OBJECTIVE:To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected,aiming to provide a theoretical ...OBJECTIVE:To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected,aiming to provide a theoretical basis for clinical diagnosis and treatment.METHODS:We retrospectively analyzed the data of patients who underwent electronic colonoscopy and were found to have colorectal polyps at the Gastrointestinal Endoscopy Center of Dongfang Hospital,Beijing University of Chinese Medicine,from January 1,2017,to December 31,2023.We also reviewed their lung CT results and used statistical software to analyze the recurrence,location,size,and pathology of colorectal polyps in relation to the presence,number,and size of pulmonary nodules.RESULTS:Both colorectal polyps and pulmonary nodules are more common in elderly males.Patients with recurrent colorectal polyps are more likely to have pulmonary nodules,which tend to be located in the left colon and are more likely to be adenomatous in nature;those without pulmonary nodules show no clear pattern in polyp distribution,with a tendency towards inflammatory and hyperplastic pathology;the data from this study suggests that the proportion of lung nodules larger than 0.5 cm in the recurrent group is higher than in the non-recurrent group,and the proportion of colorectal polyps larger than 1 cm in the recurrent group is also higher than in the non-recurrent group.CONCLUSION:There is a certain connection between the pathogenesis and treatment of colorectal polyps and pulmonary nodules.Cold,phlegm,dampness,blood stasis,and toxic coagulation are common pathogenic factors of the two diseases.Patients with larger colorectal polyps should be advised to undergo regular colonoscopy.Patients with recurrent polyps or those with left colon necrosis or cancer indicated by colonoscopy should be advised to complete lung related examinations to rule out the possibility of pulmonary nodules.展开更多
The infection of SARS-CoV-2 has triggered the COVID-19 pandemic. In addition to the fever and respiratory symptoms in the process of coronavirus infections, gastrointestinal symptoms, especially diarrhea, are prominen...The infection of SARS-CoV-2 has triggered the COVID-19 pandemic. In addition to the fever and respiratory symptoms in the process of coronavirus infections, gastrointestinal symptoms, especially diarrhea, are prominent features of its acute infection and long COVID. The associations between the lung and large intestine have been demonstrated by Western medicine in aspects such as tissue origin, microflora homeostasis, mucosal immunity, renin-angiotensin system(RAS) and autonomic nervous system as well, which are considered as the evidence of material basis and potential regulatory mechanisms for “gutlung crosstalk(肺肠串扰)” in COVID-19. We have noticed that probiotics and other preparations can regulate the intestines, and further treat COVID-19 with effective and gratifying results. In the system of traditional Chinese medicine(TCM), there's a term of “exterior-interior pairing of the lung and large intestine(肺与大肠相表里)”, showing an interconnection of the lung and the bowels. “Exterior-interior pairing of the lung and large intestine” is an important part of the theory of visceral activities proposed by ancient physicians through a long-term observation and practice. It's considered that “lung” and “large intestine” are interconnected and mutually exterior-interior in the normal physical activities and the disease development, providing a theoretical basis for treating lung diseases and bowel diseases from the perspective of overall concept. The study aims to compare the term of “exterior-interior pairing of the lung and large intestine” in TCM and “gut-lung crosstalk” in Western medicine regarding the development of COVID-19 and its intestinal symptoms, and provide more ideas for diagnosing and treating lung and bowel related diseases.展开更多
The small and large intestine of the gastrointestinal tract(GIT) have evolved to have discrete functions with distinct anatomies and immune cell composition.The importance of these differences is underlined when consi...The small and large intestine of the gastrointestinal tract(GIT) have evolved to have discrete functions with distinct anatomies and immune cell composition.The importance of these differences is underlined when considering that different pathogens have uniquely adapted to live in each region of the gut.Furthermore,different regions of the GIT are also associated with differences in susceptibility to diseases such as cancer and chronic inflammation.The large and small intestine,given their anatomical and functional differences,should be seen as two separate immunological sites.However,this distinction is often ignored with findings from one area of the GIT being inappropriately extrapolated to the other.Focussing largely on the murine small and large intestine,this review addresses the literature relating to the immunology and biology of the two sites,drawing comparisons between them and clarifying similarities and differences.We also highlight the gaps in our understanding and where further research is needed.展开更多
AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma.METHODS: Sixty-two large intestine cancer tissue samples...AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma.METHODS: Sixty-two large intestine cancer tissue samples were randomly and retrospectively selected from patients with large intestine carcinoma. Immunohistochemical staining for bcl-2, bax, GAS, SS was performed according to the standard streptavidin-biotin-peroxidase (S-P) method.According to the semi-quantitative integral evaluation, SS and GAS were divided into three groups as follows. Scores1-3 were defined as the low expression group, 4-8 as the intermediate expression group, 9-16 as the high expression group. Bax and bcl-2 protein expressions in different GAS and SS expression groups of large intestine carcinoma were assessed.RESULTS: The positive expression rate of bax had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 9.246; P＜0.05,x2GAS = 6.981). The positive expression rate of bax in SS high (80.0%, 8/10) and intermediate (76.5%, 13/17)expression groups was higher than that in low expression group (40.0%, 14/35) (P＜0.05, x2high vs low = 5.242; P＜0.05,x2middle vs low = 6.097). The positive expression rate of bax in GAS high expression group (27.3%, 3/8) was lower than that in low expression group (69.4%, 25/36) (P＜0.05,x2 = 4.594). However, bax expression in GAS intermediate expression group (46.7%, 7/15) was lower than that in low expression group, but not statistically significant. The positive expression rate of bcl-2 had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 7.178; P＜0.05, x2GAS = 13.831). The positive expression rate of bcl-2 in GAS high (90.9%, 10/11)and intermediate (86.7%, 13/15) expression groups was higher than that in low expression group (44.4%, 16/36)(P＜0.05,x2high vs low = 5.600; P＜0.05, x2 middle vs low = 7.695).However, the positive expression rate of bcl-2 in SS high (40.0%, 4/10) and intermediate (47.1%, 8/9) expression groups was lower than that in low expression group (77.1%, 27/35)(P＜0.05, x2 high vs low = 4.710; P＜0.05, x2 middle vs low = 4.706).There was a significant positive correlation between the integral ratio of GAS to SS and the integral of bcl-2 (P＜0.01,r=0.340). However, there was a negative correlation between the integral ratio of GAS to the SS and bax the integral of (P＜0.05, r = -0.299).CONCLUSION: The regulation and control of gastrin,somatostatin in cell apoptosis of large intestine carcinoma may be directly related to the abnormal expression of bcl-2, bax.展开更多
