In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was prepared.The effect of the second phases,initial texture and deformation behavior on this low mechani...In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was prepared.The effect of the second phases,initial texture and deformation behavior on this low mechanical anisotropy was investigated.The results revealed that the alloy tube contains the high content(Mg1-xZnx)11Ce phase and the low content of Mg12Ce phase.These second phases are respectively incoherent and coherent with the Mg matrix,and their influence can be ignored.Additionally,the alloy tube exhibited a weak basal fiber texture,where the c-axis was aligned along the 0°∼30°tilt from TD to ED.Such a texture made the initial deformation(at 1.0%∼1.6%strain)of the three samples controlled by comparable basalslip.As deformation progressed(1.6∼9.0%strain),larger amounts of ETWs nucleated and gradually approached saturation in the three samples,re-orienting the c-axis to a 0°∼±30°deviation with respect to the loading directions.Meanwhile,the prismatic and pyramidal<c+a>slips replaced the dominant deformation progressively until fracture.Eventually,the similar deformation mechanisms determined by the weak initial texture in the three samples contribute to the comparable strain hardening rates,resulting in the low compressive anisotropy of the alloy tube.展开更多
In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to c...In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without corrugations.The results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube sandwich.Furthermore,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their efficiency.Additionally,the tapered corrugated tubes'resistance to oblique impacts was studied.Compared to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical simulations.After conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall thickness.EA and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10.展开更多
BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its...BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its placement are often underes-timated.Upper airway obstruction with a NGT is an uncommon but potentially life-threatening complication.NGT syndrome is characterized by the presence of an NGT,throat pain and vocal cord(VC)paralysis,usually bilateral.It is poten-tially life–threatening,and early diagnosis is the key to the prevention of fatal upper airway obstruction.However,fewer cases may have been reported than might have occurred,primarily due to the clinicians'unawareness.The lack of specific signs and symptoms and the inability to prove temporal relation with NGT insertion has made diagnosing the syndrome quite challenging.AIM To review and collate the data from the published case reports and case series to understand the possible risk factors,early warning signs and symptoms for timely detection to prevent the manifestation of the complete syndrome with life-threatening airway obstruction.METHODS We conducted a systematic search for this meta-summary from the database of PubMed,EMBASE,Reference Citation Analysis(https://www.referencecitation-analysis.com/)and Google scholar,from all the past studies till August 2023.The search terms included major MESH terms"Nasogastric tube","Intubation,Gastrointestinal","Vocal Cord Paralysis",and“Syndrome”.All the case reports and case series were evaluated,and the data were extracted for patient demographics,clinical symptomatology,diagnostic and therapeutic interventions,clinical course and outcomes.A datasheet for evaluation was further prepared.RESULTS Twenty-seven cases,from five case series and 13 case reports,of NGT syndrome were retrieved from our search.There was male predominance(17,62.96%),and age at presentation ranged from 28 to 86 years.Ten patients had diabetes mellitus(37.04%),and nine were hypertensive(33.33%).Only three(11.11%)patients were reported to be immunocompromised.The median time for developing symptoms after NGT insertion was 14.5 d(interquartile range 6.25-33.75 d).The most commonly reported reason for NGT insertion was acute stroke(10,37.01%)and the most commonly reported symptoms were stridor or wheezing 17(62.96%).In 77.78%of cases,bilateral VC were affected.The only treatment instituted in most patients(77.78%)was removing the NG tube.Most patients(62.96%)required tracheostomy for airway protection.But 8 of the 23 survivors recovered within five weeks and could be decannulated.Three patients were reported to have died.CONCLUSION NGT syndrome is an uncommon clinical complication of a very common clinical procedure.However,an under-reporting is possible because of misdiagnosis or lack of awareness among clinicians.Patients in early stages and with mild symptoms may be missed.Further,high variability in the presentation timing after NGT insertion makes diagnosis challenging.Early diagnosis and prompt removal of NGT may suffice in most patients,but a significant proportion of patients presenting with respiratory compromise may require tracheostomy for airway protection.展开更多
