Mycoplasma, a genus of pathogenic bacteria, forms a membrane protrusion at a cell pole. It binds to solid surfaces with this protrusion and then glides. The mechanism is not related to known ...bacterial motility systems, such as flagella or pili, or to conventional motor proteins, including myosin. We have studied the fastest species, Mycoplasma mobile, and have proposed a working model as follows. The gliding machinery is composed of four huge proteins at the base of the membrane protrusion and supported by a cytoskeletal architecture from the cell inside. Many flexible legs approximately 50 nm long are sticking out from the machinery. The movements generated by the ATP hydrolysis cell inside are transmitted to the "leg" protein through a "gear" protein, resulting in repeated binding, pull, and release of the sialylgalactose fixed on the surface by the legs. The gliding of Mycoplasma pneumoniae, a species distantly related to M. mobile, is also discussed.
The number of buildings that adopt the multiple split-system air conditioners is increasing, especially for small and medium-sized buildings. Many researches have been done on the energy consumption ...performance of the multiple split-system, but there are still many unclear points about its actual performance, in particularly, with regard to performance under partial load condition. It is important to understand the partial load performance and set the reliable performance characteristics when we perform building energy simulation because it will have a significant influence on annual energy consumption of the system. In order to clarify the efficiency under partial load condition, we have analysed the measurement data of actual buildings and found that there is a range of the efficiency even at the same load ratio. We assume that the cause of this range is due to bias (unbalance) in the heat amount handled by multiple indoor units. The efficiency tends to be higher when the heat amount of all indoor units of the system are equal, which is same as the test condition specified by ISO 15042:2017, but the efficiency tends to be lower when the heat amount handled by the indoor units is highly unbalanced. This research clarifies the influence of the unbalanced heat load to the system energy efficiency. We measured fundamental data on the energy efficiency of the multiple split-system air-conditioner in an experimental facility that connects multiple constant temperature and humidity chambers. We found that the unbalanced load operation caused about 20% energy loss in maximum and concluded that the indoor units should be arranged so that extreme unbalanced heat load does not occur.
The twelve Mycoplasma species known to glide on solid surfaces all lack surface flagella or pili, and no genes homologous to known motility systems have been found in the five genomes sequenced to ...date. Recent studies on the fastest of these species, M. mobile , examined novel proteins involved in the gliding mechanism, binding targets on the solid surfaces, energy sources and mechanical characteristics of the movements. Accordingly, I propose a working model for the gliding mechanism, called the centipede (power stroke) model, in which the ‘leg’ proteins repeat a cycle of binding to and release from the solid surface, using energy from ATP. Another ‘inchworm model’ suggested from the structural studies of a human pathogen, M. pneumoniae , is also discussed.
In animal husbandry, antibiotics are widely used to treat and prevent diseases or to promote growth. The use of antibiotics for domestic animals enables to promote safety of livestock products and ...enhance productivity. Tetracycline antibiotics (TCs) are one of the primarily used groups of antibiotics for cattle and swine. However, the unintentional spreading of antibiotics from animal waste to the environment may leave out drug residues, promoting resistant strains of bacteria, and will adversely affect the ecosystem and human health. To prevent the spread of veterinary antibiotics in the environment, it is required to treat residual antibiotics in livestock wastewater. In this study, we investigated the electrochemical oxidation of TCs to treat livestock wastewater. The concentrations of TCs in aqueous solutions were reduced from 100 mg/L to less than 0.6 mg/L by 6 h of electrochemical treatment using a Ti/IrO2 anode with Na2SO4 electrolyte. The concentration of oxytetracycline (OTC) in livestock wastewater was also reduced from 100 mg/L to less than 0.7 mg/L by the same treatment. Thus, the electrochemical oxidation using a Ti/IrO2 anode with Na2SO4 electrolyte was found to be effective for degradation of TCs. The results suggest that the electrochemical oxidation method is a promising treatment for TCs in livestock wastewater.
Although the clinical importance of cortical microinfarcts has become well-recognized recently, the evolution of cortical microinfarcts on MR imaging is not fully understood. The aim of this study ...was to examine the temporal changes in acute cortical microinfarcts using susceptibility-weighted imaging and conventional MR imaging.
