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Conventional anaerobic digestion (AD) process was often slow and thus required a large digestion tank. Upflow anaerobic sludge blanket (UASB) reactor is an AD technology intended mainly to treat wastewater with a short hydraulic retention time (HRT). However, the potential of this reactor was often limited when treating wet solid biomass. In this study, the performance of anaerobic submerged membrane bioreactor (AnMBR) was investigated under acidic condition by varying the hydraulic retention time (HRT), from 1.5 d to 2.5 d, and sludge retention time (SRT), from 6 to 12 d, of a mixture of primary and excess sludge. The acidic permeate was thereafter utilized in a UASB reactor at an HRT of 0.5 d. The results showed a COD reduction between 26 and 36% in the AnMBR, while the average COD removal rate was 83% in the UASB reactor. The average pH in the AnMBR was 5.40 and the transmembrane pressure was below 45 mbar throughout the experimental period. The average methane yield in the UASB reactor was 0.25 L/gCOD. These results implied that operating AnMBR under acidic condition is an alternative process to minimize membrane fouling and increase the energy footprint of an AD system.

Anaerobic digestion has been acknowledged as an appropriate technology to tackle climate change and support sustainable development. In general, biogas installation in developed countries involved a high investment cost due to the size and complexity of the technology, while small and simple technologies are often used in developing countries. In this study, an 8 m3 commercial portable biodigester was modified by installing a mixing device and a heating element coil wire, and fed with liquid dairy manure, dairy by-products and food wastes. The results showed that the mixing device and heating element were effective to keep biodigester temperature around 37.7 °C at an ambient temperature between − 8 and + 25 °C. Higher temperature and longer hydraulic retention time (HRT) were related to higher digestion performance, while the opposite was observed with organic loading rate (OLR). Biodigester performance was not influenced by temperature and HRT, while it was increased with the increase of OLR. The highest biogas yield was observed during the co-digestion of liquid manure with waste milk and food waste, while the highest volumetric production of biogas was observed with liquid dairy manure co-digested with camembert cheese waste and food wastes.

Additives, such as iron oxides, have been used in anaerobic digestion (AD) to promote direct interspecies electron transfer and to boost methane yield. However, the function of additives in the AD of antibiotic-contaminated organic wastes remained unclear. In this study, the effects of ferric hydroxide and (semi) conductive iron oxides, namely hematite and magnetite, on the AD of oxytetracycline (OTC)-contaminated dairy manure were investigated. Each iron oxide was assigned to a set of experiment where 0.25 g/L of OTC was added to 1 L batch digesters, while the concentration of iron oxide was varied from 0.08 to 0.34 g/L. Generally, magnetite was the most effective iron oxide to enhance methane yield in OTC-free dairy manure followed by ferric hydroxide and hematite. However, when the manure was contaminated with OTC, higher methane yield was observed in ferric hydroxide followed by hematite, while the lowest was with magnetite. In all digesters, the highest methane yield was observed with ferric hydroxide at 0.08 g/L, which was 1.43-fold of that with OTC and without iron oxides. The kinetic studies of methane yield demonstrated that the addition of iron oxides in the AD of OTC-contaminated dairy manure did not shorten the lag phase period despite the increase of methane yield. Thus, the increase of methane yield with ferric hydroxide was attributed to the possible formation of Fe-OTC complex, which attenuated the inhibition of OTC. A strategy to recover OTC residue in the AD was proposed using magnetite, a ferromagnetic particle, and high gradient magnetic separator.

To promote primary production in oligotrophic seas, we developed a fertilization composite consisting of blast furnace cement and anaerobic digestate with a high nutrient content derived from biogas power plant byproducts. In this study, we investigated the dissolution behavior of nutrients from the fertilization composite and evaluated the effects of the fertilization composite on the growth of marine primary producers. Batch experiments and tank experiments to simulate oligotrophic coastal seas revealed that the nutrients dissolved from the fertilization composite were taken up by marine microalgae and seaweed. The fertilization composite promoted the growth of both planktonic and benthic micro algae. The total amounts of chlorophyll a in the fertilization composite tank increased by 1.4 times compared to control (p 0.01). The flow of dissolved inorganic nitrogen uptake by marine microalgae increased 3-5 times when the fertilization composite was applied. In Wakame seaweed culture experiments, the nitrogen contents of Wakame from the fertilization composite tank were 1.2 times higher than those cultured in the control tank (p 0.01). As a result, Wakame leaves cultured in the fertilization composite tank were 1.4 times longer than those cultured in the control tank. Approximately 44% of dissolved inorganic nitrogen from the fertilization composite was taken up by the seaweed. Hence, the fertilization composite was demonstrated to enhance the growth of marine microalgae and seaweed, which are primary producers in marine ecosystems. The fertilization composite proposed in this study can create novel nutrient mass flow by connecting terrigenous anaerobic digestate from biogas power plants to oligotrophic seas and thus stimulate the recovery of fishery production.