The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and damage.The disposable fracturing tube has been developed and is gradually replacing t...The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and damage.The disposable fracturing tube has been developed and is gradually replacing the Cardox tube.However,there is a lack of impact pressure testing of disposable tubes under real working conditions,selection of gas explosion design parameters,and systematic analysis of blasting vibration.This limitation has constrained the widespread application of disposable fracturing tubes in engineering.A joint monitoring of the pressure-time curves in the disposable tubes and boreholes was conducted.The rock-breaking effect of varying hole spacing parameters in the EFLCO_(2)design was analyzed,and a systematic study was carried out on the vibration peak value,frequency,and energy characteristics.The results show that(1)the pressure distribution characteristics,stress peak value,and duration in the disposable tubes are different from those of Cardox tubes,which show multi-peak distribution,low-pressure peak value,and short duration.The correlation between the pressure in the disposable tube,filling pressure,and liquid CO_(2)weight is established,and a theoretical calculation method for the borehole wall pressure is proposed;(2)The hole spacing in rocks of different hardness is suggested;and(3)At the same scale distance,the peak particle velocity(PPV)caused by EFLCO_(2)(PPVCO_(2))is significantly smaller than that caused by blasting(PPVexplosive).The ratio of PPVexplosive to PPVCO_(2)is a power function related to scale distance,and a distance-related zonality exist in this relationship.The frequency composition of the vibration signal caused by EFLCO_(2)is relatively simple with a narrow frequency band.Its PPV and energy are mainly concentrated in the low-frequency band.This research contributes to the optimization of disposable fracturing tubes,gas explosion design,and vibration hazard control.展开更多
Thin-walled structures are widely used in cars due to their lightweight construction and energy-absorbing properties.However,issues such as high initial stress and lowenergy-absorbing efficiency arise.This study propo...Thin-walled structures are widely used in cars due to their lightweight construction and energy-absorbing properties.However,issues such as high initial stress and lowenergy-absorbing efficiency arise.This study proposes a novel energy-absorbing structure inwhich a straight tube is combinedwith a conical tube and a bamboo-inspired bulkhead structure is introduced.This configuration allows the conical tube to flip outward first and then fold together with the straight tube.This deformation mode absorbs more energy and less peak force than the conical tube sinking and flipping inward.Through finite element numerical simulation,the specific energy absorption capacity of the structure is increased by 26%compared to that of a regular circular cross-section tube.Finally,the impact resistance of the bionic straight tapered tube structure is further improved through multi-objective optimization,promoting the engineering application and lightweight design of hybrid cross-section tubes.展开更多
Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their mac...Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their macroscopic assembly.The present study employed a gentle and direct self-assembly technique,wherein controlled growth of CNT sheaths occurred on the metal wire’s surface,followed by etching of the remaining metal to obtain the hollow tubes composed of CNTs.By controlling the growth time and temperature,it is possible to alter the thickness of the CNTs sheath.After immersing in a solution containing 1 g/L of CNTs at 60℃ for 24 h,the resulting CNTs layer achieved a thickness of up to 60μm.These hollow CNTs tubes with varying inner diameters were prepared through surface reinforcement using polymers and sacrificing metal wires,thereby exhibiting exceptional attributes such as robustness,flexibility,air tightness,and high adsorption capacity that effectively capture CO_(2) from the gas mixture.展开更多
