Efficient, high-speed methane fermentation for sewage sludge using subcritical water hydrolysis as pretreatment

A novel biomass-energy process for the production of methane from sewage sludge using a subcritical water (sub-CW) hydrolysis reaction as pretreatment is proposed. The main substances of sewage sludge hydrolyzed by sub-CW at 513 K for 10 min were acetic acid, formic acid, pyroglutamic acid, alanine, and glycine. Fermentation experiments were conducted in an anaerobic-sludge reactor for two different samples: real sewage sludge and a model solution containing components typically produced by the sub-CW pretreatment of sewage sludge. In the experiment for the sub-CW pretreatment of sewage sludge, methane generation was twice that for non-pretreatment after 3 days of incubation. In the model experiment, the methane conversion was about 40% with the application of mixture of organic acids and amino acids after 5 days of incubation. Furthermore, the methane conversion was about 60% for 2 days when only organic acids, such as acetic acid and formic acid, were applied. Because acetic acid is the key intermediate and main precursor of the methanogenesis step, fermentation experiments were conducted in an anaerobic-sludge reactor with high concentrations of acetic acid (0.01-0.1M). Nearly 100% of acetic acid was converted to methane and carbon dioxide in 1-3 days.

Preparation of a microporous layered organic-inorganic hybrid nanocomposite using p-aminotrimethoxysilane and a crystalline layered silicate, ilerite

The silylation of ilerite with p-aminophenyltrimethoxysilane (denoted as APhS) was conducted in order to attempt preparation of a layered organic-inorganic hybrid nanocomposite having interlayer microporosity, in which the APhS molecule bridges between the silicate layers using two heterofunctional groups containing an amino group and a methoxy one. The APhS molecules were successfully condensed and immobilized in the interlayer of the protonated ilerite. Chemical analysis and (29)Si solid-state NMR results indicated that the interlayer space was occupied by preferential condensation between the APhS molecules. Subsequent HCl treatment could remove the excess amounts of the oligomeric species of the APhS molecules. The removal brought about vacant spaces in the interlayer supported by the bridging of the residual APhS molecules. Furthermore, the immobilized APhS molecules had a significant influence on the surface properties of the resultant nanocomposite, which showed high toluene adsorptivity. Consequently, we found a means to construct a microporous, layered nanocomposite by the bridging of the organic spaces with two heterofunctional groups.

Benthic ecosystem development in an artificial tidal flat constructed from dredged spoil

Dredged spoil (DS) was used as a silt and clay additive in the construction of artificial tidal flats from mountain sand (MS). As the ratio of DS in the sediment media increased, the number of emerging macrobenthos increased. The composition of the macrobenthic community was also affected by the addition of DS, and the changes might be dependent on the ratio of DS to MS. In addition, the macrobenthos in the artificial tidal flats was more abundant than that in the control tidal flat, which was constructed with natural tidal flat sediment. With a silt and clay content of 25%, polychaetes Ceratonereis erythraeensis and Capitella sp. and the gastropod Batillaria cumingii were dominant, whereas no bivalves were present. With less silt and clay (5% and 10%), the bivalves Ruditapes philippinarum and Musculista senhousia were observed in the artificial flats, while their numbers in the control tidal flat were lower.

The ensemble of hetero-proteins in inorganic nanochannels

The assembly and proper alignment of two heterofluorescent proteins (sGFP and DsRed) in the mesoporous channels of ethanol-treated FSM6.2 (a folded-sheet mesoporous material with a pore diameter of 6.2 nm) was confirmed using a fluorescence resonance energy transfer (FRET) technique. The sGFP-DsRed-FSM6.2 conjugate showed a large decrease in the emission of donor (sGFP) fluorescence, indicating that the conjugate functions as an energy transfer system through the combination of the two heteroproteins, due to the successful encapsulation of the sGFP-DsRed pairs in the mesopores. Fluorescence spectral analysis demonstrated that the proteins were highly dispersed and homogeneously encapsulated in the mesopores of FSM6.2, even at high concentration, although they spontaneously aggregated and showed a red shift in solution at the concentration corresponding to that in the conjugate. Furthermore, an increase in the amount of sGFP and DsRed adsorbed to the pores of FSM6.2 led to a decrease in the distance between these proteins, resulting in enhancement of FRET efficiency.