OBJECTIVE:The theory of lung being connected with large intestine,which is a major topic in Traditional Chinese Medicine(TCM),has guided clinical practice for thousands of years in China.METHODS:In this study,we analy...OBJECTIVE:The theory of lung being connected with large intestine,which is a major topic in Traditional Chinese Medicine(TCM),has guided clinical practice for thousands of years in China.METHODS:In this study,we analyzed the history,main contents,clinical application,and material basis of the theory,to attempt to improve the potential clinical significance of "lung being connected with large intestine" in China.RESULTS:The lung being connected with large intestine was first described in "Huang Di Nei Jing",and formed one of the basic theories of TCM.For thousands of years,the majority of TCM practitioners explored this theory continuously,leading to its development and use as an important theory in the guidance of TCM clinics In the last decade,researchers in the field of integrated TCM and Western medicine have studied clinical applications and biomedical mechanisms with experimental methods to explore the implications of the theory.CONCLUSION:With the further development of science and technology,research concerning the theory of lung being connected with large intestine will be greatly stimulated and contribute to the modernization of TCM.展开更多
Pairing of the viscera and bowels is an important theory,which provides guidance to traditional Chinese medicine(TCM) clinical practice.Investigating this theory has been the focus of research on the basic theory of T...Pairing of the viscera and bowels is an important theory,which provides guidance to traditional Chinese medicine(TCM) clinical practice.Investigating this theory has been the focus of research on the basic theory of TCM.Recently,researchers have performed many studies on the theory that the lung and large intestine are exterior-interiorly related,which is a different point of view to that of previous literature,recent clinical studies and experimental studies,and these recent studies have enforced the theoretical connotation of the statement.However,there are problems in some of these studies including recent clinical studies and experimental studies.In the current article,literature on the viscera-related theory of the lung and large intestine are exterior-interiorly related is reviewed from physiological,pathological,and clinical views,and some opinions on the current research status are discussed.展开更多
OBJECTIVE To investigate the clinical characteristics of melanosis of the colon （MC） and its correlation with polypus and carcinoma of the large intestine. METHODS Clinical feature and colonoscopic findings of 156 M...OBJECTIVE To investigate the clinical characteristics of melanosis of the colon （MC） and its correlation with polypus and carcinoma of the large intestine. METHODS Clinical feature and colonoscopic findings of 156 MC patients were retrospectively analyzed. Final diagnosis of MC case was made after colonoscopic and pathological examination, and data of the case history was recorded. RESULTS The overall detection rate of MC was 1.12%, with 0.46% in males, 0.66% in females. An 82.69% of the patients suffered various constipations and had a history of taking cathartics. The clinical manifestation of total-colon melanosis occurred in 83.97% of the patients. There was no significant difference between the rate of concomitant polypus （27.56%） in the MC patients and the detection rate of polypus in the patients who underwent a synchronous colonoscopy （χ^2 = 1.205, P = 0.298）. Also there was no significant difference between the detection rate of carcinoma of the large intestine （8.97%） in MC patients and the detection rate of the same disease in the patients who underwent synchronous colonoscopy （χ^2 = 0.268, P = 0.604）. A logistic regression analysis has shown that the older the age of MC patients is, the more opportunities of MC and the concomitant polypus would occur. CONCLUSION MC may be related to constipations and a long-term administration of cathartics, among which total-colon melanosis ranks first in the cases. There is an earlier age of onset in the females, with a higher detection rate. The older the age of the patients is, the higher the detection rate of MC is, and the more possibility the onset of the concomitant polypus.展开更多
Ulcerative colitis(UC)is a chronic inflammatory bowel diseasethat significantly affects the quality of life of patients.Traditional treatments often have limitations,and alternative therapies are being explored.Miao M...Ulcerative colitis(UC)is a chronic inflammatory bowel diseasethat significantly affects the quality of life of patients.Traditional treatments often have limitations,and alternative therapies are being explored.Miao Medicine,particularly Jinlong Zhi Xie Fang Enema,is a traditional herbal remedy used to treat UC symptoms,especially in patients with Large Intestine Damp-Heat Syndrome.However,clinical evidence supporting its efficacy is limited.展开更多
Background:This study aimed to develop a combined model to quantify the net absorption of volatile fatty acids(VFA)in the large intestine(LI)of pigs.Methods:Fifteen female growing pigs(Duroc×Large White×Land...Background:This study aimed to develop a combined model to quantify the net absorption of volatile fatty acids(VFA)in the large intestine(LI)of pigs.Methods:Fifteen female growing pigs(Duroc×Large White×Landrace)were ranked by body weight(30±2.1 kg)on day 0 and assigned to one of three treatments,namely the basal diet containing different crude fiber(CF)levels(LCF:3.0%CF,MCF:4.5%CF,and HCF:6.0%CF).The pigs were implanted with the terminal ileum fistula and the cannulation of the ileal mesenteric vein(IMV),portal vein(PV),and left femoral artery(LFA)from days 6 to 7.[13 C]-Labeled VFA and P-aminohippuric acid were constantly perfused into the terminal ileum fistula and the cannulation of the IMV(day 15),respectively.Blood samples were collected from the PV and the LFA during perfusion(5 h),and LI samples were collected.Results:The net flux of[12 C]-acetic acid in the PV was greater for LCF versus MCF(p=0.045),but no difference was observed in the net flux of[12 C]-propionic acid(p=0.505)and[12 C]-butyric acid(p=0.35)in the PV among treatments.The deposition of[12 C]-acetic acid in the LI was greater for LCF versus MCF(p=0.014),whereas the deposition of[12 C]-propionic acid(p=0.007)and[12 C]-butyric acid(p=0.037)in the LI was greater for LCF versus HCF.Conclusions:In conclusion,this pig model was found conducive to study the net absorption of VFAs in the LI,and LCF had more net absorption of VFAs in the LI than MCF and HCF.展开更多
