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Objectives The aim of this AFIRE (Atrial Fibrillation and Ischemic Events With Rivaroxaban in Patients With Stable Coronary Artery Disease) trial subgroup analysis was to examine rivaroxaban monotherapy benefits and their relation to the time between stenting and enrollment among patients after coronary stenting. Background Of 2,215 patients with atrial fibrillation and stable coronary artery disease in the AFIRE trial, rivaroxaban monotherapy was noninferior to rivaroxaban plus antiplatelet therapy (combination therapy) in terms of efficacy and superior for safety endpoints. However, thrombotic risk after antiplatelet therapy cessation remained a concern among 1,444 patients who had undergone coronary stenting >1 year before enrollment. Methods The benefits of rivaroxaban monotherapy in coronary stenting subgroups were assessed for efficacy (a composite of stroke, systemic embolism, myocardial infarction, unstable angina requiring revascularization, or death of any cause), safety (major bleeding defined according to International Society on Thrombosis and Haemostasis criteria), ischemic endpoints, net adverse clinical event, and time between stenting and enrollment. Results Efficacy and safety endpoints for monotherapy were superior to combination therapy, with HRs of 0.70 for efficacy (95% CI: 0.50-0.98; P = 0.036) and 0.55 for safety (95% CI: 0.33-0.92; P = 0.019). For ischemic endpoints, the HR was 0.82 (95% CI: 0.58-1.15; P = 0.240). The HR became smaller with longer time between stenting and enrollment (efficacy, P for interaction = 0.158; safety, P = 0.097). Conclusions In patients with atrial fibrillation after coronary stenting, the benefits of rivaroxaban monotherapy for efficacy and safety endpoints were consistent with those in the whole AFIRE trial population. The benefits became apparent with longer time between stenting and enrollment. (Atrial Fibrillation and Ischemic Events With Rivaroxaban in Patients With Stable Coronary Artery Disease Study [AFIRE]; UMIN000016612 , NCT02642419 )

Background Limited data is available regarding the vascular response after fluoropolymer paclitaxel-eluting stent (FP-PES) implantation. We sought to assess the vascular response at 6- and 12-month after FP-PES implantation for femoropopliteal artery lesions using serial optical coherence tomography (OCT) examination. Methods and results From the IMPERIAL trial, this study evaluated 10 de novo femoropopliteal lesions treated with FP-PES. The primary study endpoint was neointimal tissue coverage at 6- and 12-month follow-up as assessed by serial OCT examination. The incidence of peri-strut low-intensity area (PLIA) and extra-stent lumen (ESL) was also assessed. A total of 203 matched cross-sectional images were evaluated at 6- and 12-month (5,615 and 5,763 struts, respectively). From 6 to 12 months, the mean neointimal thickness tended to increase from 198 μm to 233 μm with a significant reduction in the incidence of malapposed struts (0.59% vs. 0.28%, p=0.039). Conversely, uncovered struts and PLIA were more frequently observed at 12 months (4.4% vs. 7.8%, p=0.01; 12.7% vs. 21.0%, p Conclusions Neointimal proliferation was markedly inhibited from 6 to 12 months after FP-PES implantation, whereas the incidence of uncovered struts and PLIA significantly increased over time with the enlargement of ESL. Funding Acknowledgement Type of funding sources: None.