Effective immobilization of subunit protein in mesoporous silica modified with ethanol

Ethoxylated FSM-type mesoporous silica (folded-sheet mesoporous material) with a pore diameter of 6.2 nm (FSM6.2) remarkably enhances rigidly of the structure in aqueous solutions. The esterified material could be used successfully as an adsorbent to accommodate subunit protein, methemoglobin (Fe(3+)). Furthermore, methemoglobin (Fe(3+)) in the pores of ethoxy-FSM is maintained a peroxidase activity similar to the native, indicating methemoglobin retains its fore subunit structure in the pores of FSM6.2.

Right parietal activation during delusional state in episodic interictal psychosis of epilepsy: a report of two cases

Magnetoencephalography (MEG) was used to image brain activity associated with delusions in episodic interictal psychosis of epilepsy. Two female patients aged 65 and 68 with temporal lobe epilepsy were studied during and after a delusional state. Topographic images of the excess kurtosis (g2), the statistical index of spikelike activity, were obtained from unaveraged MEG recordings using an analysis called "synthetic aperture magnetometry" (SAM). For both patients, MEG waveforms and excess kurtosis images revealed spiky activity in the right inferior parietal region during the delusional state. A second MEG measurement after delusions were resolved with antipsychotic therapy revealed no excess kurtosis in the right parietal area. Likewise, the sharp waves on MEG recordings disappeared as well. Our results suggest association of the right inferior parietal cortex, including the supramarginal gyrus, with the delusional state of episodic interictal psychosis of epilepsy.

Encapsulation of Myoglobin with a Mesoporous Silicate Results in New Capabilities

A metmyoglobin (Fe3+), an oxidized form of myoglobin (Fe2+), was confined in nanospaces of about 4 nm in diameter in mesoporous silica (FSM; folded-sheet mesoporous material), forming a metmyoglobin (Fe3+)-FSM nanoconjugate. The spectral characteristics of metmyoglobin (Fe3+)- and myoglobin (Fe2+)-FSM show an absorption curve quite similar to that of native metmyoglobin, indicating that myoglobin retains its higher-order structure in the pores of FSM. The metmyoglobin (Fe3+)-FSM conjugate had not only a peroxidase-like activity in the presence of hydrogen peroxide (a hydrogen acceptor) and 2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfomic acid (ABTS) or guaiacol (a hydrogen donor) but also an advanced molecular recognition ability enabling it to distinguish between ABTS and guaiacol. Furthermore, the metmyoglobin (Fe3+)-FSM showed the peroxidase-like activity even in an organic media using benzoyl peroxide as the hydrogen acceptor and leucocrystal violet as the hydrogen donor. The simple immobilization of metmyoglobin (Fe3+) into FSM results in enhanced catalytic activity in organic media compared to that of native metmyoglobin (Fe3+).

Varus-valgus balance and range of movement after total knee arthroplasty

We performed a randomised, prospective study of 80 mobile-bearing total knee arthroplasties (80 knees) in order to measure the effects of varus-valgus laxity and balance on the range of movement (ROM) one year after operation. Forty knees had a posterior-cruciate-ligament (PCL)-retaining prosthesis and the other 40 a PCL-sacrificing prosthesis. In the balanced group (69 knees) in which the difference between varus and valgus was less than 2 degrees, the mean ROM improved significantly from 107.6 degrees to 117.7 degrees (p < 0.0001). By contrast, in the 11 knees which were unbalanced and in which the difference between varus and valgus laxity exceeded 2 degrees, the ROM decreased from a mean of 121.0 degrees to 112.7 degrees (p = 0.0061). We conclude that coronal laxity, especially balanced laxity, is important for achieving an improved ROM in mobile-bearing total knee arthroplasty.

Wavelet-Crosscorrelation Analysis: Non-Stationary Analysis of Neurophysiological Signals

OBJECTIVE

Wavelet-crosscorrelation analysis is a new application of wavelet analysis used to show the propagation of epileptiform discharges and to localize the corresponding lesions. We have shown previously that this analysis can help predict brain conditions statistically (Mizuno-Matsumoto et al. 2002). Our objective was to assess whether wavelet-crosscorrelation analysis reveals the initiation and propagation of epileptiform activity in human patients.

METHODS

The data obtained from three patients with simple partial seizures (SPS) using whole-head magnetoencephalography (MEG) were analyzed by the wavelet-crosscorrelation method. Wavelet-crosscorrelation coefficients (WCC), the coherent structure of each possible pair of signals from 64 MEG channels forvarious periods, and the time lag (TL) in two related signals, were ascertained.

RESULTS

We clearly demonstrated both localization of the irritative zone and propagation of the epileptiform discharges.

