A modelling approach consisting of best-fit relations to estimate the post-yield strength parameters is presented for simulating post-peak behavior beyond the point of residual strength of coal pillars having differen...A modelling approach consisting of best-fit relations to estimate the post-yield strength parameters is presented for simulating post-peak behavior beyond the point of residual strength of coal pillars having different w/h ratios.The model was developed based on back-analysis of the complete stress-strain behavior of specimens belonging to six different Indian coal seams with different w/h ratios of 0.5 e13.5.It was found that the simultaneous degradation of the cohesion and friction angle of the Mohr-Coulomb rock material characterizes the post-peak strength behavior of the rock.The resulting expressions are simplistic as they require parameters that can be easily determined using uniaxial and triaxial compression results.Eventually,the developed model was validated by simulating the triaxial tests of coal specimens with different sizes under varying confining stresses and comparing its findings with the published test results.The study showed that its implementation in the numerical model could reproduce laboratory-observed mechanical response,deformation behavior,and failure mechanism very closely.展开更多
Time series forecasting plays an important role in various fields, such as energy, finance, transport, and weather. Temporal convolutional networks (TCNs) based on dilated causal convolution have been widely used in t...Time series forecasting plays an important role in various fields, such as energy, finance, transport, and weather. Temporal convolutional networks (TCNs) based on dilated causal convolution have been widely used in time series forecasting. However, two problems weaken the performance of TCNs. One is that in dilated casual convolution, causal convolution leads to the receptive fields of outputs being concentrated in the earlier part of the input sequence, whereas the recent input information will be severely lost. The other is that the distribution shift problem in time series has not been adequately solved. To address the first problem, we propose a subsequence-based dilated convolution method (SDC). By using multiple convolutional filters to convolve elements of neighboring subsequences, the method extracts temporal features from a growing receptive field via a growing subsequence rather than a single element. Ultimately, the receptive field of each output element can cover the whole input sequence. To address the second problem, we propose a difference and compensation method (DCM). The method reduces the discrepancies between and within the input sequences by difference operations and then compensates the outputs for the information lost due to difference operations. Based on SDC and DCM, we further construct a temporal subsequence-based convolutional network with difference (TSCND) for time series forecasting. The experimental results show that TSCND can reduce prediction mean squared error by 7.3% and save runtime, compared with state-of-the-art models and vanilla TCN.展开更多
We establish the Stinespring dilation theorem of the link product of quantum channels in two different ways,discuss the discrimination of quantum channels,and show that the distinguishability can be improved by self-l...We establish the Stinespring dilation theorem of the link product of quantum channels in two different ways,discuss the discrimination of quantum channels,and show that the distinguishability can be improved by self-linking each quantum channel n times as n grows.We also find that the maximum value of Uhlmann's theorem can be achieved for diagonal channels.展开更多
Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily ...Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily or even hourly,which generates complicated pressures on the salt cavern.Furthermore,the mechanical behavior of rock salt may change and present distinct failure characteristics under different stress states,which affects the performance of salt cavern during the time period of full service.To reproduce a similar loading condition on the cavern surrounding rock mass,the cyclic triaxial loading/unloading tests are performed on the rock salt to explore the mechanical transition behavior and failure characteristics under different confinement.Experimental results show that the rock salt samples pre-sent a diffused shear failure band with significant bulges at certain locations in low confining pressure conditions(e.g.5 MPa,10 MPa and 15 MPa),which is closely related to crystal misorientation and grain boundary sliding.Under the elevated confinement(e.g.20 MPa,30 MPa and 40 MPa),the dilation band dominates the failure mechanism,where the large-size halite crystals are crushed to be smaller size and new pores are developing.The failure transition mechanism revealed in the paper provides additional insight into the mechanical performance of salt caverns influenced by complicated stress states.展开更多
BACKGROUND Various animal models have been used to explore the pathogenesis of choledochal cysts(CCs),but with little convincing results.Current surgical techniques can achieve satisfactory outcomes for treatment of C...BACKGROUND Various animal models have been used to explore the pathogenesis of choledochal cysts(CCs),but with little convincing results.Current surgical techniques can achieve satisfactory outcomes for treatment of CCs.Consequently,recent studies have focused more on clinical issues rather than basic research.Therefore,we need appropriate animal models to further basic research.AIM To establish an appropriate animal model that may contribute to the investigation of the pathogenesis of CCs.METHODS Eighty-four specific pathogen-free female Sprague-Dawley rats were randomly allocated to a surgical group,sham surgical group,or control group.A rat model of CC was established by partial ligation of the bile duct.The reliability of the model was confirmed by measurements of serum biochemical indices,morpho-logy of common bile ducts of the rats as well as molecular biology experiments in rat and human tissues.RESULTS Dilation classified as mild(diameter,≥1 mm to<3 mm),moderate(≥3 mm to<10 mm),and severe(≥10 mm)was observed in 17,17,and 2 rats in the surgical group,respectively,while no dilation was observed in the control and sham surgical groups.Serum levels of alanine aminotransferase,aspartate aminotrans-ferase,total bilirubin,direct bilirubin,and total bile acids were significantly elevated in the surgical group as compared to the control group 7 d after surgery,while direct bilirubin,total bilirubin,and gamma-glutamyltransferase were further increased 14 d after surgery.Most of the biochemical indices gradually decreased to normal ranges 28 d after surgery.The protein expression trend of signal transducer and activator of transcription 3 in rat model was consistent with the human CC tissues.CONCLUSION The model of partial ligation of the bile duct of juvenile rats could morphologically simulate the cystic or fusiform CC,which may contribute to investigating the pathogenesis of CC.展开更多
BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,skin changes(POEMS)syndrome is a rare paraneoplastic syndrome that encompass multiple systems.The most common clinical symptoms of POEMS syndrome are pro...BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,skin changes(POEMS)syndrome is a rare paraneoplastic syndrome that encompass multiple systems.The most common clinical symptoms of POEMS syndrome are pro-gressive sensorimotor polyneuropathy,organ enlargement,endocrine disorders,darkening skin,a monoclonal plasma cell proliferative disorder,and lymph node hyperplasia.The organomegaly consists of hepatosplenomegaly and/or lym-phadenopathy;cases of cardiomyopathy are rare.Diagnoses are often delayed because of the atypical nature of the syndrome,exposing patients to possibly severe disability.Therefore,identifying atypical symptoms can improve the prognosis and quality of life among POEMS syndrome patients.lenalidomide and dexamethasone.CONCLUSION When patients with cardiomyopathy have systemic manifestations such as numb limbs and darkening skin,the POEMS syndrome is the most possible diagnosis.展开更多
BACKGROUND Bradycardia-induced cardiomyopathy(BIC),which is a disease resulting from bradycardia,is characterized by cardiac chamber enlargement and diminished cardiac function.The correction of bradycardia can allow ...BACKGROUND Bradycardia-induced cardiomyopathy(BIC),which is a disease resulting from bradycardia,is characterized by cardiac chamber enlargement and diminished cardiac function.The correction of bradycardia can allow for significant improvements in both cardiac function and structure;however,this disease has been infrequently documented.In this case,we conducted a longitudinal followup of a patient who had been enduring BIC for more than 40 years to heighten awareness and prompt timely diagnosis and rational intervention.CASE SUMMARY A woman who presented with postactivity fatigue and dyspnea was diagnosed with bradycardia at the age of 7.Since she had no obvious symptoms,she did not receive any treatment to improve her bradycardia during the 42-year follow-up,except for the implantation of a temporary pacemaker during labor induction surgery.As time progressed,the patient's heart gradually expanded due to her low ventricular rate,and she was diagnosed with BIC.In 2014,the patient developed atrial fibrillation,her ventricular rate gradually increased,and her heart shape gradually returned to normal.This report describes the cardiac morphological changes caused by the heart rate changes in BIC patients older than 40 years,introduces another possible outcome of BIC,and emphasizes the importance of early intervention in treating BIC.CONCLUSION BIC can induce atrial fibrillation,causing an increased ventricular rate and leading to positive cardiac remodeling.展开更多
Radiological imaging findings may contribute to the differentiation of malignant biliary obstruction from choledocholithiasis in the etiology of acute cholangitis.
Radiological studies play a crucial role in the evaluation of patients with biliary duct obstruction,allowing for the guidance of clinical diagnosis towards a malignant or stone-induced etiology through the recognitio...Radiological studies play a crucial role in the evaluation of patients with biliary duct obstruction,allowing for the guidance of clinical diagnosis towards a malignant or stone-induced etiology through the recognition of relevant imaging features,which must be continuously revisited given their prognostic significance.This article aims to emphasize the importance of recognizing crucial imaging aspects of malignant and stone-induced biliary obstruction.展开更多
BACKGROUND Giant congenital biliary dilation(CBD)is a rare condition observed in clinical practice.Infants born with this condition often experience a poor overall health status,and the disease progresses rapidly,lead...BACKGROUND Giant congenital biliary dilation(CBD)is a rare condition observed in clinical practice.Infants born with this condition often experience a poor overall health status,and the disease progresses rapidly,leading to severe biliary obstruction,infections,pressure exerted by the enlarged CBD on abdominal organs,disturbances in the internal environment,and multiple organ dysfunction.The treatment of giant CBD using laparoscopy is challenging due to the high degree of variation in the shape of the bile duct and other organs,making it difficult to separate the bile duct wall from adjacent tissues or to control bleeding.CASE SUMMARY Herein,we present the details of an 11-d-old male newborn who was diagnosed with giant CBD.The patient was admitted to the neonatal surgery department of our hospital due to a history of common bile duct cyst that was detected more than 3 mo ago,and also because the patient had been experiencing yellowish skin for the past 9 d.The abnormal echo in the fetal abdomen was first noticed by the patient’s mother during a routine ultrasound examination at a local hospital,when the patient was at 24 wk+6 d of pregnancy.This finding raised concerns about the possibility of congenital biliary dilatation(22 mm×21 mm).Subsequent ultrasound examinations at different hospitals consistently confirmed the presence of a congenital biliary dilatation.No specific treatment was administered for biliary dilatation during this period.A computed tomography scan conducted during the hospitalization revealed a large cystic mass in the right upper quadrant and pelvis,measuring approximately 9.2 cm×7.4 cm×11.3 cm.Based on the CONCLUSION The analysis reveals that prenatal imaging techniques,such as ultrasound and magnetic resonance imaging,play a crucial role in the early diagnosis,fetal prognosis,and treatment plan for giant CBD.Laparoscopic surgery for giant CBD presents certain challenges,including difficulties in separating the cyst wall,anastomosis,and hemostasis,as well as severe biliary system infection and ulceration.Consequently,there is a high likelihood of converting to laparotomy.The choice between surgical methods like hepaticojejunostomy(HJ)or hepaticoduodenostomy has not been standardized yet.However,we have achieved favorable outcomes using HJ.Preoperative management of inflammation,biliary drainage,liver function protection,and supportive treatment are particularly vital in improving children’s prognosis.After discharge,it is essential to conduct timely reexamination and close follow-up to identify potential complications.展开更多
