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SUMMARY In recent years, magnetic resonance imaging (MRI) systems that operate up to under 3 T are being used in clinical practice in Japan. In order to achieve the requirements of higher image quality and shorter imaging times, devices that utilize high magnetic fields (> 3 T) and high power electromagnetic (EM) wave pulses have been developed. The rise of the static magnetic field is proportional to the increase of the EM wave frequency which raises the issue of variation in capacitance used in the radio frequency (RF) coil for MRI system. In addition, increasing power causes problems of withstanding voltage and these approaches leads to generation of non-uniform magnetic field inside the RF coil. Therefore, we proposed a birdcage coil without the use of lumped circuit elements for MRI systems in previous study. However, it is difficult to fabricate this birdcage coil. Hence, simply-structured birdcage coil with no lumped circuit elements is desired. In this paper, we propose a simply-structured birdcage coil with no lumped circuit elements for a 4 T MRI system. In addition, the authors investigated the input impedance and magnetic field distribution of the proposed coil by FDTD calculations and measurements. The results confirm that the proposed birdcage coil matches the performance of

SUMMARY In recent years, there has been rapid developments in radio-frequency identification (RFID) systems, and their industrial applications include logistics management, automatic object identification, access and parking management, etc. Moreover, RFID systems have also been introduced for the management of medical instruments in medical applications to improve the quality of medical services. In recent years, the combination of such a system with a biological monitoring system through permanent implantation in the human body has been suggested to reduce malpractice events and ameliorate the patient suffering. This paper presents an implantable RFID tag antenna design that can match the conjugate impedance of most integrated circuit (IC) chips (9.3 − j55.2 Ω at 2.45 GHz. The proposed antenna can be injected into the human body through a biological syringe, owing to its compact size of 9.3 mm × 1.0 mm × 1.0 mm. The input impedance, transmission coefficient, and received power are simulated by a finite element method (FEM). A three-layered

Rat hepatitis E virus (HEV) strains have recently been isolated in several areas of Germany, Vietnam, the United States, Indonesia and China. However, genetic information regarding these rat HEV strains is limited. A total of 369 wild rats (Rattus rattus) captured in Central Java (Solo) and on Lombok Island, Indonesia were tested for the presence of rat HEV-specific antibodies and RNA. Overall, 137 rats (37.1%) tested positive for rat anti-HEV antibodies, while 97 (26.3%) had rat HEV RNA detectable on reverse transcription-PCR with primers targeting the ORF1-ORF2 junctional region. The 97 HEV strains recovered from these viremic rats were 76.3–100% identical to each other in an 840-nucleotide sequence and 75.4–88.4% identical to the rat HEV strains reported in Germany and Vietnam. Five representative Indonesian strains, one from each of five phylogenetic clusters, whose entire genomic sequence was determined, were segregated into three genetic groups (a German type, Vietnamese type and novel type), which differed from each other by 19.5–23.5 (22.0 ± 1.7)% over the entire genome. These results suggest the presence of at least three genetic groups of rat HEV and indicate the circulation of polyphyletic strains of rat HEV belonging to three distinct genetic groups in Indonesia.

Despite the high endemicity of hepatitis A virus (HAV) in Indonesia, genetic information on those HAV strains is limited. Serum samples obtained from 76 individuals during outbreaks of hepatitis A in Jember (East Java) in 2006 and Tangerang (West Java) in 2007 and those from 82 patients with acute hepatitis in Solo (Central Java), Denpasar on Bali Island, Mataram on Lombok Island, and Makassar on Sulawesi Island in 2003 or 2007 were tested for the presence of HAV RNA by reverse transcription PCR with primers targeting the VP1-2B region (481 nucleotides, primer sequences at both ends excluded). Overall, 34 serum samples had detectable HAV RNA, including at least one viremic sample from each of the six regions. These 34 strains were 96.3-100 % identical to each other and formed a phylogenetic cluster within genotype IA. Six representative HAV isolates from each region shared 98.3-98.9 % identity over the entire genome and constituted a IA sublineage with a bootstrap value of 100 %, consisting of only Indonesian strains. HAV strains recovered from Japanese patients who were presumed to have contracted HAV infection while visiting Indonesia were closest to the Indonesian IA HAV strains obtained in the present study, with a high identity of 99.5-99.7 %, supporting the Indonesian origin of the imported strains. These results indicate that genetic analysis of HAV strains indigenous to HAV-endemic countries, including Indonesia, are useful for tracing infectious sources in imported cases of acute hepatitis A and for defining the epidemiological features of HAV infection in that country.