In this paper, a novel efficient energy absorber with free inversion of a metal foam-filled circular tube(MFFCT) is designed, and the axial compressive behavior of the MFFCT under free inversion is studied analyticall...In this paper, a novel efficient energy absorber with free inversion of a metal foam-filled circular tube(MFFCT) is designed, and the axial compressive behavior of the MFFCT under free inversion is studied analytically and numerically. The theoretical analysis reveals that the energy is mainly dissipated through the radial bending of the metal circular tube, the circumferential expansion of the metal circular tube, and the metal filled-foam compression. The principle of energy conservation is used to derive the theoretical formula for the minimum compressive force of the MFFCT over free inversion under axial loading. Furthermore, the free inversion deformation characteristics of the MFFCT are analyzed numerically. The theoretical steady values are found to be in good agreement with the results of the finite element(FE) analysis. The effects of the average diameter of the metal tube, the wall thickness of the metal tube, and the filled-foam strength on the free inversion deformation of the MFFCT are considered. It is observed that in the steady deformation stage, the load-carrying and energy-absorbing capacities of the MFFCT increase with the increase in the average diameter of the metal tube, the wall thickness of the metal tube, or the filled-foam strength. The specific energy absorption(SEA) of free inversion of the MFFCT is significantly higher than that of the metal tube alone.展开更多
The radiant tube burner was modeled and analyzed by the numerical simulation method to investigate the influence factors and rules of NO_(x) emissions in a W-type radiant tube.These factors,which include air preheatin...The radiant tube burner was modeled and analyzed by the numerical simulation method to investigate the influence factors and rules of NO_(x) emissions in a W-type radiant tube.These factors,which include air preheating temperature,excess air coefficient,and fuel gas composition,were modified to study their effects on NO_(x) emissions under varying working conditions.Simulation results were compared with the theoretical calculation value based on chemical reaction equilibrium theory and the onsite experimental value to verify the simulation accuracy.The results show that NO_(x) emissions rise with increasing air preheating temperatures.NO_(x) production increases to an extreme value and then decreases during the oxygen-poor to oxygen-enriched process with the rise of the excess air coefficient.Enhancing the proportion of coke oven gas in the fuel gas raises the combustion temperature as well as the NO_(x) discharge.Both the thermal efficiency and NO_(x) emissions should be balanced.Therefore,the recommended values based on the simulation results are as follows:the air preheating temperature should not exceed 400℃,the excess air coefficient should be between 1.1 and 1.2,and the volume fraction of the coke oven gas should not exceed 30%.展开更多
Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention ...Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention from medical staff.The aim of this study was to explore the influence of a new abdominal drainage tube fixation method for 3-port laparoscopic cholecystectomy(LC)on patients’postoperative quality of life.Methods Patients who underwent 3-port LC with abdominal drainage tubes in the Department of Hepatobiliary Surgery of Linyi People’s Hospital from March 1,2023 to October 31,2023 due to gallstones with chronic cholecystitis were selected for this study.The patients were randomly divided into an experimental group and a control group.In the experimental group,the new abdominal drainage tube fixation method was used,while in the control group,the traditional method was used.Afterward,the quality of life of patient in terms of pain,activity,recovery time,and mental health status was evaluated.The exudate around the patient’s drainage tube was collected for bacterial culture and analysis.Results A total of 139 patients were randomly divided into an experimental group(70 patients)and a control group(69 patients).The patients’baseline characteristics were not significantly different.The patients in the experimental group had better outcomes in quality of life,with higher pain scores(24.03±2.37 vs.15.48±2.29,p<0.001)and activity scores(20.57±1.78 vs.14.13±1.43,p<0.001),and a shorter postoperative recovery time(2.36±0.68 d vs.2.96±1.34 d,p<0.001).The same results were shown in linear regression analysis scores of the 2 groups.The positive rate of bacterial culture in the exudate around the patient’s drainage tube in the experimental group was significantly lower than that in the control group(12.9%vs.43.5%,p<0.001);and furthermore,the positive rate of conditional pathogenic bacteria was even lower(7.1%vs.33.3%,p<0.001)in the experimental group than in the control group.Conclusion This new abdominal drainage tube fixation method can effectively promote patient rehabilitation and improve the quality of life for patient following 3-port LC with abdominal drainage tubes.展开更多
BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnorm...BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnormalities and fallopian tube highgrade serous carcinoma(HGSC)in a young woman.CASE SUMMARY A 35-year-old woman presented with acute dull abdominal pain and a known chromosomal abnormality involving 4q13.3 duplication and 4q23q24 deletion.Upon arrival at the emergency room,her abdomen appeared ovoid and distended with palpable shifting dullness.Ascites were identified through abdominal ultrasound,and computed tomography revealed an omentum cake and an enlarged bilateral adnexa.Blood tests showed elevated CA-125 levels.Paracentesis was conducted,and immunohistochemistry indicated that the cancer cells favored an ovarian origin,making us suspect ovarian cancer.The patient underwent debulking surgery,which led to a diagnosis of stage IIIC HGSC of the fallopian tube.Subsequently,the patient received adjuvant chemotherapy with carboplatin and paclitaxel,resulting in stable current condition.CONCLUSION This study demonstrates a rare correlation between a chromosome 4q abnormality and HGSC.UBE2D3 may affect crucial cancer-related pathways,including P53,BRCA,cyclin D,and tyrosine kinase receptors,thereby possibly contributing to cancer development.In addition,ADH1 and DDIT4 may be potential influencers of both carcinogenic and therapeutic responses.展开更多
The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically.The effects of wire coil distribution(circular cross section)within the ...The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically.The effects of wire coil distribution(circular cross section)within the tube were explored experimentally,and water was employed as the working fluid.The numerical simulation was carried out using software programmer ANSYS Fluent 2019 R3 using the finite-volume approach.In the turbulent regime,six cross-sectionedwire coilswere analyzed,including:circular,rectangular,hexagonal,square,star shape,and triangle.The utilization of a tube with a wire coil has been shown to increase heat transfer rate and pump consumption.The results indicate a high level of concurrence,as the deviations are all below 8%.Compared with plain tube,the wire coils,according to the arrangement(TWD),gave the best PEC.The heat transfer enhancement ability of different cross sections follows the following order:StCS>RCS>HCS>SqCS>CCS>TCS.Also,the sequence of pump consumption for each cross section is as follows:RCS>StCS>SqCS>HCS>CCS>TCS.展开更多
Objective:To systematically evaluate the effect of modified length of gastric tube implantation in stroke patients.Methods:Randomized controlled studies on the effect of narrative therapy on negative emotions of malig...Objective:To systematically evaluate the effect of modified length of gastric tube implantation in stroke patients.Methods:Randomized controlled studies on the effect of narrative therapy on negative emotions of malignant tumor patients were published in PubMed,EMbase,Web of Science,Cochrane Library,CNKY.Wanfang Data,VIP Database and CBM disc from database establishment to May 2021.RewMan 5.2 software was used for the meta-analysis.Results:Ten articles were included,involving 1140 patients in total.Results of meta-analysis showed that improved length of gastric tube implantation could reduce the incidence of aspiration pneumonia in stroke patients with enteral nutrition[OR=0.18,95%CI(0.10,0.31),P<0.00001],reduce gastroesophageal reflux rate[OR=0.13,95%CI(0.04,0.38),P<0.0002],the incidence of aspiration[OR=0.23,95%CI(0.11,0.38),P<0.00001],the incidence of abdominal distension and diarrhea[OR=0.13,95%CI(0.06,0.28),P<0.00001],the incidence of choking cough[OR=0.20,95%CI(0.07,0.61),P<0.005],but no difference between the two groups in terms of reducing gastric residual[OR=0.10,95%CI(2.40,2.60),P=0.94].Conclusions:The modified length of the gastric tube can replace the traditional length of the gastric tube in the application of stroke patients,can reduce the complications of enteral nutrition,is safe and feasible.However,due to the limitation of the quality and quantity of the included studies,we should be cautious about the results of this meta-analysis and expect to carry out more large-sample and high-quality randomized controlled trials for demonstration.展开更多
背景:目前运动疗法是非药物治疗腰痛的有效方法,运动疗法可通过骨骼和肌肉之间的机械-化学偶联维持腰椎的稳定,但目前尚无关于运动疗法通过机械-化学偶联缓解慢性非特异性下背痛之间研究进展及最佳治疗方案的明确阐述。目的:综述运动疗...背景:目前运动疗法是非药物治疗腰痛的有效方法,运动疗法可通过骨骼和肌肉之间的机械-化学偶联维持腰椎的稳定,但目前尚无关于运动疗法通过机械-化学偶联缓解慢性非特异性下背痛之间研究进展及最佳治疗方案的明确阐述。目的:综述运动疗法时椎旁肌通过机械-化学偶联影响腰椎稳定性进而缓解慢性非特异性下背痛的相关研究进展,以及目前运动疗法治疗慢性非特异性下背痛的最佳方案。方法:在万方数据库、中国知网、维普、Web of Science和PubMed数据库进行文献检索,以“慢性非特异性下背痛,腰椎稳定,椎旁肌,运动疗法”为中文检索词,以“chronic nonspecific low back pain,lumbar stabilization,paravertebral muscle,exercise therapy”为英文检索词,检索各数据库建库至2024年1月发表的相关文献,最终纳入93篇文献进行归纳总结。结果与结论:运动疗法可以通过适当的机械刺激作用于椎旁肌和骨骼并使其产生相应的变化。运动疗法主要通过机械-化学偶联方式来提高椎旁肌的质量,进而维持腰椎稳定,从而更好地缓解慢性非特异性下背痛,是慢性非特异性下背痛的重要干预措施。但是,对于运动疗法通过腰椎稳定来治疗慢性非特异性下背痛的确切有效方案尚无明确报道。个体化运动方案的制定对于慢性非特异性下背痛的治疗和预后尤为重要。同一个体的肌肉质量与骨骼质量是密切相关的,影像学评估椎旁肌的质量和体积对于疾病的发现和干预具有重要意义。展开更多
基金supported by the National Natural Science Foundation of China(Nos.51974082,51901037)State Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization(No.2021H2279)Programme of Introducing Talents of Discipline Innovation to Universities 2.0(the 111 Project 2.0 of China,No.BP0719037).