BACKGROUND At present,there is no unified and effective treatment for extreme corrosive esophageal stenosis(CES)with esophagotracheal fistula(ETF).This case had extreme and severe esophageal stenosis(ES)and ETF after ...BACKGROUND At present,there is no unified and effective treatment for extreme corrosive esophageal stenosis(CES)with esophagotracheal fistula(ETF).This case had extreme and severe esophageal stenosis(ES)and ETF after ingesting an enzyme-based chemical detergent,resulting in a serious pulmonary infection and severe malnutrition.Upper gastrointestinal imaging showed that he had an ETF,and endoscopy showed that he had extreme and severe esophageal stricture.This case was complex and difficult to treat.According to the domestic and foreign lite-rature,there is no universal treatment that is low-risk.CASE SUMMARY A patient came to our hospital with extreme ES,an ETF,and severe malnutrition complicated with pulmonary tuberculosis 1 mo after the consumption of an enzy-me-based detergent.The ES was serious,and the endoscope was unable to pass through the esophagus.We treated him by endoscopic incision method(EIM),esophageal stent placement(ESP),and endoscopic balloon dilation(EBD)by using the bronchoscope and gastroscope.This treatment not only closed the ETF,but also expanded the esophagus,with minimal trauma,greatly reducing the pain of the patient.According to the literature,there are no similar reported cases.CONCLUSION We report,for the first time,a patient with extreme CES complicated with ETF,where the endoscope could not be passed through his esophagus but he could be examined by bronchoscopy and treated by EIM,ESP,and EBD.展开更多
BACKGROUND Incomplete congenital duodenal obstruction(ICDO)is caused by a congenitally perforated duodenal web(CPDW).Currently,only six cases of balloon dilatation of the PDW in newborns have been described.AIM To pre...BACKGROUND Incomplete congenital duodenal obstruction(ICDO)is caused by a congenitally perforated duodenal web(CPDW).Currently,only six cases of balloon dilatation of the PDW in newborns have been described.AIM To present our experience of balloon dilatation of a perforated duodenal memb-rane in newborns with ICDO.METHODS Five newborns who underwent balloon dilatation of the CPDW along a prein-stalled guidewire between 2021 and 2023 were included.Nineteen newborns diagnosed with ICDO who underwent laparotomy were included in the control group.RESULTS In all cases,good anatomical and clinical results were obtained.In three cases,a follow-up study was conducted after 1 year.The average time to start enteral feeding per os was significantly earlier in the study group(4.4 d)than in the laparotomic group(21.2 days;P<0.0001).The time spent by patients in the intensive care unit and hospital after balloon dilatation was also significantly shorter.We determined the selection criteria for possible and effective CPDW balloon dilatation in newborns as follows:(1)Presence of dynamic radiographic signs of the passage of a radiopaque substance beyond the zone of narrowing or radiographic signs of pneumatisation of the duodenum and small bowel distal to the web;(2)presence of endoscopic signs of CPDW;(3)successful cannulation with a guidewire performed parallel to the endoscope,with holes in the congenital duodenal web;and(4)successful positioning of the balloon performed along a freestanding guidewire on the web.CONCLUSION Strictly following selection criteria for newborns with ICDO caused by CPDW ensures that endoscopic balloon dilatation using a pre-installed guidewire is safe and effective and shows good 1-year follow-up results.展开更多
BACKGROUND Tracheostomy is commonly used in intensive care unit(ICU)patients who are expected to be on long-term mechanical ventilation or suffer from emergency upper airway obstruction.However,some studies have confl...BACKGROUND Tracheostomy is commonly used in intensive care unit(ICU)patients who are expected to be on long-term mechanical ventilation or suffer from emergency upper airway obstruction.However,some studies have conflicting findings regarding the optimal technique and its timing and benefits.AIM To provide evidence of practice,characteristics,and outcome concerning tracheostomy in an ICU of a tertiary care hospital.METHODS This was a retrospective cohort study including adult critical care patients in a single ICU for two consecutive years.Patients’demographic characteristics,severity of illness(APACHE II score),level of consciousness[Glasgow Coma Scale(GCS)],comorbidities,timing and type of tracheostomy procedure performed and outcome were recorded.We defined late as tracheostomy placement after 8 days or no tracheotomy.RESULTS Data of 660 patients were analyzed(median age of 60 years),median APACHE II score of 19 and median GCS score of 12 at admission.Tracheostomy was performed in 115 patients,of whom 63 had early and 52 late procedures.Early tracheostomy was mainly executed in case of altered level of consciousness and severe critical illness polyneuromyopathy,however there were no significant statistical results(47.6%vs 36.5%,P=0.23)and(23.8%vs 19.2%,P=0.55)respectively.Regarding the method selected,early surgical tracheostomy(ST)was conducted in patients with maxillofacial injuries(50.0%vs 0.0%,P=0.033),whereas late surgical tracheostomy was selected for patients with goiter(44.4%vs 0.0%P=0.033).Patients with early tracheostomy spent significantly fewer days on mechanical ventilation(15.3±8.5 vs 22.8±9.6,P<0.001)and in ICU in general(18.8±9.1 vs 25.4±11.5,P<0.001).Percutaneous dilatation tracheostomy(PDT)vs ST was preferable in older critical care patients in the case of Central Nervous System underlying cause of admission(62.5%vs 26.3%,P=0.004).ST was the method of choice in compromised airway(31.6%,vs 7.3%P=0.008).A large proportion of patients(88/115)with tracheostomy managed to wean from mechanical ventilation and were transferred out of the ICU(100%vs 17.4%,P<0.001).CONCLUSION PDT was performed more frequently in our cohort.This technique did not affect mechanical ventilation days,ventilator-associated pneumonia(VAP),ICU length of stay,or survival.No complications were observed in the percutaneous or surgical tracheostomy groups.Patients undergoing early tracheostomy benefited in terms of mechanical ventilation days and ICU length of stay but not of discharge status,presence of VAP,or survival.展开更多
