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We investigate the tunnel magnetoresistance (TMR) effect and its applied bias voltage dependence for perpendicular magnetic tunnel junctions (p-MTJs) with low resistance-area ( RA ) products of about 10 $\Omega\cdot \mu$ m $^{2}$ . We obtain a maximum TMR ratio of 248% among the examined devices. The bias-voltage dependence of the TMR ratio for these junctions is almost the same as that for junctions with RA products of about 10–1000 $\Omega \cdot\mu$ m $^{2}$ in the positive voltage region, while a fast drop in the TMR ratio is observed in the negative bias region. An output voltage of more than 200 mV is obtained for these p-MTJs.

We propose a Helmholtz-type probe coil that uses a high-temperature superconductor (HTS) for use as 700-MHz nuclear magnetic resonance (NMR) RF coils with a high unloaded quality factor (Q u ). We analyzed the microwave resonant properties of a one-turn coil set face-to-face. The coils were made of a YBa 2 Cu 3 O 7-δ (YBCO) film deposited on an r-plane sapphire substrate. The film thickness was 300 nm. The resonant frequency was found to split into in-phase (lower frequency) and out-phase (higher frequency) modes. We focused on the self-resonant frequency of the one-turn coil. We simulated the horizontal magnetic field caused by the RF coil. Although the coil could generate a sufficiently large transverse magnetic field in the in-phase mode, such a large field could not be generated in the out-phase mode. Therefore, we decided to use the in-phase mode. We also measured and simulated Qu to confirm that it was large enough for use in the 700-MHz NMR system.

Background: Diabetes is a group of metabolic disorders that affect the body’s ability to process and use sugar (glucose) for energy. Type II diabetes mellitus resulting from the combination of resistance to insulin action and inadequate insulin secretion. The success of long-term maintenance therapy for diabetes depends largely on the patients’ adherence with self managements practices. Objective: The aim of this study was to assess adherence to diabetes self management practices and its associated factors among type II diabetic patients in Ethiopia. Method: institutional based cross sectional study was employed and 320 study subjects were selected using systematic random sampling technique. And the data was collected using interviewer administered structured questionnaire; data was analyzed and cleaned using SPSS version 16. Scoring method was employed to classify patients’ self-care management practices level. The study period was from sept.2011 to May 30, 2012. Results: Of all respondents, 167 (52.2%) were female. Mean age of the respondents was 55.03 ± 10.7 years with minimum age of 30 and maximum age of 85. The mean duration of diabetes was 12.3+ 7.6 years with minimum of 6 months and maximum of 41 years. From the total respondents, one hundred and seventy (53.1%) were reported to have adhered to physical activities. Two hundred and thirteen (66.6%) respondents were reported to have adhered to the recommended diabetic foot care practices. Overall diabetes self- managements practices were reported as adhered in 178 (55.6%) respondents. Marital status, level of education, monthly income and diabetes complication were showed that association with their adherence condition to physical activity [P=0.047, AOR (95% CI)=2.99 (1.015-8.837) and P=0.006, AOR(95%CI)= 2.79(1.942-5.832)], [P=0.011, AOR (95% CI) = 2.74(1.069-7.064) and P=0.016, AOR (95%CI) = 1.79(1.1182.888)]. Gender and age were found to have association with adherence to diabetic foot care management practices [P=

The caries preventive effect of fluoride-containing materials (FCMs) might depend on the caries risk of the individuals. Two pairs of demineralizing and remineralizing solutions of pH-cycling were prepared for simulating low and high caries risk. The purpose of this study was to determine fluorine (F) uptake into human enamel around FCMs under different pH-cycling using the in-air μ-PIGE/PIXE system. Fluoride-containing glass ionomer cement (Fuji IXGP FAST CAPSULE (FN)), and composite resin (BEAUTIFIL II with FLUORO BOND SHAKE ONE (BS)) were used in this study. The pH-cycling (pH 6.8–4.5) was carried out for 5 weeks. After pH-cycling, the caries progression was analyzed using transverse micro-radiography (TMR). The fluorine and calcium distributions in the carious lesion in each specimen were evaluated using the PIGE/PIXE system. From TMR analysis, there was a difference in caries risk between the two kinds of pH-cycling. Although the caries preventive effect of BS and FN was confirmed at low risk, the effect at high risk was confirmed for FN only. From the analysis of the fluorine uptake in the outer 200 μm of the lesion we concluded that there was no significant difference between the pH-cycling solutions. However, we found different fluorine concentrations in the enamel for the two FCMs. The decreased caries progression under high risk for FN indicated that an adequate amount of fluorine supplied from the material is required at higher caries risk. It was confirmed that the caries preventive effect of FCM depends on the caries risk. The fluorine analysis of teeth under various pH-cycling conditions gives information to evaluate the caries preventive effect of fluoride-containing materials according to the caries risk.

