In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction rat...In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction ratios for this model.展开更多
Ge/SiGe heterostructure quantum wells play a pivotal role in the pursuit of scalable silicon-based qubits.The varying compressive strains within these quantum wells profoundly influence the physical characteristics of...Ge/SiGe heterostructure quantum wells play a pivotal role in the pursuit of scalable silicon-based qubits.The varying compressive strains within these quantum wells profoundly influence the physical characteristics of the qubits,yet this factor remains largely unexplored,driving our research endeavor.In this study,we utilized RP-CVD(Reduced Pressure Chemical Vapor Deposition)to grow Ge quantum wells with varied compressive strain,proposing growth schemes for lightly-strained(ε∥=-0.43%)QW(quantum well),standard-strained(ε∥=-0.61%)QW,and heavily-strained(ε∥=-1.19%)QW.Through comprehensive material characterization,particularly employing the low-temperature magneto-transport measurements,we derived the percolation densities ranging from 4.7×10^(10) to 14.2×10^(10) cm^(-2) and mobilities from 3.382×10^(5) to 7.301×10^(5) cm^(2)∙V^(-1)∙s^(-1).Combined with the first-principles calculations,our analysis delves into the trends in effective mass and percolation density at low temperatures,shedding light on the impact of quantum effects on band structures and the interplay between structural components and wave functions.This research offers a comprehensive investigation into the intrinsic mechanisms governing complex multi-strained quantum wells,spanning growth,characterization,and computational perspectives,thereby establishing a strategy for the growth of high-quality strained quantum wells.展开更多
The widespread use of polymers has made our lives increasingly convenient by offering a more convenient and dependable material.However,the challenge of efficiently decomposing these materials has resulted in a surge ...The widespread use of polymers has made our lives increasingly convenient by offering a more convenient and dependable material.However,the challenge of efficiently decomposing these materials has resulted in a surge of polymer waste,posing environment and health risk.Currently,landfill and incineration treatment approaches have notable shortcomings,prompting a shift towards more eco-friendly and sustainable biodegradation approaches.Biodegradation primarily relies on microorganisms,with research focusing on both solitary bacterial strain and multi-strain communities for polymer biodegradation.Furthermore,directed evolution and rational design of enzyme have significantly contributed to the polymer biodegradation process.However,previous reviews often undervaluing the role of multi-strain communities.In this review,we assess the current state of these three significant fields of research,provide practical solutions to issues with polymer biodegradation,and outline potential future directions for the subject.Ultimately,biodegradation,whether facilitated by single bacteria,multi-strain communities,or engineered enzymes,now represents the most effective method for managing waste polymers.展开更多
This experiment was conducted to evaluate the effect of milk or molasses kefir as a probiotic on growth performance, carcass traits, serum biochemistry and humoral immune responses in broiler chickens. A total of 192 ...This experiment was conducted to evaluate the effect of milk or molasses kefir as a probiotic on growth performance, carcass traits, serum biochemistry and humoral immune responses in broiler chickens. A total of 192 one-d-old as hatched broiler chicks(Ross 308) were randomly allotted to 4 treatments, each with 4 replicate pens of 12 chicks. The following treatments were applied: 1) a basal diet(C) and normal drinking water, 2) 2% milk kefir in drinking water, 3) 2% molasses kefir in drinking water, and 4) the diet C supplemented with commercial probiotic. At d 42, eight birds per treatment were killed for determination of carcass traits. Broilers at 28 days of age were bled for measuring antibody titers against Newcastle disease virus(NDV) and avian influenza virus(AIV), at 30 days of age for antibody titers against sheep red blood cell(SRBC), and at 42 days of age for biochemical analysis. Supplementing 2%milk kefir increased body weight of broilers at 28 and 42 days of age(P < 0.05). Supplementing 2%molasses kefir improved feed conversation ratio(FCR) of broilers during growth period(P < 0.05), but FCR of broilers in other periods was not affected. Daily feed intake, internal organ weights, and carcass traits were not influenced by the treatments except for small intestine and ceca length. Small intestinal length significantly decreased in broilers supplemented with milk and molasses kefir(P < 0.05). Molasses kefir supplementation significantly(P < 0.05) increased antibody titer against SRBC at 31 days of age but other immune related parameters were not statistically different among treatments. Biochemical parameters including serum protein, albumin, and triglyceride concentrations were not statistically(P> 0.05) influenced. Broilers supplemented with molasses kefir, had a significantly lower concentration of serum total cholesterol, low density lipoprotein cholesterol and elevated high density lipoprotein cholesterol at 42 days of age(P < 0.05). In conclusion, the results indicated that inclusion of 2% milk kefir in drinking water would improve growth performance of broiler chickens.展开更多
