Shortened Retention Time Research Articles

Antibiotic-induced gut microbe dysbiosis alters neurobehavior in mice through modulation of BDNF and gut integrity

Gut microbiota is essential for intestinal integrity and brain functions. Herein we aimed to investigate the effects of alteration of gut microbiome using broad-spectrum antibiotics on CD 1 male mice (germ-modified group (GM). Moreover, we co-administrated probiotics with or without antibiotics for four weeks and evaluated if probiotics could reverse these behavioral and intestinal effects. GM, co-administered antibiotics and probiotics, and probiotics-only groups were compared to control mice of the same sex, age, and weight that did not receive either drug (n=12 in all groups). Cultivation of aerobic and anaerobic bacteria was evaluated by fecal culture of all groups. We tested exploratory behavior, anxiety, memory, depression-like behavior, and hippocampal and frontal lobe BDNF protein level alterations in response to antibiotics and its downstream effect on the PI3K/Akt1/Bcl2 pathway. Intestinal integrity was evaluated using gene expression analysis of ZO-1, claudin, and occludin genes. Additionally, the inflammatory TLR4 and p-p38 MAPK pathways in the intestines were investigated. Twice-daily administration of oral antibiotics for four weeks significantly reduced total bacterial count and upregulated TLR4 and p-p38.GM mice showed a significant reduction in BDNF(P =0.04), impaired spatial memory, and long-term memory as evidenced by decreased T maze correct alternation trails and shortened retention time in the passive avoidance test in GM(P =0.01). Passive avoidance showed significantly increased latency after probiotics intake. Depressive-like behavior was more pronounced in GM mice as assessed by the tail suspension test (P =0.01). GM showed significant upregulation(p<0.001) of the TLR4 and p-p38 MAPK pathway. Co-administration of probiotics with antibiotics showed an increase in BDNF levels, and upregulation of the cell survival PI3K/Akt1/Bcl2 pathway, significantly higher relative abundance in the firmucutes members, a significant decrease in the Firmicutes/Bacteroidetes ratio and downregulation of TLR4 and p-p38 MAPK. The tight junction proteins ZO-1, claudin and occludin were downregulated by antibiotic administration for four weeks and restored by probiotics. Collectively, the data suggest that long-term use of antibiotics appears to disrupt the intestinal epithelial barrier and alter neurobehavioral qualities specifically, long-term memory and exploratory drive, possibly through the reduction of BDNF, and probiotics partially reverse these effects.Our study emphasizes the effect of prolonged intake of antibiotics on production of dysbiosis as well as the impact of the antibiotic induced intestinal inflammation on neurobehavioral aspects in mice as the memory and anxiety-like behavior. We also reveal that co-administration of probiotics can reverse these changes

The Effect of Operating Strategies on the Anaerobic Digestion of Gentamicin Mycelial Residues: Insights into the Enhancement of Methane Production and Attenuation of Gentamicin Resistance.

Anaerobic digestion (AD) has been widely employed for converting various biowastes into renewable energy. However, AD of gentamicin mycelial residues (GMRs, a byproduct of gentamicin production) is limited by ammonia inhibition and antimicrobial resistance risk. Compared to mesophilic AD (MMAD) of GMRs, this study looked into three semicontinuous AD processes, i.e., codigestion with wheat straw, thermophilic digestion (TAcoD), and AD at shortened retention time (RT). Results showed that a stable and safe AD could be achieved under suitable operating conditions. Co-digestion could effectively mitigate the adverse effect of ammonia inhibition. The methane production increased by 35.86% in TAcoD compared to that in MMAD and 43.99% of hazardous waste was reduced in TAcoD. Concerning the antimicrobial resistance of AD system, gentamicin was degraded efficiently and the degradation process was not involved in the expression of antibiotic resistance genes (ARGs) related to modifying enzyme. Effective removal of ARGs under three operating strategies was associated with a higher reduction in bacterial abundance of potential hosts. In addition, the changes in the relevant proteins for transformation and conjugation as predicted by PICRUSt suggested that thermophilic condition and shorter RT were conducive to the reduction of the dissemination risks of ARGs.