The authors investigated the voltage control of a magnetic anisotropy field for perpendicular-magnetic tunnel junctions (p-MTJs) with low and high resistance-area (RA) products and for synthetic antiferromagnetic free and pinned layers. It was found that the sample with low RA products was more sensitive to the applied bias voltage than the sample with high RA products. The bias voltage effect was less pronounced for our sample with the synthetic antiferromagnetic layer for high RA products compared to the MTJs with single free and pinned layers.

Information on the 240Pu/239Pu isotope ratios in human tissues for people living around the Semipalatinsk Nuclear Test Site (SNTS) was deduced from 9 sets of soft tissues and bones, and 23 other bone samples obtained by autopsy. Plutonium was radiochemically separated and purified, and plutonium isotopes (239Pu and 240Pu) were determined by sector-field high resolution inductively coupled plasma-mass spectrometry. For most of the tissue samples from the former nine subjects, low 240Pu/239Pu isotope ratios were determined: bone, 0.125 +/- 0.018 (0.113-0.145, n = 4); lungs, 0.063 +/- 0.010 (0.051-0.078, n = 5); and liver, 0.148 +/- 0.026 (0.104-0.189, n = 9). Only 239Pu was detected in the kidney samples; the amount of 240Pu was too small to be measured, probably due to the small size of samples analyzed. The mean 240Pu/239Pu isotope ratio for bone samples from the latter 23 subjects was 0.152 +/- 0.034, ranging from 0.088 to 0.207. A significant difference (a two-tailed Student's t test; 95% significant level, alpha = 0.05) between mean 240Pu/239Pu isotope ratios for the tissue samples and for the global fallout value (0.178 +/- 0.014) indicated that weapons-grade plutonium from the atomic bombs has been incorporated into the human tissues, especially lungs, in the residents living around the SNTS. The present 239,240Pu concentrations in bone, lung, and liver samples were, however, not much different from ranges found for human tissues from other countries that were due solely to global fallout during the 1970's-1980's.

We report two medical applications of particle-induced X-ray emission (PIXE) as described below (1) Observation of biological events: The kinetics of trace elements during the initiation of radiation-induced apoptosis (RIA) was observed using a micro-PIXE and PIXE. RIA is a process in which irradiated cells commit suicide; it results in the removal of severely damaged and harmful cells. During RIA, cytochrome c is released from the mitochondria and reaches the nucleus, where it activates a Ca- or Mg-dependent endonuclease. We examined this phenomenon by using a micro-PIXE and PIXE. A high concentration of Fe was detected in the stroma of cells in the early apoptotic phase. We also observed accumulation of large amounts of Ca and Mg in the nucleus.(2) Development of liquid-core microcapsules for novel cancer chemoradiotherapy: Currently, we are developing liquid-core (containing an anticancer drug) microcapsules that release their core content upon irradiation. These microcapsules will localize the anticancer drug within the irradiated field. The outer shell of these microcapsules is prepared from alginate and hyaluronic acid and polymerized by Fe, while the anticancer drug Paraplatin®(carboplatin) containing Pt is the liquid core. The micro-PIXE revealed that these microcapsules released their core content after irradiation, and the amount of carboplatin released was measured by PIXE. More than 83.1% ± 8.3% of the microcapsules were ruptured, and the amount of carboplatin released was more than 81.2% ± 2.3%. Thus, the combination of radiotherapy and chemotherapy showed improved antitumor effects and a decrease in adverse effects because of drug localization.

