early stage of sepsis, the Bmax of ET1 receptors was increased by 30％ in sarcolemma but decreased by 19％ in light vesicles, while during late stage of sepsis, the Bmax was decreased by 24％ in sarcolemma but increased by 38％ in light vesicles.The total binding of sarcolemma and light vesicles was increased by 25％ during early stage of sepsis but decreased by 17％ during late stage of sepsis. Conclusions. These data indicated that ET1 receptors in the rat heart were externalized from light vesicles to sarcolemmal membranes during early hyperdynamic phase while internalized from surface membranes to intracellular compartment during late hypodynamic phase of sepsis.展开更多
Background: The triple arthrodesis was described early by Myerson in 1923 and has been the gold standard surgical procedure for various conditions with the goal to reduce pain, improve deformity and facilitate functio...Background: The triple arthrodesis was described early by Myerson in 1923 and has been the gold standard surgical procedure for various conditions with the goal to reduce pain, improve deformity and facilitate function. Methods: The procedure consists of fusion of the subtalar joint, talonavicular joint and calcaneocuboid joint [1]. The procedure is traditionally done with internal fixation, however, Marinet al. has shown it to be performed with external fixation [2]. Dr. Marin and the associates have developed an alternative technique to perform a triple arthrodesis using internal and external fixation. This paper describes a step-by-step technique to perform a triple arthrodesis with both internal and external fixation. It will demonstrate the use of the prefabricated arches on the footplate for more precise and accurate placement of transosseous wires using arch-wire technique [3]. Results/Conclusion: We believe this technique will not only help increase the ability to achieve fusion with a less chance of non-union, but may also decrease healing time, which may allow patients to be mobile from the first week post-operatively and may diminish the risks associated with being non-weightbearing.展开更多
Background:Given the heightened risk of developmental challenges associated with preterm birth,it is crucial to explore interventions that may ameliorate potential adverse outcomes.This study aimed to examine whether ...Background:Given the heightened risk of developmental challenges associated with preterm birth,it is crucial to explore interventions that may ameliorate potential adverse outcomes.This study aimed to examine whether meeting the 24-h movement behavior(24-HMB)guidelines,which include recommendations on physical activity(PA),screen time(ST),and sleep(SL),is related to indicators of cognitive difficulties,internalizing problems(e.g.,depression and anxiety),and externalizing problems(e.g.,difficulties in making friends and arguing)in a sample of preterm youth(children and adolescents born preterm).Methods:In this cross-sectional study,data from 3410 preterm youth(aged 6 to 17 years)were included for data analyses.Multivariable logistic regression was used to investigate associations between meeting the 24-HMB guidelines and the above-mentioned health outcomes,while controlling for sociodemographic and health-related factors.Results:The prevalence of meeting 24-HMB guidelines varied across independent and integrated components of the 24-HMB guidelines.Meeting the ST guideline alone(p<0.05)and integrated guidelines(i.e.,ST+SL and ST+SL+PA)were associated with fewer cognitive difficulties and reduced internalizing and externalizing problems(p<0.05).Specifically,meeting the SL guideline alone and integrated guidelines(i.e.,SL+ST)were associated with lower odds of depression and anxiety(p<0.01).Additionally,meeting independent,and integrated(PA and/or ST)guidelines were associated with less pronounced difficulties in making friends and arguing(p<0.05).Meeting 24-HMB guidelines in an isolated and integrated manner are linked to better cognitive performance and fewer internalizing and externalizing problems in preterm youth.Conclusion:Results suggest that advocating for the implementation of the 24-HMB guidelines may reduce cognitive challenges and behavioral issues,which is of high relevance for improving public health.Future longitudinal studies in preterm youth should investigate how modifying specific 24-HMB behaviors,especially ST,influence cognitive difficulties,internalizing and externalizing problems in this vulnerable population.展开更多
The nonlinear dynamic behaviors of a double cable-stayed shallow arch model are investigated under the one-to-one-to-one internal resonance among the lowest modes of cables and the shallow arch and external primary re...The nonlinear dynamic behaviors of a double cable-stayed shallow arch model are investigated under the one-to-one-to-one internal resonance among the lowest modes of cables and the shallow arch and external primary resonance of cables. The in-plane governing equations of the system are obtained when the harmonic excitation is applied to cables. The excitation mechanism due to the angle-variation of cable tension during motion is newly introduced. Galerkin’s method and the multi-scale method are used to obtain ordinary differential equations (ODEs) of the system and their modulation equations, respectively. Frequency- and force-response curves are used to explore dynamic behaviors of the system when harmonic excitations are symmetrically and asymmetrically applied to cables. More importantly, comparisons of frequency-response curves of the system obtained by two types of trial functions, namely, a common sine function and an exact piecewise function, of the shallow arch in Galerkin’s integration are conducted. The analysis shows that the two results have a slight difference;however, they both have sufficient accuracy to solve the proposed dynamic system.展开更多
It is well known that English is the world language nowadays, and it is an official language in most countries. It is also currently the language most often taught as a foreign language. The reasons of the popularity ...It is well known that English is the world language nowadays, and it is an official language in most countries. It is also currently the language most often taught as a foreign language. The reasons of the popularity lie in both internal factors and external factors. In this paper, the author will analyze the factors that help to push English into a popular world language.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.52201312).