An in-body wireless communication system has attracted increasing attention because it can replace the connectivity of biological telemetry monitoring. However, the human body is a very complex environment (lossy, dispersive, and inhomogeneous) and affects the electromagnetic (EM) wave in the near field. Moreover, the entire human geometry affects the radiation pattern in the far field. This communication presents the behavior of the EM wave in the near and far fields at 2.45 GHz when a dipole antenna (used as an implantable antenna) is embedded in the vicinity of the clavicle, upper arm, lower arm, and hand of a human body. The effect on the electric field and radiation performance is simulated by the finite-difference time-domain method. By introducing a three-layered phantom, the antenna performance is confirmed. Moreover, the measured and simulated results are in good agreement with each other. The information derived from this study can be used in the evaluation of the link budget of in-body wireless communication.

Aim To characterize hepatitis E in Mie prefecture and to investigate whether raw pig liver sold as food in Mie is contaminated with hepatitis E virus (HEV) strains similar to those recovered from patients. Methods Seventeen patients with sporadic acute hepatitis E treated from 2004 to 2012 were studied. A total of 243 packages of raw pig liver from regional grocery stores were tested for the presence of HEV RNA. The partial genomic sequences of human and swine HEV isolates were determined and subjected to the phylogenetic analyses. Results The HEV isolates recovered from the 17 patients segregated into genotype 3 (n = 15) and genotype 4 (n = 2), and 15 genotype 3 isolates further segregated into 3e (n = 11) and 3b (n = 4). Pig liver specimens from 12 (4.9%) of the 243 packages had detectable HEV RNA. All 12 swine HEV isolates were grouped into genotype 3 (3a or 3b). Although no 3e strains were isolated from pig liver specimens, two 3b swine strains were 99.5–100% identical to two HEV strains recovered from hepatitis patients, within 412-nt partial sequences. Conclusion The 3e HEV was prevalent among hepatitis E patients. HEV RNA was detected in approximately 5% of pig liver sold as food. The presence of identical HEV strains between hepatitis patients and pig liver indicated that pigs play an important role as reservoirs for HEV in humans in Mie. Further studies are needed to clarify the source of 3e HEV in the animal and environmental reservoirs.

Hepatitis B virus (HBV) infections are sometimes overlooked when using commercial kits to measure hepatitis B virus surface antigen (HBsAg) due to their low sensitivities and reactivities to mutant strains of various genotypes. We developed an ultrasensitive bioluminescent enzyme immunoassay (BLEIA) for HBsAg using firefly luciferase, which is adaptable to a variety of HBsAg mutants, by combining four monoclonal antibodies with a polyclonal antibody against HBsAg. The measurement of seroconversion panels showed trace amounts of HBsAg during the early infection phase by the BLEIA because of its high sensitivity of 5 mIU/ml. The BLEIA detected HBsAg as early as did PCR in five of seven series and from 2.1 to 9.4 days earlier than commercial immunoassay methods. During the late infection phase, the BLEIA successfully detected HBsAg even 40 days after the disappearance of HBV DNA and the emergence of antibodies against HBsAg. The HBsAg BLEIA successfully detected all 13 recombinant HBsAg and 45 types of HBsAg mutants with various mutations within amino acids 90 to 164 in the S gene product. Some specimens had higher values determined by the BLEIA than those by a commercial chemiluminescent immunoassay; this suggests that such discrepancies were caused by the dissociation of preS1/preS2 peptides from the particle surface. With its highly sensitive detection of low-titer HBsAg, including various mutants, the HBsAg BLEIA is considered to be useful for the early diagnosis and prevention of HBV infection because of the shorter window of infection prior to detection, which facilitates early prediction of recurrence in HBV-infected individuals.