The choledochal cyst(CC)can be better termed as biliary tract malformation because of the close association of embryology and etiology in the causation of CC.Contrary to Babbitt's postulation of reflux,damage and ...The choledochal cyst(CC)can be better termed as biliary tract malformation because of the close association of embryology and etiology in the causation of CC.Contrary to Babbitt's postulation of reflux,damage and dilatation,reflux was not demonstrable as the causative factor in all varieties of CC.High pressure in the biliary system,otherwise termed ductal hypertension,is put forth as an alternative to explain the evolution of CC.The forme fruste type,which does not find a place in the standard classification,typifies the ductal hypertension hypothesis.Hence a closer,in-depth review would be able to highlight this apt terminology of biliary tract malformation.展开更多
The article collectively proposes a revolutionary perspective on the universe, intertwining concepts of time, spatial positioning, and cosmic dynamics. We introduce the idea of a rotating universe centered around Mega...The article collectively proposes a revolutionary perspective on the universe, intertwining concepts of time, spatial positioning, and cosmic dynamics. We introduce the idea of a rotating universe centered around Mega Central Energy Pools (MCEPs), where time varies relative to the distance from the universe’s center, potentially enabling time travel. This model challenges conventional notions of time and cosmology, suggesting that black holes and white holes act as cosmic recycling factories. Additionally, this model unveils a novel theory of dark matter, positing photons as its constituents and highlighting their role in energy transfer across the cosmos. Furthermore, the investigation into Venus’s unique day-length-to-year-length ratio unveils a microscopic mechanism involving swirling energy droplets, charged particles, and field interactions, offering insights into planetary dynamics on both micro and macro scales.展开更多
Dilated cardiomyopathy(DCM)is a common myocardial disease characterized by enlargement of the heart cavity and decreased systolic function,often leading to heart failure(HF)and arrhythmia.The occurrence of atrial fibr...Dilated cardiomyopathy(DCM)is a common myocardial disease characterized by enlargement of the heart cavity and decreased systolic function,often leading to heart failure(HF)and arrhythmia.The occurrence of atrial fibrillation(AF)is closely related to the progression and prognosis of the disease.In recent years,with the advancement of medical imaging and biomarkers,models for predicting the occurrence of AF in DCM patients have gradually become a research hotspot.This article aims to review the current situation of AF in DCM patients and explore the importance and possible methods of constructing predictive models to provide reference for clinical prevention and treatment.We comprehensively analyzed the risk factors for AF in DCM patients from epidemiological data,pathophysiological mechanisms,clinical and laboratory indicators,electrocardiogram and imaging parameters,and biomarkers,and evaluated the effectiveness of existing predictive models.Through analysis of existing literature and research,this article proposes a predictive model that integrates multiple parameters to improve the accuracy of predicting AF in DCM patients and provide a scientific basis for personalized treatment.展开更多
Metrological analysis shows that any clock in inertial motion in infinite space shall not have time dilation, due to relativity of such motion in such space. On the other hand, atomic clock in inertial motion in finit...Metrological analysis shows that any clock in inertial motion in infinite space shall not have time dilation, due to relativity of such motion in such space. On the other hand, atomic clock in inertial motion in finite space shall exhibit time dilation, due to alteration of momentum of clock-defining particle caused by nonzero curvature of trajectory of such motion in such space. Therefore, time dilation experiment of atomic clock in inertial motion in physical space provides a direct and decisive way of determining geometry of physical space in real-time. Phenomenon of time dilation of atomic clock in inertial motion in physical space has long been observed and confirmed experimentally. Therefore, extent of physical space has to be finite, consistent with result of high precision experiment of free particle in high-speed motion conducted a decade ago.Keywords Geometry of Physical Space, Time Dilation, Atomic Clock, Special Relativity Theory.展开更多
This paper is a further elaboration of the author’s Time Dilation Cosmology (TDC) holographic model that ties gravitation and celestial mechanics and kinematics directly to time dilation, resolving all the major conu...This paper is a further elaboration of the author’s Time Dilation Cosmology (TDC) holographic model that ties gravitation and celestial mechanics and kinematics directly to time dilation, resolving all the major conundrums in astrophysics, and ties astrophysics directly to quantum physics. It begins with a brief summary of the TDC model and contains the new derivation for the time dilation version of the formula for summing relativistic velocities, Einstein’s gravitational constant and the time dilation versions for the Lorentz factor and the Euclidean norm of the 3d velocity vector, the two of which can then be used in the Four-velocity formula. It is demonstrated how orbital curvature is manifested as the resultant of two time dilation-manifested velocities. It also explains why an interferometer cannot distinguish free fall from zero gravity and further elaborates on the author’s previous explanations of how spiral galaxies are formed, and contains mathematical proof that Black Holes are actually Magnetospheric Eternally Collapsing Objects (MECOs) that are massless spacetime vortices.展开更多
文摘A modelling approach consisting of best-fit relations to estimate the post-yield strength parameters is presented for simulating post-peak behavior beyond the point of residual strength of coal pillars having different w/h ratios.The model was developed based on back-analysis of the complete stress-strain behavior of specimens belonging to six different Indian coal seams with different w/h ratios of 0.5 e13.5.It was found that the simultaneous degradation of the cohesion and friction angle of the Mohr-Coulomb rock material characterizes the post-peak strength behavior of the rock.The resulting expressions are simplistic as they require parameters that can be easily determined using uniaxial and triaxial compression results.Eventually,the developed model was validated by simulating the triaxial tests of coal specimens with different sizes under varying confining stresses and comparing its findings with the published test results.The study showed that its implementation in the numerical model could reproduce laboratory-observed mechanical response,deformation behavior,and failure mechanism very closely.
