Effect of sound insulation on noise reduction in an agricultural tractor cab.

Tractor cab interior noise is a risk factor that degrades operators' work performance and threatens their health; therefore, the noise must be reduced to ensure farmworkers' safety and efficiency. Cab interior noise can be classified as structure-borne noise and air-borne noise. Structure-borne noise has been extensively studied. However, although air-borne noise greatly contributes to cab interior noise, detailed frequency-domain analyses have not been performed. In this study, the components of cab interior noise were identified in the frequency domain through an order analysis, which helped improve the sound insulation of the cab and reduce the effects of air-borne noise. A test was performed while driving a tractor on a chassis dynamometer in a semi-anechoic chamber for reproducible measurement and evaluation. The A-weighted sound pressure was transformed by a fast Fourier transform algorithm, and its order was tracked by the engine speed signal. In addition, a direct path was identified by acoustic images using a sound camera. The contributions of major noise sources were identified through an order analysis. We proved that air-borne noise significantly contributes to the interior noise of tractor cabs and that improvement of the cab sound insulation is an effective noise-reduction technique.

Analysis of the Effect of Tillage Depth on the Working Performance of Tractor-Moldboard Plow System under Various Field Environments.

The purpose of this study was to analyze the tillage depth effect on the tractor-moldboard plow systems in various soil environments and tillage depths using a field load measurement system. A field load measurement system can measure the engine load, draft force, travel speed, wheel axle load, and tillage depth in real-time. In addition, measurement tests of soil properties in the soil layer were preceded to analyze the effect of field environments. The presented results show that moldboard plow at the same tillage depth had a wide range of influences on the tractor's working load and performance under various environments. As the draft force due to soil-tool interaction occurred in the range of 5.6-17.7 kN depending on the field environment, the overall mean engine torque and rear axle torque were up to 2.14 times and 1.67 times higher in hard and clayey soil, respectively, than in soft soil environments. In addition, the results showed tractive efficiency of 0.56-0.73 and were analyzed to have a lugging ability of 67.8% with a 44% maximum torque rise. The engine power requirement in hardpan was similar within 3.6-9.6%, but the power demand of the rear axle differed by up to 18.4%.

One-step immunoassay without washing steps for influenza A virus detection using ISFET.

A one-step immunoassay for influenza A virus detection was developed using two different microbeads and a filter-inserted bottle. Two bead types with diameters of 15 (capture bead) and 3 (detection bead) µm were prepared to specifically detect influenza A virus. Anti-influenza A virus antibodies were coated on both bead types, whereas urease was immobilized only on the detection bead. An influenza A-positive sample could form a sandwich complex with the capture and detection beads; this complex would not pass through the filter, which had a controlled pore size. As the detection bead was used at a limiting concentration, it would be prevented from crossing the filter; thus, it would further react with the substrate urea and consequently increase the pH. An influenza A-negative sample would fail to form the sandwich complex in the presence of the capture and detection beads. Accordingly, the detection bead would pass through the filter into the urea buffer and increase the pH. The pH change in the urease reaction could be quantitatively measured by an indicator such as phenol red or using ion-selective field-effect transistor (ISFET). This one-step immunoassay was used for the detection of influenza A virus in real samples. The receiver operating characteristic (ROC) plot analysis showed an area under the curve (AUC) value of 0.931; the sensitivity and specificity of the assay was 80% and 90%, respectively, at a cutoff value of 0.9986. These results demonstrate that the one-step immunoassay could increase the sensitivity of influenza A virus detection in real samples.

Analysis of Tillage Depth and Gear Selection for Mechanical Load and Fuel Efficiency of an Agricultural Tractor Using an Agricultural Field Measuring System.

