Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ig...Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs.展开更多
Effect of UV-B radiation on ingesting and nutritional selecting behavior of the roifer Brachionus urceus on 5 species of microlgae were studied under controlled laboratory conditions. Restdts showed that enhanced UV-B...Effect of UV-B radiation on ingesting and nutritional selecting behavior of the roifer Brachionus urceus on 5 species of microlgae were studied under controlled laboratory conditions. Restdts showed that enhanced UV-B radiation significantly inhibited ingesting of the rotifer B. urceus when it was fed with 5 species of micro-algae （p〈0.05）. The ingesting selectivity rate varied with the UV-B radiation enhancement when it was fed with 5 species micro-algal mixture. Results indicated that the enhanced UV-B radiation could affect ingesting and nutritional selectivity of B. urceus.展开更多
Boundary layer ingesting(BLI)fans are required to operate under distorted inflow conditions,which significantly reduces their efficiency[1,2].Accurately predicting fan losses is crucial for designing high-performance,...Boundary layer ingesting(BLI)fans are required to operate under distorted inflow conditions,which significantly reduces their efficiency[1,2].Accurately predicting fan losses is crucial for designing high-performance,distortion-tolerant fans.展开更多
Caustic ingestion is a relatively rare but potentially catastrophic gastroentero-logical emergency.Upper gastrointestinal(GI)endoscopy is currently regarded as the gold standard modality not only to assess the depth a...Caustic ingestion is a relatively rare but potentially catastrophic gastroentero-logical emergency.Upper gastrointestinal(GI)endoscopy is currently regarded as the gold standard modality not only to assess the depth and the extension of GI caustic injury,but also to guide the appropriate treatment.Intriguingly,contrast-enhanced computed tomography(CECT)has recently emerged as a promising non-invasive and more accurate alternative to endoscopy in this setting.However,to date,evidence concerning the role of CECT as an alternative or complementary diagnostic tool to endoscopy in caustic ingestion is still limited.The aim of our review was to summarize and discuss the current evidence concerning the role of CECT in the emergency diagnosis of caustic ingestion and its value in assessing injury severity among non-pediatric patients.展开更多
BACKGROUND Venlafaxine,a serotonin-norepinephrine reuptake inhibitor,is widely prescribed for the treatment of major depressive disorder.At therapeutic dose,it is generally safe,with a low incidence of adverse effects...BACKGROUND Venlafaxine,a serotonin-norepinephrine reuptake inhibitor,is widely prescribed for the treatment of major depressive disorder.At therapeutic dose,it is generally safe,with a low incidence of adverse effects.However,massive venlafaxine inge-stion can cause serious cardiotoxicity,leading to life-threatening arrhythmias.CASE SUMMARY A 31-year-old woman with a history of depression ingested 14.8 g of venlafaxine along with 6 mg of estazolam and 6 mg of flunitrazepam.On admission,2 hours post-ingestion,she presented only with mild QTc prolongation.At 4 hours post-ingestion,she developed a generalized tonic-clonic seizure.Following endo-tracheal intubation,intravenous midazolam infusion was initiated and 50 g of activated charcoal was administered via a nasogastric tube.At 15 hours post-ingestion,she developed ventricular tachycardia that rapidly progressed to refr-actory ventricular fibrillation,which was successfully treated with veno-arterial extracorporeal membrane oxygenation.Toxicological analysis revealed serum ve-nlafaxine and O-desmethylvenlafaxine concentrations 17µg/mL and 10µg/mL,respectively,at 15 hours post-ingestion.CONCLUSION In cases of massive venlafaxine ingestion,continuous intensive monitoring,particularly of QTc,is essential for at least 24 hours,even when initial clinical signs are mild.If refractory ventricular arrhythmias occur,prompt ini-tiation of veno-arterial extracorporeal membrane oxygenation should be considered.展开更多
BACKGROUND Sharp foreign body ingestion can cause gastrointestinal tract mucosa injury and requires proper endoscopic removal.Typically,protective devices are used to reduce mucosal damage.This case presents an altern...BACKGROUND Sharp foreign body ingestion can cause gastrointestinal tract mucosa injury and requires proper endoscopic removal.Typically,protective devices are used to reduce mucosal damage.This case presents an alternative approach for the endoscopic removal of a large,irregular,and sharp foreign body(chicken bone)when traditional protective devices are inadequate,thus contributing to the management of such ingestions.CASE SUMMARY A 57-year-old male presented with a history of swallowing an irregular and sharp-pointed chicken bone.Emergent endoscopy showed it was tightly embedded in the esophageal wall,with minor bleeding.The chicken bone was grasped and moved cautiously using a foreign forceps.It was loosened after repeated attempts but could not pass through the pharynx.Considering possible mucosal damage,it was carefully pushed into the stomach cavity and then wrapped in a condom.The chicken bone was retrieved uneventfully by grasping the open edge of the condom with foreign forceps.No additional damage was found,except for primary esophageal injuries caused by the embedded chicken bone.The patient was discharged on the following day.Our experience demonstrated that condoms can be an alternative as a protective device under such conditions.CONCLUSION Condoms can serve as an alternative when traditional protective devices are unsuitable.Because of its smooth and oily nature,it can provide mucosal protection and lubrication during endoscopic removal.展开更多
BACKGROUND Cases of esophageal,airway,and pericardial perforations caused by chicken bone ingestion are rare worldwide,but their incidence has shown an upward trend in recent years.Injuries caused by chicken bones are...BACKGROUND Cases of esophageal,airway,and pericardial perforations caused by chicken bone ingestion are rare worldwide,but their incidence has shown an upward trend in recent years.Injuries caused by chicken bones are often more severe,leading to infections and,in extreme cases,perforation of the common carotid artery,pericardium,trachea,or even the heart,posing life-threatening risks.CASE SUMMARY We present a case of a patient who sustained combined esophageal and pericardial injuries with subsequent pericardial effusion due to chicken bone ingestion.The clinical manifestations included chest pain and widespread ST-segment elevation on electrocardiography.CONCLUSION The patient’s symptoms and signs were not entirely consistent with myocardial infarction.Chest computed tomography played a crucial role in clarifying the etiology and provided critical evidence for devising an effective treatment strategy.展开更多