基金supported by the National Key Research and Development Program of China(No.2018YFB2101300)the National Natural Science Foundation of China(Grant No.61871186)the Dean’s Fund of Engineering Research Center of Software/Hardware Co-Design Technology and Application,Ministry of Education(East China Normal University).
文摘Time series forecasting plays an important role in various fields, such as energy, finance, transport, and weather. Temporal convolutional networks (TCNs) based on dilated causal convolution have been widely used in time series forecasting. However, two problems weaken the performance of TCNs. One is that in dilated casual convolution, causal convolution leads to the receptive fields of outputs being concentrated in the earlier part of the input sequence, whereas the recent input information will be severely lost. The other is that the distribution shift problem in time series has not been adequately solved. To address the first problem, we propose a subsequence-based dilated convolution method (SDC). By using multiple convolutional filters to convolve elements of neighboring subsequences, the method extracts temporal features from a growing receptive field via a growing subsequence rather than a single element. Ultimately, the receptive field of each output element can cover the whole input sequence. To address the second problem, we propose a difference and compensation method (DCM). The method reduces the discrepancies between and within the input sequences by difference operations and then compensates the outputs for the information lost due to difference operations. Based on SDC and DCM, we further construct a temporal subsequence-based convolutional network with difference (TSCND) for time series forecasting. The experimental results show that TSCND can reduce prediction mean squared error by 7.3% and save runtime, compared with state-of-the-art models and vanilla TCN.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61877054,12031004,and 12271474).
文摘We establish the Stinespring dilation theorem of the link product of quantum channels in two different ways,discuss the discrimination of quantum channels,and show that the distinguishability can be improved by self-linking each quantum channel n times as n grows.We also find that the maximum value of Uhlmann's theorem can be achieved for diagonal channels.
基金This research was financially supported by the Science and Technology Department of Sichuan Province Project,China(Grant Nos.2022YFSY0007,2021YFH0010)the National Scientific Science Foundation of China(Grant No.U20A20266).
文摘Great potential of underground gas/energy storage in salt caverns seems to be a promising solution to support renewable energy.In the underground storage method,the operating cycle unfortunately may reach up to daily or even hourly,which generates complicated pressures on the salt cavern.Furthermore,the mechanical behavior of rock salt may change and present distinct failure characteristics under different stress states,which affects the performance of salt cavern during the time period of full service.To reproduce a similar loading condition on the cavern surrounding rock mass,the cyclic triaxial loading/unloading tests are performed on the rock salt to explore the mechanical transition behavior and failure characteristics under different confinement.Experimental results show that the rock salt samples pre-sent a diffused shear failure band with significant bulges at certain locations in low confining pressure conditions(e.g.5 MPa,10 MPa and 15 MPa),which is closely related to crystal misorientation and grain boundary sliding.Under the elevated confinement(e.g.20 MPa,30 MPa and 40 MPa),the dilation band dominates the failure mechanism,where the large-size halite crystals are crushed to be smaller size and new pores are developing.The failure transition mechanism revealed in the paper provides additional insight into the mechanical performance of salt caverns influenced by complicated stress states.
基金the Key R&D Program of Zhejiang,No.2023C03029Health Science and Technology Plan of Zhejiang Province,No.2022RC201Zhejiang Provincial Natural Science Foundation Project,No.LY20H030007.