Microcapsules consisting of alginate and hyaluronic acid that can be decomposed by radiation are currently under development. In this study, the composition of the microcapsule material was optimized by changing the amounts of alginate and hyaluronic acid. Solutions of 0.025%, 0.05%, 0.1%, 0.2%, or 0.4% (wt./vol.) hyaluronic acid were mixed into a 0.2% alginate solution. To these mixtures, carboplatin (0.2 mmol) was added and the resulting material was used for the capsule preparation. The capsules were prepared by spraying the material into a CaCl 2 solution (0.34 mol/l) using a microatomizer. These capsules were irradiated by a single dose of 2, 5, or 10 Gy 60 Co γ-ray radiation. Immediately after irradiation, the releasing of core content of microcapsule was determined, using a micro particle induced X-ray emission (PIXE) camera. The average diameter of the microcapsules was 22.3 ± 3.3 μm, and that of the liquid core was 10.2 ± 4.3 μm. The maximum radiation-induced content release was observed with liquid-core microcapsules containing 0.1% hyaluronic acid and 0.2% alginate. Our liquid-core microcapsules suggest a new potential use for radiation: the targeted delivery of the chemotherapeutic agents or radiosensitizers. This offers the prospect of increased combined effectiveness of radiation with chemotherapy or radiosensitization and decreased adverse side effects.

Using PIGE (Proton Induced Gamma Emission) technique at TARRI (Takasaki Advanced Radiation Research Institute), Japan, we measured fluorine (F) uptake into the tooth enamel around two fluoride-containing materials during caries progression using pH cycling. Class V cavities in extracted human teeth were drilled and filled with fluoride-containing materials (i.e. “Fuji IX” (FN) and “UniFil flow with MEGA bond” (UF)) and a non-fluoride-containing material (i.e. “SOLARE with MEGA bond” (SO)). Three 120 μm longitudinal sections including the filling material were obtained from each tooth. In order to simulate daily acid attack occurring in the oral cavity, the pH cycling (pH 6.8–4.5) was carried out for 1, 3 and 5 weeks, separately. After pH cycling, the caries progression in all specimens was observed using transverse microradiography (TMR). The F and calcium distributions of the specimens were evaluated using PIGE and PIXE techniques. The F distribution of the specimens clearly showed the F uptake from FN into enamel adjacent to the filling material, while the F uptakes from UF and SO were not detected. For UF, the MEGA bond (non-fluoride-containing) between the tooth and UniFil flow interfered with the F absorption into the tooth. For FN, the amount of F uptake into the subsurface enamel increased during pH cycling. The amount of F uptake in 5-week pH cycling had significantly higher value compared to those in 1- and 3-week pH cycling. For UF and SO, there were no significant differences between the different durations of pH cycling. Among fluoride-containing materials, there were some differences in the F uptake with increased pH cycling, which could possibly lead to obtaining difference in clinical performance. The data obtained using PIGE and PIXE techniques were useful in understanding the benefit of fluorine by means of fluoride-containing material for preventing caries.

Microcapsules comprising alginate and hyaluronic acid that can be decomposed by radiation are under development. Previously, we observed that radiation efficiently decomposes microcapsules comprising alginate and hyaluronic acid in the ratio 2:1 by weight. In this study, Yttrium ( Y ) was added to these microcapsules to improve their decomposition by radiation. Hyaluronic acid solutions (0.1% weight/volume) were mixed into 0.2% alginate solution, and carboplatin (0.2 mmol) was added; the resultant was used for capsule preparation. Capsules were prepared by spraying the material into mixtures of 4.34% CaCl 2 solution supplemented with Y at final concentrations from 0 to 1.0 × 10−2%. These capsules were irradiated by a single dose of 0.5, 1.0, 1.5, or 2 Gy with 60Co γ-rays. Immediately after irradiation, we observed the release of the core contents of the microcapsule using a micro Particle Induced X-ray Emission (PIXE) camera. The mean diameter of the microcapsules was 37.3 ± 7.8 μm . Maximum content of radiation-induced release was observed for liquid-core microcapsules prepared by polymerization in a 4.34% CaCl 2 solution supplemented with 5.5 × 10−3% Y .

The composition of the intestinal microbiota of 92 healthy Japanese men was measured following consumption of identical meals for 3 days; terminal restriction fragment length polymorphisms were then used to analyse the DNA content of their faeces. The obtained operational taxonomic units (OTUs) were further analysed using seven restriction enzymes: 516f-BslI and -HaeIII, 27f-MspI and -AluI, and 35f-HhaI, -MspI and -AluI. Subjects were classified by their body mass index (BMI) as lean (25.0). OTUs were then analysed using data mining software. Pearson correlation coefficients on data mining results indicated only a weak relationship between BMI and OTU diversity. Specific OTUs attributed to lean and obese subjects were further examined by data mining with six groups of enzymes and closely related accession numbers for lean and obese subjects were successfully narrowed down. 16S rRNA sequences showed Bacillus spp., Erysipelothrix spp. and Holdemania spp. to be present among 30 bacterial candidates related to the lean group. Fifteen candidates were classified Firmicutes, one was classified as Chloroflexi, and the others were not classified. 45 Microbacteriaceae, 11 uncultured Actinobacterium, and 3 other families were present among the 119 candidate OTUs related to obesity. We conclude that the presence of Firmicutes and Actinobacteria may be related to the BMI of the subject.