文摘In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was prepared.The effect of the second phases,initial texture and deformation behavior on this low mechanical anisotropy was investigated.The results revealed that the alloy tube contains the high content(Mg1-xZnx)11Ce phase and the low content of Mg12Ce phase.These second phases are respectively incoherent and coherent with the Mg matrix,and their influence can be ignored.Additionally,the alloy tube exhibited a weak basal fiber texture,where the c-axis was aligned along the 0°∼30°tilt from TD to ED.Such a texture made the initial deformation(at 1.0%∼1.6%strain)of the three samples controlled by comparable basalslip.As deformation progressed(1.6∼9.0%strain),larger amounts of ETWs nucleated and gradually approached saturation in the three samples,re-orienting the c-axis to a 0°∼±30°deviation with respect to the loading directions.Meanwhile,the prismatic and pyramidal<c+a>slips replaced the dominant deformation progressively until fracture.Eventually,the similar deformation mechanisms determined by the weak initial texture in the three samples contribute to the comparable strain hardening rates,resulting in the low compressive anisotropy of the alloy tube.
基金the grants from the National Natural Science Foundation of China(Nos.52078152 and 12002095)Guangzhou Government-University Union Fund(No.202201020532)。
文摘In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without corrugations.The results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube sandwich.Furthermore,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their efficiency.Additionally,the tapered corrugated tubes'resistance to oblique impacts was studied.Compared to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical simulations.After conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall thickness.EA and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10.
文摘BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its placement are often underes-timated.Upper airway obstruction with a NGT is an uncommon but potentially life-threatening complication.NGT syndrome is characterized by the presence of an NGT,throat pain and vocal cord(VC)paralysis,usually bilateral.It is poten-tially life–threatening,and early diagnosis is the key to the prevention of fatal upper airway obstruction.However,fewer cases may have been reported than might have occurred,primarily due to the clinicians'unawareness.The lack of specific signs and symptoms and the inability to prove temporal relation with NGT insertion has made diagnosing the syndrome quite challenging.AIM To review and collate the data from the published case reports and case series to understand the possible risk factors,early warning signs and symptoms for timely detection to prevent the manifestation of the complete syndrome with life-threatening airway obstruction.METHODS We conducted a systematic search for this meta-summary from the database of PubMed,EMBASE,Reference Citation Analysis(https://www.referencecitation-analysis.com/)and Google scholar,from all the past studies till August 2023.The search terms included major MESH terms"Nasogastric tube","Intubation,Gastrointestinal","Vocal Cord Paralysis",and“Syndrome”.All the case reports and case series were evaluated,and the data were extracted for patient demographics,clinical symptomatology,diagnostic and therapeutic interventions,clinical course and outcomes.A datasheet for evaluation was further prepared.RESULTS Twenty-seven cases,from five case series and 13 case reports,of NGT syndrome were retrieved from our search.There was male predominance(17,62.96%),and age at presentation ranged from 28 to 86 years.Ten patients had diabetes mellitus(37.04%),and nine were hypertensive(33.33%).Only three(11.11%)patients were reported to be immunocompromised.The median time for developing symptoms after NGT insertion was 14.5 d(interquartile range 6.25-33.75 d).The most commonly reported reason for NGT insertion was acute stroke(10,37.01%)and the most commonly reported symptoms were stridor or wheezing 17(62.96%).In 77.78%of cases,bilateral VC were affected.The only treatment instituted in most patients(77.78%)was removing the NG tube.Most patients(62.96%)required tracheostomy for airway protection.But 8 of the 23 survivors recovered within five weeks and could be decannulated.Three patients were reported to have died.CONCLUSION NGT syndrome is an uncommon clinical complication of a very common clinical procedure.However,an under-reporting is possible because of misdiagnosis or lack of awareness among clinicians.Patients in early stages and with mild symptoms may be missed.Further,high variability in the presentation timing after NGT insertion makes diagnosis challenging.Early diagnosis and prompt removal of NGT may suffice in most patients,but a significant proportion of patients presenting with respiratory compromise may require tracheostomy for airway protection.
基金financially supported by the National Key R&D Program of China(Grant No.2020YFA0711802)the Wuhan Science and Technology Bureau of China(Grant No.2023020201010081)the National Nature Science Foundation of China(Grant No.U22A20239).