文摘As oil and gas exploration moves into deeper waters,marine risers are subjected to increasingly complex service conditions,including vessel motions,ocean currents,seabed-soil interactions,and internal flow effects.This work establishes a dynamic behavior model of steel catenary risers(SCRs)with varying curvatures subjected to internal flow and external currents and considers the effects of pipe-soil interactions on the curvature profile.The governing equation is solved via the generalized integral transform technique(GITT),which yields a semi-analytical solution of a high-order nonlinear partial differential equation.Parametric studies are then performed to analyze the effects of varying curvature on the vibration frequency and amplitude of SCRs.The vibration frequency and amplitude increase with the touchdown angle and hang-off angle,although the effect of the hang-off angle is negligible.Additionally,as the curvature increases along the centerline axis,the position of the maximum amplitude of the SCR moves upward.
文摘BACKGROUND Pain in the back or pelvis or fear of back pain may affect the timing or cocontraction of the core muscles.In both static and dynamic movements,the Sahrmann core stability test provides an assessment of core muscle activation and a person's ability to stabilize the lumbopelvic complex.Preparatory cues and images can be used to increase the activation of these muscles.To attain optimal movement patterns,it will be necessary to determine what cueing will give the most effective results for core stability.AIM To investigate the effects of external and internal cues on core muscle activation during the Sahrmann five-level core stability test.METHODS Total 68 participants(21.83±3.47 years)were randomly allocated to an external(n=35)or internal cue group(n=33).Participants performed the Sahrmann fivelevel core stability test without a cue as baseline and the five-level stability exercises with an internal or external cue.External cue group received a pressure biofeedback unit(PBU),and the internal cue group received an audio cue.A Delsys Trigno^(TM)surface electromyography unit was used for muscle activation from the rectus abdominis,external oblique,and transverse abdominis/internal oblique muscles.RESULTS Linear mixed effects model analysis showed that cueing had a significant effect on core muscle activation(P=0.001);however,there was no significant difference between cue types(internal or external)(P=0.130).CONCLUSION Both external and internal cueing have significant effects on core muscle activation during the Sahrmann five-level core stability test and the PBU does not create higher muscle activation than internal cueing.
基金supported by the National Natural Science Foundation of China(Grant Nos.42130604)the National Key Research and Development Program of China(Grant No.2023YFF0804704)+2 种基金the National Natural Science Foundation of China(Grant Nos.42105044)Swedish STINT(Grant No.CH2019-8377)the Priority Academic Program Development of Jiangsu Higher Education Institutions(Grant No.164320H116)。
文摘Since the mid-20th century,the Mongolian Plateau(MP)has experienced decadal droughts coupled with extreme heatwaves,severely affecting regional ecology and social development.However,the mechanisms behind these decadalscale compound heatwavedrought events remain debated.Here,using reconstructions and simulations from the Community Earth System Model Last Millennium Ensemble,we demonstrate that,over the last millennium,decadal droughts on the MP occurred under both warm and cold conditions,differing from recent compound heatwavedrought events.We found that by examining temperature changes during these drought periods,the distinct influences of external forcings and internal variability can be simply and effectively distinguished.Specifically,colddry events were primarily driven by volcanic eruptions that weakened the East Asian summer monsoon and midlatitude westerlies,reducing moisture transport to the MP.In contrast,warmdry events were predominantly induced by internal variability,notably the negative phase of the Atlantic Multidecadal Oscillation and the expansion of the Barents Sea ice extent.The recent extreme compound event was probably influenced by the combined effects of anthropogenic forcings and internal variability.These findings deepen our understanding of how external forcings and internal variability affect decadal drought events on the MP and highlight that recent compound events are unprecedented in the context of the last millennium.