The Large Helical Device (LHD) achieves high-performance plasma confinement by the coordination of the magnetic surface region and the chaotic field line layer. It is theoretically and experimentally shown that drift surfaces exist for highly energetic particles being extended over the last closed flux surface (LCFS) in the LHD. These particles are considered lost particles due to the loss-cone in the previous theories, where the analyses are limited inside the LCFS. The present theory predicts that the loss-cone is strongly reduced in the LHD and that highly energetic particles confined over the LCFS exist. These are consistent with the LHD experimental results in both the ICRF heating experiments and the low magnetic field neutral beam injection heating experiments. From particle orbit analyses and studies on the connection length of diverter field lines, it is also shown that plasma can exist in the chaotic field line layer located outside the LCFS in the LHD. The plasma in the chaotic field line layer is clearly detected by CCD-cameras in the LHD experiment. This ambient plasma might be expected to play the role of a kind of impregnable barrier for the core plasma, which suppresses both the MHD instabilities and the cooling of the core plasma due to charge exchange processes. The line-tying effects of diverter field lines that are slipped out from the chaotic field line layer can also stabilize the ballooning mode and the vertical displacement events of the plasma column.

This paper describes environmental magnetic fields in office space, under and above power-receiving and transformer rooms. First, the distributions of environmental magnetic fields of 50 Hz and 60 Hz in office space and in power-receiving and transformer rooms were measured in two buildings. The levels of magnetic field in office space were estimated and the magnetic noise sources affecting the office floors in power-receiving and transformer rooms were presumed. Next, 3D magnetic field analysis was carried out to obtain an arrangement of silicon steel plates that can shield effectively and at a low cost against the leakage magnetic field produced by a transformer.

The target-chemetherpy directed by the radiation was tested by the two methods; 1) facilitate the carboplatin; and 2) the capsules that is decomposed by irradiation IN VITRO. The human leukemic cell (OCI/M2) cultured in RPMI 1640 was treated by the 0.5 Gy of 60 Co γ ray after the 4μmol of carboplatin administration. The uptake of carboplatin expressed as Pt signal was measured by the micro PIXE camera. The increased uptake of carboplatin was observed in the cell. There was also an increased uptake of Cu . The chelating of Cu resulted in the maximum uptake of carboplatin under the combined treatment of radiation and carboplatin. As for the capsules, it was prepared by polymerizing the alginate by CaCl 2, whose core was carboplatin. The 0.5 Gy irradiation was performed to the capsules. The carboplatin's emission was observed using a micro PIXE camera. As a result, the carboplatin was emitted from capsules, which was almost 10 %. Those two methods (increased uptake of carboplatin by low dose irradiation and the capsules decomposed by irradiation) is considered to be useful for the better therapeutic gain and less adverse effect.

The method to observe the localization of the trace elements in cultured human cell, by the micro Particle Induced X-ray Emission (PIXE) camera, was developed. The analyzed samples received the eosin staining, which colored the nucleus of cell violet. The scanned areas of the sample with particle irradiation were colored brown by the heat during irradiation. The brown scanned areas were examined by an optical microscope at 400 X magnification and photographed. Then the photo was digitized and loaded into the microcomputer. By microcomputer, the photo of the scanned area was superimposed onto the image of the micro PIXE camera, by matching the scanned area to the image of micro PIXE camera. This superimposed image enabled us to determine whether the elements exists in cytosol, or in nucleus.

A three-phase induction motor excited by a single-phase power supply is proposed. We fabricated a small prototype motor with six poles, with an exciting circuit and two parametric oscillation circuits arranged in the stator. The motors were successfully stabilized and improved by using an asymmetrical outer stator core. This paper reports the importance of stator design of the motor.