文摘The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and damage.The disposable fracturing tube has been developed and is gradually replacing the Cardox tube.However,there is a lack of impact pressure testing of disposable tubes under real working conditions,selection of gas explosion design parameters,and systematic analysis of blasting vibration.This limitation has constrained the widespread application of disposable fracturing tubes in engineering.A joint monitoring of the pressure-time curves in the disposable tubes and boreholes was conducted.The rock-breaking effect of varying hole spacing parameters in the EFLCO_(2)design was analyzed,and a systematic study was carried out on the vibration peak value,frequency,and energy characteristics.The results show that(1)the pressure distribution characteristics,stress peak value,and duration in the disposable tubes are different from those of Cardox tubes,which show multi-peak distribution,low-pressure peak value,and short duration.The correlation between the pressure in the disposable tube,filling pressure,and liquid CO_(2)weight is established,and a theoretical calculation method for the borehole wall pressure is proposed;(2)The hole spacing in rocks of different hardness is suggested;and(3)At the same scale distance,the peak particle velocity(PPV)caused by EFLCO_(2)(PPVCO_(2))is significantly smaller than that caused by blasting(PPVexplosive).The ratio of PPVexplosive to PPVCO_(2)is a power function related to scale distance,and a distance-related zonality exist in this relationship.The frequency composition of the vibration signal caused by EFLCO_(2)is relatively simple with a narrow frequency band.Its PPV and energy are mainly concentrated in the low-frequency band.This research contributes to the optimization of disposable fracturing tubes,gas explosion design,and vibration hazard control.
文摘Thin-walled structures are widely used in cars due to their lightweight construction and energy-absorbing properties.However,issues such as high initial stress and lowenergy-absorbing efficiency arise.This study proposes a novel energy-absorbing structure inwhich a straight tube is combinedwith a conical tube and a bamboo-inspired bulkhead structure is introduced.This configuration allows the conical tube to flip outward first and then fold together with the straight tube.This deformation mode absorbs more energy and less peak force than the conical tube sinking and flipping inward.Through finite element numerical simulation,the specific energy absorption capacity of the structure is increased by 26%compared to that of a regular circular cross-section tube.Finally,the impact resistance of the bionic straight tapered tube structure is further improved through multi-objective optimization,promoting the engineering application and lightweight design of hybrid cross-section tubes.
基金Project(ZCLTGS24B0101)supported by Zhejiang Provincial Natural Science Foundation of ChinaProject(Y202250501)supported by Scientific Research Fund of Zhejiang Provincial Education Department,ChinaProject supported by SRT Research Project of Jiaxing Nanhu University,China。
文摘Carbon nanotubes(CNTs)have garnered significant attention in the fields of science,engineering,and medicine due to their numerous advantages.The initial step towards harnessing the potential of CNTs involves their macroscopic assembly.The present study employed a gentle and direct self-assembly technique,wherein controlled growth of CNT sheaths occurred on the metal wire’s surface,followed by etching of the remaining metal to obtain the hollow tubes composed of CNTs.By controlling the growth time and temperature,it is possible to alter the thickness of the CNTs sheath.After immersing in a solution containing 1 g/L of CNTs at 60℃ for 24 h,the resulting CNTs layer achieved a thickness of up to 60μm.These hollow CNTs tubes with varying inner diameters were prepared through surface reinforcement using polymers and sacrificing metal wires,thereby exhibiting exceptional attributes such as robustness,flexibility,air tightness,and high adsorption capacity that effectively capture CO_(2) from the gas mixture.
基金Project supported by the National Natural Science Foundation of China (Nos. 12272290 and11872291)the State Key Laboratory of Automotive Safety and Energy of China (No. KFY2202)。
文摘In this paper, a novel efficient energy absorber with free inversion of a metal foam-filled circular tube(MFFCT) is designed, and the axial compressive behavior of the MFFCT under free inversion is studied analytically and numerically. The theoretical analysis reveals that the energy is mainly dissipated through the radial bending of the metal circular tube, the circumferential expansion of the metal circular tube, and the metal filled-foam compression. The principle of energy conservation is used to derive the theoretical formula for the minimum compressive force of the MFFCT over free inversion under axial loading. Furthermore, the free inversion deformation characteristics of the MFFCT are analyzed numerically. The theoretical steady values are found to be in good agreement with the results of the finite element(FE) analysis. The effects of the average diameter of the metal tube, the wall thickness of the metal tube, and the filled-foam strength on the free inversion deformation of the MFFCT are considered. It is observed that in the steady deformation stage, the load-carrying and energy-absorbing capacities of the MFFCT increase with the increase in the average diameter of the metal tube, the wall thickness of the metal tube, or the filled-foam strength. The specific energy absorption(SEA) of free inversion of the MFFCT is significantly higher than that of the metal tube alone.