文摘BACKGROUND Postoperative pancreatic fistula(POPF)is the most frequent cause of morbimortality after pancreaticoduodenectomy,but the best technique to use to prevent its development is unclear.The choice of drainage method external duct stent(EDS),internal duct stent(IDS),or non-ductal stent(NDS)is also controversial.AIM To compare the three groups(EDS,IDS and NDS),analyzing the patient characteristics,perioperative examinations and survival.METHODS Patients who underwent pancreaticoduodenectomy and pancreaticojejunostomy between 2012 and 2020,were divided into the EDS,IDS and NDS groups.RESULTS Of the 244 patients included,129 were in the EDS group,71 in the IDS group,and 44 in the NDS group.Except for preoperative pancreatitis in the NDS patients,comorbidities were similar among the groups.Patients in the NDS group had a high caliber of the Wirsung duct and frequently presented with a hard pancreas(P<0.001).A lower rate of grade C POPF was observed in the EDS(1.6%)compared to the NDS(9.1%)and IDS group(14.1%)(P=0.009).The groups showed similar findings for delayed gastric emptying,postoperative hemorrhage,reoperation,and 5-year survivals.Ninety-day mortality rate was significantly higher in the IDS group(5.6%)compared to the EDS(1.6%)and NDS(4.5%)groups(P=0.046).Multivariate analysis showed that the use of EDS was a protective factor for grade B/C POPF(P=0.034),and 90-day mortality(P=0.018).Additionally,a Wirsung duct diameter<3 mm was the only risk factor for grade B/C POPF(P=0.001),and 90-day mortality(P=0.031).CONCLUSION The use of the EDS was a protective factor for grade B/C POPF and 90-day mortality,and the Wirsung duct<3 mm was a risk factor for grade B/C POPF and 90-day mortality.
基金support from the National Key R&D Program of China(2024YFE0101100)the National Natural Science Foundation of China(22305132,22475112,22365021)+2 种基金the Inner Mongolia Autonomous Region“Grassland Talents”Project(2024098)the Basic Research Expenses Supported under 45 Years Old of Inner Mongolia(23600-5233706)the Inner Mongolia Natural Science Foundation(2025LHMS02016).
文摘In the domain of gas adsorption and separation,microporous materials have garnered considerable attention due to their elevated specific surface area and pore structure[1].And the dissolution of gases in liquids is limited by unstable liquid-phase pores and weak gas-liquid interactions,which leads to low solubility.However,conventional microporous materials are predominantly solid-state,which complicates their direct adsorption and separation application in liquid environments.
基金Beijing Natural Science Foundation:Research on the Mechanism of Chaiqi Decoction in Improving Vascular Endothelial Injury in Metabolic Syndrome by Regulating Pyroptosis via miR-21(No.7212181)。
文摘OBJECTIVE:To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected,aiming to provide a theoretical basis for clinical diagnosis and treatment.METHODS:We retrospectively analyzed the data of patients who underwent electronic colonoscopy and were found to have colorectal polyps at the Gastrointestinal Endoscopy Center of Dongfang Hospital,Beijing University of Chinese Medicine,from January 1,2017,to December 31,2023.We also reviewed their lung CT results and used statistical software to analyze the recurrence,location,size,and pathology of colorectal polyps in relation to the presence,number,and size of pulmonary nodules.RESULTS:Both colorectal polyps and pulmonary nodules are more common in elderly males.Patients with recurrent colorectal polyps are more likely to have pulmonary nodules,which tend to be located in the left colon and are more likely to be adenomatous in nature;those without pulmonary nodules show no clear pattern in polyp distribution,with a tendency towards inflammatory and hyperplastic pathology;the data from this study suggests that the proportion of lung nodules larger than 0.5 cm in the recurrent group is higher than in the non-recurrent group,and the proportion of colorectal polyps larger than 1 cm in the recurrent group is also higher than in the non-recurrent group.CONCLUSION:There is a certain connection between the pathogenesis and treatment of colorectal polyps and pulmonary nodules.Cold,phlegm,dampness,blood stasis,and toxic coagulation are common pathogenic factors of the two diseases.Patients with larger colorectal polyps should be advised to undergo regular colonoscopy.Patients with recurrent polyps or those with left colon necrosis or cancer indicated by colonoscopy should be advised to complete lung related examinations to rule out the possibility of pulmonary nodules.