(Digital Presentation) Magnesium Shot Filled Electrochemical Packed Bed Reactor for Phosphate Recovery

The global food-energy-water nexus encompasses energy efficient recovery and reuse of nutrients. However, limited phosphate sources and pollution from phosphate-rich fertilizers adversely affect global food security, which mandates energy-efficient technologies, like electrochemical struvite (MgNH4PO4.6H2O) production, with nutrient capture and reuse potential. In this study, we report a first-of-its-kind electrochemical struvite precipitation in an electrochemical packed bed reactor filled with pure Mg shots, which achieved shortened retention time and higher phosphate removal efficiency, compared to the previous batch electrochemical system used by our group. Mg loading, equivalent to the weight of the immersed Mg anode in the batch reactor, was fixed in the packed bed reactor at the beginning of each experiment. The feed flow rate (0.5-5 LPM) and Mg shot diameter (0.5-1.5 cm) were varied to study the performance of electrochemical precipitation column in a 10 mM synthetic solution of ammonium dihydrogen phosphate (NH4H2PO4, 10 mM) at neutral pH. The continuous flow system achieved a >40% phosphate removal over 4 h. The experimental results help in understanding the different parameters that affect struvite recovery from a flow-based reactor design, as well as an understanding of the challenges involved in transitioning from a batch reactor to a flow reactor.

Insights into capture-inactivation/oxidation of antibiotic resistance bacteria and cell-free antibiotic resistance genes from waters using flexibly-functionalized microbubbles

The spread of antibiotic resistance in the aquatic environment severely threatens the public health and ecological security. This study investigated simultaneously capturing and inactivating/oxidizing the antibiotic resistant bacteria (ARB) and cell-free antibiotic resistance genes (ARGs) in waters by flexibly-functionalized microbubbles. The microbubbles were obtained by surface-modifying the bubbles with coagulant (named as coagulative colloidal gas aphrons, CCGAs) and further encapsulating ozone in the gas core (named as coagulative colloidal ozone aphrons, CCOAs). CCGAs removed 92.4–97.5% of the sulfamethoxazole-resistant bacteria in the presence of dissolved organic matter (DOM), and the log reduction of cell-free ARGs (particularly, those encoded in plasmid) reached 1.86–3.30. The ozone release from CCOAs led to efficient in-situ oxidation: 91.2% of ARB were membrane-damaged and inactivated. In the municipal wastewater matrix, the removal of ARB increased whilst that of cell-free ARGs decreased by CCGAs with the DOM content increasing. The ozone encapsulation into CCGAs reinforced the bubble performance. The predominant capture mechanism should be electrostatic attraction between bubbles and ARB (or cell-free ARGs), and DOM enhanced the sweeping and bridging effect. The functionalized microbubble technology can be a promising and effective barrier for ARB and cell-free ARGs with shortened retention time, lessened chemical doses and simplified treatment unit.

Stepwise freezing-thawing treatment promotes short-chain fatty acids production from waste activated sludge

Waste activated sludge (WAS), as the byproducts of wastewater treatment plants, has been greatly produced. With high cost and environmental risk of WAS disposal, to explore a low-cost and environment-friendly technology has been a great challenge. Considering that WAS is a collection of organic matters, anaerobic fermentation has been selected as a sustainable way to simultaneously recover resources and reduce environmental pollution. To recover short-chain fatty acids (SCFAs) has gained great concern because of the high value-added application and high-efficiency production process. Considering the temperature in some areas of the world can reach to below 0 °C, this study proposed an efficient strategy, i.e., stepwise freezing and thawing treatment, to promote SCFAs production. The maximal production of SCFAs, i.e., 246 mg COD/g volatile suspended solid, was obtained with the shortened retention time of five days. Mechanistic studies showed that the solubilization of both extracellular polymeric substances (EPSs) and microbial cells could be accelerated, with the EPSs removal of 58.3% for proteins and 59.0% for polysaccharides. Also, the hydrolysis process was promoted to provide more substrates for subsequent acidogenisis, and the functional microorganisms, such as Romboutsia, Paraclostridium, Macellibacteroides and Conexibacter, were greatly enriched, with a total abundance of 26.2%. Moreover, compared to control, methanogenesis was inhibited at a shortened sludge retention time (e.g., five days), which benefited to the accumulation of SCFAs, but the methane production was increased by 25.2% at a longer sludge retention time (e.g., ten days). Thus, these findings of this work may provide some new solutions for the enhanced resource recovery from WAS, and further for carbon-neutral operation of wastewater treatment plants.