文摘The radiant tube burner was modeled and analyzed by the numerical simulation method to investigate the influence factors and rules of NO_(x) emissions in a W-type radiant tube.These factors,which include air preheating temperature,excess air coefficient,and fuel gas composition,were modified to study their effects on NO_(x) emissions under varying working conditions.Simulation results were compared with the theoretical calculation value based on chemical reaction equilibrium theory and the onsite experimental value to verify the simulation accuracy.The results show that NO_(x) emissions rise with increasing air preheating temperatures.NO_(x) production increases to an extreme value and then decreases during the oxygen-poor to oxygen-enriched process with the rise of the excess air coefficient.Enhancing the proportion of coke oven gas in the fuel gas raises the combustion temperature as well as the NO_(x) discharge.Both the thermal efficiency and NO_(x) emissions should be balanced.Therefore,the recommended values based on the simulation results are as follows:the air preheating temperature should not exceed 400℃,the excess air coefficient should be between 1.1 and 1.2,and the volume fraction of the coke oven gas should not exceed 30%.
基金supported by grants from the Shandong Provincial Natural Science Foundation(No.ZR2021MH033)the Linyi People’s Hospital,and the Key R&D Plan of Linyi City(No.2023xy0029).
文摘Objective Laparoscopic surgery has become a routine general surgery with many advantages,such as alleviating abdominal pain.However,postoperative pain caused by abdominal drainage tubes has attracted little attention from medical staff.The aim of this study was to explore the influence of a new abdominal drainage tube fixation method for 3-port laparoscopic cholecystectomy(LC)on patients’postoperative quality of life.Methods Patients who underwent 3-port LC with abdominal drainage tubes in the Department of Hepatobiliary Surgery of Linyi People’s Hospital from March 1,2023 to October 31,2023 due to gallstones with chronic cholecystitis were selected for this study.The patients were randomly divided into an experimental group and a control group.In the experimental group,the new abdominal drainage tube fixation method was used,while in the control group,the traditional method was used.Afterward,the quality of life of patient in terms of pain,activity,recovery time,and mental health status was evaluated.The exudate around the patient’s drainage tube was collected for bacterial culture and analysis.Results A total of 139 patients were randomly divided into an experimental group(70 patients)and a control group(69 patients).The patients’baseline characteristics were not significantly different.The patients in the experimental group had better outcomes in quality of life,with higher pain scores(24.03±2.37 vs.15.48±2.29,p<0.001)and activity scores(20.57±1.78 vs.14.13±1.43,p<0.001),and a shorter postoperative recovery time(2.36±0.68 d vs.2.96±1.34 d,p<0.001).The same results were shown in linear regression analysis scores of the 2 groups.The positive rate of bacterial culture in the exudate around the patient’s drainage tube in the experimental group was significantly lower than that in the control group(12.9%vs.43.5%,p<0.001);and furthermore,the positive rate of conditional pathogenic bacteria was even lower(7.1%vs.33.3%,p<0.001)in the experimental group than in the control group.Conclusion This new abdominal drainage tube fixation method can effectively promote patient rehabilitation and improve the quality of life for patient following 3-port LC with abdominal drainage tubes.
文摘BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnormalities and fallopian tube highgrade serous carcinoma(HGSC)in a young woman.CASE SUMMARY A 35-year-old woman presented with acute dull abdominal pain and a known chromosomal abnormality involving 4q13.3 duplication and 4q23q24 deletion.Upon arrival at the emergency room,her abdomen appeared ovoid and distended with palpable shifting dullness.Ascites were identified through abdominal ultrasound,and computed tomography revealed an omentum cake and an enlarged bilateral adnexa.Blood tests showed elevated CA-125 levels.Paracentesis was conducted,and immunohistochemistry indicated that the cancer cells favored an ovarian origin,making us suspect ovarian cancer.The patient underwent debulking surgery,which led to a diagnosis of stage IIIC HGSC of the fallopian tube.Subsequently,the patient received adjuvant chemotherapy with carboplatin and paclitaxel,resulting in stable current condition.CONCLUSION This study demonstrates a rare correlation between a chromosome 4q abnormality and HGSC.UBE2D3 may affect crucial cancer-related pathways,including P53,BRCA,cyclin D,and tyrosine kinase receptors,thereby possibly contributing to cancer development.In addition,ADH1 and DDIT4 may be potential influencers of both carcinogenic and therapeutic responses.
