Simple combined explicit/implicit water model

A simple combined water model (SCW model) for the calculation of the hydration free energy is presented. In the frame of the model a solute is placed in the centre of the spherical cavity with explicit water molecules, which are considered at the atomistic level. Rigid wall potential at the boundary of the cavity restricts the moving of the explicit water molecules. Water outside the sphere is considered as the conducting continuum (implicit part of the model). Simulation is performed in the frame of the NVT ensemble (constant number of particles, volume and temperature), density of water is fixed and equal to experimental value 1 g/cm³. The energy of electrostatic interaction of atomic point charges of the explicit water molecules with conducting continuum is calculated analytically by means of the image charges method. It provides high computational efficiency of the SCW model. For the averaging of the calculated thermodynamic and structural values over microstates of the system the thermodynamic integration method is used. The possible using of SCW for the docking problem is discussed.     

Interrelationships between water and cellular metabolism inArtemia cysts

Cysts of the crustaceanArtemia are a useful model for studies on intracellular water because they are capable of essentially complete and reversible desiccation. We have used a variety of techniques on this system, the present work being an attempt to estimate the density of intracellular water (ρ_w). The density of individual cysts was evaluated from sedimentation velocity. Heptane displacement methods were used to determine the volume of a known mass of cysts, from which the density was calculated. The two methods produce comparable results. It was shown that the densities and water contents of large masses of cysts accurately reflect those of individual cysts. Cyst densities (ρ_c) were determined over the entire range of water content from 0 to 0.63 weight fraction of water (W _f), and temperature dependence was measured for 0.61W _f over 2–41°C. The following refer to 25°C. No marked change was detected in ρ_c until the water content exceeded 0.15W _f, at which ρ_c decreased as a linear function of Wf to maximum water content. However, the cyst does not behave ideally in the sense that the densities of the nonaqueous components and added water are not additive as a function ofW _f. The partial specific volume of water in cysts at maximum hydration was estimated to be 3% larger than that of pure water. These observations are compared with density measurements on other systems, and with previous findings on the physical properties of water in this system.     

Strophiole of seeds of the black locust acts as a water gap

In Japan the black locust (Robinia pseudoacacia L.) is undergoing rapid habitat expansion, which has an adverse effect on native vegetation. It is therefore a priority to clarify the regeneration characteristics of the black locust and establish adequate management of this invasive species in Japan. To determine the germination characteristics of physically dormant black locust seeds, we observed anatomical features of the seed coat and identified the water gap that acts as a signal detector. Our microscopic observations showed that seed coats of this species had hilum, micropyle and strophiole. The anatomical features of these regions correspond to the general characteristics of papilionoid legume seeds. Based on our microscopic observations, water absorption blocking experiments and a dye tracking experiment, we identified the strophiole as a water gap in black locust seeds. Our results suggest that the opening of the strophiole is important for water uptake to the embryo and subsequent germination of black locust seeds under natural conditions.     

Oxidative photosynthetic water splitting: energetics,kinetics and mechanism

This minireview is an attempt to summarize our current knowledge on oxidative water splitting in photosynthesis. Based on the extended Kok model (Kok, Forbush, McGloin (1970) Photochem Photobiol 11:457–476) as a framework, the energetics and kinetics of two different types of reactions comprising the overall process are discussed: (i) P680^+• reduction by the redox active tyrosine Y_Z of polypeptide D1 and (ii) Y_z^ox induced oxidation of the four step sequence in the water oxidizing complex (WOC) leading to the formation of molecular oxygen. The mode of coupling between electron transport (ET) and proton transfer (PT) is of key mechanistic relevance for the redox turnover of Y_Z and the reactions within the WOC. The peculiar energetics of the oxidation steps in the WOC assure that redox state S₁ is thermodynamically most stable. This is a general feature in all oxygen evolving photosynthetic organisms and assumed to be of physiological relevance. The reaction coordinate of oxidative water splitting is discussed on the basis of the available information about the Gibbs energy differences between the individual redox states S _i+1 and S _i and the data reported for the activation energies of the individual oxidation steps in the WOC. Finally, an attempt is made to cast our current state of knowledge into a mechanism of oxidative water splitting with special emphasis on the formation of the essential O–O bond and on the active role of the protein in tuning the local proton activity that depends on time and redox state S _i . The O–O linkage is assumed to take place at the level of a complexed peroxide.     