In Japan, hepatitis E had long been considered to be a rare liver disease which can be accidentally imported from endemic countries in Asia and Africa, where the sanitation conditions are suboptimal. However, since the identification of the first autochthonous hepatitis E case and hepatitis E viremic domestic pigs in Japan in 2001, our understanding of hepatitis E virus (HEV) infection in this country has been changing markedly. This has largely been due to the development of serological and gene-based diagnostic assays, the accumulation of molecular epidemiological findings on HEV infection in humans and animals (as potential reservoirs for HEV in humans) and the recognition of the importance of zoonotic food-borne and other routes of transmission of HEV, including blood-borne transmission. Although it is now evident that autochthonous hepatitis E in Japan is far more common than was previously thought, clinical and subclinical HEV infections indigenous to Japan remain underdiagnosed and their prevalence is still underestimated due to the presence of unknown transmission routes and a low awareness of the infection status by many physicians in Japan. This review focuses on the features of HEV infection in humans and animals, as definitive or potential reservoirs for HEV, in Japan, and updates the current knowledge on the routes of transmission, including zoonotic routes, which are important for the maintenance and spread of HEV in Japan.

A 67-year-old male living in Tsu city, Mie prefecture, Japan was referred to our hospital for further examination of acute liver injury and was diagnosed as having clinical hepatitis E virus (HEV) infection in January 2010. The HEV strain (HE-JA11-1701) isolated from the patient belonged to genotype 3 and European-type subgenotype 3e. It was presumed that the patient had been infected from a wild boar (Sus scrofa leucomystax) because he consumed meat/viscera from a wild boar that he had captured himself as a hunter approximately 2 months before disease onset. A specimen of the boar meat/viscera that the patient had ingested was not available. However, the HE-JA11-1701 strain was 99.8% identical within the 412-nucleotide sequence of the open reading frame 2 region to a HEV strain (JBOAR012-Mie08) that had been recovered from a wild boar captured near the patient's hunting area in 2008. A phylogenetic analysis confirmed that the two HEV strains had a close genetic relationship and were segregated into subgenotype 3e, supported by a high bootstrap value of 99%. Of note, the HE-JA11-1701 and JBOAR012-Mie08 strains were remotely related to the 3e strains reported in Japan and European countries, with a nucleotide difference of 7.9-13.9%, reinforcing the uniqueness of the 3e strains obtained in the present study. These results strongly support our speculation that the patient developed acute hepatitis E via consumption of HEV-infected boar meat/viscera. Genetic analyses of HEV strains are useful for tracing infectious sources in sporadic cases of acute hepatitis E.

The physical channels establishing intrabody communications were first treated as capacitive circuits by Zimmerman. In Zimmerman's model, the human body is approximated as a perfect conductor. The equivalent-circuit parameters of the perfect conductor models can be strictly obtained based on electrostatic analyses; however, the perfect conductor models cannot be applied if conduction currents inside the human body are not negligible. In the present paper, a theory of the equivalent circuit for lossy conductors is described, and the physical mechanism of the communication channels inducing conduction currents inside the human body is addressed.

Aim Hepatitis A virus (HAV) is the most common cause of infectious hepatitis worldwide. Although hepatitis A cases imported from South-East Asian countries, including the Philippines, have been reported in Japan, the molecular epidemiological data have been limited for these HAV-endemic countries. Methods The full-length genomic sequences of HAV isolates were determined and subjected to the phylogenetic analyses. Results The HAV isolates (HA12-0796 and HA12-0938) obtained from two Japanese patients who developed acute hepatitis A in July 2012, 1 month after traveling to the Philippines, where they consumed undercooked shellfish, differed by only one nucleotide (nt) over the entire genome. These HAV isolates of genotype IA were 99.1–99.5% identical within 228–237 nt to those recovered from river water in the Philippines, suggesting that the HA12-0796 and HA12-0938 isolates represent HAV circulating in the Philippines. HAV isolates belonging to one of the two IA sublineages (IA-2) which were implicated in some of the mini-epidemics in 2010 in Japan are hypothesized to be connected with the Philippines. In support of this speculation, the present IA isolates (HA12-0796 and HA12-0938) shared 98.8% identity over the entire genome with one IA-2 isolate (HAJIH-Fukuo10) recovered from a Japanese female who developed a domestic HAV infection during the mini-epidemics. In the phylogenetic tree constructed based on the entire genome, these three isolates (HA12-0796, HA12-0938 and HAJIH-Fukuo10) segregated into a cluster with a bootstrap value of 100%. Conclusion These results indicate that HAV isolates belonging to the IA-2 lineage might have been imported from the Philippines.

Implantable devices have been continually anticipated as a future tool for in-body wireless communication because of their potential to replace cable connectivity with biological telemetry monitoring. This paper presents an implanted compact folded antenna of 20.3 mm × 0.8 mm × 0.8 mm that is designed to operate at one of the UHF bands (0.951-0.956 GHz). The measurement is implemented with an equivalent human phantom such as layered phantom representing the human arm. When the proposed antenna is implanted into a human arm, it has a maximum antenna gain of -23.5 dBi and wireless communication is viable because the margin exceeds 20 dB, according to link budget calculations.