This study was aimed to investigate the mechanisms of oxytetracycline (OTC) and chlortetracycline (CTC) inhibition in anaerobic digestion (AD) using four kinetic models. The results showed that the inhibition rate of OTC was faster than CTC at OTC and CTC between 0.04 and 1.28 g/L. Hydrolysis rate constant was linearly and positively correlated with OTC and increased from 0.172 to 0.193 d-1, 0.164 to 0.179 d-1 and 0.251 to 0.285 d−1 using first-order kinetic, Fitzhugh and Cone models, respectively, while the maximum specific methane production rate was linearly and negatively correlated with CTC and decreased from 0.028 to 0.016 L/gVS. Cone model was found to give the most satisfactory fitting results followed in descending order by first-order kinetic, Fitzhugh and modified Gompertz models. The kinetic modeling of methane yield helped explain the mechanism of OTC and CTC inhibition in the AD process and provided essential information for further process improvement.

1,4-Dioxane (DX) is a recalcitrant cyclic ether that has gained attention as an emerging pollutant in the aquatic environment. Enrichment of indigenous DX-degrading bacteria, which are considered to be minor populations even in DX-impacted environments, is the key for efficient biological DX removal. Therefore, this study aimed to explore carbon sources applicable for the enrichment of DX-degrading bacteria present in landfill leachate, which is a potential source of DX pollution. Microorganisms collected from landfill leachate were cultivated on six different carbon sources (DX, tetrahydrofuran (THF), 1,3,5-trioxane (TX), ethylene glycol (EG), diethylene glycol (DEG), and 1,4-butanediol (BD)) in a sequential batch mode. Consequently, enrichment cultures cultivated on THF in addition to DX improved the DX degradation ability compared to that of the original leachate sample, while those on the other test carbon sources did not. The results indicated that THF can be an alternative carbon source to enrich DX-degrading bacteria, and that TX, EG, DEG and BD are not applicable to concentrate DX-degrading bacteria in complex microbial consortia. In addition, sequencing analyses of 16S rRNA and soluble di-iron monooxygenase (SDIMO) genes revealed notable dominance of thm/dxm genes involved in group 5 SDIMO both in DX- and THF-enrichment cultures. The analysis also showed a predominance of Pseudonocardia in THF-enrichment culture, suggesting that Pseudonocardia harboring thm/dxm genes contributes to enhanced DX degradation in THF-enrichment culture.

The anaerobic treatment of antibiotic-contaminated organic wastes is often challenged by the reduction of the overall anaerobic digestion (AD) process performance. This study aimed to investigate the roles of ferric ion (Fe3+) and magnetite (Fe3O4) on process performance and volatile fatty acids (VFA) utilization pattern in an oxytetracycline (OTC)-pressured AD. Three sets of batch experiment were conducted where OTC, FeCl3 and Fe3O4 concentrations were varied from 0.07 to 0.19 g/gCOD, 0.04 to 0.15 g/gCOD and 0.07 to 0.14 g/gCOD, respectively. The results showed that the conversion of propionic and butyric acids into intermediate products was delayed by OTC. Moreover, OTC reduced methane yields (MY) between 25 and 27%. However, when FeCl3 and Fe3O4 were added, MY was increased by 7% and 33% at FeCl3 of 0.07 g/gCOD and Fe3O4 of 0.07 g/gCOD, respectively, along with the improvement of propionic and butyric acids conversion.

We examined the effects of encapsulated lactic acid bacteria administrated orally to lactating cattle on the intestinal flora. A dose of 3 X 10¹¹ colony forming unit (cfu) of freeze-dried Lactobacillus coryniformis subsp. torquens (JCM1099) encapsulated in an enteric capsule capable of bypassing the rumen was administered for seven days. DNA was extracted from feces 0 and 24 hr after daily administration. Metagenomic analysis showed an increasing trend of the alpha diversity, an index of the species diversity. Furthermore, principal component analysis of intestinal flora revealed that cattle could be differentiated by JCM1099 capsule and suspension administration via principal components 1, 2, and 3. We conclude that administration of encapsulated JCM1099 can alter the intestinal bacterial flora of cattle.