Freezing-low temperature treatment facilitates short-chain fatty acids production from waste activated sludge with short-term fermentation

This study proposed a novel and high-efficiency strategy, i.e., freezing followed by low-temperature thermal treatment, to significantly promote short-chain fatty acids (SCFAs) production from waste activated sludge compared to traditional freezing/thawing treatment. The maximal production of SCFAs was 212 mg COD/g VSS with a shortened retention time of five days, and the potentially recovered carbon source, including SCFAs, soluble polysaccharides and proteins, reached 321 mg COD/g VSS, increased by 92.1 and 28.3% compared to sole freezing and thermal treatment. Both the solubilization and hydrolysis steps of WAS were accelerated, and the acid-producing microorganisms, such as Macellibacteroides, Romboutsia and Paraclostridium, were greatly enriched, with a total abundance of 13.9%, which was only 0.54% in control. Interestingly, the methane production was inhibited at a shortened retention time, resulting in SCFAs accumulation, whereas it was increased by 32.0% at a longer sludge retention time, providing a potential solution for energy recovery from WAS.

Thermophilic Co-Fermentation of Wood Wastes and High in Nitrogen Animal Manures into Bio-Methane with the Aid of Fungi and its Potential in the USA

A novel process is proposed whereby wood wastes from forest tree mortalities and improved forest management are co-digested with high in nitrogen content animal manures to yield bio-methane along with nitrogen, phosphorous, and potassium bio-fertilizers. The process mimics the well-known wood conversion to methane process in lower termites but relies on thermophilic fungi, bacteria, and archaea instead. It is based on the modified state-of-the art two-step, hyperthermophilic (70 °C) hydrolysis and thermophilic (55 °C) fermentation, dry (30% TS), anaerobic digestion technology with a high organic loading and shortened retention time. The process is augmented with the thermophilic fermentation of carbon dioxide in the biogas into secondary bio-methane by employing hydrogen produced via wind-powered electrolysis. The entire process comprised of five distinct steps is designated as “Wood to Methane 3 + 2”. An industrial type, standardized plant unit has been developed that can be employed in a modular fashion. The implementation of these plant units across the US, utilizing the estimated waste wood potential along with 3/4 of the produced poultry and pig manure, would generate the equivalent of 2/3 of transportation fuel consumption and would supply about 11% of current US energy use per annum. The produced bio-methane can be cost-competitive only if it is employed as a transportation fuel to replace fossil gasoline and diesel fuels. The required annual investment over a 20-year period is well within the means of the US economy in a public–private development partnership.

A comparative evaluation of two electrode systems on continuous electrocoagulation of boron from produced water and mass transfer resistance

This study evaluated the performance of aluminum and iron plate electrode systems on the continuous electrocoagulation of boron from produced water under varying conditions of retention time, initial concentration and electrode distance. The experimental data were validated for mass transfer resistance using the modified mass transfer factor (MMTF) model. Results show a similar trend for both electrode systems. Boron removal decreased from 78.7–60% for aluminum electrode and 67.3–53.3% for iron electrode with shortening retention time from 45 to 30 min.. Boron removal further decreased from 84 to 72.7 % for aluminum electrode and 76 to 61.3 % for iron electrode with increasing electrode distance from 0.5 cm to 1.5 cm. Analyses of the mass transfer resistance showed that the driving force (B) for boron mass transfer was concentration dependent and increased from 0.1037 to 0.4002 mg.g for aluminum electrode and 0.0445 to 0.1258 mg.g for iron electrode with increasing initial boron concentration from 5 to 15 mg/L. A similar trend was observed for the affinity between boron and the electroactive species. Analyses of boron mass transfer resistance related to the global and film mass transfer, and porous diffusion show that boron mass transfer resistance correlated to the film mass transfer for both electrode systems. Aluminum electrode system showed better performance for boron removal and higher mass transfer kinetics. This study clearly demonstrates that continuous electrocoagulation is a suitable alternative for boron removal from produced water.