Hyperthermia is one of the modalities for cancer treatment, utilizing the difference of thermal sensitivity between tumor and normal tissue. Interstitial microwave hyperthermia is one of the heating schemes and it is applied to a localized tumor. In the treatments, heating pattern control around antennas are important, especially for the treatment in and around critical organs. This paper introduces a coaxial-dipole antenna, which is one of the thin microwave antennas and can generate a controllable heating pattern. Moreover, generations of an arbitrary shape heating patterns by an array applicator composed of four coaxial-dipole antennas are described. key words: hyperthermia, microwave heating, internal heating, controllable heating pattern, array applicator

The viral factors associated with the development of fulminant hepatitis B are not fully understood. We recently found four unique mutations [G to A at nucleotide 1742 (G1742A), C1766T, T1768A and T1809C] in the basal core promoter (BCP) region of a genotype A hepatitis B virus (HBV) strain (FH) obtained from a 53-year-old man with fatal fulminant hepatitis. To elucidate the association of the mutations of the FH genome with the disease, we constructed a 1.3-fold FH genome and its five variants by replacing one or two mutated nucleotides with wild-type nucleotide(s) via site-directed mutagenesis, and transfected human hepatoma cells (HepG2/C3A) with the constructs. There were no discernible differences between FH and two variants (FH_A1742G and FH_C1809T) with regard to viral replication and protein expression. However, in comparison to three other variants (FH_T1766C, FH_A1768T and FH_T1766C/A1768T) with wild-type nucleotide(s) at 1766 and/or 1768, the FH genome exhibited a 2.5–5-fold enhancement of viral replication by heightened pregenomic RNA synthesis and a 1.5–2.5-fold reduction in the hepatitis B e antigen (HBeAg) synthesis by the downregulation of the precore mRNA level. An immunofluorescence analysis revealed the increased and predominant cytoplasmic localization of the core protein in the FH genome. The present study demonstrates that the C1766T/T1768A mutations in the BCP region of genotype A HBV enhance viral replication, downregulate HBeAg expression and are responsible for the predominant localization of the core protein in the cytoplasm, which are likely associated with the development of fulminant hepatitis.

In recent years, electromagnetic (EM) applications have become common, and the opportunities of using the devices emitting EM waves have become increasing. Therefore, influences for the human body exposed to EM waves have been investigated and reported. However, there are few studies about EM exposure due to novel mobile phones such as smartphones. In this study, we developed the realistic computational smartphone model for the EM wave source. Furthermore, we estimated specific absorption rate (SAR) for the human body from the smartphone model placed in front of the abdomen.

Recently, the technology of MIMO (Multiple-Input Multiple-Output) using multiple antennas and CA (Carrier Aggregation) using multiple frequency bands are introduced in a mobile terminal. If plural MIMO antennas are installed closely, mutual coupling between the antennas must be reduced to suppress deterioration of radiation efficiency and increase of the correlation coefficient. In previous studies, a decoupling method for single-band using bifurcation elements has been confirmed. However, if operating for single-band, it is not possible to introduce CA technology. This paper proposes a decoupling method for dual-band using trifurcation elements.

To evaluate the clinical and virological features of acute hepatitis E (AH-E) in Gunma prefecture and focus on the hepatitis E virus (HEV) infection in immunocompromised patients.A total of 30 patients with AH-E diagnosed at our Gunma University Hospital, and located in 3-39-15 Showa-machi, Maebashi, Gunma 371-8511 Japan, and its affiliated hospitals from 2004 to 2015, were studied. We evaluated the detailed medical histories, laboratory examinations and virological features of these participants.Of the 30 patients, 21 patients were men, with a median age of 61 years. Three of these patients had a history of recent oversea travel. A total of 14 patients had eaten raw or undercooked meat/viscera from animals, and two patients had contracted transfusion-transmitted AH-E. Eight patients were immunocompromised, including those with hematological disease, cancer receiving systemic chemotherapy and kidney transplant or connective tissue disease undergoing immunosuppressive medications. The alanine aminotransferase and total bilirubin levels were more significantly reduced in these immunocompromised patients than in the non-immunocompromised patients. Severe thrombocytopenia, an extra-hepatic manifestation of AH-E, occurred in one case. Among the 22 HEV strains whose subgenotype was determined, two were imported strains (1a and 1f), and 11 strains formed four distinct phylogenetic clusters within subgenotype 3b. The remaining nine strains differed from each other by 9.8-22.4%, and were classified into four subgenotypes (3a, 3b, 3e and 3f).Markedly divergent HEV strains (3a, 3b, 3e and 3f) were found to circulate in Gunma. Although immunosuppression appears to play a crucial role in establishing chronic sequels, AH-E in eight immunocompromised patients, including transfusion-transmitted HEV infection in two patients, did not become chronic.

