The self similar sets satisfying the open condition have been studied. An estimation of fractal, by the definition can only give the upper limit of its Hausdorff measure. So to judge if such an upper limit is its exac...The self similar sets satisfying the open condition have been studied. An estimation of fractal, by the definition can only give the upper limit of its Hausdorff measure. So to judge if such an upper limit is its exact value or not is important. A negative criterion has been given. As a consequence, the Marion’s conjecture on the Hausdorff meas\| ure of the Koch curve has been proved invalid.展开更多
In this study,the wave propagation properties of lattice metamaterials with Koch fractal structures are investigated in terms of band structures and directional wave propagation.The analytical models of lattice metama...In this study,the wave propagation properties of lattice metamaterials with Koch fractal structures are investigated in terms of band structures and directional wave propagation.The analytical models of lattice metamaterials are established using the finite element method,and the dispersion relation is solved using the Bloch’s theorem.The band structures of the lattice metamaterials with different numbers of iterations are studied,and the group velocities at a selected frequency are calculated to analyze the directional wave propagation characteristics.Furthermore,dynamic responses of the finite structures are calculated using commercial finite element software to verify the band gaps and directional wave propagation behaviors in the lattice metamaterials.The results show that multiple and low band gaps are present in the lattice materials with various geometric parameters of the Koch fractal,and the position of the lowest band gap decreases as the number of iterations increases.The results indicate the potential applications of lattice metamaterials with Koch fractals for vibration isolation and multi-functional design.展开更多
Cankered, dying seedlings of Juglans regia were observed in Shaanxi province in the northwest region of China. Neofusicoccum parvum was isolated from these cankered tissues, with the identification based on mor- pholo...Cankered, dying seedlings of Juglans regia were observed in Shaanxi province in the northwest region of China. Neofusicoccum parvum was isolated from these cankered tissues, with the identification based on mor- phology and an ITS-nrDNA sequence. In order to demonstrate how cultures of N. parvum could cause the expected symptoms, artificial infection, using these isolates and re-isolation of the pathogen, was used. This is the first report on this taxon as a walnut canker pathogen in China.展开更多
Background The morphological and electrophysiological characteristics of cardiac cells in Koch triangle are still disputed. We studied the appearance and electrical properties of these diverse myocytes to elucidate th...Background The morphological and electrophysiological characteristics of cardiac cells in Koch triangle are still disputed. We studied the appearance and electrical properties of these diverse myocytes to elucidate their complex electrophysiological phenomena. Methods Experiments were conducted using cooled charge coupling device (CCD) system and whole cell, patch clamp technique to determine the morphology, action potential and sodium current density of single viable myocytes enzymatically isolated from the Koch triangle of rabbit hearts. Results Morphologically, cardiac cells in shape of spider, tiny spindle, slender spindle, rod and strip were observed in percentage of 3.0±0.3, 35.0±5.0, 15.0±2.0, 40.0±5.0 and 6.0±0.7 respectively. The cellular dimensions and capacitance gradually increased in the above order (all P〈0.05). Electrophysiologically, action potential configurations recorded from them were similar respectively to nodal (N), atrial nodal (AN), nodal Hisian (NH), atrial (A) and Hisian like potentials obtained from the intact atrioventricular nodal preparations. Diastolic depolarization appeared in all myocytes except for rod cells. Sodium current density increased in the order of tiny spindle, strip, rod, slender spindle cell (all P〈0.05), but could not be detected in spider-shaped cells. Linear regression analysis revealed that membrane capacitance was correlated negatively to the rate of diastolic depolarization r=-0.70, P〈0.001, but positively to maximum depolarization potential, amplitude of action potential, upstroke velocity and maximum peak value of sodium current density r=0.84, 0.80, 0.87 and 0.75, respectively; all P〈0.001. Conclusions The results demonstrated that spider-shaped, spindle, rod and strip cells in Koch triangle might correspond to pacemaking, transitional, atrial and Purkinje like cells, respectively. Furthermore, tiny spindle and slender spindle cells were referred to transitional cell α (TCα) and β (TCβ) accordingly consid展开更多