This study was conducted to analyze the effects of tillage depth and gear selection on the mechanical load and fuel efficiency of an agricultural tractor during plow tillage. In order to analyze these effects, we developed an agricultural field measuring system consisting of a load measurement part (wheel torque meter, proximity sensor, and real-time kinematic (RTK) global positioning system (GPS)) and a tillage depth measurement part (linear potentiometer and inclinometer). Field tests were carried out using moldboard plows with a maximum tillage depth of 20 cm and three gear selections (M2H, M3L, and M3H) in a rice stubble paddy field for plow tillage. The average travel speed and slip ratio had the lowest M2H and the highest M3L. M3H had the highest theoretical speed, but the travel speed was 0.13 km/h lower than M3L due to the reduction in the axle rotational speed at deep tillage depth. Regarding engine load, the higher the gear, the greater the torque and the lower the axle rotation speed. The front axle load was not significantly affected by the tillage depth as compared to other mechanical parts, except for the M3H gear. The rear axle load generated about twice the torque of the front wheel and overall, it tended to show a higher average rear axle torque at higher gear selection. The rear axle load and fuel rate were found to be most affected by the combination of the tillage depth and gear selection combination. Overall, field test results show that the M3H had the highest fuel efficiency and a high working speed while overcoming high loads at the same tillage depth. In conclusion, M3H is the most suitable gear stage for plow cultivation, and the higher the gear stage and the deeper the tillage depth during plowing, the higher the fuel efficiency. The results of this study will be useful for analyzing mechanical load and fuel efficiency during farm operations. In a future study, we will conduct load analysis studies in other farming operations that consider various soil mechanics factors as well as tillage depths and gear selections.

Development of a Real-Time Tillage Depth Measurement System for Agricultural Tractors: Application to the Effect Analysis of Tillage Depth on Draft Force during Plow Tillage.

The objectives of this study were to develop a real-time tillage depth measurement system for agricultural tractor performance analysis and then to validate these configured systems through soil non-penetration tests and field experiment during plow tillage. The real-time tillage depth measurement system was developed by using a sensor fusion method, consisting of a linear potentiometer, inclinometer, and optical distance sensor to measure the vertical penetration depth of the attached implement. In addition, a draft force measurement system was developed using six-component load cells, and an accuracy of 98.9% was verified through a static load test. As a result of the soil non-penetration tests, it was confirmed that sensor fusion type A, consisting of a linear potentiometer and inclinometer, was 6.34-11.76% more accurate than sensor fusion type B, consisting of an optical distance sensor and inclinometer. Therefore, sensor fusion type A was used during field testing as it was found to be more suitable for use in severe working environments. To verify the accuracy of the real-time tillage depth measurement system, a linear regression analysis was performed between the measured draft and the predicted values calculated using the American Society of Agricultural and Biological Engineers (ASABE) standards-based equation. Experimental data such as traveling speed and draft force showed that it was significantly affected by tillage depth, and the coefficient of determination value at M3-Low was 0.847, which is relatively higher than M3-High. In addition, the regression analysis of the integrated data showed an R-square value of 0.715, which is an improvement compared to the accuracy of the ASABE standard prediction formula. In conclusion, the effect of tillage depth on draft force of agricultural tractors during plow tillage was analyzed by the simultaneous operation of the proposed real-time tillage depth measurement system and draft force measurement system. In addition, system accuracy is higher than the predicted accuracy of ±40% based on the ASABE standard equation, which is considered to be useful for various agricultural machinery research fields. In future studies, real-time tillage depth measurement systems can be used in tractor power train design and to ensure component reliability, in accordance with agricultural working conditions, by predicting draft force and axle loads depending on the tillage depth during tillage operations.

Comparison between modified and conventional one-handed chest compression techniques for child cardiopulmonary resuscitation: A randomised, non-blind, cross-over simulation trial.

AIM: Chest compression depth (CCD) decreases significantly when performing one-handed chest compression (OHCC). We modified OHCC posture to increase CCD as follows: first, the axis of the compression hand was adjusted to the compression area; second, the opposite hand was wrapped around the elbow of the compression arm. This study compared modified OHCC with conventional OHCC for child cardiopulmonary resuscitation. METHODS: A total of 46 health-care providers performed 2 min of continuous chest compression using conventional OHCC (trial 1) and modified OHCC (trial 2) in a random order on a 5-year-old-sized child manikin lying on a bed. Chest compression parameters were assessed with an accelerometer and analysed by comparing the mean values of 30-s segments. RESULTS: The average CCD decreased significantly in all segments in both trials (trial 1 (segments 1-4): 40.9 ± 5.6 mm, 39.4 ± 6.6 mm, 38.0 ± 6.9 mm, 36.7 ± 7.3 mm, P < 0.001; trial 2 (segments 1-4): 42.3 ± 5.4 mm, 41.2 ± 6.2 mm, 40.1 ± 6.8 mm, 39.0 ± 6.9 mm, P < 0.001). However, the average CCD in trial 2 was significantly greater in all segments than that in trial 1 (segments 1-4: P = 0.016; P = 0.009; P = 0.004; P = 0.001). The average chest compression rates were comparable in all segments in both trials. CONCLUSION: By modifying OHCC posture, a deeper mean CCD could be maintained for 2 min than by using conventional OHCC.