Introduction The Glasgow prognostic score, a marker of systemic inflammation, is associated with clinical outcomes in different cancers including prostate cancer. However, there is no evidence for the relationship between the high-sensitivity modified Glasgow prognostic score (Hs-mGPS) in prostate cancer and its prognosis. Objective This study aimed to investigate the prognostic significance of Hs-mGPS in castration-resistant prostate cancer (CRPC) treated with docetaxel. Methods We retrospectively analyzed clinical datasets from 131 CRPC patients who received docetaxel treatment at Chiba University Hospital and a related hospital. Clinical factors including Hs-mGPS before docetaxel treatment were evaluated according to overall survival. Results The numbers of patients with Hs-mGPS of 0, 1, and 2 were 88, 30, and 13, respectively. The median prostate-specific antigen (PSA) level was 28.9 ng/mL. The median testosterone level was 13.0 ng/dL. The percentages of bone and visceral metastases were 80.8% and 10.2%, respectively. For overall survival, Hs-mGPS ≥ 1 (hazard ratio of 2.41; p = 0.0048), testosterone ≥ 13.0 ng/dL (hazard ratio of 2.23; p = 0.0117), and PSA ≥ 28.9 ng/mL (hazard ratio of 2.36; p = 0.0097) were significant poor prognostic factors in the multivariate analysis. The results of the two-group analysis showed that a higher Hs-mGPS was associated with high PSA, alkaline phosphatase, and testosterone levels. The median testosterone levels for Hs-mGPS of 0, 1, and 2 were 9.0, 16.5, and 23.0, respectively. Based on the multivariate analysis, we created a combined score with three prognostic factors: Hs-mGPS, testosterone, and PSA. The low-risk group (score of 0-1) showed a significantly longer overall survival compared to the intermediate-risk (score of 2-3) and high-risk (score of 4) groups (p < 0.0001). Conclusion Our results demonstrated that an elevated Hs-mGPS was an independent prognostic factor in CRPC patients treated with docetaxel therapy. Risk classification based on Hs-mGPS, testosterone, and PSA may be useful in predicting the prognosis of CRPC patients. Disclosure Work supported by industry: no.

The two main classes of liquid crystals are thermotropic (containing no solvent) and lyotropic (containing solvent). Both of these classes possess the nematic phase, the most simple of liquid crystal phases with only uniaxial orientational order. For both of these classes, if the constituent molecules are chiral or if a chiral dopant is added, the preferred direction of orientation rotates in helical fashion in what is called the chiral nematic phase. Recent research has shown that because the ordering entities of the two classes are quite different (molecules versus molecular assemblies), important differences in the properties of the nematic phase can result. While thermotropic chiral nematics have been extensively examined, less is known about lyotropic chiral nematics, especially for the most ideal case, a chiral–racemic system. Furthermore, none of the lyotropic chiral–racemic studies has included lyotropic chromonic liquid crystals, which are solutions of dyes, drugs, and nucleic acids. Inverse pitch measurements are reported for a chiral–racemic system of a chromonic liquid crystal across the entire chiral fraction range and over a 30 °C temperature interval. The inverse pitch depends linearly on chiral fraction and decreases with increasing temperature, indicating that achiral and chiral molecules participate in the assembly structure similarly. The helical twisting power is significantly larger than for other chiral lyotropic liquid crystals due to the very high scission energy of the investigated system.

Background Impact of SYNTAX score II (SSII) on long-term clinical outcomes after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation remains unclear. Methods Between February 2010 and May 2011, 1064 consecutive patients with 1440 lesions were treated only with CoCr-EES implantation. Of these, the SSII was calculated in 1013 patients with 1345 lesions. Patients were divided into the tertile group: Tertiles for SSII (low SSII [12–28.9], n=334; intermediate SSII [29–39.1], n=339; and high SSII [39.2–80.8], n=340). We assessed the cumulative 7-year incidences of major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, definite stent thrombosis, and clinically driven target lesion revascularization (CDTLR) based on SSII groupings. Results Cumulative 7-year incidence of MACE was significantly higher in the high SSII group than in the other groups (34.1% vs. 18.6% vs. 17.2%, p Conclusions SSII has significantly impact on 7 years clinical outcomes after CoCr-EES implantation. Cumulative incidence of MACE Funding Acknowledgement Type of funding source: None