Identifying the best plant water status indicator for bio‐energy poplar genotypes

This contribution provides better insights in the water relations and the physiological traits of four commercial poplar genotypes of different genetic background, 'Bakan', 'Oudenberg', 'Koster' and 'Grimminge'. The main continuous (nondestructive and providing continuous and automated data records) and discontinuous (destructive and not allowing automation) plant water status (PWS) indicators were monitored at a multigenotype, commercial‐scale short‐rotation coppice plantation in East‐Flanders (Belgium), and their relationships with the principal environmental variables were assessed. All measurements were performed during the entire 2016 growing season on the third year of the third rotation in multistemmed trees. The discontinuous PWS indicators were measured on 10 separate days with a different evaporative demand and soil water content, while the continuous PWS indicators were recorded from April to November. The genotypes responded differently to environmental drivers and to soil conditions, based on the PWS indicators, featuring a different water behaviour in relation to the level of isohydricity. Poplar genotypes 'Koster' and 'Bakan' showed the typical water‐conserving behaviour of isohydric species, while 'Grimminge' was more in line with the anisohydric ones. A principal component analysis showed that sap flow (F_s) was the most suitable PWS indicator. The F_s and therefore the sap flow‐based canopy transpiration (E_c) were tightly linked to the phenological stage of the trees as well as to vapour pressure deficit and photosynthetic photon flux density, based on relationships between E_c and environmental variables. A quantitative predictive model was developed to estimate the crop water requirements for specific genotypes, by calculating transpiration per unit of ground area with a few environmental variables, monitored with easy‐to‐handle sensors.     

Distinguish water utilization strategies of trees growing on earth‐rocky mountainous area with transpiration and water isotopes

Water stress is regarded as a global challenge to forests. Unlike other water‐limited areas, the water use strategies of rocky mountainous forests, which play an important ecohydrological role, have not received sufficient attention. To prove our hypothesis that species adopt different water use strategies to avoid competition of limited water resources, we used site abiotic monitoring, sap flow and stable isotope method to study the biophysiological responses and water use preferences of two commonly distributed forest species, Pinus tabuliformis (Pt) and Quercus variabilis (Qv). The results showed that Pt transpired higher than Qv. Pt was also prone to adopt isohydric water use strategy as it demonstrated sensitive stomatal control over water loss through transpiration. Qv developed cavitation which was reflected by the dropping E_c in response to high vapor pressure deficit, concentrated peak sap flux density (J_s), and enlarged hysteresis loop. Considering the average soil depth of 52.8 cm on the site, a common strategy shared by both species was the ability to tap water from deep soil layers (below 40 cm) when soil water was limited, and this contributed to the whole growing season transpiration. The contribution of surface layer water to plant water use increased and became the main water source for transpiration after rainfall. Qv was more efficient at using water from surface layer than Pt due to the developed surface root system when soil water content was not stressed. Our study proves that different water‐using strategies of co‐occurring species may be conducive to avoid competition of limited water resources to guarantee their survival. Knowledge of water stress‐coping strategies of trees has implications for the understanding and prediction of vegetation composition in similar areas and can facilitate forest management criteria for plantations.     

Evaluation of Gambierdiscus survival after exposure to ballast water

The dinoflagellate Gambierdiscus was exposed to ballast water from a trans-oceanic vessel, and maintained at a variety of temperatures in the dark to determine if viability would be maintained. Logarithmically growing Gambierdiscus inocula were admixed (1:6, vol:vol) with ballast water, maintained in the dark at 22.6 °C, 24.6 °C, 26.8 °C and 29.0 °C and assessed for numerical abundance over six days. Calculated growth rates from the biomass time series showed no indication that ballast water negatively impacted Gambierdiscus viability; accompanying microscopic inspections supported this conclusion. Filtration of large volumes of collected ballast water failed to show the presence of any Gambierdiscus cells contained therein. Recovery and microscopic examination of the experimental inocula after 10 weeks in the dark, failed to show cyst development at any temperature regime. This examination of ballast water showed no evidence of cytotoxicity to Gambierdiscus spp.     