In a series of 130 cases of adenocarcinomas of the large intestine, enterochromaffin (EC) cells were detected in 54 cases (41.3%) by limmunocytochemistry with anti-chromogranin monoclonal antibody. Among the 54 cases,...In a series of 130 cases of adenocarcinomas of the large intestine, enterochromaffin (EC) cells were detected in 54 cases (41.3%) by limmunocytochemistry with anti-chromogranin monoclonal antibody. Among the 54 cases, 30 were found positive for serotonin, 14 for somatostatin, 11 for glucagon, 5 for pancreatic polypeptide, and only one for gastrin. The cases with EC cell (++) or polypeptide positive cells exhibited higher grade of differentiation, earlier stage of tumor extension and higher survival rate than those without EC cells. A significant difference of the EC cell population pattern among different histological grades of the tumors and non-neoplastic mucosa was found. The proportion of hormone, especially polypeptied positive cells was the highest in the mucosa and lowest in the moderately or poorly-differentiated carcinomas. The incidence, methodology and clinicopathological significance of EC cells found in the tumors are discussed.展开更多
In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random vari...In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case.展开更多
Model evaluation using benchmark datasets is an important method to measure the capability of large language models(LLMs)in specific domains,and it is mainly used to assess the knowledge and reasoning abilities of LLM...Model evaluation using benchmark datasets is an important method to measure the capability of large language models(LLMs)in specific domains,and it is mainly used to assess the knowledge and reasoning abilities of LLMs.Therefore,in order to better assess the capability of LLMs in the agricultural domain,Agri-Eval was proposed as a benchmark for assessing the knowledge and reasoning ability of LLMs in agriculture.The assessment dataset used in Agri-Eval covered seven major disciplines in the agricultural domain:crop science,horticulture,plant protection,animal husbandry,forest science,aquaculture science,and grass science,and contained a total of 2283 questions.Among domestic general-purpose LLMs,DeepSeek R1 performed best with an accuracy rate of 75.49%.In the realm of international general-purpose LLMs,Gemini 2.0 pro exp 0205 standed out as the top performer,achieving an accuracy rate of 74.28%.As an LLMs in agriculture vertical,Shennong V2.0 outperformed all the LLMs in China,and the answer accuracy rate of agricultural knowledge exceeded that of all the existing general-purpose LLMs.The launch of Agri-Eval helped the LLM developers to comprehensively evaluate the model's capability in the field of agriculture through a variety of tasks and tests to promote the development of the LLMs in the field of agriculture.展开更多
This study demonstrates a novel integration of large language models,machine learning,and multicriteria decision-making to investigate self-moderation in small online communities,a topic under-explored compared to use...This study demonstrates a novel integration of large language models,machine learning,and multicriteria decision-making to investigate self-moderation in small online communities,a topic under-explored compared to user behavior and platform-driven moderation on social media.The proposed methodological framework(1)utilizes large language models for social media post analysis and categorization,(2)employs k-means clustering for content characterization,and(3)incorporates the TODIM(Tomada de Decisão Interativa Multicritério)method to determine moderation strategies based on expert judgments.In general,the fully integrated framework leverages the strengths of these intelligent systems in a more systematic evaluation of large-scale decision problems.When applied in social media moderation,this approach promotes nuanced and context-sensitive self-moderation by taking into account factors such as cultural background and geographic location.The application of this framework is demonstrated within Facebook groups.Eight distinct content clusters encompassing safety,harassment,diversity,and misinformation are identified.Analysis revealed a preference for content removal across all clusters,suggesting a cautious approach towards potentially harmful content.However,the framework also highlights the use of other moderation actions,like account suspension,depending on the content category.These findings contribute to the growing body of research on self-moderation and offer valuable insights for creating safer and more inclusive online spaces within smaller communities.展开更多
In the era of AI,especially large models,the importance of open source has become increasingly prominent.First,open source allows innovation to avoid starting from scratch.Through iterative innovation,it promotes tech...In the era of AI,especially large models,the importance of open source has become increasingly prominent.First,open source allows innovation to avoid starting from scratch.Through iterative innovation,it promotes technical exchanges and learning globally.Second,resources required for large model R&D are difficult for a single institution to obtain.The evaluation of general large models also requires the participation of experts from various industries.Third,without open source collaboration,it is difficult to form a unified upper-layer software ecosystem.Therefore,open source has become an important cooperation mechanism to promote the development of AI and large models.There are two cases to illustrate how open source and international standards interact with each other.展开更多
The Yingxiu-Beichuan fault zone(YBFZ)has long been active and experienced repeated large earthquakes.The physicochemical properties of the deep fault zone(>1000 m)are the key to understanding the deformation mechan...The Yingxiu-Beichuan fault zone(YBFZ)has long been active and experienced repeated large earthquakes.The physicochemical properties of the deep fault zone(>1000 m)are the key to understanding the deformation mechanism of large earthquakes.This study uses rock magnetic,microstructural,and geochemical analyses of representative samples exposed in FZ1681 within the Wenchuan Earthquake Fault Scientific Drilling borehole 2(WFSD-2)cores.Fault gouge and fault breccia have higher magnetic susceptibility values than wall rocks,and they contain abundant paramagnetic minerals and small quantities of magnetite and monoclinic pyrrhotite.The magnetite and monoclinic pyrrhotite in the fault gouge were mainly formed by coseismic frictional heating,indicating that large earthquakes with frictional heating temperatures of~500-900℃once occurred in the YBFZ.The seismogenic and coseismic environment was reducing with a relatively high sulfur content.The monoclinic pyrrhotite in the fault breccia was formed mainly by low-temperature hydrothermal fluid.This indicates that the fault zone experienced reducing and low-temperature(<400℃)hydrothermal fluid with a relatively high sulfur content after the earthquake.The YBFZ,which experiences frequent large earthquakes,is weakly oxidizing environment at different depths,but the effect of the low-temperature hydrothermal fluid is weaker at depth.展开更多