The wild hawthorn species, Crataegus songorica K. Koch., is an important wild germplasm resource in Xinjiang, China that has been endangered in recent years. The genetic diversity of C. songorica K. Koch. germplasm in...The wild hawthorn species, Crataegus songorica K. Koch., is an important wild germplasm resource in Xinjiang, China that has been endangered in recent years. The genetic diversity of C. songorica K. Koch. germplasm in five populations from Daxigou, Xinjiang, China were evaluated based on phenotypic traits and ISSR molecular markers to provide basic infor- mation on resource protection, rational utilization and genetic improvement. The F-value for the phenotypic differentiation coefficient of the 33 traits measured ranged from 0.266 to 15.128, and mean value was 13.85%. The variation among populations was found to be lower than that within population. A total of 303 loci were detected within the five populations by 12 primers. Within 298,polymorphic loci, the polymorphism was 98.35%, showing a high genetic diversity in C. songorica K. Koch. The gene diversity within population, total population genetic diversity, genetic differentiation coefficient and gene flow were 0.2779, 0.3235, 0.1408, and 3.0511, respectively. Our results showed that C. songorica K. Koch. from Xinjiang has a high level of genetic diversity at both the phenotypic and molecular levels. Significant genetic differentiation existed within population and the differentiation trend showed a regional association. And in this study, in situ and ex situ conser- vation approaches were raised for wild hawthorn protection utilization.展开更多
Magnoline(1),a new isoquinoline derivative,was isolated from the leaves of Magnolia sieboldii K.Koch(Magnoliaceae).Its structure was elucidated on the basis of spectral analysis including 1D,2D NMR and HR-TOF-MS.
In this paper, we study the scaling for the mean first-passage time (MFPT) of the random walks on a generalized Koch network with a trap. Through the network construction, where the initial state is transformed from...In this paper, we study the scaling for the mean first-passage time (MFPT) of the random walks on a generalized Koch network with a trap. Through the network construction, where the initial state is transformed from a triangle to a polygon, we obtain the exact scaling for the MFPT. We show that the MFPT grows linearly with the number of nodes and the dimensions of the polygon in the large limit of the network order. In addition, we determine the exponents of scaling efficiency characterizing the random walks. Our results are the generalizations of those derived for the Koch network, which shed light on the analysis of random walks over various fractal networks.展开更多
Background Few studies have explored the inward sodium current (INa) kinetics of transitional cardiomyocytes. This study aimed to explore the kinetics of transitional cardiomyocytes types α and β. Methods The whol...Background Few studies have explored the inward sodium current (INa) kinetics of transitional cardiomyocytes. This study aimed to explore the kinetics of transitional cardiomyocytes types α and β. Methods The whole-cell patch clamp technique was used to study the rapid INa of isolated transitional cardiomyocytes in the Koch triangle of rabbit hearts. Results Maximal amplitude and density of INa in type a and type β was (-1627±288) pA (α), (-35.17±6.56) pA/pF (β) and (-3845±467) pA (α), (-65.64±10.23) pA/pF (β) (P 〈0.05). Steady state activation curves of INa, fitted to a Boltzmann distribution for both types, were sigmoid in shape. Half activation voltage and slope factors did not significantly differ between types at (-43.46±0.85) mV (α), (-41.39±0.47) mV (β) or (9.04±0.66) mV (α), (11.08±0.89) mV (β). Steady state inactivation curves of INa, fitted to a Boltzmann distribution in both types were inverse "S" shape. Half inactivation voltage and slope factors were (-109.9±0.62) mV (α), (-107.5±0.49) mV (β) and (11.78±0.36) mV (α), (11.57±0.27) mV (β), (P〉0.05), but time constants of inactivation were significantly different at (1.10±0.19) mV (α) and (2.37±0.33) ms (β), (P 〈0.05). Time constants of recovery from inactivation of INa for both types were (122.16±27.43) mV (α) and (103.84±2.8.97) ms (β) (P 〈0.05). Conclusions Transitional cardiomyocytes in rabbit hearts show a heterogeneous, voltage gated and time dependent fast inward sodium current. Types α and β show the features of INa similar to those in slow- and fast-response myocytes, with probably better automaticity and conductivity, respectively.展开更多
Objective: To study the quinoline alkaloids from the ethanol extract of Scolopendra subspinipes mutilans(SSM).Methods: The chemical constituents were isolated and purified by macroporous resin column, medium pressure ...Objective: To study the quinoline alkaloids from the ethanol extract of Scolopendra subspinipes mutilans(SSM).Methods: The chemical constituents were isolated and purified by macroporous resin column, medium pressure preparation chromatography, and semi-preparative HPLC. Their structures were elucidated by IR,MS, and NMR experiments.Results: Three quinolone alkaloids were obtained and identified as 3-hydroxy-4-methoxyquinolin-8-yl hydrogen sulfate(1), jineol-8-sulfate(2), and jineol(3), respectively.Conclusion: Compound 1 is a new compound from SSM.展开更多