Inducible spy Transcription Acts as a Sensor for Envelope Stress of Salmonella typhimurium.

Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella.

Electromagnetic field-induced converse cell growth during a long-term observation.

PURPOSE: Professional and public concern about the potential adverse effects of man-made electromagnetic fields (EMF) on the human body has dramatically expanded in recent years. Despite numerous attempts to investigate this issue, the long-standing challenge of reproducibility surrounding alternating EMF effects on human health remains unresolved. Our chief aim was to investigate a plausible mechanism for this phenomenon. MATERIALS AND METHODS: Growth of cultured human cancer cells, DU145 and Jurkat, exposed to power frequency magnetic field (MF) (60 Hz, 1 mT) for 3 days, was determined using a 2-(4-Iodophenyl)- 3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-1) assay and a trypan blue exclusion assay. This experiment was repeated at incubators long-term monitoring period up to 5.3 years. A periodogram analysis was performed to investigate periodic patterns in the MF and sham effects on cell growth. RESULTS: Unlike conventional assumptions, the MF effect on growth in both cell types was promotive or suppressive in a period-dependent manner. The converse cell growth induced by the MF was consistent in incubators, with little variation. CONCLUSIONS: Spatiotemporal evidence suggests that the period-dependent converse cell growth by the MF may contribute to the poor reproducibility and explain the adverse effects observed in previous experimental and epidemiological investigations. Additionally, the novel approach of this study may be applied to design features required to experimentally determine the effects of EMF on living organisms in a convincing manner.

Measurement of urinary N-telopeptides and serum C-telopeptides from type I collagen using a lateral flow-based immunoassay.

Measuring bone turnover markers could detect early stages of osteoporosis and early responses to anti-osteoporotic treatments. Currently, commonly used bone turnover markers, N-telopeptides (NTx) and C-telopeptides (CTx), are measured using ELISA tests, which demands time and increases cost. Bone turnover markers need to be measured more easily for general use. Lateral flow-based immunoassay would be an appropriate method for this context. This study was performed to investigate the precision of a newly developed lateral flow-based immunoassay for measuring the urinary NTx and serum CTx, and their correlations with ELISA measurements. Urine NTx and serum CTx concentrations were determined by photoscan of newly developed strips, using a lateral flow-based immunoassay for 36 subjects (mean age 66.2 years, SD 7.5 years; four males and 32 females). Repeated measurement of urinary NTx and serum CTx were performed three times, using this technology for a precision test. The correlation of the lateral flow-based immunoassay with the ELISA measurements was analyzed. Precision of the newly developed lateral flow based immunoassay was 0.974 (ICC, 95% confidence interval, 0.955 to 0.986) and 0.995 (ICC, 95% confidence interval, 0.991 to 0.997) for urinary NTx and serum CTx, respectively. The correlation of lateral flow based immunoassay with ELISA was 0.913 for urinary NTx and 0.872 for serum CTx. These results suggest that measuring the urinary NTx and serum CTx, using a lateral flow-based immunoassay, is a relevant method for point-of-care testing and screening of bone resorption markers.

Measurement of urinary N-telopeptides from type I collagen using a colloidal gold-based immunoassay.