Patients with acute infarcts located in the cortical and/or juxtacortical region measuring ≤10 mm in axial diameter based on diffusion-weighted imaging who had a follow-up 3T MR imaging were retrospectively included in the study. All lesions did not show hypointensity on initial T2*WI. For cortical and/or juxtacortical microinfarcts detected on initial DWI, 2 neuroradiologists evaluated the follow-up MR imaging (T2WI, FLAIR, T2*WI, and SWI) and assessed lesion signal intensities and locations (cortical microinfarcts or microinfarcts with juxtacortical white matter involvement).
On initial DWI, 2 radiologists observed 180 cortical and/or juxtacortical microinfarcts in 35 MR imaging examinations in 25 patients; on follow-up, the neuroradiologists identified 29 cortical microinfarcts (16%) on T2WI, 9 (5%) on FLAIR, 4 (2%) on T2*, and 97 (54%) on SWI. All cortical microinfarcts detected with any follow-up MR imaging showed hyperintensity on T2WI/FLAIR and/or hypointensity on T2*WI and SWI.
SWI revealed conversion (paramagnetic susceptibility changes) of acute cortical microinfarcts, suggesting that a substantial number of cortical microinfarcts may contain hemorrhagic components.
In the design stage of air-conditioning equipment, by predicting the annual air-conditioning energy and heat load with high accuracy and by comparing multiple designed air-conditioning systems, it is ...possible to select optimal equipment and reduce capital investment. However, occasionally, it is difficult to predict energy consumption by means of energy simulation (ES) assuming that the thermal environment of the room is uniform, because of various reasons such as the influence of the uneven distribution of the pieces of equipment that act as heat loads, and mixing loss due to the air-conditioning system. In addition, when evaluating an air-conditioning system considering human comfort in a room, it is necessary to calculate a comfort index such as the Predict Mean Vote (PMV). In that case, it is important to predict the distribution of the thermal environment such as the bias in wall surface temperature. Therefore, attempts have been made to combine Computational Fluid Dynamics (CFD) with energy simulation for predicting the distribution of the thermal environment. However, in a few cases, measurements are made considering thermal load fluctuations in actual outdoor environments, and validation of CFD analysis is performed. Therefore, in this study, in a laboratory simulating an office, considering the effect of actual solar radiation, we measured the performance by changing the air-conditioning system of the perimeter zone and analysed the behaviour of thermal load in the room. Subsequently, by comparing the actual measurement results with the results of unsteady CFD analysis, the prediction accuracy of indoor temperature distribution and air-conditioning heat quantity was validated. As a result, it was clarified that the prediction accuracy of indoor temperature distribution is affected by how the airflow that was directed out of the air conditioner in the perimeter section collides with the window shade.
Printing technology is expected to provide innovative and environmentally friendly processes for thermoelectric (TE) module fabrication. As described in this paper, we propose an orientation control ...process using plastic deformation at high temperatures and present high-oriented TE nano-bulks fabricated from bismuth telluride (Bi-Te) TE inks using this process. In the case of
n
-type Bi-Te, surface x-ray diffraction reveals that crystalline grains in the plastic-deformed nano-bulk demonstrate a
c
-plane orientation parallel to the pressed face. According to the high orientation, electrical resistivity
ρ
, thermal conductivity
κ
, and figure of merit
ZT
show anisotropic behavior. It is noteworthy that (
ZT
)
//
almost reaches unity (
ZT
)
//
∼1 at 340 K, even at low temperatures of the plastic deformation process. In contrast, the
ZT
of plastic-deformed
p
-type nano-bulk indicates isotropic behavior. The difference in the process temperature dependence of
ZT
suggests that
n
-type and
p
-type nano-bulk orientation mechanisms mutually differ.
Dry etching characteristics of single crystal (100) CdTe epitaxial layers grown on GaAs substrates were studied using CH
4
, H
2
, and Ar as process gases in an electron cyclotron resonance plasma. A ...smooth and anisotropic etching was obtained with CH
4
, H
2
, and Ar. No hydrocarbon polymer was found on the etched surface, which was confirmed by x-ray photoelectron spectroscopy measurement. Etching of the CdTe surface was also possible with H
2
and Ar; however, no etching was observed in the absence of H
2
. Dependence of the etch rate on plasma gas composition and flow rates was studied. Mechanisms of etching with and without CH
4
supply were also studied. Etched CdTe layers also showed no deterioration of electrical properties, which was confirmed by photoluminescence measurement at 4.2 K and Hall measurement at 300 K.
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