AIM:To investigate the clinical characteristics and treatment outcomes,including visual function and overall survival(OS)of patients with ocular adnexal diffuse large B-cell lymphoma(OA-DLBCL).METHODS:This retrospecti...AIM:To investigate the clinical characteristics and treatment outcomes,including visual function and overall survival(OS)of patients with ocular adnexal diffuse large B-cell lymphoma(OA-DLBCL).METHODS:This retrospective cohort study enrolled 29 patients diagnosed with OA-DLBCL based on histopathological biopsy between 2006 and 2023.Patients were stratified into two subgroups:primary OA-DLBCL(no prior history of lymphoma)and secondary OA-DLBCL(history of DLBCL at non-ocular adnexal sites).OS was defined as the time interval from OA-DLBCL diagnosis to death from any cause.Survival analysis was performed using the Kaplan–Meier method,and prognostic factors affecting OS were identified using multivariate Cox proportional hazards regression with a stepwise selection approach.RESULTS:The cohort included 24 patients with primary OA-DLBCL(13 males,11 females;mean age:61.36±18.29y)and 5 patients with secondary OA-DLBCL(2 males,3 females;mean age:50.94±18.17y).Among the primary OA-DLBCL subgroup,12 patients(50%)presented with advanced disease(Ann Arbor stage IIIE–IV),and 16 patients(66%)were classified as T4 disease according to the tumor-node-metastasis(TNM)staging system.The mean final visual acuity was 1.72±1.10 in the primary group and 0.90±1.18 in the secondary group.The 5-year OS rate for the entire cohort was 27.7%.Multivariate analysis identified five factors significantly associated with poor survival outcomes:epiphora[adjusted hazard ratio(aHR),36.95],atherosclerotic cardiovascular disease(aHR,10.08),human immunodeficiency virus(HIV)infection(aHR,12.47),M1 stage(aHR,6.99),and secondary OA-DLBCL(aHR,6.03;all P<0.05).The median OS was 1.68y for primary OA-DLBCL and 1.12y for secondary OA-DLBCL.CONCLUSION:A substantial proportion of patients with primary OA-DLBCL present with advanced-stage disease at diagnosis.Epiphora,atherosclerotic cardiovascular disease,HIV infection,M1 stage,and secondary OA-DLBCL are independent prognostic factors for poor survival outcomes.These findings emphasize the urgent need for optimized therapeutic strategies and early screening protocols to improve the management of OA-DLBCL,particularly in developing countries.展开更多
The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature a...The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature and a high temperature of 1900 K∼60within a millimeter-sized sample volume in a Kawai-type LVP(KLVP)using hard tungsten carbide(WC)and newly designed assem-blies.The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe_(2)O_(3) pressure standard upon compression.The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils.Our study has enabled the routine gener-ation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs.This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs,but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.展开更多
Following the groundbreaking introduction of the Transformer architecture in 2017,the development of Large Language Models(LLMs)formally commenced.In May 2020,Chat GPT-3,with over one hundred billion parameters,entere...Following the groundbreaking introduction of the Transformer architecture in 2017,the development of Large Language Models(LLMs)formally commenced.In May 2020,Chat GPT-3,with over one hundred billion parameters,entered the public eye,marking a significant milestone in LLM advancement.展开更多
Stall flutter poses great challenges to flight safety.To alleviate this problem,a steady blowing control considering the perturbation and wake-induced vibration at a large angle of attack is developed in this paper,wh...Stall flutter poses great challenges to flight safety.To alleviate this problem,a steady blowing control considering the perturbation and wake-induced vibration at a large angle of attack is developed in this paper,where two blowings are configured on upper and lower tail surfaces to suppress the stall flutter.The stall flutter with one-degree-of-freedom is first evaluated by numerical simulation.The equation of motion for stall flutter is solved by the Newmark-β method.Then,the stall flutter responses for five blowing speeds,i.e.,0,4,12,20,and 28 m/s under the airspeed range of 3–9 m/s,are studied in detail.The stall flutter suppression mechanism can be summarized as follows:a large blowing speed can inject energy into the boundary layer and enhance the high-pressure zone,which delays the flow separation on the suction surface.In this way,the formation of the leading-edge separation vortex is suppressed.Thus,the dynamic stall vortex is weakened and accelerates shedding.In addition,the driving moment is reduced,which leads to a decrement in the stall flutter amplitude.When the blowing speed is 28 m/s(stall flutter amplitude=0.1357 rad),compared with uncontrolled case(stall flutter amplitude=0.6002 rad),the amplitude can decrease by 77.39%,which demonstrates the effectiveness of the proposed steady blowing based active control strategy.展开更多
A two-dimensional large eddy simulation numerical model is proposed to study the transient vortex flow and pressure oscillation of a large-aspect-ratio solid rocket motor.The numerical model is validated through exper...A two-dimensional large eddy simulation numerical model is proposed to study the transient vortex flow and pressure oscillation of a large-aspect-ratio solid rocket motor.The numerical model is validated through experimental data,finite element analysis and cumulative error analysis.The numerical simulations are executed to obtain the characteristics of the vortex-acoustic and pressure oscillation.The results show that the burning surface regression decreases the motor aspect ratio,increasing the corresponding natural frequency from 260 Hz to 293 Hz.The pressure oscillation phenomenon is formed due to the vortex-acoustic coupling.Decreasing the corner vortex shedding intensity shows negative effects on the dimensionless amplitude of the pressure oscillation.The head cavity without the injection can decrease the vortex-acoustic coupling level at the acoustic pressure antinode.The modified motor with head cavity can obtain a lower dimensionless oscillating pressure amplitude 0.00149 in comparison with 0.00895 of the original motor.The aspect ratio and volume of the head cavity without the injection have great effects on the pressure oscillation suppression,particularly at the low aspect ratio or large volume.The reason is that the mass in the region around the acoustic pressure antinode is extracted centrally,reducing the energy contribution to the acoustic system.With the volume increasing,the acoustic energy capacity increases.展开更多
基金Beijing Natural Science Foundation:Research on the Mechanism of Chaiqi Decoction in Improving Vascular Endothelial Injury in Metabolic Syndrome by Regulating Pyroptosis via miR-21(No.7212181)。