One hundred sixteen rats (Rattus rattus) captured in Indonesia from 2011 to 2012 were investigated for the prevalence of hepatitis E virus (HEV)-specific antibodies and HEV RNA. Using an ELISA based on HEV genotype 4 with an ad hoc cutoff value of 0.500, 18.1 % of the rats tested positive for anti-HEV IgG. By nested RT-PCR, 14.7 % of the rats had rat HEV RNA, and none were positive for HEV genotype 1-4. A high HEV prevalence among rats was associated with lower sanitary conditions in areas with a high population density. Sixteen of the 17 HEV isolates obtained from infected rats showed >93.0 % nucleotide sequence identity within the 840-nucleotide ORF1-ORF2 sequence and were most closely related to a Vietnamese strain (85.9-87.9 % identity), while the remaining isolate differed from known rat HEV strains by 18.8-23.3 % and may belong to a novel lineage of rat HEV. These results suggest a wide distribution of rat HEV with divergent genomes.

Mutual coupling is a critical problem in the design of MIMO antennas because it deteriorates the performance of MIMO systems, which not only affects the antenna efficiency but also influences the correlation. Therefore, in this paper, using parasitic elements to reduce mutual coupling is studied. By adding parasitic elements a double-coupling path is introduced and it can create a reverse coupling to reduce mutual coupling. As an example, a dual-slot-element antenna with parasitic monopoles for mobile terminals is described. The discussion on channel capacity shows that the antenna can be considered as a good candidate for MIMO systems. Furthermore, based on the study of current distributions, it is concluded that the technique is sensitive to relative positions between parasitic elements, and relative positions between active element and parasitic element. Finally, we also extend the technique to a tri-element antenna.

Recently, electromagnetic interference (EMI) of an implanted cardiac pacemaker with a mobile radio terminal has been investigated [1]-[3]. Based on these studies, national authorities have recommended that a mobile radio terminal should keep 22 cm from the pacemaker in Japan [4].

Four novel subgenotypes (C6, C11, C12, and D6) of hepatitis B virus (HBV) were identified in Papua, a multiethnic province of Indonesia. To characterize the HBV strains in Papua, serum samples collected from 515 indigenous inhabitants (mean age: 26.6 ± 9.6 years) in a previously unexamined area, Nabire, located in northern Papua, were used in the present study. Among 46 samples whose 1.6-kilobase (kb) HBV DNA sequence was amplified, 38 (83%) were typeable into known subgenotypes [B3 (n = 4), C1 (n = 2), C5, (n = 1), C6 (n = 5), C12 (n = 13), and D6 (n = 13)]. An analysis of the full-length sequence of the eight remaining HBV/C isolates whose sequence was either unclassifiable or uncertain within the 1.6-kb sequence showed no significant evidence of recombination in six isolates, and inter-genotypic recombination in two isolates (NAB20 and NAB46). By pairwise comparisons and a maximum-likelihood phylogenetic analysis, six non-recombinant isolates were considered significantly remote from known HBV/C isolates of subgenotypes C1−C12, and were classifiable into four novel subgenotypes (tentatively designated C13–C16). NAB20 and NAB46 were hybrids of C13/B3 and C12/G, respectively, displaying recombination breakpoints in the 5′-terminus of the P gene. Notably, the distribution of presumably indigenous subgenotypes C11−C16 was associated with particular language speakers in Papua.

The miniaturization of electronic devices is leading to the creation of body-centric wireless communications, in which wireless devices are attached to human body. However, the human body environment is often uninviting for wireless signals owing to the mutual influence between the human body and wireless devices' antennas, namely wearable antennas. Therefore, wearable antennas need to be carefully designed. In this paper, a small wearable antenna with folded ground at 2.4GHz is proposed. The folded ground has two effects: one is to improve efficiency and the other is to enhance bandwidth. When the antenna is very close to human body, it has an efficiency of 50.7% and a wide operation bandwidth of 130MHz.