Background 13N-ammonia PET (NH3-PET) can detect myocardial perfusion abnormalities in patients with coronary artery disease (CAD) and also obtain diagnostic quantitative values of absolute myocardial blood flow and myocardial flow reserve (MFR). Low MFR (MFR Purpose We aimed to investigate the affect of LAP to MFR in intermediate CAD. Methods One hundred five patients (age 67±9 years, 65% male) with CAD underwent NH3-PET and CCTA within 6 months between April 2015 and March 2019 were enrolled. Based on the results of CCTA, mild and moderate stenosis were defined as 1% to 49% and 50% to 69% stenosis. Ischemic territories for major three vessels were identified by stress/rest NH3-PET images. Finally, 194 coronary arteries with mild to moderate stenosis corresponding to non-ischemic territory were analyzed in this study. LAP was defined as plaques containing CT value less than 90HU. Partially calcified plaques were included in LAP. Entirely calcification plaque without LAP was defined as calcified plaque. MFR for major three vessels were calculated from dynamic scan at stress/rest NH3-PET. Results CCTA showed 80 coronary arteries with LAP (41%), 104 coronary arteries with calcified plaque (54%), 102 vessels with mild stenosis (53%), and 92 vessels with moderate stenosis (47%). MFRs for coronary arteries with LAP were significantly lower than those without LAP (2.1±0.6 vs 2.5±0.6, p In 58 coronary arteries with MFR Conclusion The presence of LAP burdens MFR in mild to moderate CAD. On the other hand, calcified plaque alone had no adverse effect on MFR. LAP is an important sign in CAD risk assessment even without significant coronary stenosis. MFR and stress MPI Funding Acknowledgement Type of funding source: None

Objective To compare regional nicotinic cholinergic receptor binding in older adults with Alzheimer disease (AD) and healthy older adults in vivo and to assess relationships between receptor binding and clinical symptoms. Methods Using cross-sectional positron emission tomography (PET) neuroimaging and structured clinical assessment, outpatients with mild to moderate AD (N = 24) and healthy older adults without cognitive complaints (C group; N = 22) were studied. PET imaging of α4β2* nicotinic cholinergic receptor binding using 2-[ 18 F]fluoro-3-(2(S)azetidinylmethoxy)pyridine (2FA) and clinical measures of global cognition, attention/processing speed, verbal memory, visuospatial memory, and neuropsychiatric symptoms were used. Results 2FA binding was lower in the AD group compared with the C group in the medial thalamus, medial temporal cortex, anterior cingulate, insula/opercula, inferior caudate, and brainstem (p s = −0.55, p = 0.008; right: r s = −0.50, p = 0.02; N = 22) and hippocampus (left: r s = −0.65, p = 0.001; right: r s = −0.55, p = 0.009; N = 22) and the Trails A score. The AD group had inverse correlation between 2FA binding in anterior cingulate (left: r s = −0.50, p = 0.01; right: r s = −0.50, p = 0.01; N = 24) and Neurobehavioral Rating Scale agitation/disinhibition factor score. Conclusion Cholinergic receptor binding is reduced in specific brain regions in mild to moderate AD and is related to neuropsychiatric symptoms. Among healthy older adults, lower receptor binding may be associated with slower processing speed. Cholinergic receptor binding in vivo may reveal links to other key brain changes associated with aging and AD and may provide a potential molecular treatment target.

We are reporting the first silicon electron device for the realization of detection in slip of grasping by laparoscopic forceps under very low friction condition. Even under "zero-level" friction, slip of grasping object is detectable with the original algorithm inspired from our finger’s sense of slip. At present, the surgeons of laparoscopic surgery or robotic surgery can able to get through monitor visual information only. It is one of the essential reasons why endoscopic surgeries requires much higher skills than conventional open surgery. Since organ surface is very slippery by blood and body fluid, very low friction around the organs is an essential issue especially in the case of laparoscopic surgery. Fabricated silicon slip sensing imager can visualize the grasping force distribution on the slippery organ surface, and the slippage of the organ is digitized by calculation of the center of load distribution. This is the first demonstration of slip detection at sub-mm spatial resolution under a very low friction condition on the tip of laparoscopic forceps, which is not only applicable to the medical treatment but also industrial robotics applications.