文摘Artificial Intelligence(AI),as a strategic technology leading the new round of scientific and technological revolution and industrial transformation,is reshaping the global power dynamics.Major countries are accelerating their strategic deployment around technological innovation,standard-setting,and rule-building,making technology increasingly intertwined with geopolitics.Since the U.S.released Preparing for the Future of Artificial Intelligence in 2016,it has integrated AI into its national strategic system and continuously upgraded it,aiming to maintain its dominance in the global competition.Meanwhile,the internal and external tensions of the U.S.AI strategy have become increasingly prominent,profoundly influencing its global strategy and future trajectory.
基金supported by Istanbul Technical University(Project No.45698)supported through the“Young Researchers’Career Development Project-training of doctoral students”of the Croatian Science Foundation.
文摘This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels.
文摘Materialist dialectics holds that internal causes are the basis of change and the external causes are the condition of change, and that external causes become operative through internal causes. This law can be applied into SLA. The internal causes and external causes influence SLA greatly. This paper mainly discusses the factors involved in SLA process.
文摘External and internal rectal prolapse with their affiliated rectocele and enterocele, are associated with debilitating symptoms such as obstructed defecation, pelvic pain and faecal incontinence. Since perineal procedures are associated with a higher recurrence rate, an abdominal approach is commonly preferred. Despite the description of greater than three hundred different procedures, thus far no clear superiority of one surgical technique has been demonstrated. Ventral mesh rectopexy(VMR) is a relatively new and promising technique to correct rectal prolapse. In contrast to the abdominal procedures of past decades, VMR avoids posterolateral rectal mobilisation and thereby minimizes the risk of postoperative constipation. Because of a perceived acceptable recurrence rate, good functional results and low mesh-related morbidity in the short to medium term, VMR has been popularized in the past decade. Laparoscopic or robotic-assisted VMR is now being progressively performed internationally and several articles and guidelines propose the procedure as the treatment of choice for rectal prolapse. In this article, an outline of the current status of laparoscopic and robotic ventral mesh rectopexy for the treatment of internal and external rectal prolapse is presented.
基金Supported by National Natural Science Foundation of China(Grant No.51475084)
文摘Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out.However,the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated.An eight-degree-of-freedom(8-DOF)nonlinear spur gear-rotor-bearing model,which contains backlash,transmission error,eccentricity,gravity and input/output torque,is established,and the coupled lateral-torsional vibration characteristics are studied.Based on the equations of motion,the coupled spur gear-rotor-bearing system(SGRBS)is investigated using the Runge-Kutta numerical method,and the effects of rotational speed,error fluctuation and load fluctuation on the dynamic responses are explored.The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion,quasi-periodic motion,chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations.Significantly,the changing rotational speed could effectively control the vibration of the system.Vibration level increases with the increasing error fluctuation.Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase,the chaotic motion may be restricted.The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.
基金Key project from the Natural Science Foundation of China (59836250)
文摘Internal and external wall surface temperatures (Tws) in April, August and December in Kunming, a city in low latitude plateau, were investigated. Results showed that the Tws in April were of the highest among the three, followed by August and December. The Tws differences among walls with different orientation were higher in April and December when the weather tends to be sunny, and lower in August with more cloudy days in the time. In April and August, Tws of E-wall was the highest, followed by S- and N-wall. But in December Tws of S-wall might be sometimes higher than E one. Diurnal range of internal Tws was usually smaller than that of the external, with also a time lag for the occurrence of its maximum and minimum. The results can serve as a basis for further research on building microclimate and urban architecture designs. It also gives suggestions for similar studies in other areas.
文摘The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively.