文摘The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically.The effects of wire coil distribution(circular cross section)within the tube were explored experimentally,and water was employed as the working fluid.The numerical simulation was carried out using software programmer ANSYS Fluent 2019 R3 using the finite-volume approach.In the turbulent regime,six cross-sectionedwire coilswere analyzed,including:circular,rectangular,hexagonal,square,star shape,and triangle.The utilization of a tube with a wire coil has been shown to increase heat transfer rate and pump consumption.The results indicate a high level of concurrence,as the deviations are all below 8%.Compared with plain tube,the wire coils,according to the arrangement(TWD),gave the best PEC.The heat transfer enhancement ability of different cross sections follows the following order:StCS>RCS>HCS>SqCS>CCS>TCS.Also,the sequence of pump consumption for each cross section is as follows:RCS>StCS>SqCS>HCS>CCS>TCS.
文摘Objective:To systematically evaluate the effect of modified length of gastric tube implantation in stroke patients.Methods:Randomized controlled studies on the effect of narrative therapy on negative emotions of malignant tumor patients were published in PubMed,EMbase,Web of Science,Cochrane Library,CNKY.Wanfang Data,VIP Database and CBM disc from database establishment to May 2021.RewMan 5.2 software was used for the meta-analysis.Results:Ten articles were included,involving 1140 patients in total.Results of meta-analysis showed that improved length of gastric tube implantation could reduce the incidence of aspiration pneumonia in stroke patients with enteral nutrition[OR=0.18,95%CI(0.10,0.31),P<0.00001],reduce gastroesophageal reflux rate[OR=0.13,95%CI(0.04,0.38),P<0.0002],the incidence of aspiration[OR=0.23,95%CI(0.11,0.38),P<0.00001],the incidence of abdominal distension and diarrhea[OR=0.13,95%CI(0.06,0.28),P<0.00001],the incidence of choking cough[OR=0.20,95%CI(0.07,0.61),P<0.005],but no difference between the two groups in terms of reducing gastric residual[OR=0.10,95%CI(2.40,2.60),P=0.94].Conclusions:The modified length of the gastric tube can replace the traditional length of the gastric tube in the application of stroke patients,can reduce the complications of enteral nutrition,is safe and feasible.However,due to the limitation of the quality and quantity of the included studies,we should be cautious about the results of this meta-analysis and expect to carry out more large-sample and high-quality randomized controlled trials for demonstration.
文摘背景:目前运动疗法是非药物治疗腰痛的有效方法,运动疗法可通过骨骼和肌肉之间的机械-化学偶联维持腰椎的稳定,但目前尚无关于运动疗法通过机械-化学偶联缓解慢性非特异性下背痛之间研究进展及最佳治疗方案的明确阐述。目的:综述运动疗法时椎旁肌通过机械-化学偶联影响腰椎稳定性进而缓解慢性非特异性下背痛的相关研究进展,以及目前运动疗法治疗慢性非特异性下背痛的最佳方案。方法:在万方数据库、中国知网、维普、Web of Science和PubMed数据库进行文献检索,以“慢性非特异性下背痛,腰椎稳定,椎旁肌,运动疗法”为中文检索词,以“chronic nonspecific low back pain,lumbar stabilization,paravertebral muscle,exercise therapy”为英文检索词,检索各数据库建库至2024年1月发表的相关文献,最终纳入93篇文献进行归纳总结。结果与结论:运动疗法可以通过适当的机械刺激作用于椎旁肌和骨骼并使其产生相应的变化。运动疗法主要通过机械-化学偶联方式来提高椎旁肌的质量,进而维持腰椎稳定,从而更好地缓解慢性非特异性下背痛,是慢性非特异性下背痛的重要干预措施。但是,对于运动疗法通过腰椎稳定来治疗慢性非特异性下背痛的确切有效方案尚无明确报道。个体化运动方案的制定对于慢性非特异性下背痛的治疗和预后尤为重要。同一个体的肌肉质量与骨骼质量是密切相关的,影像学评估椎旁肌的质量和体积对于疾病的发现和干预具有重要意义。