检索结果-南通市图书馆

The Bistability Theorem in a Model of Metastatic Cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2016年第10期7卷 1183-1206页

作者： jens christian larsen Vanlose Alle 50 2 mf tv 2720 Vanlose Copenhagen Denmark

The main theorem of the present paper is the bistability theorem for a four dimensional cancer model, in the variables representing primary cancer C, metastatic cancer , growth factor GF and growth inhibitor GI, respectively. It says that for some values of the para- meters this system is bistable, in the sense that there are exactly two positive singular points of this vector field. And one is stable and the other unstable. We also find an expression for for the discrete model T of the introduction, with variables , where C is cancer, are growth factors and growth inhibitors respectively. We find an affine vector field Y whose time one map is T2 and then compute , where is an integral curve of Y through . We also find a formula for the first escape time for the vector field associated to T, see section four.

关键词： Bistability Cancer Mass Action Kinetic System Discrete Dynamical System

A Study on Multipeutics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2017年第5期8卷 746-773页

作者： jens christian larsen Vanlø se Alle 50 2. mf. tv 2720 Vanl&oslash se Copenhagen Denmark

Multipeutics is the simultaneous application of m ≥ 4 cancer treatments. m = 4 is quadrapeutics, which was invented by researchers at Rice University, Northeastern University, MD Anderson Cancer Centre and China Medical University, see [1]. Multipeutics is our idea. From section 6 Summary, it follows that multipeutics can be more potent than quadrapeutics by comparing these two mathematical models. The first two treatments in quadrapeutics are systemically administered nano gold particles G and lysosomal chemo therapeutic drug D. They form mixed clusters M primarily in cancer cells and can be excited by a laser pulse, the third treatment, to form plasmonic nanobubbles N. These nanobubbles can kill the cancer cells by mechanical impact. If they do not the chemo therapeutic drug can be released into the cytoplasm, which might be lethal to the cancer cell. The fourth treatment is x rays X and the cancer cells have been sensitized to x rays by the treatment. We present an ODE (ordinary differential equations) model of quadrapeutics and of multipeutics, which is quadrapeutics and n ≥ 1 immune or chemo therapies. In the present paper we have found a polynomial p of degree at most 2(n + 3), such that a singular point (C, D, G, M, N, I1, …, In) will have p(M) = 0 Here I1, …, In are immune or chemo therapies. So this gives us candidates for singular points. Quadrapeutics is treated extensively. We find in theorem 3 a polynomium s of degree at most six in M such that a positive singular point (C, D, G, M, N) of the quadrapeutics system will have s(M) = 0. The main theorem of the present paper is the multipeutics theorem, saying that the more treatments we apply the lower the cancer burden, even if we take the doses of each treatment smaller. From the proof of this theorem, we can say, that quadrapeutics can outperform chemo radiation if the nanobubble kill rate k21 is sufficiently big. See also Figure 1 and Figure 2 and the text explaining them.

关键词： Cancer Mass Action Kinetic System Quadrapeutics Immune Therapy

Optimal Control of Cancer Growth

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2019年第4期10卷 173-195页

作者： jens christian larsen Vanlose Alle 50 2. mf. tv 2720 Vanlose Copenhagen Denmark

The purpose of the present paper is to apply the Pontryagin Minimum Principle to mathematical models of cancer growth. In [1], I presented a discrete affine model T of cancer growth in the variables C for cancer, GF for growth factors and GI for growth inhibitors. One can sometimes find an affine vector field X on whose time one map is T. It is to this vector field we apply the Pontryagin Minimum Principle. We also apply the Discrete Pontryagin Minimum Principle to the model T. So we prove that maximal chemo therapy can be optimal and also that it might not depending on the spectral properties of the matrix A, (see below). In section five we determine an optimal strategy for chemo or immune therapy.

关键词： Cancer Models of Cancer Growth Pontryagin Minimum Principle

Models of Cancer Growth Revisited

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2018年第4期9卷 418-447页

作者： jens christian larsen Vanlø se Alle 50 2. mf. tv 2720 Vanl&oslash se Copenhagen Denmark

In the present paper we study models of cancer growth, initiated in jens Chr. larsen: Models of cancer growth [1]. We consider a cancer model in variables C cancer cells, growth factors GFi?,i= 1,,p, (oncogene, tumor suppressor gene or carcinogen) and growth inhibitor GFi?,i= 1,,p, (cells of the immune system or chemo or immune therapy). For q =1 this says, that cancer grows if (1) below holds and is eliminated if the reverse inequality holds. We shall prove formulas analogous to (1) below for arbitrary p, q∈N, p ≥ q . In the present paper, we propose to apply personalized treatment using the simple model presented in the introduction.

关键词： Cancer Mass Action Kinetic System Immunity

Development of fungal cell factories for the production of secondary metabolites:Linking genomics and metabolism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Synthetic and Systems Biotechnology 2017年第1期2卷 5-12页

作者： jens christian Nielsen jens Nielsen Chalmers University of Technology Kemivagen 10Sweden

The genomic era has revolutionized research on secondary metabolites and bioinformatics methods have in recent years revived the antibiotic discovery process after decades with only few new active molecules being *** computational tools are driven by genomics and metabolomics analysis,and enables rapid identification of novel secondary *** translate this increased discovery rate into industrial exploitation,it is necessary to integrate secondary metabolite pathways in the metabolic engineering *** this review,we will describe the novel advances in discovery of secondary metabolites produced by filamentous fungi,highlight the utilization of genome-scale metabolic models(GEMs)in the design of fungal cell factories for the production of secondary metabolites and review strategies for optimizing secondary metabolite production through the construction of high yielding platform cell factories.

