BACKGROUND Nodular lymphoid hyperplasia(NLH)in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface.Patients with terminal ileal NLH may experience long-term ab...BACKGROUND Nodular lymphoid hyperplasia(NLH)in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface.Patients with terminal ileal NLH may experience long-term abdominal pain,diarrhea,and abdominal distension,among other symptoms.Supplementation with probiotics could mitigate these symptoms.NLH is linked to the immune system,and it may result from accumulation of plasma-cell precursors due to a maturational defect during the development of B lymphocytes.The intestinal microbiome plays an essential role in the immune system.Thus,we speculate that the gut flora plays a key role in terminal ileal NLH.AIM To explore the correlation between intestinal flora and terminal ileal NLH.METHODS We collected mucosal biopsy samples that were obtained via colonoscopy from 15 patients with terminal ileal NLH(the test group)and 15 normal subjects(the control group).We subsequently performed 16 S-r RNA gene amplicon sequencing of these samples,and the results were evaluated using alpha diversity,beta diversity and microbial composition analyses.The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict the metabolic pathways and orthologous groups according to the Kyoto Encyclopedia of Genes and Genomes database.RESULTS Compared with the control group,the terminal ileal NLH group showed an increased alpha diversity(P<0.05).The overall intestinal microbiota in the NLH group was significantly different from that of the control group(P<0.05),implying that there was the dysbiosis in the terminal ileal NLH patients.The relative abundance of phylum Bacteroidetes was significantly lower in the NLH group,while that of Patescibacteria and Campilobacterota was significantly higher.The genus Bacteroides was the dominant gut microbiota in both groups,but its abundance was significantly lower in the test group than it was in the control group.Conversely,the relative abundances of Haemophilus,Streptococcus,Pseudomonas,Actinomyces,TM7 X,Fusobacterium nucleatum,Parvimonas,Granulicatella,Helicobacter,and the[Eubacterium]nodatum group were significantly higher in the test group than they were in the control group.In addition,several altered metabolic pathways,orthologous groups,and modules were found.For example,the Peptidoglycan biosynthesis and Aminoacyl t RNA biosynthesis were both increased in the test group.CONCLUSION Maintaining the microbial balance and supplementing targeted protective bacteria could improve symptoms and potentially reduce the risk of lymphoma transformation in patients with terminal ileal NLH.展开更多
We propose an exact explicit closed-form Laguerre series expansion formula to compute the q-scale function of a spectrally negative Lévy process(SNLP),and other functions associated to the scale function for the ...We propose an exact explicit closed-form Laguerre series expansion formula to compute the q-scale function of a spectrally negative Lévy process(SNLP),and other functions associated to the scale function for the first time.The proposed closed-form formula for the scale function has many applications in applied probability and in particular in the Lévy insurance risk theory.We shall show that the new series expansion formulas can be used to express the expected discounted penalty functions,the moments of the present value of total dividend payments as well as the time value of Parisian ruin in the Lévy risk models.展开更多
In this paper,we construct tight lower and upper bounds for the price of an American strangle,which is a special type of strangle consisting of long positions in an American put and an American call,where the early ex...In this paper,we construct tight lower and upper bounds for the price of an American strangle,which is a special type of strangle consisting of long positions in an American put and an American call,where the early exercise of one side of the position will knock out the remaining side.This contract was studied in Chiarella and Ziogas(J Econ Dyn Control 29:31–62,2005)with the corresponding nonlinear integral equations derived,which are hard to be solved efficiently through numerical methods.We extend the approach in the paper of Broadie and Detemple(Rev Finance Stud 9:1211–1250,1996)from the case of American call options to the case of American strangles.We establish theoretical properties of the lower and upper bounds,and propose a sequential optimization algorithm in approximating the early exercise boundary of the American strangle. The theoretical bounds obtained can beeasily evaluated, and numerical examples confirm the accuracy of the approximationscompared to the literature.展开更多
基金Supported by the Science and Technology Project of Jiading Hospital,Shanghai General Hospital,No.202134A,No.202125A。