土壤水分及其垂直分布对内蒙古草原冰草和冷蒿竞争的影响

内蒙古退化冷蒿草原围封恢复演替3-4年,植物群落更替出现半灌木冷蒿（Artemisia frigida）向禾草冰草（Agropyron cristatum）群落突然转变的现象,这对内蒙古草原植被恢复具有积极的作用,但目前关于冰草-冷蒿演替和竞争机制的研究鲜见报道。水分作为草原植被生长的主要限制因子,是影响群落演替的重要因素。气候干旱和过度放牧导致草原土壤水分垂直分布发生明显变化。由于冰草和冷蒿的根系分布深浅不同,土壤水分垂直变化可能会影响冰草-冷蒿的竞争。为探讨土壤水分及其垂直分布对冰草和冷蒿竞争的影响,本盆栽试验设置冰草、冷蒿单种以及混种处理,并进行不同土壤深度（0-30cm,30-60cm）的水分处理（上干下湿、上湿下干、上干下干）,结果表明：（1）与冷蒿相比,冰草受土壤水分变化影响显著,相对于上干下干处理,冰草在湿润（上干下湿或者上湿下干）处理的地上、地下生物量均显著增加,而冷蒿没有显著变化;（2）上干下湿和上湿下干处理间,冰草、冷蒿的地上、地下总生物量和根长差异均不显著;（3）不同水分处理,冰草和冷蒿的根系均可分布在30-60cm土壤中,且土壤30-60cm层冰草单种的根生物量和根长显著高于冷蒿单种;（4）相对竞争强度和竞争攻击力系数表明：湿润处理冰草的竞争力大于冷蒿;上干下干处理冷蒿的竞争力大于冰草。土壤水分变化引起冰草、冷蒿的明显竞争,上湿下干与上干下湿处理间冰草与冷蒿竞争力差异不显著。由于冰草和冷蒿均为多年生物种,冰草-冷蒿的竞争实验仍需在今后的研究中反复地验证。     

Evapotranspiration,crop coefficient and water use efficiency of giant reed (Arundo donax L.) and miscanthus (Miscanthus × giganteus Greef et Deu.) in a Mediterranean environment.

Giant reed (Arundo donax L.) and miscanthus (Miscanthus × giganteus Greef et Deu.) are two perennial rhizomatous grasses (PRGs), considered as promising sources of lignocellulosic biomass for renewable energy production. Although the agronomic performance of these species has been addressed by several studies, the literature dedicated to the crop water use of giant reed and miscanthus is still limited. Our objective was thus to investigate giant reed and miscanthus water use by assessing crop evapotranspiration (ET_c), crop coefficients (K_c) and water use efficiency (WUE). The study was carried out in central Italy and specifically designed water-balance lysimeters were used to investigate the water use of these PRGs during the 2010 and 2011 growing seasons. Giant reed showed the highest cumulative evapotranspiration, with an average consumption of approximately 1100 mm, nearly 20% higher than miscanthus (900 mm). Crop evapotranspiration rates differed significantly between the species, particularly during the midseason (from June to September), when average daily ET_c was 7.4 and 6.2 mm in giant reed and miscanthus respectively. The K_c values determined in our study varied from 0.4 to 1.9 for giant reed and 0.3 to 1.6 for miscanthus. Finally, WUE was higher in miscanthus than in giant reed, with average values of 4.2 and 3.1 g L⁻¹ respectively. Further studies concerning water use under nonoptimal water conditions should be carried out and an assessment of the response to water stress of both crops is necessary to integrate the findings from this study.     

Mechanistic Insight into the Electrochemical Performance of Zn/VO2 Batteries with an Aqueous ZnSO4 Electrolyte

Rechargeable aqueous zinc‐ion batteries (ZIBs) are promising for cheap stationary energy storage. Challenges for Zn‐ion insertion hosts are the large structural changes of the host structure upon Zn‐ion insertion and the divalent Zn‐ion transport, challenging cycle life and power density respectively. Here a new mechanism is demonstrated for the VO₂ cathode toward proton insertion accompanied by Zn‐ion storage through the reversible deposition of Zn₄(OH)₆SO₄·5H₂O on the cathode surface, supported by operando X‐ray diffraction, X‐ray photoelectron spectroscopy, neutron activation analysis, and density functional theory simulations. This leads to an initial discharge capacity of 272 mAh g^?1 at a current density of 3.0 A g^?1, of which 75.5% is maintained after 945 cycles. It is proposed that the competition between proton and Zn‐ion insertion in the VO₂ host is determined by the solvation energy of the salt anion and proton insertion energetics, where proton insertion has the advantage of minimal structural distortion leading to a long cycle life. As the discharge kinetics are capacitive for the first half of the process and diffusion limited for the second half, the VO₂ cathode takes the middle road possessing both fast kinetics and high practical capacities revealing a reaction mechanism that provides new perspective for the development of aqueous ZIBs.     