文摘OBJECTIVE:To explore the relationship between colorectal polyps and pulmonary nodules from the perspective of the lung and the large intestine being internally and externally connected,aiming to provide a theoretical basis for clinical diagnosis and treatment.METHODS:We retrospectively analyzed the data of patients who underwent electronic colonoscopy and were found to have colorectal polyps at the Gastrointestinal Endoscopy Center of Dongfang Hospital,Beijing University of Chinese Medicine,from January 1,2017,to December 31,2023.We also reviewed their lung CT results and used statistical software to analyze the recurrence,location,size,and pathology of colorectal polyps in relation to the presence,number,and size of pulmonary nodules.RESULTS:Both colorectal polyps and pulmonary nodules are more common in elderly males.Patients with recurrent colorectal polyps are more likely to have pulmonary nodules,which tend to be located in the left colon and are more likely to be adenomatous in nature;those without pulmonary nodules show no clear pattern in polyp distribution,with a tendency towards inflammatory and hyperplastic pathology;the data from this study suggests that the proportion of lung nodules larger than 0.5 cm in the recurrent group is higher than in the non-recurrent group,and the proportion of colorectal polyps larger than 1 cm in the recurrent group is also higher than in the non-recurrent group.CONCLUSION:There is a certain connection between the pathogenesis and treatment of colorectal polyps and pulmonary nodules.Cold,phlegm,dampness,blood stasis,and toxic coagulation are common pathogenic factors of the two diseases.Patients with larger colorectal polyps should be advised to undergo regular colonoscopy.Patients with recurrent polyps or those with left colon necrosis or cancer indicated by colonoscopy should be advised to complete lung related examinations to rule out the possibility of pulmonary nodules.
基金financed by the grant from the Fundamental Research Funds for the Central Universities (No. 2019-JYB-TD004)。
文摘The infection of SARS-CoV-2 has triggered the COVID-19 pandemic. In addition to the fever and respiratory symptoms in the process of coronavirus infections, gastrointestinal symptoms, especially diarrhea, are prominent features of its acute infection and long COVID. The associations between the lung and large intestine have been demonstrated by Western medicine in aspects such as tissue origin, microflora homeostasis, mucosal immunity, renin-angiotensin system(RAS) and autonomic nervous system as well, which are considered as the evidence of material basis and potential regulatory mechanisms for “gutlung crosstalk(肺肠串扰)” in COVID-19. We have noticed that probiotics and other preparations can regulate the intestines, and further treat COVID-19 with effective and gratifying results. In the system of traditional Chinese medicine(TCM), there's a term of “exterior-interior pairing of the lung and large intestine(肺与大肠相表里)”, showing an interconnection of the lung and the bowels. “Exterior-interior pairing of the lung and large intestine” is an important part of the theory of visceral activities proposed by ancient physicians through a long-term observation and practice. It's considered that “lung” and “large intestine” are interconnected and mutually exterior-interior in the normal physical activities and the disease development, providing a theoretical basis for treating lung diseases and bowel diseases from the perspective of overall concept. The study aims to compare the term of “exterior-interior pairing of the lung and large intestine” in TCM and “gut-lung crosstalk” in Western medicine regarding the development of COVID-19 and its intestinal symptoms, and provide more ideas for diagnosing and treating lung and bowel related diseases.
基金Supported by BBSRC/CASE studentship awarded(to Rowann Bowcutt)BBSRC studentship awarded(to M Glymnaki)Wellcome Trust Project grant,No.092323
文摘The small and large intestine of the gastrointestinal tract(GIT) have evolved to have discrete functions with distinct anatomies and immune cell composition.The importance of these differences is underlined when considering that different pathogens have uniquely adapted to live in each region of the gut.Furthermore,different regions of the GIT are also associated with differences in susceptibility to diseases such as cancer and chronic inflammation.The large and small intestine,given their anatomical and functional differences,should be seen as two separate immunological sites.However,this distinction is often ignored with findings from one area of the GIT being inappropriately extrapolated to the other.Focussing largely on the murine small and large intestine,this review addresses the literature relating to the immunology and biology of the two sites,drawing comparisons between them and clarifying similarities and differences.We also highlight the gaps in our understanding and where further research is needed.
基金Supported by National Natural Science Foundation of China, No.39270769, Natural Science Foundation of Anhui Province, No.03043704, Natural Science Foundation of Education Bureau of Anhui Province, No.2002kj307
文摘AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma.METHODS: Sixty-two large intestine cancer tissue samples were randomly and retrospectively selected from patients with large intestine carcinoma. Immunohistochemical staining for bcl-2, bax, GAS, SS was performed according to the standard streptavidin-biotin-peroxidase (S-P) method.According to the semi-quantitative integral evaluation, SS and GAS were divided into three groups as follows. Scores1-3 were defined as the low expression group, 4-8 as the intermediate expression group, 9-16 as the high expression group. Bax and bcl-2 protein expressions in different GAS and SS expression groups of large intestine carcinoma were assessed.RESULTS: The positive expression rate of bax had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 9.246; P＜0.05,x2GAS = 6.981). The positive expression rate of bax in SS high (80.0%, 8/10) and intermediate (76.5%, 13/17)expression groups was higher than that in low expression group (40.0%, 14/35) (P＜0.05, x2high vs low = 5.242; P＜0.05,x2middle vs low = 6.097). The positive expression rate of bax in GAS high expression group (27.3%, 3/8) was lower than that in low expression group (69.4%, 25/36) (P＜0.05,x2 = 4.594). However, bax expression in GAS intermediate expression group (46.7%, 7/15) was lower than that in low expression group, but not statistically significant. The positive expression rate of bcl-2 had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 7.178; P＜0.05, x2GAS = 13.831). The positive expression rate of bcl-2 in GAS high (90.9%, 10/11)and intermediate (86.7%, 13/15) expression groups was higher than that in low expression group (44.4%, 16/36)(P＜0.05,x2high vs low = 5.600; P＜0.05, x2 middle vs low = 7.695).However, the positive expression rate of bcl-2 in SS high (40.0%, 4/10) and intermediate (47.1%, 8/9) expression groups was lower than that in low expression group (77.1%, 27/35)(P＜0.05, x2 high vs low = 4.710; P＜0.05, x2 middle vs low = 4.706).There was a significant positive correlation between the integral ratio of GAS to SS and the integral of bcl-2 (P＜0.01,r=0.340). However, there was a negative correlation between the integral ratio of GAS to the SS and bax the integral of (P＜0.05, r = -0.299).CONCLUSION: The regulation and control of gastrin,somatostatin in cell apoptosis of large intestine carcinoma may be directly related to the abnormal expression of bcl-2, bax.