CONCLUSIONS

Wavelet-crosscorrelation analysis can help reveal and visualize the dynamic changes of brain conditions. The method of this analysis can compensate for other existing methods for the analysis of MEG, electroencephalography (EEG) or Elecotrocorticography (ECoG).

SIGNIFICANCE

Our proposed method suggests that revealing and visualizing the dynamic changes of brain conditions can help clinicians and even patients themselves better understand such conditions.

Effect of flexion angle on coronal laxity in patients with mobile-bearing total knee arthroplasty prostheses

Proper soft tissue tension is one of the important factors in mobile-bearing total knee arthroplasty (TKA). We evaluated varus/valgus laxities, particularly at flexion, which is a key factor in reducing the risk of subluxation and dislocation of bearings to assess the effect that the flexion angle and the presence or absence of the posterior cruciate ligament (PCL) have on laxity in patients with low-contact stress (LCS) prostheses of the PCL-retaining (24 patients, 24 knees) and PCL-sacrificing (24 patients, 24 knees) type designs during extension and flexion. Both types of prosthesis had about 4 degrees laxity at extension and 3 degrees at flexion. PCL-retaining prostheses had significantly less laxity at flexion than at extension (P = 0.0004 in varus, P = 0.0043 in valgus). For good clinical outcomes following TKA, 3 degrees-4 degrees laxity in the varus and valgus orientations is recommended. In addition, the PCL might be involved in flexion and could affect varus/valgus laxity in PCL-retaining prostheses.

Sagittal laxity in vivo after total knee arthroplasty

INTRODUCTION

A stress arthrometry study of 77 knees undergoing total knee arthroplasty was performed to determine the difference in anteroposterior (AP) laxity between posterior cruciate ligament (PCL)-retaining (PCLR) and PCL-substituting (PCLS) prostheses using the Genesis I TKA.

MATERIALS AND METHODS

Fifty-three knees had PCLR and 24 had PCLS prostheses. The selected patients had successful arthroplasties after a minimum follow-up of 5 years. AP laxity was measured with a KT-2000 arthrometer (Medmetric, San Diego, CA, USA) using standard protocols.

RESULTS

At 30 degrees of flexion, there was no statistical difference in anterior (PCLR: 4.7 mm, PCLS: 4.5 mm), posterior (PCLR: 1.1 mm, PCLS: 0.7 mm), or total (PCLR: 5.8 mm, PCLS: 5.3 mm) displacement. At 75 degrees , significant differences were seen in both anterior (PCLR: 3.3 mm, PCLS: 2.3 mm) and total (PCLR: 4.8 mm, PCLS: 3.4 mm) displacement (p=0.001 and p=0.009, respectively), although there was no statistical difference in posterior displacement (PCLR: 1.5 mm, PCLS: 1.1 mm).

CONCLUSION

The above values are considered the suitable degree of AP laxity in total knee arthroplasty for a satisfactory clinical outcome 5-9 years after surgery. The PCL in a PCLR prosthesis and the central tibial spine and femoral cam in a PCLS prosthesis might play comparable roles in determining the laxity in the posterior direction in these prostheses.

Dynamic neuromagnetic responses to auditory motion: a novel index for evaluation of attention

Our previous studies have demonstrated that there is a motion-related magnetic response evoked by moving sound but not stationary sound. The motion-related response reflects the dynamic activities of brain processing of auditory motion. This study focuses on the effect of attention on the response. Six normal hearing subjects were studied using a 151-channel whole-cortex magnetoencephalography (MEG) system. Four sound stimuli were designed: two sounds moved from left to right (rightward) and the other two sounds moved from right to left (leftward). Two sounds moving in the same direction were separated with an attention task. The attention task was a mathematical calculation. The results showed that when subjects listened to the moving sound, there was a clearly auditory motion related response at a latency of 649 +/- 14.2 ms. However, when subjects were doing the calculation while listening to the moving sounds, the motion related response completely disappeared. Strikingly, there was a dent at a latency of 600 ms. To our knowledge, this is probably the first study showing a neuromagnetic response which can be clearly elicited or inhibited by an attention task. We consider that the motion related response has the potential to be an objective index for the study of attention.