Physical channels of the intra-body communications, in which communications are performed by exciting electric field around the human body, have been treated as a capacitive circuit from the beginning of the development. Although the circuit-like understanding of the channels are helpful to design devices and systems, there is a problem that the results may be invalid if the circuit parameters are incorrectly estimated. In the present study, the values of the circuit parameters are properly derived by solving a boundary value problem of electric potentials of the conductors. Furthermore, approximate models which are appropriate for cases that some of the conductors are grounded are investigated.

A hepatitis C virus (HCV) strain (HC10-0804) recovered from a 12-year-old Japanese female with chronic hepatitis C segregated into discordant genotypes, 2b and 1b, in the 5'UTR/core and NS5B regions, respectively, thus suggesting an inter-genotypic recombination. The HC10-0804 isolate had a genomic length of 9,423 nucleotides (nt), excluding the poly(U) tract at the 3' terminus, and encoded a single open reading frame (ORF) for a polyprotein of 3,014 amino acids (aa). Based on Simplot and Bootscan analyses, the crossover point from 2b to 1b was estimated at nt 3443/3444 (aa 1034/1035), just after the beginning of the NS3 region. Comparison of the entire genomic sequence showed that the HC10-0804 strain was only 90.2% identical to the previously reported 2b/1b recombinant strain (SE-03-07-1689) from the Philippines, whose putative crossover point was 24 nt downstream of that of HC10-0804. These results indicate the circulation of a novel inter-genotypic (2b/1b) recombinant HCV in Japan.

To investigate the nationwide prevalence of hepatitis E virus (HEV) infection and to characterize HEV genomes among Japanese wild boars (Sus scrofa leucomystax), 578 boars captured in 25 prefectures from 2003 to 2010 were studied. Anti-HEV IgG was detected in 8.1%, and HEV RNA in 3.3% of boars. Among the 19 boar HEV isolates obtained from infected boars, 14 isolates (74%) were classified as genotype 3, 4 isolates (21%) as genotype 4, and the remaining isolate (wbJOY_06) was distantly related to all known HEV isolates of genotypes 1-4, differing by 18.4-25.0% and 18.0-24.3% within the 412-nucleotide sequence of ORF1 and ORF2, respectively. A genotype 4 boar HEV isolate (wbJGF_08-1) obtained herein shared 98.6% identity over the entire genome with a human HEV isolate obtained from a patient who developed acute hepatitis after consuming undercooked wild boar meat, suggesting that wild boars are also reservoirs for genotype 4 HEV in humans.

The reactivity between nanoimprint mold materials and optical glass has been investigated by measuring the contact angle between these materials in a nitrogen atmosphere at high temperatures up to 1000 °C. Since low-softening-temperature optical glass was chosen in this study, the thermal upper limit of the contact angle measurement was set as 800 °C. As mold materials, electrodeposited Ni-W alloy containing 40 wt-% W and glasslike carbon (GC) were chosen. In the case of GC, the contact angle did not change greatly at temperatures up to 800 °C, and an obvious reactant phase in the interface layer between the GC and the molten glass was observed. In the case of the Ni-W alloy, the contact angle decreased with increasing temperature, and no reactant phase was observed at the interface. This indicates that the Ni-W alloy is suitable as a mold material for B2O3-La2O3-based optical glass. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(2): 17–22, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10301

我が国においてE型肝炎患者数が最も多い北海道におけるE型肝炎ウイルス（HEV）感染の地域差の有無を検討するため，釧路市721例および根室市687例の血清検体についてIgG型HEV抗体を測定し，既報の札幌市および北見市の住民での測定結果と比較した．抗体陽性率は釧路市で5.4％，根室市で2.0％であり，両市とも男性で有意に高率であった（釧路市，男性8.5％ vs. 女性3.0％，P=0.0010；根室市，4.0％ vs. 0.5％，P=0.0012）．40歳以上の年代で各市の抗体陽性率を比較すると，釧路市と北見市，札幌市との間で有意差は認められなかったが（それぞれ7.9％，12.1％，6.4％），根室市では2.1％に過ぎず，北見市，札幌市および釧路市よりも有意に低率であった．道内4都市での感染率の地域差は地域産業および食文化の相違を背景にしたブタ肉・内臓消費量の違いに由来すると推測された．