We have examined the correlation between the critical current density (J c ) and the surface resistance (R s ) of an YBa 2 Cu 3 O 7-δ (YBCO) thin film. YBCO films were prepared in an inductively coupled plasma sputtering system on MgO and BSC/MgO substrates. BaSnO 3 (BSO) was used as a buffer material for the MgO substrates. J c was determined by magnetic measurements, and R s was measured using a sapphire rod resonator method. The correlation of critical current and surface resistance has been reported previously, however, there is few researches in which a systematic correlation of R S and Jc using the same sample has been done. To begin with, we measured R s by the dielectric resonator method, and next, J c was measured using the magnetic field method. As a result, it was proven that there was a strong correlation between R s and J c . We found that the relationship between J c and R s (at 22 GHz) could be expressed by the following equation, R s = 2.0 x 10 7 J c -1, where the unit of R s is the ohm, and the unit of J c is A/m 2 . It was found that the relation was applicable in a wide temperature range under T c . The value of the surface resistance can be estimated, if an accurate critical current is obtained.

The 137Cs, 238Pu and 239,240Pu activity concentrations were determined together with the atomic ratios of 240Pu/239Pu for the soil samples at 19 sites from the Ust"""-Kamenogorsk district, located more than 300 km east of the Semipalatinsk nuclear test site (SNTS). The mean areal deposition of 137Cs ranged from 1,500 to 4,100 Bq/m2. However, some hot spot-like areas showing high concentrations of 5,500–7,700 Bq/m2 were foundat some sites within the city. The 239,240Pu levels ranged from

We developed a micro-PIXE system for the analysis of frozen cellular samples at atmospheric pressure under helium gas cooling. We analyzed bovine aortic endothelial (BAE) cells previously cultured in a medium containing bromodeoxyuridine (BrdU). It is known that these cells take BrdU into their nuclei at the S phase of their metabolic cycle. We examined the Br uptake for incubation times of 6, 12 and 24 h, respectively. The Br maps showed an accumulation in the nuclei and the Br concentration was found strongly dependent on the incubation time. We have demonstrated that in-air micro-PIXE analysis is a relevant technique for examining the molecular uptake in cells.

A rapid analytical method of Pu in environmental samples by alpha-ray spectrometry and high-resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) using a 3M Empore™ anion exchange resin disk for solid phase extraction has been developed. A trace amount of Pu was quantitatively adsorbed with an Empore™ anion exchange resin disk (47 mm diam.) at a flow rate of 150–200 ml/min from 8M HNO3 sample solution. The disk was washed with 10 ml of 8M HNO3 and 12 ml of 9M HCl and then the Pu was quantitatively eluted with 15 ml of 1M HNO3/0.03M ascorbic acid solution. The time needed to separate Pu from the sample solution with the present method was about 20 minutes. The separated Pu was determined with alpha-ray spectrometry and HR-ICP-MS. The present method was applied to the determination of Pu in the certified reference material (IAEA-135) and the environmental soil sample. The analytical results were almost in good agreement with the literature values.

We report on the first implementation and performance investigation of a 60-GHz-band optoelectronic image rejection mixing scheme based on a broad-band integrated optical single-sideband modulator. We have confirmed a few advantageous features over electrical image rejection mixers, arising from its nature of being free from electrical phase control of millimeter-wave signals. We obtained at the IF frequency of 800 MHz rejection ratios of >40 dB for the image signal and of >20 dB for the local oscillator (LO) signal in the LO frequency range of 55-65 GHz. The LO bandwidth can be extended further. The IF bandwidth with an image rejection ratio of >20 dB was also confirmed to be as broad as 550 MHz, which is limited not by the configuration but by the bandwidth of the 90/spl deg/ hybrid used in this experiment. Furthermore, fiber-optic transmission of a 155.52-Mb/s-DPSK 59.8-GHz optical millimeter-wave signal was successfully demonstrated for a 20-km standard single-mode fiber. A bit error rate of