SAM(g2) analysis for detecting spike localization: a comparison with clinical symptoms and ECD analysis in an epileptic patient

SAM(g2) analysis, a combination of synthetic aperture magnetometry (SAM) and excess kurtosis (g2) method, is a novel epilepsy analysis procedure based on a spatial filtering technique. By producing a three-dimensional image of the g2 values and superimposing them onto a patient's MR images, this analysis can automatically estimate spike localization from raw MEG epilepsy signals including spikes. The aim of this study is to examine SAM(g2) analysis using MEG signals of an epileptic patient, whose clinical symptoms of colored elementary visual auras had ceased in accordance with the changes of the estimated localizations of the equivalent current dipoles (ECDs) of the interictal spikes. His visual auras were experienced in 1997, while they ceased in 1999 with effective medication. The patient provided written informed consent for the experimental procedures. The MEG signals were recorded in 1997 and 1999, and were analyzed using both ECD and SAM(g2) analyses. For the MEG signals of 1997, ECD analysis estimated most of the interictal spikes in the right fusiform and inferior temporal gyri, which subserve human color processing. SAM(g2) analysis also estimated them in the same areas. For those of 1999, both ECD and SAM(g2) analyses estimated them in the right transverse gyrus of Heschl. As well as ECD analysis, SAM(g2) analysis successfully estimated the changes of the localizations of the interictal spikes in accordance with the changes of the patient's clinical symptoms, indicating that SAM(g2) analysis is useful for detection of interictal spike localization in epileptic patients.

MEG analysis of "theory of mind" in emotional vignettes comprehension

OBJECTIVE

Several studies suggested that an impaired "theory of mind" might play a key role in psychiatric disorders, such as autism and schizophrenia. Medial frontal lobe lesions of the right frontal lobe were reported to impair this ability. The aim of our study was to locate areas of the brain associated with the process of "theory of mind" in normal subjects.

METHODS

In order to index the activity of brain areas related to "theory of mind" reasoning in sixteen normal adults, we administered an emotional ("happy", "sad", "angry" and "neutral") vignettes comprehension task during magnetoencephalography (MEG) recordings and analyzed these data by using SAM (synthetic aperture magnetometry), SPM99 and the permutation method. Subjects were presented with eight different videotaped social situations (each emotion has two vignettes) and were asked to indicate which emotion they represented.

RESULTS

Statistically significant activation in the comparison of "happy"-"sad" and "angry"-"sad" was observed in the bilateral medial prefrontal cortices in the alpha frequency band. There were no significant differences in comparisons of each type of emotional vignette to the neutral vignettes, "happy"-"angry" comparison, and male-female comparisons. There was no significant difference in other frequency bands.

CONCLUSION

This result suggests that bilateral medial prefrontal cortex are involved in the comprehension of emotional states of others.

Effect of total knee arthroplasty on patients' bone quality-ultrasound measurement of the calcaneus

We used ultrasonographic heel measurements to compare the bone quality of patients who underwent total knee arthroplasty (TKA), age-matched controls and patients who suffered from hip fracture. The broadband ultrasound attenuation (BUA; dB/MHz) of the TKA (70), control (70) and hip fracture (107) groups was 42.2+/-15.5, 40.2+/-14.9 and 22.9+/-13.3, respectively. The hip fracture group was significantly different from both the TKA and control groups (P<0.0001). The TKA group had better BUA than the control group, although the difference was not significant (P=0.712). The increase in activity after artificial replacement of an arthritic joint might result in bone quality equivalent to that of controls. Considering that none of TKA patients suffered from hip fracture in the follow-up period, which ranged from 62 to 113 months, TKA might contribute to a decrease in the risk of later hip fracture, by allowing increased mobility and maintaining or improving bone quality.

Preparation of porous clay minerals with organic–inorganic hybrid pillars using solvent-extraction route

A microporous clay mineral with organic-inorganic hybrid pillars was synthesized using a hydrochloric acid (HCl)/ethanol extraction method after intercalation of tetraethoxysilane (TEOS) or TEOS/methyltriethoxysilane (MTS) into the cetyltrimetylammonium ion (CTA)-exchanged vermiculite. The products retained their layered structure, due to the formation of stable pillars by the polymerization of hydrolyzed TEOS and MTS during the HCl/ethanol treatment. The BET surface areas, which increased to above 500 m2g(-1) with an increase in the HCl concentration up to 0.4 moldm(-3), are nearly equal to that of the calcined product obtained by the conventional method. However, the pore sizes of HCl/ethanol-treated materials were narrower than those of the calcined product, owing to the formation of the polysiloxane networks in the gallery. A water adsorption study showed that the product treated with a TEOS/MTS mixture had a hydrophobic surface as a result of the successful incorporation of methyl groups at the surface of the pillars. This novel method is advantageous for the synthesis of organophilic pillared clays with different kinds of organic materials in the interlayers.