Comparison of diet digestibility, rumen fermentation, rumen rate of passage, and feed efficiency in dairy heifers fed ad-libitum versus precision diets with low and high quality forages

ABSTRACTThis study compared ad-libitum versus precision-fed diets with 2 forages and different levels of neutral detergent fibre (NDF) to evaluate rumen fermentation, diet digestibility, feed efficiency, and digesta passage rate. Eight Holstein heifers (18.4 ± 0.6 mo) fitted with rumen cannulas were used in a 2-factor, split-plot, Latin square design. The whole-plot factor was feeding system with ad-libitum or precision feeding and 4 heifers in each plot. The subplot included 2 factors: forage quality and NDF content. Diets were formulated to provide the same energy level (0.234 Mcal of ME intake/kg of empty body weight0.75 for precision-fed heifers and 110% of previous intake for ad-libitum-fed heifers. Forage quality and NDF level affected dry matter intake. Mean rumen pH was lower for ad-libitum than for precision-fed diets and volatile fatty acid concentrations were affected principally by forage quality. Ad-libitum diets showed faster rate of passage for solid feeds and fluids, increased rate of digestion, and shorter retention time in the rumen. In addition, both high NDF and low quality forage modified rumen passage rate and shortened retention time. Feed efficiency was improved in precision-fed heifers.

Applications of 2, 2, 2 trifluoroethanol as a versatile co-solvent in supercritical fluid chromatography for purification of unstable boronate esters, enhancing throughput, reducing epimerization, and for additive free purifications

Analysis and purification of boronic acid pinacol esters by RPLC is very challenging due to their degradation in aqueous and alcoholic solvents. These compounds are difficult to purify by SFC too as they are equally sensitive to traditional co-solvents like methanol, ethanol, and 2-propanol. 2,2,2 trifluoroethanol (TFE), which has been reported for the purification of a few alcohol sensitive compounds, was evaluated as a co-solvent in this study for the purification of chiral and achiral boronate esters by SFC. Examples of twelve compounds were presented in this paper where degradation of boronic acid pinacol esters was successfully controlled by replacing methanol with TFE as the co-solvent in SFC. A separate study showed that TFE can also control the epimerization of the enantiomers of 3 substituted 1,4 benzodiazepine analogues during the purification process. In addition to above benefits, 2,2,2trifloroethanol showed improved selectivity and resolution for most of the compounds. With its stronger solvent strength compared to other alcohols, TFE could also be used to reduce the co-solvent percentage needed for elution and to shorten retention time of highly polar samples which did not elute even in 50% of other co-solvents in SFC. A case study of compound B demonstrated that TFE provided a reduced co-solvent percentage and a shorter cycle time with much improved resolution as compared to methanol, thus resulting in higher loading and throughput with reduction of total solvent consumption.

Exploration of trade-offs in the design of volatile STT–RAM cache

Abstract STT–RAM is considered as a promising alternative to SRAM due to its low static power (non-volatility) and high density. However, write operation of STT–RAM is inefficient in terms of energy and speed compared to SRAM and thus various device-/circuit-/architecture-level solutions have been proposed to tackle this inefficiency. One of the proposed solutions is redesigning STT–RAM cell for better write characteristics at the cost of shortened retention time (volatile STT–RAM). Because the retention failure of STT–RAM has a stochastic property, an extra overhead of periodic scrubbing with error correcting code (ECC) is required to tolerate the failure. The more frequent scrubbing and stronger ECC are used, the shorter retention time is allowed. With an analysis based on analytic STT–RAM model, we have conducted extensive experiments on various volatile STT–RAM cache design parameters including scrubbing period, ECC strength, and target failure rate. The experimental results show the impact of the parameter variations on last-level cache energy and performance and provide a guideline for designing a volatile STT–RAM with ECC and scrubbing.

High-solid Anaerobic Co-digestion of Food Waste and Rice Straw for Biogas Production

Anaerobic co-digestion of food waste (FW) and rice straw (RS) in continuously stirred tank reactor (CSTR) at high organic loading rate (OLR) was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid (VS) concentration of more than 3 gVS · L−1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand (COD) and volatile fatty acids (VFAs) were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 mL·gV·S−1 · d−1 at a mass ratio (FW/RS) of 3 : 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than mono-digestions in higher organic loading system.