Prevention has a paramount role in reducing the incidence of corrosive ingestion especially in children, yet this goal is far from being reached in developing countries, where such injuries are largely unreported and ...Prevention has a paramount role in reducing the incidence of corrosive ingestion especially in children, yet this goal is far from being reached in developing countries, where such injuries are largely unreported and their true prevalence simply cannot be extrapolated from random articles or personal experience. The specific pathophysiologic mechanisms are becoming better understood and may have a role in the future management and prevention of long-term consequences, such as esophageal strictures. Whereas the mainstay of diagnosis is considered upper gastrointestinal endoscopy, computed tomography and ultrasound are gaining a more significant role, especially in addressing the need for emergency surgery, whose morbidity and mortality remains high even in the best hands. The need to perform emergency surgery has a persistent long-term negative impact both on survival and functional outcome. Medical or endoscopic prevention of stricture is debatable, yet esophageal stents, absorbable or not, show promising data. Dilatation is the first therapeutic option for strictures and bougies should be considered especially for long, multiple and tortuous narrowing. It is crucial to avoid malnutrition, especially in developingcountries where management strategies are influenced by malnutrition and poor clinical conditions. Late reconstructive surgery, mainly using colon transposition, offers the best results in referral centers, either in children or adults, but such a difficult surgical procedure is often unavailable in developing countries. Possible late development of esophageal cancer, though probably overemphasized, entails careful and long-term endoscopic screening.展开更多
AIM:To study a retrospective analysis of patients who presented to the emergency departments(ED)with complaints related to foreign body ingestions.METHODS:Patients older than 16 years of age who presented to the ED be...AIM:To study a retrospective analysis of patients who presented to the emergency departments(ED)with complaints related to foreign body ingestions.METHODS:Patients older than 16 years of age who presented to the ED between January 1stand December 31stof 2010 with complaints related to swallowed foreign bodies were identified from electronic health records and patient charts.RESULTS:A total of 100 patients presented with a complaint of foreign body ingestion during the study period.Overall,an X-ray was performed on 75 patients,and a fiberoptic evaluation was performed on45 patients.A foreign body was detected in 46(46%)patients.The diagnostic yield of the X-ray was 27(36%)out of 75 patients,while the diagnostic yield of the fiberoptic evaluations was 21(47%)out of 45 patients.The detected foreign bodies were mostly located in the esophagus(17 out of 46 foreign bodies detected).When the types of ingested foreign bodies were evaluated,52(52%)patients reported ingesting food,and19(19%)patients reported swallowing pins.An X-ray was performed on 33 patients with accidental food ingestions but yielded a positive result in only two cases.In 12 out of 21 patients with accidental food ingestion who underwent fiberoptic evaluation,the foreign material was detected and removed.CONCLUSION:Plain radiography is helpful in the localization of radiopaque swollen foreign bodies,while fiberoptic methods are useful as both diagnostic and therapeutic tools,regardless of radiopacity.展开更多
A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or...A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or compressor effects could be simplified as body forces along the streamline. These body forces which are functions of local parameters could be added as source terms in Navier-Stokes equations to replace solid boundary conditions of blades and hubs. The val- idation of SBFM with uniform inlet and distortion inlet of compressors shows that pressure performance characteristics agree well with experimental data. A three-dimensional simulation of the integration configuration, via a blended wing body aircraft with a distributed propulsion system using the SBFM, has been completed. Lift coefficient and drag coefficient agree well with wind tunnel test results. Results show that to reach the goal of rapid integrated simulation combining internal and external flow fields, the computational fluid dynamics method based on SBFM is reasonable.展开更多
The intentional ingestion of foreign objects(IIFO) is described more commonly in prison populations than in the general population, with an estimated annual incidence of 1 in 1900 inmates in our state correctional fac...The intentional ingestion of foreign objects(IIFO) is described more commonly in prison populations than in the general population, with an estimated annual incidence of 1 in 1900 inmates in our state correctional facilities. Incidents often involve ingestion of small metal objects(e.g., paperclips, razor blades) or other commonly available items like pens or eating utensils. Despite ingestion of relatively sharp objects, most episodes can be clinically managed with either observation or endoscopy. Surgery should be reserved for those with signs or symptoms of gastrointestinal perforation or obstruction. For those with a history of IIFO, efforts should focus on prevention of recurrenceas subsequent episodes are associated with higher morbidity, significant healthcare and security costs. The pattern of IIFO is often repetitive, with escalation both in frequency of ingestions and in number of items ingested. Little is known about successful prevention strategies, but efforts to monitor patients and provide psychiatric care are potential best-practice strategies. This article aims to provide state-of-the art review on the topic, followed by a set of basic recommendations.展开更多