文摘BACKGROUND Various animal models have been used to explore the pathogenesis of choledochal cysts(CCs),but with little convincing results.Current surgical techniques can achieve satisfactory outcomes for treatment of CCs.Consequently,recent studies have focused more on clinical issues rather than basic research.Therefore,we need appropriate animal models to further basic research.AIM To establish an appropriate animal model that may contribute to the investigation of the pathogenesis of CCs.METHODS Eighty-four specific pathogen-free female Sprague-Dawley rats were randomly allocated to a surgical group,sham surgical group,or control group.A rat model of CC was established by partial ligation of the bile duct.The reliability of the model was confirmed by measurements of serum biochemical indices,morpho-logy of common bile ducts of the rats as well as molecular biology experiments in rat and human tissues.RESULTS Dilation classified as mild(diameter,≥1 mm to<3 mm),moderate(≥3 mm to<10 mm),and severe(≥10 mm)was observed in 17,17,and 2 rats in the surgical group,respectively,while no dilation was observed in the control and sham surgical groups.Serum levels of alanine aminotransferase,aspartate aminotrans-ferase,total bilirubin,direct bilirubin,and total bile acids were significantly elevated in the surgical group as compared to the control group 7 d after surgery,while direct bilirubin,total bilirubin,and gamma-glutamyltransferase were further increased 14 d after surgery.Most of the biochemical indices gradually decreased to normal ranges 28 d after surgery.The protein expression trend of signal transducer and activator of transcription 3 in rat model was consistent with the human CC tissues.CONCLUSION The model of partial ligation of the bile duct of juvenile rats could morphologically simulate the cystic or fusiform CC,which may contribute to investigating the pathogenesis of CC.
文摘BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,skin changes(POEMS)syndrome is a rare paraneoplastic syndrome that encompass multiple systems.The most common clinical symptoms of POEMS syndrome are pro-gressive sensorimotor polyneuropathy,organ enlargement,endocrine disorders,darkening skin,a monoclonal plasma cell proliferative disorder,and lymph node hyperplasia.The organomegaly consists of hepatosplenomegaly and/or lym-phadenopathy;cases of cardiomyopathy are rare.Diagnoses are often delayed because of the atypical nature of the syndrome,exposing patients to possibly severe disability.Therefore,identifying atypical symptoms can improve the prognosis and quality of life among POEMS syndrome patients.lenalidomide and dexamethasone.CONCLUSION When patients with cardiomyopathy have systemic manifestations such as numb limbs and darkening skin,the POEMS syndrome is the most possible diagnosis.
基金Supported by National Natural Science Foundation of China,No.81970241Tianfu Qingcheng Project-Tianfu Science and Technology Elite,No.1358.
文摘BACKGROUND Bradycardia-induced cardiomyopathy(BIC),which is a disease resulting from bradycardia,is characterized by cardiac chamber enlargement and diminished cardiac function.The correction of bradycardia can allow for significant improvements in both cardiac function and structure;however,this disease has been infrequently documented.In this case,we conducted a longitudinal followup of a patient who had been enduring BIC for more than 40 years to heighten awareness and prompt timely diagnosis and rational intervention.CASE SUMMARY A woman who presented with postactivity fatigue and dyspnea was diagnosed with bradycardia at the age of 7.Since she had no obvious symptoms,she did not receive any treatment to improve her bradycardia during the 42-year follow-up,except for the implantation of a temporary pacemaker during labor induction surgery.As time progressed,the patient's heart gradually expanded due to her low ventricular rate,and she was diagnosed with BIC.In 2014,the patient developed atrial fibrillation,her ventricular rate gradually increased,and her heart shape gradually returned to normal.This report describes the cardiac morphological changes caused by the heart rate changes in BIC patients older than 40 years,introduces another possible outcome of BIC,and emphasizes the importance of early intervention in treating BIC.CONCLUSION BIC can induce atrial fibrillation,causing an increased ventricular rate and leading to positive cardiac remodeling.
文摘Radiological imaging findings may contribute to the differentiation of malignant biliary obstruction from choledocholithiasis in the etiology of acute cholangitis.
文摘Radiological studies play a crucial role in the evaluation of patients with biliary duct obstruction,allowing for the guidance of clinical diagnosis towards a malignant or stone-induced etiology through the recognition of relevant imaging features,which must be continuously revisited given their prognostic significance.This article aims to emphasize the importance of recognizing crucial imaging aspects of malignant and stone-induced biliary obstruction.
基金Supported by National Natural Science Foundation of China,No.82170676Natural Science Foundation of Shaanxi Provincial Key Industries Innovation Chain(Cluster)-Social Development Project,No.2020ZDLSF02-03Xi’an Talents Plan Project:Clinical Application of Minimally Invasive Treatment of Alimentary Tract Malformation in Children by Combining Medical and Industrial Innovative Technology of Magnetic Surgery,No.XAYC210064.