Electrostatics of proteins: Description in terms of two dielectric constants simultaneously

In the semi-continuum treatment of the energetics of charge formation (or transfer) inside a protein, two components of the energy are inevitably present: the energy of interaction of the ion with the pre-existing intraprotein electric field, and the energy due to polarization of the medium by the newly formed charge. The pre-existing field is set up by charges (partial or full) of the protein atoms fixed in a definite structure. The calculation of this field involves only the electronic polarization (the optical dielectric constant ϵ_o) of the protein because the polarization due to shifts of heavy atoms has already been accounted for by their equilibrium coordinates. At the same time, the aqueous surroundings should be described by the static constant ϵ_sw, as the positions of water molecules are not fixed. The formation of a new charge, absent in the equilibrium X-ray structure, results in shifts of electrons and polar atoms, i.e., it involves all kinds of medium polarization described by the static dielectric constant of protein ϵ_s. Thus, in calculations of the total energy, two different dielectric constants of the protein are operative simultaneously. This differs from a widely used algorithm employing one effective dielectric constant for both components of the ion's energy. Proteins: 28:174–182, 1997. © 1997 Wiley-Liss Inc.     

Differences in the exploitation of bream in three shallow lake systems and their relation to water quality

SUMMARY 1. The development of bream populations, water transparency, chlorophyll‐a concentration, extent of submerged vegetation and densities of the zebra mussel, Dreissena polymorpha, were analysed in three shallow eutrophic lake systems subject to different fish management. 2. In Lake Veluwemeer, the bream population was reduced from c. 100 to 20 kg ha^?1 after 5 years of fishing. The mortality caused by the fishery was estimated at 38% of bream >15 cm in addition to a 13% natural mortality of bream >17 cm. The decline was followed by an expansion of the Chara beds present in the shallow parts, an increase in water transparency in the open‐water zone, an increase in the density of zebra mussels and a decrease in chlorophyll‐a concentrations. 3. The newly created Lake Volkerak showed trends opposite to those in Lake Veluwemeer. Bream colonised the lake in 1988 and reached a biomass of c. 140 kg ha^?1 in 1998. The water transparency decreased from a maximum of 3 m to c. 1 m and the chlorophyll‐a concentration increased from 5 to 45 μg L^?1. Submerged vegetation colonised up to 20% of the total lake area in the first 5 years after creation of the lake in 1987 but decreased to 10% as turbidity increased. 4. Seine fishery in the Frisian lake system did not appear to affect the bream population despite annual catches as high as 40–50 kg ha^?1. The estimated natural mortality of fish >15 cm was 15% and mortality by fishery was 26%. The high loss was apparently compensated by good recruitment and high growth rates resulting from a c. 1 °C higher water temperature during the years when bream were removed by fishing. There was only a slight decrease in chlorophyll‐a concentrations and a slight increase in water transparency. 5. The results of this study suggest that the effects of bream exploitation in eutrophic lakes can vary depending on the efficiency of the fishery, recruitment success and temperature regime. In the absence of fishery, bream dominated the fish community in the study lakes and apparently prevented D. polymorpha and submerged vegetation from establishing because of physical disturbance, enhanced internal P‐loading and resettling of resuspended sediments.     

A cytochrome c fusion protein domain for convenient detection, quantification, and enhanced production of membrane proteins in Escherichia coli��Expression and characterization of cytochrome-tagged Complex I subunits

Overproduction of membrane proteins can be a cumbersome task, particularly if high yields are desirable. NADH:quinone oxidoreductase (Complex I) contains several very large membrane‐spanning protein subunits that hitherto have been impossible to express individually in any appreciable amounts in Escherichia coli. The polypeptides contain no prosthetic groups and are poorly antigenic, making optimization of protein production a challenging task. In this work, the C‐terminal ends of the Complex I subunits NuoH, NuoL, NuoM, and NuoN from E. coli Complex I and the bona fide antiporters MrpA and MrpD were genetically fused to the cytochrome c domain of Bacillus subtilis cytochrome c₅₅₀. Compared with other available fusion‐protein tagging systems, the cytochrome c has several advantages. The heme is covalently bound, renders the proteins visible by optical spectroscopy, and can be used to monitor, quantify, and determine the orientation of the polypeptides in a plethora of experiments. For the antiporter‐like subunits NuoL, NuoM, and NuoN and the real antiporters MrpA and MrpD, unprecedented amounts of holo‐cytochrome fusion proteins could be obtained in E. coli. The NuoHcyt polypeptide was also efficiently produced, but heme insertion was less effective in this construct. The cytochrome c₅₅₀ domain in all the fusion proteins exhibited normal spectra and redox properties, with an E_m of about +170 mV. The MrpA and MrpD antiporters remained functional after being fused to the cytochrome c‐tag. Finally, a his‐tag could be added to the cytochrome domain, without any perturbations to the cytochrome properties, allowing efficient purification of the overexpressed fusion proteins.     