AIM:To evaluate the Z-line visualization by the PillCamTM SB2 using three different ingestion protocols. METHODS:Ninety consecutive patients undergoing small bowel capsule endoscopy(SBCE)between January and May 2008 w...AIM:To evaluate the Z-line visualization by the PillCamTM SB2 using three different ingestion protocols. METHODS:Ninety consecutive patients undergoing small bowel capsule endoscopy(SBCE)between January and May 2008 were included in the study. They swallowed the capsule in the standing(Group A= 30),supine(Group B=30)and right supine positions (Group C=30).Baseline patient characteristics, difficulties in capsule ingestion,esophageal transit times(ETT)and Z-line visualization were noted. RESULTS:No significant differences were found between the groups with regard to baseline patient characteristics,ingestion difficulties and complete SB examinations(P>0.05).At least 1 frame of the Z-line was detected in 15.8%,46.7%and 90%of patients in groups A,B and C,respectively(P<0.001).The average number of Z-line images was 0.21±0.53,3.23 ±6.59 and 5.53±7.55 and the mean%of the Z-linedetected was 71.3,25.1 and 8.3,in groups A,B and C, respectively(both P<0.001).ETT times were longer in the supine group followed by the right supine and the standing groups(median of 237 s vs 64 s and 39 s, respectively;P<0.001). CONCLUSION:Z-line visualization in patients undergoing SBCE can be accurately achieved in most cases when the capsule is swallowed in the right supine position.展开更多
In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrus...In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrusion amount.The parameters of different dimensionless sealing flow were measured under the condition that the annulus Reynolds number was 4.39 × 10~5 and the rotating Reynolds number was 1.05 × 10~6.The results show that the change of the amount of protrusions has little effect on the static pressure in the cavity, and the static pressure change near the sealing ring is almost negligible.But the total pressure and sealing efficiency increase first and then decrease with the increase of the amount of protrusion.The variation of power consumption is the same.A complex vortex structure will appear at the high radius region when the protrusion is installed.On the other hand, the protrusion can effectively reduce the minimum sealing flow of the rotor–stator cavity.Furthermore, considering the sealing efficiency and power consumption,the best range of the protrusion amount is about 36.The ratio near this range can optimally balance the alleviation of the gas ingestion and the reduction of the power consumption.展开更多
AIM： To sum up the recent 30-year experience in the prevention and treatment of gastrointestinal dysfunction in severe burn patients, and propose practicable guidelines for the prevention and treatment of gastrointes...AIM： To sum up the recent 30-year experience in the prevention and treatment of gastrointestinal dysfunction in severe burn patients, and propose practicable guidelines for the prevention and treatment of gastrointestinal （GI） dysfunction. METHODS： From 1980 to 2007, a total of 219 patients with large area and extraordinarily large area burns （LAB） were admitted, who were classified into three stages according the therapeutic protocols used at the time： Stage 1 from 1980 to 1989, stage 2 from 1990 to 1995, and stage 3 from 1996 to 2007. The occurrence and mortality of GI dysfunction in patients of the three stages were calculated and the main causes were analyzed. RESULTS： The occurrence of stress ulcer in patients with LAB was 8.6% in stage 1, which was significantly Dower than that in stage 1 （P 〈 0.05）. No massive hemorrhage from severe stress ulcer and enterogenic infections occurred in stages 2 and 3. The occurrence of abdominal distension and stress ulcer and the mortality in stage 3 patients with extraordinarily LAB was 7.1%, 21.4% and 28.5%, respectively, which were significantly lower than those in stage 1 patients （P 〈 0.05 or P 〈 0.01）, and the occurrence of stress ulcer was also significantly lower than that in stage 2 patients （P 〈 0.05）. CONCLUSION： Comprehensive fluid resuscitation, early excision of necrotic tissue, staged food ingestion, and administration of specific nutrients are essential strategies for preventing gastrointestinal complications and lowering mortality in severely burned patients.展开更多
The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists ha...The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists have emphasized its effect on the sealing efficiency,proposing that installation of protrusion could alleviate gas ingestion.However,the protrusion shape which is an influential factor on the sealing efficiency has not been focused in previous research.Using the experimental method of measuring CO2 volume fraction,cavity pressure,and power consumption,we investigated the effects of several typical protrusion shapes on various parameters for two sealing structures,in order to obtain the optimal shape.Results showed that a variation of the protrusion shape had little impact on the static pressure,but the total pressure and the sealing efficiency increased in different degrees.Furthermore,even though the hexagon shape resulted in the highest sealing efficiency,we observed that the drop shape had the best overall performance in all of the eight models,which could result in higher efficiency of the turbine cavity.The combination of a radial seal structure and protrusion could improve sealing efficiency better.展开更多
The tire spray produced by aircraft running on wet runways may enter the intake of engines,which may lead to the compressor stall,surge,or even combustion flameout.Therefore,it is necessary to do some research work on...The tire spray produced by aircraft running on wet runways may enter the intake of engines,which may lead to the compressor stall,surge,or even combustion flameout.Therefore,it is necessary to do some research work on the tire spray to help to solve this problem.Firstly,the mechanism of tire spray is analyzed,and some parameters are defined to describe the spray pattern.Secondly,the numerical model of tire spray is established by coupled Smoothed Particle Hydrodynamics(SPH)and Finite Element Method(FEM)in LS-DYNA software,and the model is validated by a simplified water spray experiment.Then some influence factors on the spray pattern are studied by numerical simulation.Finally,some suggestions are proposed on different types of aircraft to avoid too much tire spray being ingested into the engine intakes.展开更多
Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propul...Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propulsion interaction effect of the wing section,we built a DEP demonstrator with 24"high-lift"Electric Ducted Fans(EDFs)distributed along the wing’s trailing edge.This paper explores and compares the aero-propulsion coupling characteristics under various upstream speed,throttle,and EDF mounting surface deflection angles using a series of wind tunnel tests.We compare various lift-augmentation power conditions to the clean configuration without propulsion unit under the experiment condition of 15-25 m/s freestream flow and angles of attack from-4°to 16°.The comparison of computational results to the experimental results verifies the effectiveness of the computational fluid dynamic analysis method and the modeling method for the DEP configuration.The results show that the EDFs can produce significant lift increment and drag reduction simultaneously,which is accordant with the potential benefit of Boundary Layer Ingestion(BLI)at low airspeed.展开更多
Ingestion of caustic substances and its long-term effect on the gastrointestinal system maintain its place as an important public health issue in spite of the multiple efforts to educate the public and contain its gro...Ingestion of caustic substances and its long-term effect on the gastrointestinal system maintain its place as an important public health issue in spite of the multiple efforts to educate the public and contain its growing number. This is due to the ready availability of caustic agents and the loose regulatory control on its production. Substances with extremes of pH are very corrosive and can create severe injury in the upper gastrointestinal tract. The severity of injury depends on several aspects: Concentration of the substance, amount ingested, length of time of tissue contact, and p H of the agent. Solid materials easily adhere to the mouth and pharynx, causing greatest damage to these regions while liquids pass through the mouth and pharynx more quickly consequently producing its maximum damage in the esophagus and stomach. Esophagogastroduodenoscopy is therefore a highly recommended diagnostic tool in the evaluation of caustic injury. It is considered the cornerstone not only in the diagnosis but also in the prognostication and guide to management of caustic ingestions. The degree of esophageal injury at endoscopy is a predictor of systemic complication and death with a 9-fold increase in morbidity and mortality for every increased injury grade. Because of this high rate of complication, prompt evaluation cannot be overemphasized in order to halt development and prevent progression of complications.展开更多
Carnivorous fish have poor tolerance to carbohydrate in feed and low utilization rate of carbohydrate.Therefore,the balance of carbohydrate and lipids in the nutrient metabolism of carnivorous fish,the ef fective conv...Carnivorous fish have poor tolerance to carbohydrate in feed and low utilization rate of carbohydrate.Therefore,the balance of carbohydrate and lipids in the nutrient metabolism of carnivorous fish,the ef fective conversion and utilization of carbohydrate and lipids,and the feedback regulation of feeding are the key links for the e fficient utilization of carnivorous fish feed.Carbohydrate response element binding protein(ChREBP)is a new transcription factor found in recent years in the glucose signaling pathway,and can also participate in feeding regulation.We performed in-vivo and in-vitro experiments to reveal the role of ChREBP in the glucose metabolism and feeding in mandarin fish.The mRNA expression of ChREBP and appetite regulatory factors were measured after intraperitoneal injection of glucose in mandarin fish Siniperca chuatsi and cotransfection with glucose and glucose+siRNA in the hypothalamic cells in mandarin fish.The results reveal that at hour 2 and 4 post intraperitoneal injection with 1 mg/g BW glucose,the blood glucose level of the mandarin fish increased significantly,but food intake decreased significantly,and it also displayed a significantly increased ChREBP mRNA expression levels in liver.At hour 4 post injection,hypothalamic ChREBP mRNA level was significantly increased,whereas the mRNA expression levels of appetite genes neuropeptide Y(npy)and agouti-related peptide(AgRP)were decreased significantly.When the glucose concentration was 40 mmol/L,the expression level of ChREBP mRNA in mandarin fish hypothalamic cells was significantly up-regulated,but the expression level of appetite gene npy mRNA was down-regulated.When siRNA and glucose were co-transfected into mandarin fish brain cells,the expression level of chrebp mRNA was significantly decreased,and the appetite gene npy mRNA was significantly increased.The results indicated that glucose regulated food intake through the modulation of appetite gene npy by ChREBP.展开更多
The field of gastroenterology has recently seen a surge in wearable technology to monitor physical activity,sleep quality,pain,and even gut activity.The past decade has seen the emergence of wearable devices including...The field of gastroenterology has recently seen a surge in wearable technology to monitor physical activity,sleep quality,pain,and even gut activity.The past decade has seen the emergence of wearable devices including Fitbit,Apple Watch,AbStats,and ingestible sensors.In this review,we discuss current and future devices designed to measure sweat biomarkers,steps taken,sleep efficiency,gastric electrical activity,stomach pH,and intestinal contents.We also summarize several clinical studies to better understand wearable devices so that we may assess their potential benefit in improving healthcare while also weighing the challenges that must be addressed.展开更多
基金supports of the National Natural Science Foundation of China(Nos.52076129,92360308,52376027)the Shanghai Municipal Education Commission of China(No.2023-02-4)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe United Innovation Center(UIC)of Aerothermal Technologies for Turbomachinery of China.