The dairy industry disposes of a large volume of waste milk with antibiotic residues, which is a great cause of much concern in soil and water environments. In this study, the electrochemical oxidation of tetracycline antibiotics (TCs) in cow's milk was investigated. Milk contains a high concentration of organic matter, and the concentrations of TCs residues are extremely low. The effects of anode materials and electrolytes on the degradation of oxytetracycline (OTC) were investigated. A higher degradation rate for the OTC was attained using the inactive anode or a NaCl electrolyte. It was found that a physically adsorbed oxidant on the surface of the anode and indirect oxidation using electrogenerated hypochlorite could enhance the degradation of OTC in raw milk. The organic components in milk samples affected the removal rate of the OTC. The removal rate constants for the OTC in raw milk were 2.8-7.7 times higher than the chemical oxygen demand values. It was found that electrochemical oxidation could decompose low concentrations of TCs in high concentrations of organic matter solutions selectively. The results indicate that electrochemical oxidation is an effective method for the treatment of TCs in waste milk.

The movement of the posterior cruciate ligament (PCL) during flexion of the living knee is unknown. The purpose of the present study was to analyze the movement of the PCL using magnetic resonance imaging (MRI). The posterior cruciate ligaments in 20 normal knees were visualized using MRI from extension to deep flexion. Sagittal inclination relative to the longitudinal axis of the tibia was measured and analyzed with reference to the patellar tendon (PT) and the anterior cruciate ligament (ACL). Although the PCL was slack in extension, it straightened with anterior inclination (24.1+/-5.1 degrees ) at 90 degrees flexion. At active maximum flexion (129.2+/-8.1 degrees ), the ligament was almost parallel (3.9+/-7.4 degrees inclination) to the longitudinal axis of the tibia. At passive maximum flexion (158.8+/-5.8 degrees ), the inclination was reversed anteroposteriorly, measuring -23.0+/-6.7 degrees . The PCL and PT moved in a corresponding manner within 20 degrees of discrepancy. The results of this in vivo study of the PCL have clinical relevance to conservative therapy for PCL knee injuries. The results of this study could also be useful in PCL reconstruction surgery to determine the optimum graft position to allow maximum postoperative motion.

In bioelectrochemical systems, the electrode potential is an important parameter affecting the electron flow between electrodes and microbes and microbial metabolic activities. Here, we investigated the metabolic characteristics of a glucose-utilizing strain of engineered Shewanella oneidensis under electrode-respiring conditions in electrochemical reactors for gaining insight into how metabolic pathways in electrochemically active bacteria are affected by the electrode potential. When an electrochemical reactor was operated with its working electrode poised at +0.4 V (vs. an Ag/AgCl reference electrode), the engineered S. oneidensis strain, carrying a plasmid encoding a sugar permease and glucose kinase of Escherichia coli, generated current by oxidizing glucose to acetate and produced D-lactate as an intermediate metabolite. However, D-lactate accumulation was not observed when the engineered strain was grown with a working electrode poised at 0 V. We also found that transcription of genes involved in pyruvate and D-lactate metabolisms was upregulated at a high electrode potential compared with their transcription at a low electrode potential. These results suggest that the carbon catabolic pathway of S. oneidensis can be modified by controlling the potential of a working electrode in an electrochemical bioreactor.

The purpose of this study is to assess the incidence of post-operative femoral bone tunnel communication after anterior cruciate ligament double-bundle reconstruction (ACL-DBR) with two drilling techniques by transparent 3-dimensional computed tomography (CT) and elucidate the factors associated with post-operative femoral bone tunnel communication. Fifty-five patients underwent ACL-DBR using outside-in technique (Group A, 25 patients) and transportal technique (Group B, 30 patients) for the drilling of femoral tunnel. CT was taken at 1 week and 6 months post-operatively. The femoral and tibial bone tunnel orientation, position, the divergency and the distance of bone bridge between the tunnels were measured using reconstructed CT images. In order to identify the factors related to post-operative femoral bone tunnel communication, patients were divided into two groups depending on whether femoral bone tunnels communicated (Group F–C) or remained (Group F–R) at 6 months post-operatively. Femoral bone tunnels in Group B were orientated horizontally and dorsally compared to those in Group A. Tunnel divergency between two femoral tunnels was greater in Group A (11.7°) than in Group B (10.0°). Average distance of bone bridge at 1 week post-operatively was 1.8 mm in Group A and 1.7 mm in Group B (n.s.). Post-operative femoral bone tunnel communication occurred in 16 patients (64 %) in Group A and in 18 patients (60 %) in Group B at 6 months after ACL-DBR, respectively (n.s.). Regarding tibial tunnels, there were no significant differences in tunnel orientation, position, divergency and incidence of post-operative tibial tunnel communication between Groups A and B. Mean distance of femoral bone bridge at 1 week in Group F–R (2.5 mm) was significantly greater than in Group F–C (1.3 mm) (p