A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during the inspection of defects.However,the extent of the lift-off effect on differential probes,including differe...A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during the inspection of defects.However,the extent of the lift-off effect on differential probes,including different coil structures,varies.In this study,two planar eddy current probes with differential pickup structures and the same size,Koch and circular probes,were used to compare lift-off effects.The eddy current distributions of the probes perturbed by 0°and 90°cracks were obtained by finite element analysis.The analysis results show that the 90°crack can impede the eddy current induced by the Koch probe even further at relatively low lift-off distance.The peak-to-peak values of the signal output from the two probes were compared at different lift-off distances using finite element analysis and experimental methods.In addition,the effects of different frequencies on the lift-off were studied experimentally.The results show that the signal peak-to-peak value of the Koch probe for the inspection of cracks in 90°orientation is larger than that of the circular probe when the lift-off distance is smaller than 1.2 mm.In addition,the influence of the lift-off distance on the peak-to-peak signal value of the two probes was studied via normalization.This indicates that the influence becomes more evident with an increase in excitation frequency.This research discloses the lift-off effect of differential planar eddy current probes with different coil shapes and proves the detection merit of the Koch probe for 90°cracks at low lift-off distances.展开更多
对临沂市兰陵县苍山大蒜贮藏期病害情况进行了调查,采用柯赫氏法则和病斑显微观察法对病原菌株lyu20170012进行了验证,并通过形态学特征和r DNA ITS序列分析对其进行了鉴定。结果表明,从病斑上分离得到4种真菌和1种细菌,经致病性检测发...对临沂市兰陵县苍山大蒜贮藏期病害情况进行了调查,采用柯赫氏法则和病斑显微观察法对病原菌株lyu20170012进行了验证,并通过形态学特征和r DNA ITS序列分析对其进行了鉴定。结果表明,从病斑上分离得到4种真菌和1种细菌,经致病性检测发现菌株lyu20170012具有致病性,将lyu20170012菌株鉴定为尖孢镰刀菌(Fusarium oxysporum)。展开更多
This paper focuses on two cases of two-dimensional wave equations with fractal boundaries. The first case is the equation with classical derivative. The formal solution is obtained. And a definition of the solution is...This paper focuses on two cases of two-dimensional wave equations with fractal boundaries. The first case is the equation with classical derivative. The formal solution is obtained. And a definition of the solution is given. Then we prove that under certain conditions, the solution is a kind of fractal function, which is continuous, differentiable nowhere in its domain. Next, for specific given initial position and 3 different initial velocities, the graphs of solutions are sketched. By computing the box dimensions of boundaries of cross-sections for solution surfaces, we evaluate the range of box dimension of the vibrating membrane. The second case is the equation with p-type derivative. The corresponding solution is shown and numerical example is given.展开更多
The manuscript titled "Vacuoles of Candida yeast behave as a specialized niche for Helicobacter pylori(H.pylori)" not only has not been prepared in a scientific manner but the methodology used was not adequa...The manuscript titled "Vacuoles of Candida yeast behave as a specialized niche for Helicobacter pylori(H.pylori)" not only has not been prepared in a scientific manner but the methodology used was not adequate, and therefore the conclusion reached was not correct. First of all, "yeast" is a broad terminology covering a great number of genera and species of unicellular micro-organisms. The authors should have defined the organism with its binary scientific name. This measure would allow experiment reproduction by the scientific community. Moreover, the criteria established by Robert Koch to identify a specific microorganism or pathogen was not adopted in the methodology used. Regarding the methodology applied, use of the chicken eggyolk(Ig Y) antibody and PCR of the apparently tainted yeast population to prove H. pylori existence in the yeast vacuoles might be main factors for their wrong conclusions. Bacterial tropism toward yeast extract is a known phenomenon, and yeast extract is one of the main ingredients in culture media. Their internalization through phagocytosis or similar pathways does not seem possible or practical because of the thick and cellulosic yeast wall. While the small size of yeast cells does not support their ability in harboring several H. pylori, other observations such as inefficiency of antifungal therapy as anti-Helicobacter therapy strongly reject the conclusion reached by the above-mentioned article.展开更多
文摘The self similar sets satisfying the open condition have been studied. An estimation of fractal, by the definition can only give the upper limit of its Hausdorff measure. So to judge if such an upper limit is its exact value or not is important. A negative criterion has been given. As a consequence, the Marion’s conjecture on the Hausdorff meas\| ure of the Koch curve has been proved invalid.