Canopy scale measurements of CO2 and water vapor exchange along a precipitation gradient in southern Africa

Short‐term measurements of carbon dioxide, water, and energy fluxes were collected at four locations along a mean annual precipitation gradient in southern Africa during the wet (growing) season with the purpose of determining how the observed vegetation–atmosphere exchange properties are functionally related to the long‐term climatic conditions. This research was conducted along the Kalahari Transect (KT), one in the global set of International Geosphere‐Biosphere Program transects, which covers a north–south aridity gradient, all on a homogenous sand formation. Eddy covariance instruments were deployed on a permanent tower in Mongu, Zambia (879 mm of rainfall per year), as well as on a portable tower in Maun (460 mm yr^?1), Okwa River Crossing (407 mm yr^?1), and Tshane (365 mm yr^?1), Botswana for several days at each site. The relationships between CO₂ flux, F_c, and photosynthetically active radiation were described well by a hyperbolic fit to the data at all locations except for Mongu, the wettest site. Here, there appeared to be an air temperature effect on F_c. While daytime values of F_c routinely approached or exceeded ?20 μmol m^?2 s^?1 at Mongu, the magnitude of F_c remained less than ?10 μmol m^?2 s^?1 when the air temperature was above 27°C. Canopy resistances to water vapor transfer, r_c, displayed an overall decline from the wetter sites to the more arid sites, but the differences in r_c could be almost exclusively accounted for by the decrease in leaf area index (LAI) from north to south along the KT. Ecosystem water use efficiency (WUE), defined as the ratio of net carbon flux to evapotranspiration, showed a general decrease with increasing vapor pressure deficit, D, for all of the sites. The magnitudes of WUE at a given D, however, were dissimilar for the individual sites and were found to be stratified according to the position of the sites along the long‐term aridity gradient. For example, Mongu, which has the wettest climate, has a much lower WUE for like levels of D than Tshane, which historically has the most arid climate. Given the similar inferred stomatal resistances between the sites, the disparate carbon uptake behavior for the grass vs. woody vegetation is the likely cause for the observed differences in WUE along the aridity gradient. The short‐term flux measurements provide a framework for evaluating the vegetation's functional adaptation to the long‐term climate and provide information that may be useful for predicting the dynamic response of the vegetation to future climate change.     

Extended cardiolipin anchorage to cytochrome c: a model for protein–mitochondrial membrane binding

Two models have been proposed to explain the interaction of cytochrome c with cardiolipin (CL) vesicles. In one case, an acyl chain of the phospholipid accommodates into a hydrophobic channel of the protein located close the Asn52 residue, whereas the alternative model considers the insertion of the acyl chain in the region of the Met80-containing loop. In an attempt to clarify which proposal offers a more appropriate explanation of cytochrome c–CL binding, we have undertaken a spectroscopic and kinetic study of the wild type and the Asn52Ile mutant of iso-1-cytochrome c from yeast to investigate the interaction of cytochrome c with CL vesicles, considered here a model for the CL-containing mitochondrial membrane. Replacement of Asn52, an invariant residue located in a small helix segment of the protein, may provide data useful to gain novel information on which region of cytochrome c is involved in the binding reaction with CL vesicles. In agreement with our recent results revealing that two distinct transitions take place in the cytochrome c–CL binding reaction, data obtained here support a model in which two (instead of one, as considered so far) adjacent acyl chains of the liposome are inserted, one at each of the hydrophobic sites, into the same cytochrome c molecule to form the cytochrome c–CL complex.     