In this paper,we study a multi-strain SEIR epidemic model with both bilinear and nonmonotone incidence functions.Under biologically motivated assumptions,we show that the model has two basic reproduction numbers that ...In this paper,we study a multi-strain SEIR epidemic model with both bilinear and nonmonotone incidence functions.Under biologically motivated assumptions,we show that the model has two basic reproduction numbers that we noted R0,1 and R0,2;and four equilibrium points.Using the Lyapunov method,we prove that if R0,1 and R0,2 are less than one then the disease-free equilibrium is Globally Asymptotically Stable,thus the disease will be eradicated.However,if one of the two basic reproduction numbers is greater than one,then the strain that persists is that with the larger basic reproduction number.And finally if both of the two basic reproduction numbers are equal or greater than one then the total endemic equilibrium is globally asymptotically stable.A numerical simulation is also presented to illustrate the influence of the psychological effect,of people to infection,on the spread of the disease in the population.This simulation can be used to determine the status of different diseases in a region using the corresponding data and infectious disease parameters.展开更多
A vaccine breakthrough infection and a rebound infection cases of COVID-19 are studied and analyzed for the ten U.S.Department of Health and Human Services(HHS)regions and the United States as a nation in this work.An...A vaccine breakthrough infection and a rebound infection cases of COVID-19 are studied and analyzed for the ten U.S.Department of Health and Human Services(HHS)regions and the United States as a nation in this work.An innovative multi-strain susceptible-vacci-nated-exposed-asymptomatic-symptomatic-recovered(SVEAIR)epidemic model is devel-oped for this purpose for a population assumed to be susceptible to n-different variants of the disease,and those who are vaccinated and recovered from a specific strain k(kn)of the disease are immune to present strain and its predecessors j=1,2,…,k,but can still be infected by newer emerging strains j=k+1,k+2,…,n.The model is used to estimate epidemiological parameters,namely,the latent and infectious periods,the transmission rates,vaccination rates,recovery rates for each of the Delta B.1.617.2,Omicron B.1.1.529,and lineages BA.2,BA.2.12.1,BA.4,BA.5,BA.1.1,BA.4.6,and BA.5.2.6 for the United States and for each of the ten HHS regions.The transmission rate is estimated for both the asymptomatic and symptomatic cases.The effect of vaccines on each strain is analyzed.Condition that guarantees existence of an endemic with certain number of strains is derived and used to describe the endemic state of the population.展开更多
文摘In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction ratios for this model.
基金supported by the Innovation Program for Quantum Science and Technology (Project ID.2021ZD0302301)the National Natural Science Foundation of China (Grant No.6240033549).
文摘Ge/SiGe heterostructure quantum wells play a pivotal role in the pursuit of scalable silicon-based qubits.The varying compressive strains within these quantum wells profoundly influence the physical characteristics of the qubits,yet this factor remains largely unexplored,driving our research endeavor.In this study,we utilized RP-CVD(Reduced Pressure Chemical Vapor Deposition)to grow Ge quantum wells with varied compressive strain,proposing growth schemes for lightly-strained(ε∥=-0.43%)QW(quantum well),standard-strained(ε∥=-0.61%)QW,and heavily-strained(ε∥=-1.19%)QW.Through comprehensive material characterization,particularly employing the low-temperature magneto-transport measurements,we derived the percolation densities ranging from 4.7×10^(10) to 14.2×10^(10) cm^(-2) and mobilities from 3.382×10^(5) to 7.301×10^(5) cm^(2)∙V^(-1)∙s^(-1).Combined with the first-principles calculations,our analysis delves into the trends in effective mass and percolation density at low temperatures,shedding light on the impact of quantum effects on band structures and the interplay between structural components and wave functions.This research offers a comprehensive investigation into the intrinsic mechanisms governing complex multi-strained quantum wells,spanning growth,characterization,and computational perspectives,thereby establishing a strategy for the growth of high-quality strained quantum wells.
基金supported by the National Natural Science Foundation of China(22078011,21908003,and 32022002)the National Key Research and Development Program of China(2021YFC2100600)+1 种基金the seed funding of China Petrochemical Corporation(Sinopec Group)(223260)the Fundamental Research Funds for the Central Universities(QNTD2023-01).