文摘Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs.
基金Supported by the National Natural Science Foundation of China (30270258, 40506028)the National High Technology Research and Development Program of China (2002AA648010)+1 种基金the Encouraging Foundation for Outstanding Youth Scientists of Shandong Province (03BS120)China Postdoctoral Sience Foundation(2005037237)
文摘Effect of UV-B radiation on ingesting and nutritional selecting behavior of the roifer Brachionus urceus on 5 species of microlgae were studied under controlled laboratory conditions. Restdts showed that enhanced UV-B radiation significantly inhibited ingesting of the rotifer B. urceus when it was fed with 5 species of micro-algae （p〈0.05）. The ingesting selectivity rate varied with the UV-B radiation enhancement when it was fed with 5 species micro-algal mixture. Results indicated that the enhanced UV-B radiation could affect ingesting and nutritional selectivity of B. urceus.
基金supported by the National Key Research and Development Program(Grant No.2022YFF0708903)the Ningbo Key Technology Re-search and Development Program(Grant No.2023Z018)+3 种基金the National Natural Science Foundation of China(Grant No.52275043)the Youth Fund of National Natural Science Foundation of China(Grant Nos.72301015,52105046)the Young Elite Scientist Sponsorship Program by China Association for Science and Technology(Grant Nos.2022QNRC001,YESS20220292)the Liupanshan Laboratory Basic Research Program(Grant No.LPS-2024-KY-D-JC-0009)。
文摘Boundary layer ingesting(BLI)fans are required to operate under distorted inflow conditions,which significantly reduces their efficiency[1,2].Accurately predicting fan losses is crucial for designing high-performance,distortion-tolerant fans.
文摘Caustic ingestion is a relatively rare but potentially catastrophic gastroentero-logical emergency.Upper gastrointestinal(GI)endoscopy is currently regarded as the gold standard modality not only to assess the depth and the extension of GI caustic injury,but also to guide the appropriate treatment.Intriguingly,contrast-enhanced computed tomography(CECT)has recently emerged as a promising non-invasive and more accurate alternative to endoscopy in this setting.However,to date,evidence concerning the role of CECT as an alternative or complementary diagnostic tool to endoscopy in caustic ingestion is still limited.The aim of our review was to summarize and discuss the current evidence concerning the role of CECT in the emergency diagnosis of caustic ingestion and its value in assessing injury severity among non-pediatric patients.
文摘BACKGROUND Venlafaxine,a serotonin-norepinephrine reuptake inhibitor,is widely prescribed for the treatment of major depressive disorder.At therapeutic dose,it is generally safe,with a low incidence of adverse effects.However,massive venlafaxine inge-stion can cause serious cardiotoxicity,leading to life-threatening arrhythmias.CASE SUMMARY A 31-year-old woman with a history of depression ingested 14.8 g of venlafaxine along with 6 mg of estazolam and 6 mg of flunitrazepam.On admission,2 hours post-ingestion,she presented only with mild QTc prolongation.At 4 hours post-ingestion,she developed a generalized tonic-clonic seizure.Following endo-tracheal intubation,intravenous midazolam infusion was initiated and 50 g of activated charcoal was administered via a nasogastric tube.At 15 hours post-ingestion,she developed ventricular tachycardia that rapidly progressed to refr-actory ventricular fibrillation,which was successfully treated with veno-arterial extracorporeal membrane oxygenation.Toxicological analysis revealed serum ve-nlafaxine and O-desmethylvenlafaxine concentrations 17µg/mL and 10µg/mL,respectively,at 15 hours post-ingestion.CONCLUSION In cases of massive venlafaxine ingestion,continuous intensive monitoring,particularly of QTc,is essential for at least 24 hours,even when initial clinical signs are mild.If refractory ventricular arrhythmias occur,prompt ini-tiation of veno-arterial extracorporeal membrane oxygenation should be considered.