Supplemental material, DS_10.1177_0022034519857714 for Systemic Immunologic Consequences of Chronic Periodontitis by D.K. Gaudilliere, A. Culos, K. Djebali, A.S. Tsai, E.A. Ganio, W.M. Choi, X. Han, A. Maghaireh, B. Choisy, Q. Baca, J.F. Einhaus, J.J. Hedou, B. Bertrand, K. Ando, R. Fallahzadeh, M.S. Ghaemi, R. Okada, N. Stanley, A. Tanada, M. Tingle, T. Alpagot, J.A. Helms, M.S. Angst, N. Aghaeepour and B. Gaudilliere in Journal of Dental Research

The role that changes in DNA methylation and histone modifications have in human malignancies is poorly understood. p300 and CREB-binding protein (CBP), two distinct but highly homologous lysine acetyltransferases, are mutated in several cancers, suggesting their role as tumor suppressors. In the current study, we found that deletion of p300, but not CBP, markedly accelerated the leukemogenesis ofNup98-HoxD13 (NHD13) transgenic mice, an animal model that phenotypically copies human myelodysplastic syndrome (MDS). p300 deletion restored the ability of NHD13 expressing hematopoietic stem and progenitor cells (HSPCs) to self-renew in vitro, and to expand in vivo, with an increase in stem cell symmetric self-renewal divisions and a decrease in apoptosis. Furthermore, loss of p300, but not CBP, promoted cytokine signaling, including enhanced activation of the MAPK and JAK/STAT pathways in the HSPC compartment. Altogether, our data indicate that p300 has a pivotal role in blocking the transformation of MDS to acute myeloid leukemia, a role distinct from that of CBP.

In this study, we investigated the temperature dependence of magnetostriction in the twinned rhombohedral perovskite structure-based lanthanum cobaltite La0.8Sr0.2CoO3. The magnetostriction measured in a magnetic field applied along the pseudocubic [111]c axis showed large hysteresis and residual strains. The residual strains are caused by the twin deformation, which we observed using x-ray diffraction. We found that the critical magnetic field for the twin deformation of La0.8Sr0.2CoO3 increases with temperature. The twin deformation occurs in a sufficiently strong magnetic field (∼6 T), even in the paramagnetic region at room temperature. We also confirmed that the temperature dependence of the critical magnetic field for twin deformation is related to the temperature dependence of the magnetization.

The purpose of this study is to extend the three-dimensional (3-D) passive dynamic biped walker to a 3-D dynamic biped walker, i.e., a walker that can walk on a horizontal surface based on a passive dynamic walking. A new prototype of 3-D biped walker called RW04, which has telescopic knee joints, was developed and its ability for walking was validated through some experiments. A sinusoidal oscillation, which is regarded as a central pattern generator with no sensory feedback, was provided to the knee joints to achieve the biped walking. The results showed that the biped gait of RW04 was possible only via a sinusoidal oscillation of the knee joint. Moreover, the 3-D dynamic walking gait via frequency response and zero moment point (ZMP) trajectory was also analyzed. The biped locomotion had a resonance, i.e., the frequency matched the natural frequency of the locomotion in the gain property. An “8” shaped ZMP trajectory was observed, which was found to be similar to that of the human gait. However, the simple sinusoidal oscillation had limitations such as stride reduction or discontinuation by phase difference. Therefore, in future work, more adaptable control strategy such as a sensory feedback using ZMP should be provided.

This chapter describes an experiment on the inverse spin Hall effect (ISHE) induced by spin pumping. Spin pumping is the generation of spin currents as a result of magnetization M(t) precession; in a ferromagnetic/paramagnetic bilayer system, a conduction-electron spin current is pumped out of the ferromagnetic layer into the paramagnetic conduction layer in a ferromagnetic resonance condition. The sample used in the experiment is a Ni81Fe19/Pt bilayer film comprising a 10-nm-thick ferromagnetic Ni81Fe19layer and a 10-nm-thick paramagnetic Pt layer. For the measurement, the sample system is placed near the centre of a TE011 microwave cavity at which the magnetic-field component of the microwave mode is maximized while the electric-field component is minimized.

This chapter introduces the concept of exchange spin current, which derives from rewriting the exchange interaction in magnets and formulating a spin-wave spin current. States of matter can be classified into several types in terms of magnetic properties. In paramagnetic and diamagnetic states, matter has no magnetic order and exhibits zero magnetization in the absence of external magnetic fields. In ferromagnetic states, the permanent magnetic moments of atoms or ions align parallel to a certain direction, and the matter exhibits finite magnetization even in the absence of external magnetic fields. In ferrimagnets, the moments align antiparallel but the cancellation is not perfect and net magnetization appears. This interaction that aligns spins is called the exchange interaction.