文摘The widespread use of polymers has made our lives increasingly convenient by offering a more convenient and dependable material.However,the challenge of efficiently decomposing these materials has resulted in a surge of polymer waste,posing environment and health risk.Currently,landfill and incineration treatment approaches have notable shortcomings,prompting a shift towards more eco-friendly and sustainable biodegradation approaches.Biodegradation primarily relies on microorganisms,with research focusing on both solitary bacterial strain and multi-strain communities for polymer biodegradation.Furthermore,directed evolution and rational design of enzyme have significantly contributed to the polymer biodegradation process.However,previous reviews often undervaluing the role of multi-strain communities.In this review,we assess the current state of these three significant fields of research,provide practical solutions to issues with polymer biodegradation,and outline potential future directions for the subject.Ultimately,biodegradation,whether facilitated by single bacteria,multi-strain communities,or engineered enzymes,now represents the most effective method for managing waste polymers.
文摘This experiment was conducted to evaluate the effect of milk or molasses kefir as a probiotic on growth performance, carcass traits, serum biochemistry and humoral immune responses in broiler chickens. A total of 192 one-d-old as hatched broiler chicks(Ross 308) were randomly allotted to 4 treatments, each with 4 replicate pens of 12 chicks. The following treatments were applied: 1) a basal diet(C) and normal drinking water, 2) 2% milk kefir in drinking water, 3) 2% molasses kefir in drinking water, and 4) the diet C supplemented with commercial probiotic. At d 42, eight birds per treatment were killed for determination of carcass traits. Broilers at 28 days of age were bled for measuring antibody titers against Newcastle disease virus(NDV) and avian influenza virus(AIV), at 30 days of age for antibody titers against sheep red blood cell(SRBC), and at 42 days of age for biochemical analysis. Supplementing 2%milk kefir increased body weight of broilers at 28 and 42 days of age(P < 0.05). Supplementing 2%molasses kefir improved feed conversation ratio(FCR) of broilers during growth period(P < 0.05), but FCR of broilers in other periods was not affected. Daily feed intake, internal organ weights, and carcass traits were not influenced by the treatments except for small intestine and ceca length. Small intestinal length significantly decreased in broilers supplemented with milk and molasses kefir(P < 0.05). Molasses kefir supplementation significantly(P < 0.05) increased antibody titer against SRBC at 31 days of age but other immune related parameters were not statistically different among treatments. Biochemical parameters including serum protein, albumin, and triglyceride concentrations were not statistically(P> 0.05) influenced. Broilers supplemented with molasses kefir, had a significantly lower concentration of serum total cholesterol, low density lipoprotein cholesterol and elevated high density lipoprotein cholesterol at 42 days of age(P < 0.05). In conclusion, the results indicated that inclusion of 2% milk kefir in drinking water would improve growth performance of broiler chickens.
文摘In this paper,we study a multi-strain SEIR epidemic model with both bilinear and nonmonotone incidence functions.Under biologically motivated assumptions,we show that the model has two basic reproduction numbers that we noted R0,1 and R0,2;and four equilibrium points.Using the Lyapunov method,we prove that if R0,1 and R0,2 are less than one then the disease-free equilibrium is Globally Asymptotically Stable,thus the disease will be eradicated.However,if one of the two basic reproduction numbers is greater than one,then the strain that persists is that with the larger basic reproduction number.And finally if both of the two basic reproduction numbers are equal or greater than one then the total endemic equilibrium is globally asymptotically stable.A numerical simulation is also presented to illustrate the influence of the psychological effect,of people to infection,on the spread of the disease in the population.This simulation can be used to determine the status of different diseases in a region using the corresponding data and infectious disease parameters.
文摘A vaccine breakthrough infection and a rebound infection cases of COVID-19 are studied and analyzed for the ten U.S.Department of Health and Human Services(HHS)regions and the United States as a nation in this work.An innovative multi-strain susceptible-vacci-nated-exposed-asymptomatic-symptomatic-recovered(SVEAIR)epidemic model is devel-oped for this purpose for a population assumed to be susceptible to n-different variants of the disease,and those who are vaccinated and recovered from a specific strain k(kn)of the disease are immune to present strain and its predecessors j=1,2,…,k,but can still be infected by newer emerging strains j=k+1,k+2,…,n.The model is used to estimate epidemiological parameters,namely,the latent and infectious periods,the transmission rates,vaccination rates,recovery rates for each of the Delta B.1.617.2,Omicron B.1.1.529,and lineages BA.2,BA.2.12.1,BA.4,BA.5,BA.1.1,BA.4.6,and BA.5.2.6 for the United States and for each of the ten HHS regions.The transmission rate is estimated for both the asymptomatic and symptomatic cases.The effect of vaccines on each strain is analyzed.Condition that guarantees existence of an endemic with certain number of strains is derived and used to describe the endemic state of the population.