文摘BACKGROUND Sharp foreign body ingestion can cause gastrointestinal tract mucosa injury and requires proper endoscopic removal.Typically,protective devices are used to reduce mucosal damage.This case presents an alternative approach for the endoscopic removal of a large,irregular,and sharp foreign body(chicken bone)when traditional protective devices are inadequate,thus contributing to the management of such ingestions.CASE SUMMARY A 57-year-old male presented with a history of swallowing an irregular and sharp-pointed chicken bone.Emergent endoscopy showed it was tightly embedded in the esophageal wall,with minor bleeding.The chicken bone was grasped and moved cautiously using a foreign forceps.It was loosened after repeated attempts but could not pass through the pharynx.Considering possible mucosal damage,it was carefully pushed into the stomach cavity and then wrapped in a condom.The chicken bone was retrieved uneventfully by grasping the open edge of the condom with foreign forceps.No additional damage was found,except for primary esophageal injuries caused by the embedded chicken bone.The patient was discharged on the following day.Our experience demonstrated that condoms can be an alternative as a protective device under such conditions.CONCLUSION Condoms can serve as an alternative when traditional protective devices are unsuitable.Because of its smooth and oily nature,it can provide mucosal protection and lubrication during endoscopic removal.
文摘BACKGROUND Cases of esophageal,airway,and pericardial perforations caused by chicken bone ingestion are rare worldwide,but their incidence has shown an upward trend in recent years.Injuries caused by chicken bones are often more severe,leading to infections and,in extreme cases,perforation of the common carotid artery,pericardium,trachea,or even the heart,posing life-threatening risks.CASE SUMMARY We present a case of a patient who sustained combined esophageal and pericardial injuries with subsequent pericardial effusion due to chicken bone ingestion.The clinical manifestations included chest pain and widespread ST-segment elevation on electrocardiography.CONCLUSION The patient’s symptoms and signs were not entirely consistent with myocardial infarction.Chest computed tomography played a crucial role in clarifying the etiology and provided critical evidence for devising an effective treatment strategy.
文摘Prevention has a paramount role in reducing the incidence of corrosive ingestion especially in children, yet this goal is far from being reached in developing countries, where such injuries are largely unreported and their true prevalence simply cannot be extrapolated from random articles or personal experience. The specific pathophysiologic mechanisms are becoming better understood and may have a role in the future management and prevention of long-term consequences, such as esophageal strictures. Whereas the mainstay of diagnosis is considered upper gastrointestinal endoscopy, computed tomography and ultrasound are gaining a more significant role, especially in addressing the need for emergency surgery, whose morbidity and mortality remains high even in the best hands. The need to perform emergency surgery has a persistent long-term negative impact both on survival and functional outcome. Medical or endoscopic prevention of stricture is debatable, yet esophageal stents, absorbable or not, show promising data. Dilatation is the first therapeutic option for strictures and bougies should be considered especially for long, multiple and tortuous narrowing. It is crucial to avoid malnutrition, especially in developingcountries where management strategies are influenced by malnutrition and poor clinical conditions. Late reconstructive surgery, mainly using colon transposition, offers the best results in referral centers, either in children or adults, but such a difficult surgical procedure is often unavailable in developing countries. Possible late development of esophageal cancer, though probably overemphasized, entails careful and long-term endoscopic screening.
文摘AIM:To study a retrospective analysis of patients who presented to the emergency departments(ED)with complaints related to foreign body ingestions.METHODS:Patients older than 16 years of age who presented to the ED between January 1stand December 31stof 2010 with complaints related to swallowed foreign bodies were identified from electronic health records and patient charts.RESULTS:A total of 100 patients presented with a complaint of foreign body ingestion during the study period.Overall,an X-ray was performed on 75 patients,and a fiberoptic evaluation was performed on45 patients.A foreign body was detected in 46(46%)patients.The diagnostic yield of the X-ray was 27(36%)out of 75 patients,while the diagnostic yield of the fiberoptic evaluations was 21(47%)out of 45 patients.The detected foreign bodies were mostly located in the esophagus(17 out of 46 foreign bodies detected).When the types of ingested foreign bodies were evaluated,52(52%)patients reported ingesting food,and19(19%)patients reported swallowing pins.An X-ray was performed on 33 patients with accidental food ingestions but yielded a positive result in only two cases.In 12 out of 21 patients with accidental food ingestion who underwent fiberoptic evaluation,the foreign material was detected and removed.CONCLUSION:Plain radiography is helpful in the localization of radiopaque swollen foreign bodies,while fiberoptic methods are useful as both diagnostic and therapeutic tools,regardless of radiopacity.
基金supported by the National Natural Science Foundation of China (No.51176005)
文摘A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or compressor effects could be simplified as body forces along the streamline. These body forces which are functions of local parameters could be added as source terms in Navier-Stokes equations to replace solid boundary conditions of blades and hubs. The val- idation of SBFM with uniform inlet and distortion inlet of compressors shows that pressure performance characteristics agree well with experimental data. A three-dimensional simulation of the integration configuration, via a blended wing body aircraft with a distributed propulsion system using the SBFM, has been completed. Lift coefficient and drag coefficient agree well with wind tunnel test results. Results show that to reach the goal of rapid integrated simulation combining internal and external flow fields, the computational fluid dynamics method based on SBFM is reasonable.