This study aimed to investigate precision of a newly developed gold nanoparticle-based immunoassay for measuring urinary N-telopeptides (NTx) and its correlation with ELISA measurement. NTx concentrations were determined by absorption changes using spectroscopy at 535 nm, which were measured three times with an interval of two hours for precision test, using urine samples of 60 subjects (32 males and 28 females; mean age 30.4 years, SD 21.9 years). The correlation of the immunoassay with the measurement of ELISA kit was also analyzed. Precision of the immunoassay and its correlation with ELISA were 0.924 (ICC, 95% confidence interval, 0.661-0.971) and 0.90 (p<0.001). Our findings suggested that this immunoassay of urinary NTx could be used as a means of screening for bone resorption and point-of-care testing.

[Immunohistochemical analysis of nuclear factor, p38, and cyclin D1 proteins in premalignant lesions and carcinomas of the colorectal mucosa].

BACKGROUND/AIMS: Nuclear factor-kappaB p65 (NF-kappaB p65), nuclear factor-kappaB1 p50 (NF-kappaB p50) have been shown to play a role in cell proliferation, apoptosis, cytokine production, and oncogenesis. Recently, p38 mitogen-activated protein kinase (MAPK)/ NF-kappaB/ cyclin D1 signaling pathway has been shown to play an important part in the pathogenesis of human cancers. This study was designed to investigate the expression of NF-kappaB p65, NF-kappaB p50, p38 MAPKalpha, and cyclin D1 proteins in premalignant lesions of colon and colorectal adenocarcinoma. METHODS: Paraffin sections of 20 normal mucosa, 20 low-grade tubular adenoma, 20 high-grade tubular adenoma and 64 adenocarcinoma tissues were analysed immunohistochemically for the expression of NF-kappaB p65, NF-kappaB p50, p38 MAPKalpha, and cyclin D1 proteins. RESULTS: The expression of NF-kappaB p65, NF-kappaB p50, and p38 MAPKalpha proteins were significantly higher in adenocarcinoma tissue in comparison with that in normal mucosa, low-grade tubular adenoma, and high-grade tubular adenoma tissues. Expression of NF-kappaB p50 was more frequent in poorly differentiated histologic grade, presence of nodal metastasis, and advanced stage. Expression of p38 MAPKalpha protein was higher in advanced tumor stage, presence of nodal metastasis and advanced stage. Synchronous expression of NF-kappaB p65, NF-kappaB p50, p38 MAPKalpha, and cyclin D1 proteins were significantly higher in adenocarcinoma tissue. CONCLUSIONS: With the increased expression of NF-kappaB p65, NF-kappaB p50, and p38 MAPKalpha proteins, p38 MAPK/ NF-kappaB/ cyclin D1 signaling pathway may play a role in the pathogenesis of colorectal carcinoma.

Mast cell and macrophage counts and microvessel density in invasive breast carcinoma-comparison analysis with clinicopathological parameters.

PURPOSE: The purpose of this study was to evaluate the clinicopathological significance of the microvessel density and macrophage and mast cell counts in invasive breast carcinomas. MATERIALS AND METHODS: 45 invasive breast carcinomas were immunohistochemically stained with the endothelial antigen, CD34, and macrophage marker, CD68. 0.1% toluidine blue was used to highlight mast cells. The microvessel and mast cell counts were performed at x200 magnification and the macrophages at x400 magnification. RESULTS: With the 45 invasive breast carcinomas, there were no statistically significant associations between the mast cell, macrophage and microvessel counts and the tumor size and lymph node status. ER and PR negative mast cells infiltrated more than in cases of positive stati, with statistical significance (p-value=0.010 and 0.005, respectively). The macrophage counts were negatively correlated with the PR status (p-value=0.030). With respect to the c-erbB-2 status, there was no significance correlation with the mast cell, macrophage and microvessel counts. The mast cell counts showed significantly positive correlation with the microvessel counts in the invasive breast carcinomas (p-value=0.015). In a comparison of the macrophage counts with the microvessel counts, a positive tendency for both parameters, but without statistical significance (p-value=0.310). CONCLUSION: Increasing numbers of mast cells and macrophages were recruited in invasive breast carcinomas, which contribute to angiogenesis. The microvessel density in invasive breast carcinomas had no statistically significant association with the tumor size, lymph node status, and histological grade, presence of DCIS component, estrogen/progesterone receptor status and cerbB-2 status. The evaluation of angiogenesis using these methods is not thought to provide an independent clinicopathological factor in invasive breast carcinomas.