Two novel subgenotypes (C6 and D6) of hepatitis B virus (HBV) were identified recently in Papua, a multiethnic area of Indonesia. To characterize further the HBV strains in Papua, serum samples collected from 59 viremic subjects (44 males and 15 females; mean age: 30.0 ± 15.5 years) among indigenous inhabitants in Papua, were subjected to phylogenetic analysis of an 1.6-kb partial sequence. Forty-five samples (76%) had genotype C HBV (HBV/C) [C5 (n = 1), C6 (n = 40), and unclassifiable (n = 4)], while seven samples (12%) were HBV/D [D1 (n = 1) and D6 (n = 6)] and six samples (10%) were HBV/B [B2 (n = 1), B3 (n = 3), B7 (n = 1), and B8 (n = 1)]; the remaining sample possessed B3 and C6. An analysis of the full-length sequence of the four HBV/C isolates (NMB09122, NMB09124, NMB09075, and MRK89073) that were unclassifiable into any of the 10 known HBV/C subgenotypes (C1-C10) showed no significant evidence of recombination. Over the entire genome, the NMB09122 and NMB09124 isolates shared 99.8% identity and segregated into a cluster with a bootstrap value of 100%, differing from HBV/C1-HBV/C10 by 3.8-6.9% (mean, ≥4.0%), indicating that NMB09122 and NMB09124 can be classified into a novel subgenotype within genotype C (tentatively designated C11). The NMB09075 and MRK89073 isolates were 97.4% identical to each other and differed from known HBV/C isolates, including the C11 strains, by 4.0-7.2% (mean, ≥4.5%) over the entire genome, indicating that NMB09075 and MRK89703 can be classified into another novel HBV/C subgenotype (C12). The distribution of C11 and C12 seemed to be associated with particular language speakers in Papua.

We have previously demonstrated that the release of hepatitis E virus (HEV) from infected cells depended on ORF3 protein, which harbours one or two PSAP motifs. To elucidate the PSAP motif(s) in the ORF3 protein during virion egress, five PSAP mutants derived from an infectious genotype 3 cDNA clone of pJE03-1760F/wt that can grow efficiently in PLC/PRF/5 cells were analysed. Four mutants, including mutLSAP, mutPSAL, mutLSAL (the substituted amino acids in the authentic PSAP motif are underlined) and mutPLAP/PSAP (the changed amino acid in the additional PSAP motif is underlined) generated progenies as efficiently as the wild-type virus. Conversely, the HEV RNA level in the culture supernatant of mutPLAP/LSAL RNA-transfected cells was significantly lower than in cells transfected with the wild-type RNA, similar to an ORF3-null mutant. Consistent with the ORF3-deficient mutant, the mutPLAP/LSAL mutant with no intact PSAP motifs banded at 1.26-1.27 g ml(-1) in sucrose, and was captured by anti-ORF2, but not by anti-ORF3, with or without prior treatment with detergent (0.1 % sodium deoxycholate). The absence of the ORF3 protein on the mutant particles in the culture supernatant was confirmed by Western blotting, despite the expression of ORF3 protein in the RNA-transfected cells, as detected by immunofluorescence and Western blotting. Therefore, at least one of the two intact PSAP motifs in the ORF3 protein is required for the formation of membrane-associated HEV particles possessing ORF3 proteins on their surface, thus suggesting that the PSAP motif plays a role as a functional domain for HEV budding.

The authors have proposed electrical circuits accumulated by injecting electroconductive materials into patterns imprinted on the surface of fibers and weaving the fibers like a mesh. For these circuits, a built-in guide structures, which determine the positions where the fibers are to make contact with each other and exchange pertinent information, must be fabricated on fibers. In the experiments, a concave 21-μm-deep structure to serve as weaving guide was processed on the surface of 90-μm-diameter nylon fibers by thermal imprinting with a plane mold. The guides were made with two types of cross sections: rectangular and arc shaped. The rectangular structure was fabricated by a combination of microelectromechanical systems processing and Ni-electroforming technologies, whereas the arc-shaped structure involved dicing and fine machining operations. These structures on molds were designed to imprint weaving-guide structures on fibers with arrays of poles (20 μm in diameter and 10 μm in height) at their bo...