Highly sensitive microwave devices that are operational at room temperature are important for high-speed multiplex telecommunications. Quantum devices such as superconducting bolometers possess high performance but work only at low temperature. On the other hand, semiconductor devices, although enabling high-speed operation at room temperature, have poor signal-to-noise ratios. In this regard, the demonstration of a diode based on spin-torque-induced ferromagnetic resonance between nanomagnets represented a promising development, even though the rectification output was too small for applications (1.4 mV mW(-1)). Here we show that by applying d.c. bias currents to nanomagnets while precisely controlling their magnetization-potential profiles, a much greater radiofrequency detection sensitivity of 12,000 mV mW(-1) is achievable at room temperature, exceeding that of semiconductor diode detectors (3,800 mV mW(-1)). Theoretical analysis reveals essential roles for nonlinear ferromagnetic resonance, which enhances the signal-to-noise ratio even at room temperature as the size of the magnets decreases.

An exhaustive experimental investigation has been carried out for accurate determination of interstitial heat transfer coefficients of ceramic foams in forced convective flows. The single-blow method was used, in which, the fluid temperature varies with time and convective heat transfer becomes time-dependent. The method results in a transient and conjugate heat transfer phenomena between the foam and fluid. These transient temperature data are then compared with the theoretical results to obtain the corresponding interstitial heat transfer coefficients between the fluid and foam solid surface. The interstitial coefficients thus determined are compared against available sets of experimental data, so as to ex- amine the consistency among the reported experimental data.

Naming people, places, and things is a fundamental human ability that is often impaired in patients with language-dominant anterior temporal lobe (ATL) dysfunction or ATL resection as part of epilepsy treatment. Convergent lines of evidence point to the importance of the ATL in name retrieval. The physiologic mechanisms that mediate name retrieval in the ATL, however, are not well understood. The purpose of this study was to characterize the electrophysiologic responses of the human ATL during overt cued naming of famous people and objects. Eight neurosurgical patients with suspected temporal lobe epilepsy who underwent implantation of intracranial electrodes for seizure focus localization were the subjects of this study. Specialized coverage of the ATL was achieved in each subject. The subjects named pictures of U.S. presidents and images of common hand-held tools. Event-related band power was measured for each ATL recording site. Both the left and right ATL demonstrated robust and focal increases in beta-band (14–30 Hz) power during person and tool naming. The onset of this response typically occurred at 400 ms but sometimes as early as 200 ms. Visual naming of famous people and tools is associated with robust and localized modulation of the beta band in both the left and right ATL. Measurement of visual naming responses may provide the groundwork for future mapping modalities to localize eloquent cortex in the ATL.

The R6/2 mouse is the most frequently used model for experimental and preclinical drug trials in Huntington's disease (HD). When the R6/2 mouse was first developed, it carried exon 1 of the huntingtin gene with ∼150 cytosine-adenine-guanine (CAG) repeats. The model presented with a rapid and aggressive phenotype that shared many features with the human condition and was particularly similar to juvenile HD. However, instability in the CAG repeat length due to different breeding practices has led to both decreases and increases in average CAG repeat lengths among colonies. Given the inverse relationship in human HD between CAG repeat length and age at onset and to a degree, the direct relationship with severity of disease, we have investigated the effect of altered CAG repeat length. Four lines, carrying ∼110, ∼160, ∼210, and ∼310 CAG repeats, were examined using a battery of tests designed to assess the basic R6/2 phenotype. These included electrophysiological properties of striatal medium-sized spiny neurons, motor activity, inclusion formation, and protein expression. The results showed an unpredicted, inverted “U-shaped” relationship between CAG repeat length and phenotype; increasing the CAG repeat length from 110 to 160 exacerbated the R6/2 phenotype, whereas further increases to 210 and 310 CAG repeats greatly ameliorated the phenotype. These findings demonstrate that the expected relationship between CAG repeat length and disease severity observed in humans is lost in the R6/2 mouse model and highlight the importance of CAG repeat-length determination in preclinical drug trials that use this model.