Impacts of Cu Contamination on Device Reliabilities in 3-D IC Integration

The impacts of Cu contamination from a backside surface of a thinned wafer and Cu via on device reliabilities in 3-D IC integration are electrically evaluated. Intrinsic gettering (IG) layer, which was formed by high density oxygen precipitate, shows excellent Cu retardation characteristics from the backside surface of the thinned wafer. Extrinsic gettering (EG) layer, which was formed by postgrinded dry polish (DP) treatment shows good Cu retardation characteristics compared with other postgrinded treatments. The minimal 30-nm-thick Ta barrier layer in Cu via shows good barrier property to Cu diffusion from Cu via after annealing up to 60 min at 300 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C. However, it is not enough at 400 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C annealing, because the generation lifetime shows significant degradation after the initial annealing for 5 min. The DRAM cell characteristics show severe shortening retention time after an intentional Cu diffusion from the backside of the thinned DRAM chip at relatively low temperature of 300 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C.

Mechanical vibration may be a novel adjuvant approach to promoting stability and retention following orthodontic treatment

Introduction: Orthodontic tooth movement occurs as a consequence of paradental tissue remodeling in response to applied mechanical forces. Retention is a necessary procedure to prevent relapse when orthodontic appliances are removed. Developing new methods to promote stability and retention following orthodontic treatment has always been desired. Recent studies have demonstrated the favorable effects of low magnitude, high frequency (LMHF) mechanical vibration on bone homeostasis through an ability to stimulate cell metabolism and to enhance osteoblast proliferation, osteoblastic gene expression and bone formation. The Hypothesis: In this paper, we propose that LMHF mechanical vibration is a viable adjuvant method to accelerate bone and periodontal tissue remodeling, thereby promoting stability and shortening retention time. Evaluation of the Hypothesis: Much effort has been made to explore therapies to prevent relapse and shorten orthodontic retention time with limited success. LMHF mechanical vibration may be a promising approach to accelerate alveolar bone remodeling, ultimately promote stability and shorten retention time.

Degradation of Memory Retention Characteristics in DRAM Chip by Si Thinning for 3-D Integration

The Young's modulus (E) of Si substrate begin to noticeably decrease below 50-μm thickness. The Young's modulus in 30-μm thick Si substrate decreased by 30% compared to the modulus of 50-μm thickness. In 30-μm thick Si substrate, the lattice structure of Si atom is highly distorted. Large distortion of the lattice structure induces the Young's modulus reduction, consequently weakens the mechanical strength. A DRAM chip of 200-μm thickness is bonded to a Si interposer and thinned down to 50/40/30/20-μm thickness, respectively. The retention characteristics of DRAM cell are degraded depending on the decreasing of the chip thickness, especially dramatically degraded below 50-μm thickness. The retention time of DRAM cell in the 20- μm thick chip is shortened by ~ 40% compared to the 50-μm thick chip, regardless of the well structure (triple-well, twin-well). The distortion of the lattice structure in the thin chip effects carrier recombination rates, consequently a shortening retention time of DRAM cell.

DETERMINATION OF SULFATE IN COASTAL SALT MARSH SEDIMENTS WITH HIGH-CHLORIDE CONCENTRATION BY ION CHROMATOGRAPHY: A REVISED METHOD

In order to elucidate the relationship between sulfate reduction and mineralization of organic matter in coastal sediments, the content of sulfate in sediment samples should be measured. Chloride, sulfate, bromide, nitrate, and phosphate are the standard anions in coastal sediment samples. Ion chromatography (IC) is one of the popularly used techniques for determinations of these anions. However, the peaks of the five anions in the IC system coincide with each other under high chloride conditions when using the normal method. In this article, an improved, highly sensitive method for simultaneous separation and determination of sulfate, bromide, nitrate, and phosphate in the samples with high chloride concentration is established and evaluated by IC. In high concentrations of chloride samples, the effects of eluent concentration on the retention time and separation of other anions are studied. The peaks of these anions can be well separated on an AS11 ion-exchange column by a low concentration of NaOH eluent (10 mM). in one injection. Gradient elution is helpful to shorten retention time, especially for phosphate. The method detection limit of sulfate is 0.091 mg · L−1. The recovery of sulfate ranged from 100.5% to 106.8%, when the concentrations of standard solution are close to those of the samples. This technique was validated by determining the content of sulfate and chloride in coastal salt marsh sediment samples.