This study explored a simplified micro-scale Cu damascene process based on UV-assisted thermal imprinting of SU-8 to investigate its process merits and potential defects that may occur during and after processing. For comparative study, arbitrary electrical circuits composed of Cu wiring structures with widths ranging from 10@mm to 1mm were developed in SU-8/Si patterned by UV-assisted thermal imprinting and in oxidized Si samples prepared by reactive ion etching (RIE) followed by thermal oxidation. The imprint-based approach could lower process cycles, equipment cost, and etching gas use, whereas it induced a higher residual stress and more delamination defects. The process studied here are expected to be applied to fabricate micro-scale Cu structures, such as coils, antennas, electrical circuits, and wiring and connecting lines if further enhancements of the adhesion ability between layers and the design of pattern fields in a mold are accomplished.

For the next generation of micro-electro-mechanical-systems (MEMS) with flexibility and large size, we are developing new kinds of MEMS that will be woven fabric of ''on-fiber-devices''. An on-fiber-device is realized by thin-film-coating, patterning, and etching on the surface of a thin fiber that is then transformed into fiber-shaped device to make MEMS such as sensors and actuators. These on-fiber-devices that themselves are in shape of fibers are woven and criss-crossed resulting in new devices with novel functions. The contact points, interconnecting the woven fibers are designed to be fixed with respect to each other where they can make electrical contacts as necessary. We have developed a thermal nanoimprint technology to fabricate weaving guide structures supporting electric contact points on the surface of a thin fiber. The cross-sectional shape of the weaving guide structure was made to be rectangular, and arrays of cylinder poles of 5, 10 and [email protected] in diameters were arranged as supporting structures for making electrical contacts with the bottom of the weaving guide structure. A mold for this purpose required a two-step structure capable of imprinting weaving guide structure, and the contact points on the surface of a fiber in one stamping operation. Such a mold was fabricated by combining MEMS processing with Ni-electroforming technology. Four kinds of guide structures with depths of 20, 30, 40 and [email protected] were processed by adjusting the dry-etching during the making of a Si master. Using these electroformed-Ni molds, these different weaving guide structures, each with a set of 5-, 10- and [email protected] diameter cylinder poles were transferred onto a [email protected] diameter nylon fiber by thermal imprinting.

We recently developed a cell culture system for hepatitis E virus (HEV) in PLC/PRF/5 and A549 cells, using fecal specimens from HEV-infected patients. Since transfusion-associated hepatitis E has been reported, we examined PLC/PRF/5 and A549 cells for the ability to support replication of HEV in various serum samples obtained from 23 patients with genotype 1, 3, or 4 HEV. HEV progenies emerged in culture media of PLC/PRF/5 cells, regardless of the coexistence of HEV antibodies in serum but dependent on the load of HEV inoculated (31% at 2.0 × 104copies per well and 100% at ≥3.5 × 104copies per well), and were successfully passaged in A549 cells. HEV particles in serum, with or without HEV antibodies, banded at a sucrose density of 1.15 to 1.16 g/ml, which was markedly lower than that for HEV particles in feces, at 1.27 to 1.28 g/ml, and were nonneutralizable by immune sera in this cell culture system. An immuno-capture PCR assay of HEV virions treated with or without detergent indicated that HEV particles in serum are associated with lipids and HEV ORF3 protein, similar to those in culture supernatant. By immunoprecipitation, it was found that >90% of HEV particles in the circulation exist as free virions not complexed with immunoglobulins, despite the coexistence of HEV antibodies. These results suggest that ourin vitrocell culture system can be used for propagation of a wide variety of HEV strains in sera from various infected patients, allowing extended studies on viral replication specific to different HEV strains.

This study computationally assessed the temperature elevations due to electromagnetic wave energy deposition during magnetic resonance imaging in non-pregnant and pregnant woman models. We used a thermal model with thermoregulatory response of the human body for our calculations. We also considered the effect of blood temperature variation on body core temperature. In a thermal equilibrium state, the temperature elevations in the intrinsic tissues of the woman and fetal tissues were 0.85 and 0.61 degrees C, respectively, at a whole-body averaged specific absorption rate of 2.0 W kg(-1), which is the restriction value of the International Electrotechnical Commission for the normal operating mode. As predicted, these values are below the temperature elevation of 1.5 degrees C that is expected to be teratogenic. However, these values exceeded the recommended temperature elevation limit of 0.5 degrees C by the International Commission on Non-Ionizing Radiation Protection. We also assessed the irradiation time required for a temperature elevation of 0.5 degrees C at the aforementioned specific absorption rate. As a result, the calculated irradiation time was 40 min.