基金Supported by The National Basic Research Program of China(973 Program)(2009CB522707)the Distinguished Young Scholars Project from the Education Department of Hubei Province(Q20101081)the Science Fund for Distinguished Young Scholars of Wuhan City(D201050231081)
文摘OBJECTIVE:The theory of lung being connected with large intestine,which is a major topic in Traditional Chinese Medicine(TCM),has guided clinical practice for thousands of years in China.METHODS:In this study,we analyzed the history,main contents,clinical application,and material basis of the theory,to attempt to improve the potential clinical significance of "lung being connected with large intestine" in China.RESULTS:The lung being connected with large intestine was first described in "Huang Di Nei Jing",and formed one of the basic theories of TCM.For thousands of years,the majority of TCM practitioners explored this theory continuously,leading to its development and use as an important theory in the guidance of TCM clinics In the last decade,researchers in the field of integrated TCM and Western medicine have studied clinical applications and biomedical mechanisms with experimental methods to explore the implications of the theory.CONCLUSION:With the further development of science and technology,research concerning the theory of lung being connected with large intestine will be greatly stimulated and contribute to the modernization of TCM.
基金Supported by National Key Basic Research and Development Program "The research of literature review and comprehensive analysis on the theory of lung and large intestine are exterior-interior related"(No.2009CB522701)
文摘Pairing of the viscera and bowels is an important theory,which provides guidance to traditional Chinese medicine(TCM) clinical practice.Investigating this theory has been the focus of research on the basic theory of TCM.Recently,researchers have performed many studies on the theory that the lung and large intestine are exterior-interiorly related,which is a different point of view to that of previous literature,recent clinical studies and experimental studies,and these recent studies have enforced the theoretical connotation of the statement.However,there are problems in some of these studies including recent clinical studies and experimental studies.In the current article,literature on the viscera-related theory of the lung and large intestine are exterior-interiorly related is reviewed from physiological,pathological,and clinical views,and some opinions on the current research status are discussed.
文摘OBJECTIVE To investigate the clinical characteristics of melanosis of the colon （MC） and its correlation with polypus and carcinoma of the large intestine. METHODS Clinical feature and colonoscopic findings of 156 MC patients were retrospectively analyzed. Final diagnosis of MC case was made after colonoscopic and pathological examination, and data of the case history was recorded. RESULTS The overall detection rate of MC was 1.12%, with 0.46% in males, 0.66% in females. An 82.69% of the patients suffered various constipations and had a history of taking cathartics. The clinical manifestation of total-colon melanosis occurred in 83.97% of the patients. There was no significant difference between the rate of concomitant polypus （27.56%） in the MC patients and the detection rate of polypus in the patients who underwent a synchronous colonoscopy （χ^2 = 1.205, P = 0.298）. Also there was no significant difference between the detection rate of carcinoma of the large intestine （8.97%） in MC patients and the detection rate of the same disease in the patients who underwent synchronous colonoscopy （χ^2 = 0.268, P = 0.604）. A logistic regression analysis has shown that the older the age of MC patients is, the more opportunities of MC and the concomitant polypus would occur. CONCLUSION MC may be related to constipations and a long-term administration of cathartics, among which total-colon melanosis ranks first in the cases. There is an earlier age of onset in the females, with a higher detection rate. The older the age of the patients is, the higher the detection rate of MC is, and the more possibility the onset of the concomitant polypus.
基金Research Topic on traditional Chinese medicine and ethnic medicine science and technology of Guizhou Provincial Administration of Traditional Chinese Medicine(Project No.:QZYY-2024-100)。
文摘Ulcerative colitis(UC)is a chronic inflammatory bowel diseasethat significantly affects the quality of life of patients.Traditional treatments often have limitations,and alternative therapies are being explored.Miao Medicine,particularly Jinlong Zhi Xie Fang Enema,is a traditional herbal remedy used to treat UC symptoms,especially in patients with Large Intestine Damp-Heat Syndrome.However,clinical evidence supporting its efficacy is limited.
基金National Natural Science Foundation of China,Grant/Award Number:31201833 and 31872373Open Project of Hubei Key Laboratory of Animal Nutrition and Feed Science,Grant/Award Number:202306Scientific Research Plan Guiding Project of Hubei Provincial Education Department,Grant/Award Number:B2018082。
文摘Background:This study aimed to develop a combined model to quantify the net absorption of volatile fatty acids(VFA)in the large intestine(LI)of pigs.Methods:Fifteen female growing pigs(Duroc×Large White×Landrace)were ranked by body weight(30±2.1 kg)on day 0 and assigned to one of three treatments,namely the basal diet containing different crude fiber(CF)levels(LCF:3.0%CF,MCF:4.5%CF,and HCF:6.0%CF).The pigs were implanted with the terminal ileum fistula and the cannulation of the ileal mesenteric vein(IMV),portal vein(PV),and left femoral artery(LFA)from days 6 to 7.[13 C]-Labeled VFA and P-aminohippuric acid were constantly perfused into the terminal ileum fistula and the cannulation of the IMV(day 15),respectively.Blood samples were collected from the PV and the LFA during perfusion(5 h),and LI samples were collected.Results:The net flux of[12 C]-acetic acid in the PV was greater for LCF versus MCF(p=0.045),but no difference was observed in the net flux of[12 C]-propionic acid(p=0.505)and[12 C]-butyric acid(p=0.35)in the PV among treatments.The deposition of[12 C]-acetic acid in the LI was greater for LCF versus MCF(p=0.014),whereas the deposition of[12 C]-propionic acid(p=0.007)and[12 C]-butyric acid(p=0.037)in the LI was greater for LCF versus HCF.Conclusions:In conclusion,this pig model was found conducive to study the net absorption of VFAs in the LI,and LCF had more net absorption of VFAs in the LI than MCF and HCF.