[Positron emission tomography with fluorine-18-fluorodeoxyglucose is useful for predicting the prognosis of patients with hepatocellular carcinoma].

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is heterogenous in terms of its glucose metabolism. Positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) shows various levels of FDG uptake for patients with HCC. This study was designed to assess the usefulness of FDG-PET for predicting the outcome of the patients with HCC. METHODS: FDG-PET was performed for 27 patients with HCC. The standardized uptake value (SUV) and SUV ratio (defined as the tumor-to-nontumor ratio of SUV) was calculated for each patient. The clinical factors of the outcome were analyzed by regression analysis using Cox's multivariate proportional hazard model. The survival rate was calculated by the Kaplan-Meier method. RESULTS: Among the analyzed clinical factors including tumor size, number of tumors, AFP, involvement of major vessels, presence of systemic metastases, Child-Pugh class the SUV and SUV ratio, only the SUV was the only significant independent prognostic factor (p=0.001). On the basis of the SUV, the patients were divided into two groups of roughly equal size: group A, SUV of <7; group B, SUV > or =7. The cumulative survival rate was significantly lower for group B than for group A, and the median survival time was significantly different (4 months vs 15 months, respectively) (p=0.003). CONCLUSIONS: These results suggest that FDG-PET is useful to predict the outcome for patients with hepatocellular carcinoma.

Use of complementary and alternative medicine among Korean cancer patients.

BACKGROUND: Complementary and alternative medicine (CAM) is now being increasingly used among cancer patients. The objectives of our study were to assess the prevalence, types, cost, subjective effects, and side effects of CAM use, reasons for CAM use, characteristics of CAM users compared to those of nonusers, and patients' expectations of doctors regarding their CAM use among Korean cancer patients at a single cancer center. METHODS: From April to August, 2003, we interviewed 186 cancer patients hospitalized in the Korea Cancer Center Hospital using a structured questionnaire, and analyzed the data. RESULTS: 78.5% of experimental subjects (146 patients) had been treated with at least one type of CAM, in addition to conventional Western treatment, with a mean monthly cost of 1,380,000 Won/person (approximately, 1,100 U.S. dollars on July, 2004). The most prevalent types of CAM used by these patients included medicinal mushrooms (67.1%), herbs (54.1%), vegetable diets (50.6%), and ginseng (46.5%). The main reported reasons for the use of CAM in addition to conventional medicine were nutritional support (19.1%) and physical strengthening (17.8%). 5% of CAM users experienced side effects. The younger and more educated the patients were, the more likely they were to employ CAM. 66% of CAM users wanted to discuss CAM techniques with their doctors. CONCLUSION: More than two-thirds of cancer patients used various kinds of CAM, incurring considerable costs. Therefore, in order to help patients make informed decisions, medical society should be open to communication with patients. Not only the scientific aspects, but also the economic aspects of CAM usage should be examined more thoroughly, in order to ensure proper distribution of medical resources.

Cloning and expression of male-specific protein (MSP) from the hemolymph of greater wax moth, Galleria mellonella L.

Male-specific protein (MSP) is a soluble protein that accumulates in high amounts in the hemolymph and other organs of adult male wax moth. The MSP was purified from adult male wax moth by gel filtration and reversed phase column chromatography, and its amino acid sequence was determined. Because of blocked N-terminus, several internal amino acid sequences of MSP were obtained by the in-gel digestion method using trypsin. RT-PCR was conducted using degenerate primers designed from the internal amino acid sequences. 5'-RACE PCR was used to obtain the complete coding region and 5'-UTR sequence. The full length MSP cDNA sequence encodes a 239 amino acid polypeptide with an 18 amino acid signal peptide. The putative mature MSP has a molecular mass of 24,317 Da and an isoelectric point (pI) of 6.00, but shows a molecular mass of 27 kDa on SDS-PAGE. Sequence alignment showed a significant similarity between MSP and juvenile hormone binding proteins (JHBPs) of several lepidopteran species, including G. mellonella.