西北干旱荒漠绿洲区葡萄园水热通量特征及其主要影响因素

为提高干旱绿洲区农田地表过程的科学认识及改善农业水管理，该研究基于涡度相关技术，运用葡萄园生长季能量平衡观测资料，分析了不同时间尺度的水热通量变化特征，以及干旱平流和冠层导度(G_c)在不同生长阶段上对水热通量的影响，并应用通径分析研究了环境因子对潜热通量(LE)的影响路径和程度。结果表明：(1)日尺度上，LE呈现出不同程度多峰状，其余水热通量总体上呈单峰状。整体上，各生长阶段日间净辐射(R_n)>LE>感热通量(H)>土壤热通量(G)。G相较于R_n呈现出明显的滞后现象。(2)整个生长季上，LE和H分别占白天可利用能量(R_n-G)的86%和14%,表明LE始终是白天葡萄园可利用能量的主要消耗项。干旱平流对白天LE的贡献范围为5%～59%,全生长季平均贡献为28%;G_c对LE的影响在生长季上呈动态变化，且在新梢生长期和落叶期对LE的影响强于中间生长阶段。(3)LE主要受R_n的影响，饱和水汽压差(VPD)和气温(T_a)对LE...     

Belowground inter‐ramet water transport capacity in Populus euphratica,a Central Asian desert phreatophyte

• Populus euphratica Oliv. is a widespread phreatophytic tree species that forms riparian forests in (hyper‐)arid regions of Central Asia. Its recruitment strongly relies on vegetative propagation from ‘root suckers’ that emerge from underground root spacers. The water transport through the spacers, although decisive for emerging ramets, has only rarely been quantified, but is crucial for the vegetative regeneration of the forests.
• In root spacers with different diameters collected from a mature poplar forest in northwest China, we calculated the hydraulic conductivity (k_c) from anatomical investigations on the basis of a modified Hagen‐Poiseuille equation and measured it (k_m) with a perfusion solution in the laboratory. The k_m values were compared with the water use by young and mature P. euphratica trees determined in previous studies.
• We obtained a significant correlation between k_m and k_c (which, however, was higher by at least one order of magnitude). Due to the extensive occurrence of tyloses, particularly in older conduits and thicker spacers, and because the conduit area did not increase with spacer diameter, neither k_c nor k_m increased with an increase in spacer diameter. The water supply through the spacers would be sufficient to meet the water demand even of mature trees.
• Our results provide a mechanistic explanation for the observed occurrence of P. euphratica clones across large areas and, provided that they are also valid for stands with larger distances to the water table, for the sustained growth and vegetative reproduction of P. euphratica stands growing at larger distances from the groundwater.

     

New records of microcyclic conidiogenesis in some powdery mildew fungi

Microcyclic conidiogenesis (MC) was recently described in several species of powdery mildew fungi. This process, defined as the production of conidia on a fungal spore without any, or only a minimal, involvement of hyphal growth, was observed on powdery mildew conidia that have already germinated on host plant surfaces and have been attached to the epidermal cells. Most probably, MC contributes to a quick propagation of young powdery mildew colonies because new conidia are sometimes produced in a shorter time on microcyclic conidiophores than on the hyphae of the young mycelium. This article reports MC in Erysiphe necator ex grapevine, Podosphaera leucotricha ex apple, Golovinomyces orontii ex tobacco, and Neoerysiphe galeopsidis ex Lamium purpureum based on light and low-temperature scanning electron microscopic studies.     

DICOM-RT Ion interface to utilize MC simulations in routine clinical workflow for proton pencil beam radiotherapy

To adopt Monte Carlo (MC) simulations as an independent dose calculation method for proton pencil beam radiotherapy, an interface that converts the plan information in DICOM format into MC components such as geometries and beam source is a crucial element. For this purpose, a DICOM-RT Ion interface (https://github.com/topasmc/dicom-interface) has been developed and integrated into the TOPAS MC code to perform such conversions on-the-fly. DICOM-RT objects utilized in this interface include Ion Plan (RTIP), Ion Beams Treatment Record (RTIBTR), CT image, and Dose. Beamline geometries, gantry and patient coordinate systems, and fluence maps are determined from RTIP and/or RTIBTR. In this interface, DICOM information is processed and delivered to a MC engine in two steps. A MC model, which consists of beamline geometries and beam source, to represent a treatment machine is created by a DICOM parser of the interface. The complexities from different DICOM types, various beamline configurations and source models are handled in this step. Next, geometry information and beam source are transferred to TOPAS on-the-fly via the developed TOPAS extensions. This interface with two treatment machines was successfully deployed into our automated MC workflow which provides simulated dose and LET distributions in a patient or a water phantom automatically when a new plan is identified. The developed interface provides novel features such as handling multiple treatment systems based on different DICOM types, DICOM conversions on-the-fly, and flexible sampling methods that significantly reduce the burden of handling DICOM based plan or treatment record information for MC simulations.