基金the National Natural Science Foundation of China (Nos. 10702045 and 10872135)the Aerospace Foundation of China (No. 2009ZA018)the Natural Science Foundation of Liaoning Province (No. 2009A572)
文摘Applying the multidimensional Lindstedt-Poincare （MDLP） method, we study the forced vibrations with internal resonance of a clamped-clamped pipe conveying fluid under ex- ternal periodic excitation. The frequency-amplitude response curves of the first-mode resonance with internal resonance are obtained and its characteristics are discussed; moreover, the motions of the first two modes are also analyzed in detail. The present results reveal rich and complex dynamic behaviors caused by internal resonance and that some of the internal resonances are de- cided by the excitation amplitude. The MDLP method is also proved to be a simple and efficient technique to deal with nonlinear dynamics.
文摘BACKGROUND Reconstruction of the pelvic ring anatomy in unstable anterior pelvic ring injuries is a significant step to reduce the mortality rate associated with these injuries efficiently.There is a debate on using either an anterior subcutaneous pelvis internal fixator(INFIX)or an anterior supra-acetabular external fixator(EXFIX)to manage an unstable anterior pelvic ring fracture.AIM To compare the functional and radiological outcomes and complications of INFIX vs EXFIX in managing unstable pelvic ring injuries.METHODS A prospective cohort study included 54 patients with unstable pelvic ring fractures.The patients were divided into two groups;the INFIX group,in which 30 cases were fixed by INFIX,and the EXFIX group,in which 24 patients were treated by EXFIX.The average age in the EXFIX group was 31.17 years(16-57 years),while in the INFIX group,it was 34.5 years(17-53 years).The study included 20(66.7%)males and 10(33.3%)females in the INFIX group and 10(41.7%)males and 14(58.3%)females in the EXFIX group.The radiological outcomes were evaluated using Matta and Tornetta's score,and the functional outcomes using the Majeed score.RESULTS The results revealed a statistically significant difference between both groups(P=0.013)regarding radiological outcomes,according to Matta and Tornetta's score in favor of the INFIX group.Sitting,standing,and walking abilities were measured at a 3-mo follow-up visit using Majeed score modules.It was significantly better among the INFIX group than the EXFIX group in all three modules.At the final follow-up,both groups had no statistically significant difference according to the Majeed score;92.35 in the INFIX group and 90.99 in the EXFIX group(P=0.513).A lower surgical site infection rate was noticed in the INFIX group(P=0.007).CONCLUSION Anterior subcutaneous pelvis INFIX is associated with better radiological outcomes and a lower infection rate than anterior supra-acetabular EXFIX in managing patients with unstable anterior pelvic ring fractures.
基金This study was supported by the National Nature Scientific Fund (No.39730220).
文摘To study the redistribution of endothelin- 1 (ET- 1) receptors in two subcellular organelles , the sarcolemmal membrane and the light vesicle, of rat heart during the progression of sepsis. Methods. Sepsis was induced by cecal ligation and puncture (CLP). ET1 receptor was assayed by using [125I]- ET1 binding. Marker enzyme activities, protein yield, and dry- to- wet weight ratio of cardiac membranes were measured. Results. Septic rat heart exhibited two distinct phases: an initial hyperdynamic phase( 9h after CLP; early stage of sepsis) followed by a hypodynamic (18h after CLP, late stage of sepsis) phase. [125I]- ET1 binding study showed that during early stage of sepsis, the Bmax of ET1 receptors was increased by 30％ in sarcolemma but decreased by 19％ in light vesicles, while during late stage of sepsis, the Bmax was decreased by 24％ in sarcolemma but increased by 38％ in light vesicles.The total binding of sarcolemma and light vesicles was increased by 25％ during early stage of sepsis but decreased by 17％ during late stage of sepsis. Conclusions. These data indicated that ET1 receptors in the rat heart were externalized from light vesicles to sarcolemmal membranes during early hyperdynamic phase while internalized from surface membranes to intracellular compartment during late hypodynamic phase of sepsis.