文摘The intentional ingestion of foreign objects(IIFO) is described more commonly in prison populations than in the general population, with an estimated annual incidence of 1 in 1900 inmates in our state correctional facilities. Incidents often involve ingestion of small metal objects(e.g., paperclips, razor blades) or other commonly available items like pens or eating utensils. Despite ingestion of relatively sharp objects, most episodes can be clinically managed with either observation or endoscopy. Surgery should be reserved for those with signs or symptoms of gastrointestinal perforation or obstruction. For those with a history of IIFO, efforts should focus on prevention of recurrenceas subsequent episodes are associated with higher morbidity, significant healthcare and security costs. The pattern of IIFO is often repetitive, with escalation both in frequency of ingestions and in number of items ingested. Little is known about successful prevention strategies, but efforts to monitor patients and provide psychiatric care are potential best-practice strategies. This article aims to provide state-of-the art review on the topic, followed by a set of basic recommendations.
文摘AIM:To evaluate the Z-line visualization by the PillCamTM SB2 using three different ingestion protocols. METHODS:Ninety consecutive patients undergoing small bowel capsule endoscopy(SBCE)between January and May 2008 were included in the study. They swallowed the capsule in the standing(Group A= 30),supine(Group B=30)and right supine positions (Group C=30).Baseline patient characteristics, difficulties in capsule ingestion,esophageal transit times(ETT)and Z-line visualization were noted. RESULTS:No significant differences were found between the groups with regard to baseline patient characteristics,ingestion difficulties and complete SB examinations(P>0.05).At least 1 frame of the Z-line was detected in 15.8%,46.7%and 90%of patients in groups A,B and C,respectively(P<0.001).The average number of Z-line images was 0.21±0.53,3.23 ±6.59 and 5.53±7.55 and the mean%of the Z-linedetected was 71.3,25.1 and 8.3,in groups A,B and C, respectively(both P<0.001).ETT times were longer in the supine group followed by the right supine and the standing groups(median of 237 s vs 64 s and 39 s, respectively;P<0.001). CONCLUSION:Z-line visualization in patients undergoing SBCE can be accurately achieved in most cases when the capsule is swallowed in the right supine position.
文摘In this paper, the effect of different amount of protrusion on various parameters in rotor–stator system was experimentally studied by measuring CO_2 concentration and pressure, in order to obtain the optimal protrusion amount.The parameters of different dimensionless sealing flow were measured under the condition that the annulus Reynolds number was 4.39 × 10~5 and the rotating Reynolds number was 1.05 × 10~6.The results show that the change of the amount of protrusions has little effect on the static pressure in the cavity, and the static pressure change near the sealing ring is almost negligible.But the total pressure and sealing efficiency increase first and then decrease with the increase of the amount of protrusion.The variation of power consumption is the same.A complex vortex structure will appear at the high radius region when the protrusion is installed.On the other hand, the protrusion can effectively reduce the minimum sealing flow of the rotor–stator cavity.Furthermore, considering the sealing efficiency and power consumption,the best range of the protrusion amount is about 36.The ratio near this range can optimally balance the alleviation of the gas ingestion and the reduction of the power consumption.
基金The National Natural Science Foundation of China, No. C30600646
文摘AIM： To sum up the recent 30-year experience in the prevention and treatment of gastrointestinal dysfunction in severe burn patients, and propose practicable guidelines for the prevention and treatment of gastrointestinal （GI） dysfunction. METHODS： From 1980 to 2007, a total of 219 patients with large area and extraordinarily large area burns （LAB） were admitted, who were classified into three stages according the therapeutic protocols used at the time： Stage 1 from 1980 to 1989, stage 2 from 1990 to 1995, and stage 3 from 1996 to 2007. The occurrence and mortality of GI dysfunction in patients of the three stages were calculated and the main causes were analyzed. RESULTS： The occurrence of stress ulcer in patients with LAB was 8.6% in stage 1, which was significantly Dower than that in stage 1 （P 〈 0.05）. No massive hemorrhage from severe stress ulcer and enterogenic infections occurred in stages 2 and 3. The occurrence of abdominal distension and stress ulcer and the mortality in stage 3 patients with extraordinarily LAB was 7.1%, 21.4% and 28.5%, respectively, which were significantly lower than those in stage 1 patients （P 〈 0.05 or P 〈 0.01）, and the occurrence of stress ulcer was also significantly lower than that in stage 2 patients （P 〈 0.05）. CONCLUSION： Comprehensive fluid resuscitation, early excision of necrotic tissue, staged food ingestion, and administration of specific nutrients are essential strategies for preventing gastrointestinal complications and lowering mortality in severely burned patients.
文摘The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists have emphasized its effect on the sealing efficiency,proposing that installation of protrusion could alleviate gas ingestion.However,the protrusion shape which is an influential factor on the sealing efficiency has not been focused in previous research.Using the experimental method of measuring CO2 volume fraction,cavity pressure,and power consumption,we investigated the effects of several typical protrusion shapes on various parameters for two sealing structures,in order to obtain the optimal shape.Results showed that a variation of the protrusion shape had little impact on the static pressure,but the total pressure and the sealing efficiency increased in different degrees.Furthermore,even though the hexagon shape resulted in the highest sealing efficiency,we observed that the drop shape had the best overall performance in all of the eight models,which could result in higher efficiency of the turbine cavity.The combination of a radial seal structure and protrusion could improve sealing efficiency better.
基金supported by the Aeronautical Science Foundation of China(No.2016ZD53038)the support of the Commercial Aircraft Corporation of China Ltd.