关键词： Secondary metabolism Fungi Biosynthetic gene clusters Genome mining Metabolic modeling Cell factories

Is serine racemase(SRR) a second hit target for LRRK2-G2019S induced Parkinson's disease?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第3期16卷 498-499页

作者： Sarah Louise Nickels jens christian Schwamborn Luxembourg Centre for Systems Biomedicine(LCSB) University of LuxembourgBelvauxLuxembourg Riken Institute for Medical Sciences(IMS) KanagawaJapan

To date,at least 7 million people are suffering from Parkinson's disease(PD)worldwide,which is the second most prevalent,age-associated,and progressive neurodegenerative disorder(Tysnes and Storstein,2017).Given the accelerated global pace of aging,it becomes of fundamental importance that we start understanding the origins of neurodegeneration in order to develop effective disease modifying *** PD patients suffer from a combination of motor and nonmotor disabilities.

关键词： second patients suffering

A concurrent optimization approach for energy efficient multiple axis positioning tasks

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Control and Decision 2016年第4期3卷 223-247页

作者： christian Hansen jens Kotlarski Tobias Ortmaier Institute of Mechatronic Systems Leibniz Universitat HannoverHanoverGermany

Automated production systems typically comprise numerous electrical servo drives,many of which conduct positioning motions,*** handling or manipulation *** power electronics of modern multi-axis systems often comprise coupled DC-links,enabling for internal exchange of recuperative brake ***,the motion sequences of manipulators are often commanded at maximum dynamics for minimum time motion,neglecting possible optimization potential,*** idle time,leading to inefficient energy management.A robust trajectory optimization approach based on the particle swarm algorithm and well-established path planning methods is presented for the adaption of multi-axis positioning tasks with only two parameters per axis and positioning motion during system *** results prove that,depending on the positioning task and chosen optimization constraints,energy demands are distinctly *** approach is applicable to diverse multi-axis configurations and enables for considerable energy savings without additional hardware invest.

关键词： Multiple axis systems electrical servo drive energy efficient control trajectory optimization positioning tasks

Ethyl-iophenoxic acid as a quantitative bait marker for small mammals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2022年第6期17卷 981-990页

作者： Kyra JACOBLINNERT christian IMHOLT Detlef SCHENKE jens JACOB Julius Kühn Institute(JKI) Federal Research Centre for Cultivated PlantsInstitute for Plant Protection in Horticulture and ForestsVertebrate ResearchMünsterGermany Department of Behavioral Biology University of OsnabrückOsnabrückGermany Julius Kühn Institute(JKI) Federal Research Centre for Cultivated PlantsInstitute for Ecological ChemistryPlant Analysis and Stored Product ProtectionBerlinGermany

Bait markers are indispensable for ecological research but in small mammals,most markers are invasive,expensive and do not enable quantitative analyses of ***-iophenoxic acid(Et-IPA)is a non-toxic,quantitative bait marker,which has been used for studying bait uptake in several carnivores and *** developed a bait with Et-IPA,assessed its palatability to common voles(Microtus arvalis),and determined the dose-residue-relation for this important agricultural pest rodent ***-IPA concentrations of 40 to 1280μg Et-IPA per g bait were applied to wheat using sunﬂower oil or polyethylene glycol 300 as potential *** a laboratory study,common voles were offered the bait and blood samples were collected 1,7,and 14 days after *** samples were analyzed with LC-ESI-MS/MS for blood residues of ***ﬂower-oil was the most suitable bait ***-IPA seemed to be palatable to common voles at all test ***-dependent residues could be detected in blood samples in a dose-dependent manner and up to 14 days after uptake enabling generation of a calibration curve of the dose-residue ***-IPA was present in common vole blood for at least 14 days,but there was dissipation by 33–37%depending on ***-IPA meets many criteria for an“ideal”quantitative bait marker for use in futureﬁeld studies on common voles and possibly other small mammal species.

关键词： baiting biomarker Microtus arvalis quantitative bait marker small mammals

Wear dependent virtual flow rate sensor for progressing cavity pumps with deformable stator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1346-1353页

作者： jens Müller Sebastian Leonow Johannes Schulz christian Hansen Martin Monnigmann Ruhr-Universitat Bochum Universit atsstraûe 150Bochum44801Germany SEEPEX GmbH Scharnh olzstraûe 344Bottrop46240Germany

This contribution presents a novel wear dependent virtual flow rate sensor for single stage single lobe progressing cavity pumps. We study the wear-induced material loss of the pump components and the impact of this material loss on the volumetric efficiency. The results are combined with an established backflow model to implement a backflow calculation procedure that is adaptive to wear. We use a laboratory test setup with a highly abrasive fluid and operate a pump from new to worn condition to validate our approach. The obtained measurement data show that the presented virtual sensor is capable of calculating the flow rate of a pump being subject to wear during its regular operation.

关键词： Backflow Progressing cavity pump Virtual sensor Wear