文摘BACKGROUND Giant congenital biliary dilation(CBD)is a rare condition observed in clinical practice.Infants born with this condition often experience a poor overall health status,and the disease progresses rapidly,leading to severe biliary obstruction,infections,pressure exerted by the enlarged CBD on abdominal organs,disturbances in the internal environment,and multiple organ dysfunction.The treatment of giant CBD using laparoscopy is challenging due to the high degree of variation in the shape of the bile duct and other organs,making it difficult to separate the bile duct wall from adjacent tissues or to control bleeding.CASE SUMMARY Herein,we present the details of an 11-d-old male newborn who was diagnosed with giant CBD.The patient was admitted to the neonatal surgery department of our hospital due to a history of common bile duct cyst that was detected more than 3 mo ago,and also because the patient had been experiencing yellowish skin for the past 9 d.The abnormal echo in the fetal abdomen was first noticed by the patient’s mother during a routine ultrasound examination at a local hospital,when the patient was at 24 wk+6 d of pregnancy.This finding raised concerns about the possibility of congenital biliary dilatation(22 mm×21 mm).Subsequent ultrasound examinations at different hospitals consistently confirmed the presence of a congenital biliary dilatation.No specific treatment was administered for biliary dilatation during this period.A computed tomography scan conducted during the hospitalization revealed a large cystic mass in the right upper quadrant and pelvis,measuring approximately 9.2 cm×7.4 cm×11.3 cm.Based on the CONCLUSION The analysis reveals that prenatal imaging techniques,such as ultrasound and magnetic resonance imaging,play a crucial role in the early diagnosis,fetal prognosis,and treatment plan for giant CBD.Laparoscopic surgery for giant CBD presents certain challenges,including difficulties in separating the cyst wall,anastomosis,and hemostasis,as well as severe biliary system infection and ulceration.Consequently,there is a high likelihood of converting to laparotomy.The choice between surgical methods like hepaticojejunostomy(HJ)or hepaticoduodenostomy has not been standardized yet.However,we have achieved favorable outcomes using HJ.Preoperative management of inflammation,biliary drainage,liver function protection,and supportive treatment are particularly vital in improving children’s prognosis.After discharge,it is essential to conduct timely reexamination and close follow-up to identify potential complications.
文摘BACKGROUND At present,there is no unified and effective treatment for extreme corrosive esophageal stenosis(CES)with esophagotracheal fistula(ETF).This case had extreme and severe esophageal stenosis(ES)and ETF after ingesting an enzyme-based chemical detergent,resulting in a serious pulmonary infection and severe malnutrition.Upper gastrointestinal imaging showed that he had an ETF,and endoscopy showed that he had extreme and severe esophageal stricture.This case was complex and difficult to treat.According to the domestic and foreign lite-rature,there is no universal treatment that is low-risk.CASE SUMMARY A patient came to our hospital with extreme ES,an ETF,and severe malnutrition complicated with pulmonary tuberculosis 1 mo after the consumption of an enzy-me-based detergent.The ES was serious,and the endoscope was unable to pass through the esophagus.We treated him by endoscopic incision method(EIM),esophageal stent placement(ESP),and endoscopic balloon dilation(EBD)by using the bronchoscope and gastroscope.This treatment not only closed the ETF,but also expanded the esophagus,with minimal trauma,greatly reducing the pain of the patient.According to the literature,there are no similar reported cases.CONCLUSION We report,for the first time,a patient with extreme CES complicated with ETF,where the endoscope could not be passed through his esophagus but he could be examined by bronchoscopy and treated by EIM,ESP,and EBD.
基金The study was reviewed and approved by the Research Ethics Committee of Republican Scientific and Practical Center of Pediatric Surgery Minsk,Republic of Belarus(Protocol 9 of August 24,2023).
文摘BACKGROUND Incomplete congenital duodenal obstruction(ICDO)is caused by a congenitally perforated duodenal web(CPDW).Currently,only six cases of balloon dilatation of the PDW in newborns have been described.AIM To present our experience of balloon dilatation of a perforated duodenal memb-rane in newborns with ICDO.METHODS Five newborns who underwent balloon dilatation of the CPDW along a prein-stalled guidewire between 2021 and 2023 were included.Nineteen newborns diagnosed with ICDO who underwent laparotomy were included in the control group.RESULTS In all cases,good anatomical and clinical results were obtained.In three cases,a follow-up study was conducted after 1 year.The average time to start enteral feeding per os was significantly earlier in the study group(4.4 d)than in the laparotomic group(21.2 days;P<0.0001).The time spent by patients in the intensive care unit and hospital after balloon dilatation was also significantly shorter.We determined the selection criteria for possible and effective CPDW balloon dilatation in newborns as follows:(1)Presence of dynamic radiographic signs of the passage of a radiopaque substance beyond the zone of narrowing or radiographic signs of pneumatisation of the duodenum and small bowel distal to the web;(2)presence of endoscopic signs of CPDW;(3)successful cannulation with a guidewire performed parallel to the endoscope,with holes in the congenital duodenal web;and(4)successful positioning of the balloon performed along a freestanding guidewire on the web.CONCLUSION Strictly following selection criteria for newborns with ICDO caused by CPDW ensures that endoscopic balloon dilatation using a pre-installed guidewire is safe and effective and shows good 1-year follow-up results.