文摘In a series of 130 cases of adenocarcinomas of the large intestine, enterochromaffin (EC) cells were detected in 54 cases (41.3%) by limmunocytochemistry with anti-chromogranin monoclonal antibody. Among the 54 cases, 30 were found positive for serotonin, 14 for somatostatin, 11 for glucagon, 5 for pancreatic polypeptide, and only one for gastrin. The cases with EC cell (++) or polypeptide positive cells exhibited higher grade of differentiation, earlier stage of tumor extension and higher survival rate than those without EC cells. A significant difference of the EC cell population pattern among different histological grades of the tumors and non-neoplastic mucosa was found. The proportion of hormone, especially polypeptied positive cells was the highest in the mucosa and lowest in the moderately or poorly-differentiated carcinomas. The incidence, methodology and clinicopathological significance of EC cells found in the tumors are discussed.
文摘In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case.
文摘Model evaluation using benchmark datasets is an important method to measure the capability of large language models(LLMs)in specific domains,and it is mainly used to assess the knowledge and reasoning abilities of LLMs.Therefore,in order to better assess the capability of LLMs in the agricultural domain,Agri-Eval was proposed as a benchmark for assessing the knowledge and reasoning ability of LLMs in agriculture.The assessment dataset used in Agri-Eval covered seven major disciplines in the agricultural domain:crop science,horticulture,plant protection,animal husbandry,forest science,aquaculture science,and grass science,and contained a total of 2283 questions.Among domestic general-purpose LLMs,DeepSeek R1 performed best with an accuracy rate of 75.49%.In the realm of international general-purpose LLMs,Gemini 2.0 pro exp 0205 standed out as the top performer,achieving an accuracy rate of 74.28%.As an LLMs in agriculture vertical,Shennong V2.0 outperformed all the LLMs in China,and the answer accuracy rate of agricultural knowledge exceeded that of all the existing general-purpose LLMs.The launch of Agri-Eval helped the LLM developers to comprehensively evaluate the model's capability in the field of agriculture through a variety of tasks and tests to promote the development of the LLMs in the field of agriculture.
基金funded by the Office of the Vice-President for Research and Development of Cebu Technological University.
文摘This study demonstrates a novel integration of large language models,machine learning,and multicriteria decision-making to investigate self-moderation in small online communities,a topic under-explored compared to user behavior and platform-driven moderation on social media.The proposed methodological framework(1)utilizes large language models for social media post analysis and categorization,(2)employs k-means clustering for content characterization,and(3)incorporates the TODIM(Tomada de Decisão Interativa Multicritério)method to determine moderation strategies based on expert judgments.In general,the fully integrated framework leverages the strengths of these intelligent systems in a more systematic evaluation of large-scale decision problems.When applied in social media moderation,this approach promotes nuanced and context-sensitive self-moderation by taking into account factors such as cultural background and geographic location.The application of this framework is demonstrated within Facebook groups.Eight distinct content clusters encompassing safety,harassment,diversity,and misinformation are identified.Analysis revealed a preference for content removal across all clusters,suggesting a cautious approach towards potentially harmful content.However,the framework also highlights the use of other moderation actions,like account suspension,depending on the content category.These findings contribute to the growing body of research on self-moderation and offer valuable insights for creating safer and more inclusive online spaces within smaller communities.
文摘In the era of AI,especially large models,the importance of open source has become increasingly prominent.First,open source allows innovation to avoid starting from scratch.Through iterative innovation,it promotes technical exchanges and learning globally.Second,resources required for large model R&D are difficult for a single institution to obtain.The evaluation of general large models also requires the participation of experts from various industries.Third,without open source collaboration,it is difficult to form a unified upper-layer software ecosystem.Therefore,open source has become an important cooperation mechanism to promote the development of AI and large models.There are two cases to illustrate how open source and international standards interact with each other.
基金supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(2024ZD1000500)the National Natural Science Foundation of China(42172262 and 42372266)+1 种基金the China Geological Survey(DD20240041)the Fundamental Research Funds of the Institute of Geomechanics(DZLXJK202516).
文摘The Yingxiu-Beichuan fault zone(YBFZ)has long been active and experienced repeated large earthquakes.The physicochemical properties of the deep fault zone(>1000 m)are the key to understanding the deformation mechanism of large earthquakes.This study uses rock magnetic,microstructural,and geochemical analyses of representative samples exposed in FZ1681 within the Wenchuan Earthquake Fault Scientific Drilling borehole 2(WFSD-2)cores.Fault gouge and fault breccia have higher magnetic susceptibility values than wall rocks,and they contain abundant paramagnetic minerals and small quantities of magnetite and monoclinic pyrrhotite.The magnetite and monoclinic pyrrhotite in the fault gouge were mainly formed by coseismic frictional heating,indicating that large earthquakes with frictional heating temperatures of~500-900℃once occurred in the YBFZ.The seismogenic and coseismic environment was reducing with a relatively high sulfur content.The monoclinic pyrrhotite in the fault breccia was formed mainly by low-temperature hydrothermal fluid.This indicates that the fault zone experienced reducing and low-temperature(<400℃)hydrothermal fluid with a relatively high sulfur content after the earthquake.The YBFZ,which experiences frequent large earthquakes,is weakly oxidizing environment at different depths,but the effect of the low-temperature hydrothermal fluid is weaker at depth.