Impact of Cu Contamination on Memory Retention Characteristics in Thinned DRAM Chip for 3-D Integration

The influence of Cu diffusion at the backside surface of a thinned dynamic random access memory (DRAM) chip for 3-D integration on memory retention characteristics was electrically evaluated. A DRAM test chip was bonded to a Si interposer at 300 °C for 2 min and thinned down to 30-μm thickness. The DRAM cell characteristics, which show 50% failure at 200 μs, were not degraded from the packaged sample (prethinning) even after chip bonding, chip thinning, and no-Cu postannealing for 30 min at 300 °C. Meanwhile, the DRAM cell array shows 50% failure at 70 μs after an intentional Cu diffusion from the backside surface for 30 min at 300 ° C. It means that Cu atoms at the back surface reach the Si-SiO2 interface of the front surface in active areas and cause functional failures such as increasing carrier recombination rate, consequently shortening retention time. However, the NMOS transistor characteristics show no significant change even after Cu diffusion. The on-current performance characterized by majority carriers is not an effective criterion to characterize sensitively the Cu contamination effect.

Risk factors and nursing of fungal infection in patients undergoing abdomen surgical operation

Objective To study the risk factors of fungal infection in patients undergoing abdomen surgical operation and its nursing intervention measures. Methods 62 patients who developed fungal infection after abdomen surgical operation and 395 randomly selected cases who did not develop fungal infection from January 2000 to December 2010 were enrolled into the study, and their clinical data and nursing records were analyzed retrospectively and compared respectively. Causes, clinical characteristics and nursing measures of those with fungal infections were summarized. Results Totally 65 strains of fungi were isolated from 62 patients. Candida albicans is one of the major strains, accounting for 55.4%. One way analysis of variance and Logistic regression revealed that the high risk factors of fungal infection mainly included： age, hospital stay, long-term broad-spectrum antibiotics use, corticosteroids use, neutropenia, and invasive treatments. Conclusions Fungal infection is an important complication of patients undergoing abdomen surgical operation. It may do great harm to patients＇ prognosis and recovery. Carefully observing disease development, enhancing and strengthening patients＇ resistance, rationally using antibiotics, reducing the invasive procedures, shortening retention time of catheters, reinforcing basic care, keeping wards clean and strengthening the concept of asepsis are effective nursing measures for preventing oatients from fungal infection. Key words: Surgical operation; Risk factors ; Infection; Nursing

High-performance liquid chromatography purification of biosurfactant isoforms produced by a marine bacterium

A marine Bacillus strain produced biosurfactant during its growth in a defined glucose-containing medium. An efficient method for separation and purification of biosurfactant isoforms was developed and optimized in high-performance liquid chromatography (HPLC) by manipulating solvent gradient program and flow rates. Starting with an initial run time of 60 min, the final optimized method had a significantly reduced run time of 20 min. By using this method, all the surface-active isoforms (fractions A-D) were eluted within 12 min of elution with much shortened retention time of each component. The purity levels of the isoforms were enhanced using the optimized method as evident from their lower CMC values. Among the four surface-active fractions, antimicrobial action was solely displayed by HPLC fraction A. FTIR analysis revealed all the HPLC fractions to be lipopeptide in nature and MALDI-ToF mass spectral analysis showed that these belonged to the fengycin family containing C(15), C(16), and C(17) fengycins.

Functions of Mobile-Robot Step-On Interface

To improve HFAMRO-1 mobile robot maneuverability and safety, we added a step-on interface (SOI) to direct robotic or mechatronic tasks and operations (HFAMRO: “human-friendly amusing” mobile robot). To do so, a projector displays a direction screen on a floor or other surface, and an operator specifies a button showing the selected movement by stepping or pointing. We modified the direction screen so that among buttons displayed on two lines, stepped-on buttons directing movement are displayed only on the lower line. We also shortened retention time and had selected movement executed only when the foot was removed from the stepped-on button. The robot has 2 SOIs and multiple projection screens, and can be controlled from either direction for the same function. We synchronized direction and preliminary-announcement screens to inform passers-by which way the robot would move. Using range scanner data, the robot distinguishes feet from other objects based on size and autonomous movement fusion control to avoid obstacles is implemented.