文摘BACKGROUND Tracheostomy is commonly used in intensive care unit(ICU)patients who are expected to be on long-term mechanical ventilation or suffer from emergency upper airway obstruction.However,some studies have conflicting findings regarding the optimal technique and its timing and benefits.AIM To provide evidence of practice,characteristics,and outcome concerning tracheostomy in an ICU of a tertiary care hospital.METHODS This was a retrospective cohort study including adult critical care patients in a single ICU for two consecutive years.Patients’demographic characteristics,severity of illness(APACHE II score),level of consciousness[Glasgow Coma Scale(GCS)],comorbidities,timing and type of tracheostomy procedure performed and outcome were recorded.We defined late as tracheostomy placement after 8 days or no tracheotomy.RESULTS Data of 660 patients were analyzed(median age of 60 years),median APACHE II score of 19 and median GCS score of 12 at admission.Tracheostomy was performed in 115 patients,of whom 63 had early and 52 late procedures.Early tracheostomy was mainly executed in case of altered level of consciousness and severe critical illness polyneuromyopathy,however there were no significant statistical results(47.6%vs 36.5%,P=0.23)and(23.8%vs 19.2%,P=0.55)respectively.Regarding the method selected,early surgical tracheostomy(ST)was conducted in patients with maxillofacial injuries(50.0%vs 0.0%,P=0.033),whereas late surgical tracheostomy was selected for patients with goiter(44.4%vs 0.0%P=0.033).Patients with early tracheostomy spent significantly fewer days on mechanical ventilation(15.3±8.5 vs 22.8±9.6,P<0.001)and in ICU in general(18.8±9.1 vs 25.4±11.5,P<0.001).Percutaneous dilatation tracheostomy(PDT)vs ST was preferable in older critical care patients in the case of Central Nervous System underlying cause of admission(62.5%vs 26.3%,P=0.004).ST was the method of choice in compromised airway(31.6%,vs 7.3%P=0.008).A large proportion of patients(88/115)with tracheostomy managed to wean from mechanical ventilation and were transferred out of the ICU(100%vs 17.4%,P<0.001).CONCLUSION PDT was performed more frequently in our cohort.This technique did not affect mechanical ventilation days,ventilator-associated pneumonia(VAP),ICU length of stay,or survival.No complications were observed in the percutaneous or surgical tracheostomy groups.Patients undergoing early tracheostomy benefited in terms of mechanical ventilation days and ICU length of stay but not of discharge status,presence of VAP,or survival.
文摘The choledochal cyst(CC)can be better termed as biliary tract malformation because of the close association of embryology and etiology in the causation of CC.Contrary to Babbitt's postulation of reflux,damage and dilatation,reflux was not demonstrable as the causative factor in all varieties of CC.High pressure in the biliary system,otherwise termed ductal hypertension,is put forth as an alternative to explain the evolution of CC.The forme fruste type,which does not find a place in the standard classification,typifies the ductal hypertension hypothesis.Hence a closer,in-depth review would be able to highlight this apt terminology of biliary tract malformation.
文摘The article collectively proposes a revolutionary perspective on the universe, intertwining concepts of time, spatial positioning, and cosmic dynamics. We introduce the idea of a rotating universe centered around Mega Central Energy Pools (MCEPs), where time varies relative to the distance from the universe’s center, potentially enabling time travel. This model challenges conventional notions of time and cosmology, suggesting that black holes and white holes act as cosmic recycling factories. Additionally, this model unveils a novel theory of dark matter, positing photons as its constituents and highlighting their role in energy transfer across the cosmos. Furthermore, the investigation into Venus’s unique day-length-to-year-length ratio unveils a microscopic mechanism involving swirling energy droplets, charged particles, and field interactions, offering insights into planetary dynamics on both micro and macro scales.
文摘Dilated cardiomyopathy(DCM)is a common myocardial disease characterized by enlargement of the heart cavity and decreased systolic function,often leading to heart failure(HF)and arrhythmia.The occurrence of atrial fibrillation(AF)is closely related to the progression and prognosis of the disease.In recent years,with the advancement of medical imaging and biomarkers,models for predicting the occurrence of AF in DCM patients have gradually become a research hotspot.This article aims to review the current situation of AF in DCM patients and explore the importance and possible methods of constructing predictive models to provide reference for clinical prevention and treatment.We comprehensively analyzed the risk factors for AF in DCM patients from epidemiological data,pathophysiological mechanisms,clinical and laboratory indicators,electrocardiogram and imaging parameters,and biomarkers,and evaluated the effectiveness of existing predictive models.Through analysis of existing literature and research,this article proposes a predictive model that integrates multiple parameters to improve the accuracy of predicting AF in DCM patients and provide a scientific basis for personalized treatment.
文摘Metrological analysis shows that any clock in inertial motion in infinite space shall not have time dilation, due to relativity of such motion in such space. On the other hand, atomic clock in inertial motion in finite space shall exhibit time dilation, due to alteration of momentum of clock-defining particle caused by nonzero curvature of trajectory of such motion in such space. Therefore, time dilation experiment of atomic clock in inertial motion in physical space provides a direct and decisive way of determining geometry of physical space in real-time. Phenomenon of time dilation of atomic clock in inertial motion in physical space has long been observed and confirmed experimentally. Therefore, extent of physical space has to be finite, consistent with result of high precision experiment of free particle in high-speed motion conducted a decade ago.Keywords Geometry of Physical Space, Time Dilation, Atomic Clock, Special Relativity Theory.
文摘This paper is a further elaboration of the author’s Time Dilation Cosmology (TDC) holographic model that ties gravitation and celestial mechanics and kinematics directly to time dilation, resolving all the major conundrums in astrophysics, and ties astrophysics directly to quantum physics. It begins with a brief summary of the TDC model and contains the new derivation for the time dilation version of the formula for summing relativistic velocities, Einstein’s gravitational constant and the time dilation versions for the Lorentz factor and the Euclidean norm of the 3d velocity vector, the two of which can then be used in the Four-velocity formula. It is demonstrated how orbital curvature is manifested as the resultant of two time dilation-manifested velocities. It also explains why an interferometer cannot distinguish free fall from zero gravity and further elaborates on the author’s previous explanations of how spiral galaxies are formed, and contains mathematical proof that Black Holes are actually Magnetospheric Eternally Collapsing Objects (MECOs) that are massless spacetime vortices.