基金Funding for this work has been provided by the National Natural Science Foundation of China(Nos.11872313 and 11502202)National Key R&D Program of China(2017YFB1102801)Fundamental Research Funds for the Central Universities and Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical University(CX2020107).
文摘In this study,the wave propagation properties of lattice metamaterials with Koch fractal structures are investigated in terms of band structures and directional wave propagation.The analytical models of lattice metamaterials are established using the finite element method,and the dispersion relation is solved using the Bloch’s theorem.The band structures of the lattice metamaterials with different numbers of iterations are studied,and the group velocities at a selected frequency are calculated to analyze the directional wave propagation characteristics.Furthermore,dynamic responses of the finite structures are calculated using commercial finite element software to verify the band gaps and directional wave propagation behaviors in the lattice metamaterials.The results show that multiple and low band gaps are present in the lattice materials with various geometric parameters of the Koch fractal,and the position of the lowest band gap decreases as the number of iterations increases.The results indicate the potential applications of lattice metamaterials with Koch fractals for vibration isolation and multi-functional design.
基金supported by the program for tacking key problem of Shaanxi agricultural scientific and technological extent(2015NY124)Project NSFC(31270690)+1 种基金Project PCSIRT(NO.IRT1035)special funding for basic S&T work of Ministry of Science and Technology(2009FY210100)of China
文摘Cankered, dying seedlings of Juglans regia were observed in Shaanxi province in the northwest region of China. Neofusicoccum parvum was isolated from these cankered tissues, with the identification based on mor- phology and an ITS-nrDNA sequence. In order to demonstrate how cultures of N. parvum could cause the expected symptoms, artificial infection, using these isolates and re-isolation of the pathogen, was used. This is the first report on this taxon as a walnut canker pathogen in China.
文摘Background The morphological and electrophysiological characteristics of cardiac cells in Koch triangle are still disputed. We studied the appearance and electrical properties of these diverse myocytes to elucidate their complex electrophysiological phenomena. Methods Experiments were conducted using cooled charge coupling device (CCD) system and whole cell, patch clamp technique to determine the morphology, action potential and sodium current density of single viable myocytes enzymatically isolated from the Koch triangle of rabbit hearts. Results Morphologically, cardiac cells in shape of spider, tiny spindle, slender spindle, rod and strip were observed in percentage of 3.0±0.3, 35.0±5.0, 15.0±2.0, 40.0±5.0 and 6.0±0.7 respectively. The cellular dimensions and capacitance gradually increased in the above order (all P〈0.05). Electrophysiologically, action potential configurations recorded from them were similar respectively to nodal (N), atrial nodal (AN), nodal Hisian (NH), atrial (A) and Hisian like potentials obtained from the intact atrioventricular nodal preparations. Diastolic depolarization appeared in all myocytes except for rod cells. Sodium current density increased in the order of tiny spindle, strip, rod, slender spindle cell (all P〈0.05), but could not be detected in spider-shaped cells. Linear regression analysis revealed that membrane capacitance was correlated negatively to the rate of diastolic depolarization r=-0.70, P〈0.001, but positively to maximum depolarization potential, amplitude of action potential, upstroke velocity and maximum peak value of sodium current density r=0.84, 0.80, 0.87 and 0.75, respectively; all P〈0.001. Conclusions The results demonstrated that spider-shaped, spindle, rod and strip cells in Koch triangle might correspond to pacemaking, transitional, atrial and Purkinje like cells, respectively. Furthermore, tiny spindle and slender spindle cells were referred to transitional cell α (TCα) and β (TCβ) accordingly consid
基金supported by the Special Research Projects of National Forestry Industry of Public Benefit,China(201304701-1)the Key Discipline of Horticultural of Xinjiang Uygur Autonomous Region of China(2016-10758-3)the Key Laboratory of Characteristics of Fruit Trees Center of Xinjiang Agricultural University,China