文摘The tire spray produced by aircraft running on wet runways may enter the intake of engines,which may lead to the compressor stall,surge,or even combustion flameout.Therefore,it is necessary to do some research work on the tire spray to help to solve this problem.Firstly,the mechanism of tire spray is analyzed,and some parameters are defined to describe the spray pattern.Secondly,the numerical model of tire spray is established by coupled Smoothed Particle Hydrodynamics(SPH)and Finite Element Method(FEM)in LS-DYNA software,and the model is validated by a simplified water spray experiment.Then some influence factors on the spray pattern are studied by numerical simulation.Finally,some suggestions are proposed on different types of aircraft to avoid too much tire spray being ingested into the engine intakes.
基金supported by the National Natural Science Foundation of China(No.51877178)。
文摘Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propulsion interaction effect of the wing section,we built a DEP demonstrator with 24"high-lift"Electric Ducted Fans(EDFs)distributed along the wing’s trailing edge.This paper explores and compares the aero-propulsion coupling characteristics under various upstream speed,throttle,and EDF mounting surface deflection angles using a series of wind tunnel tests.We compare various lift-augmentation power conditions to the clean configuration without propulsion unit under the experiment condition of 15-25 m/s freestream flow and angles of attack from-4°to 16°.The comparison of computational results to the experimental results verifies the effectiveness of the computational fluid dynamic analysis method and the modeling method for the DEP configuration.The results show that the EDFs can produce significant lift increment and drag reduction simultaneously,which is accordant with the potential benefit of Boundary Layer Ingestion(BLI)at low airspeed.
文摘Ingestion of caustic substances and its long-term effect on the gastrointestinal system maintain its place as an important public health issue in spite of the multiple efforts to educate the public and contain its growing number. This is due to the ready availability of caustic agents and the loose regulatory control on its production. Substances with extremes of pH are very corrosive and can create severe injury in the upper gastrointestinal tract. The severity of injury depends on several aspects: Concentration of the substance, amount ingested, length of time of tissue contact, and p H of the agent. Solid materials easily adhere to the mouth and pharynx, causing greatest damage to these regions while liquids pass through the mouth and pharynx more quickly consequently producing its maximum damage in the esophagus and stomach. Esophagogastroduodenoscopy is therefore a highly recommended diagnostic tool in the evaluation of caustic injury. It is considered the cornerstone not only in the diagnosis but also in the prognostication and guide to management of caustic ingestions. The degree of esophageal injury at endoscopy is a predictor of systemic complication and death with a 9-fold increase in morbidity and mortality for every increased injury grade. Because of this high rate of complication, prompt evaluation cannot be overemphasized in order to halt development and prevent progression of complications.
基金Supported by the China Agriculture Research System (No.CARS-46)the National Key R&D Program of China (No.2018YFD0900400)。
文摘Carnivorous fish have poor tolerance to carbohydrate in feed and low utilization rate of carbohydrate.Therefore,the balance of carbohydrate and lipids in the nutrient metabolism of carnivorous fish,the ef fective conversion and utilization of carbohydrate and lipids,and the feedback regulation of feeding are the key links for the e fficient utilization of carnivorous fish feed.Carbohydrate response element binding protein(ChREBP)is a new transcription factor found in recent years in the glucose signaling pathway,and can also participate in feeding regulation.We performed in-vivo and in-vitro experiments to reveal the role of ChREBP in the glucose metabolism and feeding in mandarin fish.The mRNA expression of ChREBP and appetite regulatory factors were measured after intraperitoneal injection of glucose in mandarin fish Siniperca chuatsi and cotransfection with glucose and glucose+siRNA in the hypothalamic cells in mandarin fish.The results reveal that at hour 2 and 4 post intraperitoneal injection with 1 mg/g BW glucose,the blood glucose level of the mandarin fish increased significantly,but food intake decreased significantly,and it also displayed a significantly increased ChREBP mRNA expression levels in liver.At hour 4 post injection,hypothalamic ChREBP mRNA level was significantly increased,whereas the mRNA expression levels of appetite genes neuropeptide Y(npy)and agouti-related peptide(AgRP)were decreased significantly.When the glucose concentration was 40 mmol/L,the expression level of ChREBP mRNA in mandarin fish hypothalamic cells was significantly up-regulated,but the expression level of appetite gene npy mRNA was down-regulated.When siRNA and glucose were co-transfected into mandarin fish brain cells,the expression level of chrebp mRNA was significantly decreased,and the appetite gene npy mRNA was significantly increased.The results indicated that glucose regulated food intake through the modulation of appetite gene npy by ChREBP.
文摘The field of gastroenterology has recently seen a surge in wearable technology to monitor physical activity,sleep quality,pain,and even gut activity.The past decade has seen the emergence of wearable devices including Fitbit,Apple Watch,AbStats,and ingestible sensors.In this review,we discuss current and future devices designed to measure sweat biomarkers,steps taken,sleep efficiency,gastric electrical activity,stomach pH,and intestinal contents.We also summarize several clinical studies to better understand wearable devices so that we may assess their potential benefit in improving healthcare while also weighing the challenges that must be addressed.