文摘BACKGROUND Nodular lymphoid hyperplasia(NLH)in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface.Patients with terminal ileal NLH may experience long-term abdominal pain,diarrhea,and abdominal distension,among other symptoms.Supplementation with probiotics could mitigate these symptoms.NLH is linked to the immune system,and it may result from accumulation of plasma-cell precursors due to a maturational defect during the development of B lymphocytes.The intestinal microbiome plays an essential role in the immune system.Thus,we speculate that the gut flora plays a key role in terminal ileal NLH.AIM To explore the correlation between intestinal flora and terminal ileal NLH.METHODS We collected mucosal biopsy samples that were obtained via colonoscopy from 15 patients with terminal ileal NLH(the test group)and 15 normal subjects(the control group).We subsequently performed 16 S-r RNA gene amplicon sequencing of these samples,and the results were evaluated using alpha diversity,beta diversity and microbial composition analyses.The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict the metabolic pathways and orthologous groups according to the Kyoto Encyclopedia of Genes and Genomes database.RESULTS Compared with the control group,the terminal ileal NLH group showed an increased alpha diversity(P<0.05).The overall intestinal microbiota in the NLH group was significantly different from that of the control group(P<0.05),implying that there was the dysbiosis in the terminal ileal NLH patients.The relative abundance of phylum Bacteroidetes was significantly lower in the NLH group,while that of Patescibacteria and Campilobacterota was significantly higher.The genus Bacteroides was the dominant gut microbiota in both groups,but its abundance was significantly lower in the test group than it was in the control group.Conversely,the relative abundances of Haemophilus,Streptococcus,Pseudomonas,Actinomyces,TM7 X,Fusobacterium nucleatum,Parvimonas,Granulicatella,Helicobacter,and the[Eubacterium]nodatum group were significantly higher in the test group than they were in the control group.In addition,several altered metabolic pathways,orthologous groups,and modules were found.For example,the Peptidoglycan biosynthesis and Aminoacyl t RNA biosynthesis were both increased in the test group.CONCLUSION Maintaining the microbial balance and supplementing targeted protective bacteria could improve symptoms and potentially reduce the risk of lymphoma transformation in patients with terminal ileal NLH.
基金supported by the National Natural Science Foundation of China(No.12401612)the Natural Science Foundation of Chongqing(No.CSTB2025NSCQ-GPX1016)+3 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN202400508)the Chongqing Normal University Foundation(No.23XLB018)supported by National Science Foundation(NSF-CNS 2113906)the Chongqing Natural Science Foundation Joint Fund for Innovation and Development Project(No.CSTB2024NSCQ-LZX0085)。
文摘We propose an exact explicit closed-form Laguerre series expansion formula to compute the q-scale function of a spectrally negative Lévy process(SNLP),and other functions associated to the scale function for the first time.The proposed closed-form formula for the scale function has many applications in applied probability and in particular in the Lévy insurance risk theory.We shall show that the new series expansion formulas can be used to express the expected discounted penalty functions,the moments of the present value of total dividend payments as well as the time value of Parisian ruin in the Lévy risk models.
基金The work was supported by the National Natural Science Foundation of China(No.11671323)Program for New Century Excellent Talents in University(No.NCET-12-0922)the Fundamental Research Funds for the Central Universities(No.15CX141110).
文摘In this paper,we construct tight lower and upper bounds for the price of an American strangle,which is a special type of strangle consisting of long positions in an American put and an American call,where the early exercise of one side of the position will knock out the remaining side.This contract was studied in Chiarella and Ziogas(J Econ Dyn Control 29:31–62,2005)with the corresponding nonlinear integral equations derived,which are hard to be solved efficiently through numerical methods.We extend the approach in the paper of Broadie and Detemple(Rev Finance Stud 9:1211–1250,1996)from the case of American call options to the case of American strangles.We establish theoretical properties of the lower and upper bounds,and propose a sequential optimization algorithm in approximating the early exercise boundary of the American strangle. The theoretical bounds obtained can beeasily evaluated, and numerical examples confirm the accuracy of the approximationscompared to the literature.