文摘The wild hawthorn species, Crataegus songorica K. Koch., is an important wild germplasm resource in Xinjiang, China that has been endangered in recent years. The genetic diversity of C. songorica K. Koch. germplasm in five populations from Daxigou, Xinjiang, China were evaluated based on phenotypic traits and ISSR molecular markers to provide basic infor- mation on resource protection, rational utilization and genetic improvement. The F-value for the phenotypic differentiation coefficient of the 33 traits measured ranged from 0.266 to 15.128, and mean value was 13.85%. The variation among populations was found to be lower than that within population. A total of 303 loci were detected within the five populations by 12 primers. Within 298,polymorphic loci, the polymorphism was 98.35%, showing a high genetic diversity in C. songorica K. Koch. The gene diversity within population, total population genetic diversity, genetic differentiation coefficient and gene flow were 0.2779, 0.3235, 0.1408, and 3.0511, respectively. Our results showed that C. songorica K. Koch. from Xinjiang has a high level of genetic diversity at both the phenotypic and molecular levels. Significant genetic differentiation existed within population and the differentiation trend showed a regional association. And in this study, in situ and ex situ conser- vation approaches were raised for wild hawthorn protection utilization.
文摘Magnoline(1),a new isoquinoline derivative,was isolated from the leaves of Magnolia sieboldii K.Koch(Magnoliaceae).Its structure was elucidated on the basis of spectral analysis including 1D,2D NMR and HR-TOF-MS.
基金Project supported by the Research Foundation of Hangzhou Dianzi University,China (Grant Nos. KYF075610032 andzx100204004-7)the Hong Kong Research Grants Council,China (Grant No. CityU 1114/11E)
文摘In this paper, we study the scaling for the mean first-passage time (MFPT) of the random walks on a generalized Koch network with a trap. Through the network construction, where the initial state is transformed from a triangle to a polygon, we obtain the exact scaling for the MFPT. We show that the MFPT grows linearly with the number of nodes and the dimensions of the polygon in the large limit of the network order. In addition, we determine the exponents of scaling efficiency characterizing the random walks. Our results are the generalizations of those derived for the Koch network, which shed light on the analysis of random walks over various fractal networks.
基金This study was supported by the National Natural Science Foundation of China (No. 30070307) and the National Special Fund for Doctoral Education & Research Program, Ministry of Education, China (No. 20030698009).
文摘Background Few studies have explored the inward sodium current (INa) kinetics of transitional cardiomyocytes. This study aimed to explore the kinetics of transitional cardiomyocytes types α and β. Methods The whole-cell patch clamp technique was used to study the rapid INa of isolated transitional cardiomyocytes in the Koch triangle of rabbit hearts. Results Maximal amplitude and density of INa in type a and type β was (-1627±288) pA (α), (-35.17±6.56) pA/pF (β) and (-3845±467) pA (α), (-65.64±10.23) pA/pF (β) (P 〈0.05). Steady state activation curves of INa, fitted to a Boltzmann distribution for both types, were sigmoid in shape. Half activation voltage and slope factors did not significantly differ between types at (-43.46±0.85) mV (α), (-41.39±0.47) mV (β) or (9.04±0.66) mV (α), (11.08±0.89) mV (β). Steady state inactivation curves of INa, fitted to a Boltzmann distribution in both types were inverse "S" shape. Half inactivation voltage and slope factors were (-109.9±0.62) mV (α), (-107.5±0.49) mV (β) and (11.78±0.36) mV (α), (11.57±0.27) mV (β), (P〉0.05), but time constants of inactivation were significantly different at (1.10±0.19) mV (α) and (2.37±0.33) ms (β), (P 〈0.05). Time constants of recovery from inactivation of INa for both types were (122.16±27.43) mV (α) and (103.84±2.8.97) ms (β) (P 〈0.05). Conclusions Transitional cardiomyocytes in rabbit hearts show a heterogeneous, voltage gated and time dependent fast inward sodium current. Types α and β show the features of INa similar to those in slow- and fast-response myocytes, with probably better automaticity and conductivity, respectively.