文摘Background: The triple arthrodesis was described early by Myerson in 1923 and has been the gold standard surgical procedure for various conditions with the goal to reduce pain, improve deformity and facilitate function. Methods: The procedure consists of fusion of the subtalar joint, talonavicular joint and calcaneocuboid joint [1]. The procedure is traditionally done with internal fixation, however, Marinet al. has shown it to be performed with external fixation [2]. Dr. Marin and the associates have developed an alternative technique to perform a triple arthrodesis using internal and external fixation. This paper describes a step-by-step technique to perform a triple arthrodesis with both internal and external fixation. It will demonstrate the use of the prefabricated arches on the footplate for more precise and accurate placement of transosseous wires using arch-wire technique [3]. Results/Conclusion: We believe this technique will not only help increase the ability to achieve fusion with a less chance of non-union, but may also decrease healing time, which may allow patients to be mobile from the first week post-operatively and may diminish the risks associated with being non-weightbearing.
基金supported by the Shenzhen Educational Research Funding(Grant No.zdzb2014)the Shenzhen Science and Technology Innovation Commission(Grant No.202307313000096)+3 种基金the Social Science Foundation from China’s Ministry of Education(Grant No.23YJA880093)a Post-Doctoral Fellowship(Grant No.2022M711174)the National Center for Mental Health(Grant No.Z014)a Research Excellence Scholarship of Shenzhen University(Grant No.ZYZD2305).
文摘Background:Given the heightened risk of developmental challenges associated with preterm birth,it is crucial to explore interventions that may ameliorate potential adverse outcomes.This study aimed to examine whether meeting the 24-h movement behavior(24-HMB)guidelines,which include recommendations on physical activity(PA),screen time(ST),and sleep(SL),is related to indicators of cognitive difficulties,internalizing problems(e.g.,depression and anxiety),and externalizing problems(e.g.,difficulties in making friends and arguing)in a sample of preterm youth(children and adolescents born preterm).Methods:In this cross-sectional study,data from 3410 preterm youth(aged 6 to 17 years)were included for data analyses.Multivariable logistic regression was used to investigate associations between meeting the 24-HMB guidelines and the above-mentioned health outcomes,while controlling for sociodemographic and health-related factors.Results:The prevalence of meeting 24-HMB guidelines varied across independent and integrated components of the 24-HMB guidelines.Meeting the ST guideline alone(p<0.05)and integrated guidelines(i.e.,ST+SL and ST+SL+PA)were associated with fewer cognitive difficulties and reduced internalizing and externalizing problems(p<0.05).Specifically,meeting the SL guideline alone and integrated guidelines(i.e.,SL+ST)were associated with lower odds of depression and anxiety(p<0.01).Additionally,meeting independent,and integrated(PA and/or ST)guidelines were associated with less pronounced difficulties in making friends and arguing(p<0.05).Meeting 24-HMB guidelines in an isolated and integrated manner are linked to better cognitive performance and fewer internalizing and externalizing problems in preterm youth.Conclusion:Results suggest that advocating for the implementation of the 24-HMB guidelines may reduce cognitive challenges and behavioral issues,which is of high relevance for improving public health.Future longitudinal studies in preterm youth should investigate how modifying specific 24-HMB behaviors,especially ST,influence cognitive difficulties,internalizing and externalizing problems in this vulnerable population.
基金Project supported by the National Natural Science Foundation of China(Nos.11572117,11502076,and 11872176)
文摘The nonlinear dynamic behaviors of a double cable-stayed shallow arch model are investigated under the one-to-one-to-one internal resonance among the lowest modes of cables and the shallow arch and external primary resonance of cables. The in-plane governing equations of the system are obtained when the harmonic excitation is applied to cables. The excitation mechanism due to the angle-variation of cable tension during motion is newly introduced. Galerkin’s method and the multi-scale method are used to obtain ordinary differential equations (ODEs) of the system and their modulation equations, respectively. Frequency- and force-response curves are used to explore dynamic behaviors of the system when harmonic excitations are symmetrically and asymmetrically applied to cables. More importantly, comparisons of frequency-response curves of the system obtained by two types of trial functions, namely, a common sine function and an exact piecewise function, of the shallow arch in Galerkin’s integration are conducted. The analysis shows that the two results have a slight difference;however, they both have sufficient accuracy to solve the proposed dynamic system.
文摘It is well known that English is the world language nowadays, and it is an official language in most countries. It is also currently the language most often taught as a foreign language. The reasons of the popularity lie in both internal factors and external factors. In this paper, the author will analyze the factors that help to push English into a popular world language.