In an attempt to characterize proteins secreted by the corpus luteum, explant cultures of luteal slices from cows taken on Days 3, 7, 11, 14, 17, and 19 of the estrous cycle, and Days 17, 88, 180, and > 240 of pregnancy were incubated with 3 H-leucine for 24 h. Proteins in luteal-conditioned medium were separated by two-dimensional PAGE, transferred to polyvinylidene fluoride membrane, and subjected to N-terminal amino acid microsequencing. Micro-sequence analysis revealed that the bovine corpus luteum synthesized and released de novo synthesized apolipoproteins (Apo) E and A-I in culture during the estrous cycle and pregnancy. Release of Apo E was observed only on Day 3 of the estrous cycle. Release of Apo A-I was observed on Days 11, 14, 17, and 19 of the estrous cycle, and on all days of pregnancy examined. To demonstrate the presence of the appropriate mRNA and characterize the temporal relationship for these identified proteins, total RNA was isolated from corpora lutea on Days 2, 3, 7, 16, 17, and 20 of the estrous cycle, and on Days 17, 90, 170, 180, and 272 of pregnancy, and submitted to Northern and dot blot analysis. Apo E mRNA was expressed only on Days 2-3 of the estrous cycle and was not expressed on the other days of the cycle or during pregnancy. A single Apo E mRNA transcript about 1.0 kilobase (kb) in size was observed. Expression of Apo A-I mRNA was detected on all days of the estrous cycle and pregnancy examined. Apo A-I cDNA hybridized with a single mRNA transcript about 1.0 kb in size. Apo A-I mRNA levels did not differ among days of the estrous cycle, although higher levels of Apo A-I mRNA were observed during later stages of pregnancy. Serum concentrations of Apo A-I and progesterone were correlated across the estrous cycle but not during the prepartum period or after parturition. This study demonstrates for the first time that the corpus luteum synthesizes Apo E and Apo A-I and expresses their respective mRNAs. The pattern of expression of Apo E and Apo A-I mRNAs paralleled that of de novo synthesis of their respective proteins after incubation of luteal tissue with [ 3 H]leucine. The role of luteal apolipoproteins may involve an autocrine/paracrine function influencing luteal development, tissue remodeling, and steroidogenesis.

Pt/Co/Pt sandwich films grown on single-crystal MgO substrates have been found to show an anomalous enhancement of the in-plane magnetic anisotropy for ultrathin Co layers below 1 nm. The in-plane sixfold anisotropy of (111)-oriented films yielded a maximum value of about −1 × 10 6 erg/cm 3 for 1 nm thickness, which is two orders of magnitude larger than that of fcc Co. For samples with (100) orientation, in-plane fourfold anisotropy increases with decreasing Co layer thickness, showing a maximum value of +1.9 × 10 6 erg/cm 3 at a thickness of one monolayer.

Nakagawa, H., Oikawa, S., Oohashi, T. and Katoh, N., 1997. Decreased serum lecithin:cholesterol acyltransferase activity in spontaneous cases of fatty liver in cows. Veterinary Research Communications, 21 (1), 1-8. Lecithin:cholesterol acyltransferase (LCAT) activity in serum was evaluated in spontaneous cases of fatty liver in cows. The enzyme activity of 631 ± 62 U (mean ± SEM, decrease in nmol of free cholesterol per h per ml of serum) in cows with fatty liver (n = 16) was significantly (p < 0.01) lower than that in cows without fatty liver (979 ± 22 U; n = 16). In addition to the decrease in LCAT activity, the concentrations of phosphatidylcholine (a fatty aryl donor for esterification of free cholesterol) and of cholesteryl esters (products of the LCAT reaction) were reduced in the high-density lipoprotein fractions from cows with fatty livers. The concentration in the serum of apolipoprotein A-I, an activator of LCAT, was also reduced in cows with fatty livers. These results suggest that the decreased LCAT activity, which may be attributable to impaired hepatic secretion or to the suppression of the activity in the plasma by reduced concentrations of phosphatidylcholine and apolipoprotein A-I, resulted in the lower concentrations of cholesteryl esters. Because cholesteryl esters are utilized in steroidogenic tissues for the synthesis of steroid hormones such as progesterone and glucocorticoids, an insufficient supply of the cholesterols may be of relevance to the reduced fertility and immune competence observed in cows with fatty livers.

This study was designed to investigate the apoptotic process in peripheral blood mononuclear cells (PBMC) and polymorphonuclear neutrophil leukocytes (PMN) in dairy cattle during the transition period. Blood samples were collected from 4 dairy cattle at 3 weeks before the expected parturition (wk -3), parturition (wk 0) and 3 weeks after parturition (wk +3). The DNA damage of PBMC and PMN was evaluated based on the comet assay using visual scoring (arbitrary units). Undamaged DNA remained within the core (score 0) and the broken DNA migrated from the core towards the anode forming the tail of a comet (scores 1-4). Significantly higher scores in PBMC at wk 0 and wk +3 were observed compared with those in PMN although there were no significant changes of scores in either cell type during the experimental period. It is suggested that the apoptotic rate of PBMC is accelerated compared with that of PMC during the transition period.