基金supported by the Special Project (No. 1811) for the Scientific & Technological Innovation and Development of Lanshan District, Linyi
文摘Objective: To study the quinoline alkaloids from the ethanol extract of Scolopendra subspinipes mutilans(SSM).Methods: The chemical constituents were isolated and purified by macroporous resin column, medium pressure preparation chromatography, and semi-preparative HPLC. Their structures were elucidated by IR,MS, and NMR experiments.Results: Three quinolone alkaloids were obtained and identified as 3-hydroxy-4-methoxyquinolin-8-yl hydrogen sulfate(1), jineol-8-sulfate(2), and jineol(3), respectively.Conclusion: Compound 1 is a new compound from SSM.
基金Supported by Gansu Provincial Natural Science Foundation of China(Grant No.22JR5RA229)National Natural Science Foundation of China(Grant Nos.51807086,12162021)Hongliu Youth Found of Lanzhou University of Technology and Gansu Provincial Outstanding Graduate Student Innovation Star of China(Grant No.2021CXZX-453).
文摘A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during the inspection of defects.However,the extent of the lift-off effect on differential probes,including different coil structures,varies.In this study,two planar eddy current probes with differential pickup structures and the same size,Koch and circular probes,were used to compare lift-off effects.The eddy current distributions of the probes perturbed by 0°and 90°cracks were obtained by finite element analysis.The analysis results show that the 90°crack can impede the eddy current induced by the Koch probe even further at relatively low lift-off distance.The peak-to-peak values of the signal output from the two probes were compared at different lift-off distances using finite element analysis and experimental methods.In addition,the effects of different frequencies on the lift-off were studied experimentally.The results show that the signal peak-to-peak value of the Koch probe for the inspection of cracks in 90°orientation is larger than that of the circular probe when the lift-off distance is smaller than 1.2 mm.In addition,the influence of the lift-off distance on the peak-to-peak signal value of the two probes was studied via normalization.This indicates that the influence becomes more evident with an increase in excitation frequency.This research discloses the lift-off effect of differential planar eddy current probes with different coil shapes and proves the detection merit of the Koch probe for 90°cracks at low lift-off distances.
文摘对临沂市兰陵县苍山大蒜贮藏期病害情况进行了调查,采用柯赫氏法则和病斑显微观察法对病原菌株lyu20170012进行了验证,并通过形态学特征和r DNA ITS序列分析对其进行了鉴定。结果表明,从病斑上分离得到4种真菌和1种细菌,经致病性检测发现菌株lyu20170012具有致病性,将lyu20170012菌株鉴定为尖孢镰刀菌(Fusarium oxysporum)。
基金Supported by National Natural Science Foundation of China(Grant No.10571084)
文摘This paper focuses on two cases of two-dimensional wave equations with fractal boundaries. The first case is the equation with classical derivative. The formal solution is obtained. And a definition of the solution is given. Then we prove that under certain conditions, the solution is a kind of fractal function, which is continuous, differentiable nowhere in its domain. Next, for specific given initial position and 3 different initial velocities, the graphs of solutions are sketched. By computing the box dimensions of boundaries of cross-sections for solution surfaces, we evaluate the range of box dimension of the vibrating membrane. The second case is the equation with p-type derivative. The corresponding solution is shown and numerical example is given.
文摘The manuscript titled "Vacuoles of Candida yeast behave as a specialized niche for Helicobacter pylori(H.pylori)" not only has not been prepared in a scientific manner but the methodology used was not adequate, and therefore the conclusion reached was not correct. First of all, "yeast" is a broad terminology covering a great number of genera and species of unicellular micro-organisms. The authors should have defined the organism with its binary scientific name. This measure would allow experiment reproduction by the scientific community. Moreover, the criteria established by Robert Koch to identify a specific microorganism or pathogen was not adopted in the methodology used. Regarding the methodology applied, use of the chicken eggyolk(Ig Y) antibody and PCR of the apparently tainted yeast population to prove H. pylori existence in the yeast vacuoles might be main factors for their wrong conclusions. Bacterial tropism toward yeast extract is a known phenomenon, and yeast extract is one of the main ingredients in culture media. Their internalization through phagocytosis or similar pathways does not seem possible or practical because of the thick and cellulosic yeast wall. While the small size of yeast cells does not support their ability in harboring several H. pylori, other observations such as inefficiency of antifungal therapy as anti-Helicobacter therapy strongly reject the conclusion reached by the above-mentioned article.