基金Supported by the Faculty of Medicine,Prince of Songkla University.Wainipitapong S has received grants from the Faculty of Medicine,Prince of Songkla University。
文摘AIM:To investigate the clinical characteristics and treatment outcomes,including visual function and overall survival(OS)of patients with ocular adnexal diffuse large B-cell lymphoma(OA-DLBCL).METHODS:This retrospective cohort study enrolled 29 patients diagnosed with OA-DLBCL based on histopathological biopsy between 2006 and 2023.Patients were stratified into two subgroups:primary OA-DLBCL(no prior history of lymphoma)and secondary OA-DLBCL(history of DLBCL at non-ocular adnexal sites).OS was defined as the time interval from OA-DLBCL diagnosis to death from any cause.Survival analysis was performed using the Kaplan–Meier method,and prognostic factors affecting OS were identified using multivariate Cox proportional hazards regression with a stepwise selection approach.RESULTS:The cohort included 24 patients with primary OA-DLBCL(13 males,11 females;mean age:61.36±18.29y)and 5 patients with secondary OA-DLBCL(2 males,3 females;mean age:50.94±18.17y).Among the primary OA-DLBCL subgroup,12 patients(50%)presented with advanced disease(Ann Arbor stage IIIE–IV),and 16 patients(66%)were classified as T4 disease according to the tumor-node-metastasis(TNM)staging system.The mean final visual acuity was 1.72±1.10 in the primary group and 0.90±1.18 in the secondary group.The 5-year OS rate for the entire cohort was 27.7%.Multivariate analysis identified five factors significantly associated with poor survival outcomes:epiphora[adjusted hazard ratio(aHR),36.95],atherosclerotic cardiovascular disease(aHR,10.08),human immunodeficiency virus(HIV)infection(aHR,12.47),M1 stage(aHR,6.99),and secondary OA-DLBCL(aHR,6.03;all P<0.05).The median OS was 1.68y for primary OA-DLBCL and 1.12y for secondary OA-DLBCL.CONCLUSION:A substantial proportion of patients with primary OA-DLBCL present with advanced-stage disease at diagnosis.Epiphora,atherosclerotic cardiovascular disease,HIV infection,M1 stage,and secondary OA-DLBCL are independent prognostic factors for poor survival outcomes.These findings emphasize the urgent need for optimized therapeutic strategies and early screening protocols to improve the management of OA-DLBCL,particularly in developing countries.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(Grant Nos.42272041 and 52302043)+2 种基金the National Natural Science Foundation of China(Grant No.U23A20561)the Jilin University High-level Innovation Team Foundation(Grant No.2021TD–05)the Shanghai Synchrotron Radiation Facility(Grant Nos.2024-SSRF-PT-510031 and 505511).
文摘The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature and a high temperature of 1900 K∼60within a millimeter-sized sample volume in a Kawai-type LVP(KLVP)using hard tungsten carbide(WC)and newly designed assem-blies.The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe_(2)O_(3) pressure standard upon compression.The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils.Our study has enabled the routine gener-ation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs.This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs,but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.
文摘Following the groundbreaking introduction of the Transformer architecture in 2017,the development of Large Language Models(LLMs)formally commenced.In May 2020,Chat GPT-3,with over one hundred billion parameters,entered the public eye,marking a significant milestone in LLM advancement.
基金co-supported by the National Natural Science Foundation of China(Nos.52472394,52425211,52201327,52272360)。
文摘Stall flutter poses great challenges to flight safety.To alleviate this problem,a steady blowing control considering the perturbation and wake-induced vibration at a large angle of attack is developed in this paper,where two blowings are configured on upper and lower tail surfaces to suppress the stall flutter.The stall flutter with one-degree-of-freedom is first evaluated by numerical simulation.The equation of motion for stall flutter is solved by the Newmark-β method.Then,the stall flutter responses for five blowing speeds,i.e.,0,4,12,20,and 28 m/s under the airspeed range of 3–9 m/s,are studied in detail.The stall flutter suppression mechanism can be summarized as follows:a large blowing speed can inject energy into the boundary layer and enhance the high-pressure zone,which delays the flow separation on the suction surface.In this way,the formation of the leading-edge separation vortex is suppressed.Thus,the dynamic stall vortex is weakened and accelerates shedding.In addition,the driving moment is reduced,which leads to a decrement in the stall flutter amplitude.When the blowing speed is 28 m/s(stall flutter amplitude=0.1357 rad),compared with uncontrolled case(stall flutter amplitude=0.6002 rad),the amplitude can decrease by 77.39%,which demonstrates the effectiveness of the proposed steady blowing based active control strategy.
基金supported by the Natural Science Foundation of Hunan Province of China(No.2023JJ40672)the Innovation Science Fund Project of National University of Defense Technology,China(No.ZK2023-039)。
文摘A two-dimensional large eddy simulation numerical model is proposed to study the transient vortex flow and pressure oscillation of a large-aspect-ratio solid rocket motor.The numerical model is validated through experimental data,finite element analysis and cumulative error analysis.The numerical simulations are executed to obtain the characteristics of the vortex-acoustic and pressure oscillation.The results show that the burning surface regression decreases the motor aspect ratio,increasing the corresponding natural frequency from 260 Hz to 293 Hz.The pressure oscillation phenomenon is formed due to the vortex-acoustic coupling.Decreasing the corner vortex shedding intensity shows negative effects on the dimensionless amplitude of the pressure oscillation.The head cavity without the injection can decrease the vortex-acoustic coupling level at the acoustic pressure antinode.The modified motor with head cavity can obtain a lower dimensionless oscillating pressure amplitude 0.00149 in comparison with 0.00895 of the original motor.The aspect ratio and volume of the head cavity without the injection have great effects on the pressure oscillation suppression,particularly at the low aspect ratio or large volume.The reason is that the mass in the region around the acoustic pressure antinode is extracted centrally,reducing the energy contribution to the acoustic system.With the volume increasing,the acoustic energy capacity increases.