For peroneal tendon dislocation, various surgical procedures have been described. Das De et al. reported good clinical results using retinaculum repair. However, their reports are limited to case series. We have simplified the Das De procedure since 1996. The purpose of this study is to investigate the clinical outcomes of our modified Das De procedure (MD) and compare these clinical outcomes to those of the Du Vries procedure (DV) that was performed in our hospital until 1996. From 1996 to 2007, 19 patients were treated by MD and from 1988 to 1996, 15 patients were treated by DV. A mean preoperative Ankle-Hindfoot Scale was 78.4 points (range: 65–84) in the MD group and 77.2 points (range: 67–87) in the DV group. A mean postoperative Ankle-Hindfoot Scale was 93.4 points in the MD group and 89.4 points in the DV group. Two patients (13.3%) in the DV group suffered postoperative peroneal tendon redislocation. In the MD group, there was no postoperative peroneal tendon redislocation or complication related to skin incision. In athletes, 80.0% in the MD group and 54.5% in the DV group were able to return to their previous sports. The mean duration to return to sports was 2.9 months in the MD group and 3.9 months in the DV group (p

Osteochondritis dissecans (OCD) of the lateral femoral condyle sometimes occurs with a discoid lateral meniscus. Recently, it was reported that OCD of the lateral femoral condyle occurred after total removal of the lateral meniscus. We report the case of a 12-year-old boy with bilateral OCD of the lateral femoral condyle following bilateral total removal for discoid lateral meniscus. Valgus deviation of the knee after total removal and increased sporting activity might have concentrated excessive stress on the lateral condyles in the standing position. As a result, bilateral OCD might have occurred. Drilling of the areas of OCD on the bilateral lateral femoral condyles was done and the patient wore inner wedge arch supports postoperatively. After 2 years, neither knee pain nor arthrosis has occurred so far, but long-term follow-up of this patient is considered to be necessary.

The anatomical structure at bone-tendon and bone-ligament interfaces is called the enthesis. Histologically, the enthesis is characterized by a transitional series of tissue layers from the end of the tendon to bone, including tendon, fibrocartilage, calcified fibrocartilage, and bone. This arrangement yields stronger direct connection of the soft tissues to bone. In surgical repair, the enthesis has proven difficult to reproduce, and the success of ligament-bone bonding has depended on the fibrous attachment that forms after any ligament reconstructions. In this study, we attempted to generate a direct-insertion enthesis in two stages. First, recombinant human bone morphogenetic protein-2 (rhBMP-2) was injected into the flexor digitorum communis tendon in the rabbit hind limb to induce ectopic ossicle formation. In a second step, the resultant tendon/ossicle complex was then surgically transferred onto the surface of the rabbit tibia to generate a stable tendon-bone junction. One month following surgery, histomorphological examination confirmed direct insertion of tendon-bone structures in the proximal tibia of the rabbit. Ultimate failure loads of the BMP-2-generated tendon-bone junction were significantly higher than in the control group (p < 0.01). These findings suggest that it is possible to successfully regenerate a direct tendon-to-bone enthesis. Use of this approach may enable successful reconstruction of joints rendered unstable after ligamentous rupture or laxity after anterior cruciate ligament injury.

Ethanol-1-14C method for the measurement of intrahepatic shunted blood flow was compared with the method of continuous infusion of D-galactose-1-14C. In controls, in chronic hepatitis, and in hepatic cirrhosis, per cent intrahepatic shunt measured by the ethanol-1-14C method was about a half or one-third of that measured by the D-galactose-1-14C method. Study of radioactivity-dye con-centration ratio of the blood sampled from the inferior vena cava showed that per cent intrahepatic shunt was underestimated by the ethanol-1-14C method because of permeability of ethanol-1-14C through the capillaries. In patients with hepatic carcinoma, in whom the carcinomatous tissue was supplied mainly by the hepatic artery, there was no significant difference in per cent intrahepatic shunt between both methods.