We report a large enhancement of spin-torque diode sensitivity in CoFeB/MgO/CoFeB magnetic tunnel junctions measured under perpendicular magnetic fields and dc bias currents. In the measurement of homodyne detection, a large dc output voltage of 190 μV was obtained when an RF signal power of -30 dB ·m and a dc current of +1.0 mA were applied. This value corresponds to the diode sensitivity of 190 mV/mW (260 mV/mW after impedance matching correction). The main origin of this enhancement is an offset of the damping torque and an increase in the precession angle induced by the spin-transfer torque due to the dc bias current application.

This research entailed the production of stereoscopic 3D (S3D) contents using 2D-to-S3D conversion for exhibition at a museum and subjective evaluation. Hybrid production combining S3D images of existing live-action videos using the 2D-to-S3D conversion technology and computer graphic ones created via stereo rendering was conducted. Design and control of the chronological analysis of the parallactic angle was conducted on the produced contents, using binocular information as well as subjective evaluations, with the intent of conducting an investigation on the characteristics of such contents from the perspectives of the producers and viewers. An investigation was also conducted on the effects of the viewing position on the impressions of the S3D images.

Surface damage of carbon fiber composite (CFC) and tungsten (W) due to repetitive ELM-like pulsed plasma irradiation has been investigated by using a magnetized coaxial plasma gun. CX2002U CFC and stress-relieved W samples were exposed to repetitive pulsed deuterium plasmas with duration of ∼0.5 ms, incident ion energy of ∼30 eV, and surface absorbed energy density of ∼0.3–0.7 MJ/m 2 . Bright spots on a CFC surface during pulsed plasma exposures were clearly observed with a high-speed camera, indicating a local surface heating. No melting of a W surface was observed under a single plasma pulse exposure at energy density of ∼0.7 MJ/m 2 , although cracks were formed. Cracking of the W surface grew with repetitive pulsed plasma exposures. Subsequently, the surface melted due to localized heat absorption.

The effect of several vitamin K homologs on plasma vitamin K concentration was determined to assess their potential as a vitamin K supplement for adult horses. Sixteen Thoroughbred horses consisting of 8 mares and 8 geldings, aged 8.4 ± 3.6 yr and weighing 520.8 ± 36.1 kg, were allocated to 4 groups (n = 4). Each group was given phylloquinone, menaquinone-4, or menadione at 58 µmol/d, or no vitamin K supplement for 7 d. Plasma samples were collected before feeding, and 2, 4, and 8 h after feeding on d 7, and plasma concentrations of phylloquinone and menaquinone-4 were determined. Plasma phylloquinone concentration was greater in the phylloquinone group than in the other groups (P < 0.001). The phylloquinone concentration quadratically increased (P < 0.001) after feeding in the phylloquinone group but no changes in the plasma phylloquinone concentration were observed after feeding in the other groups. Plasma menaquinone-4 concentration was greater (P < 0.001) in the menadione group than the other groups, including the menaquinone-4 group. Menaquinone-4 concentration did not change (P = 0.192) after feeding in each group. Menaquinone-4 has been considered the most potent vitamin K homolog for bone metabolism; therefore, the present experiment indicates that menadione is a good source of vitamin K for bone health in horses because it is the only vitamin K homolog that increased the plasma concentrations of menaquinone-4.

Radial and longitudinal strain assessment in the carotid artery wall using speckle tracking

Properties of various carbon nanomaterials in bilirubin adsorption have been studied to develop a new adsorbent in the plasma apheresis. Carbon nanomaterials we used as adsorbents are single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), and single-walled carbon nanohorns (SWNHs). The adsorbent was mixed with a bilirubin solution, and the adsorption capacity was obtained by measuring the concentrations of residual bilirubin in the solution after the adsorption process. We found that the bundled MWCNTs exhibit the largest capacity in the saturated amount of adsorbed bilirubin among the examined materials, and that the oxidized SWNHs exhibit the fastest rate in the early stage of the adsorption. We also found that the amount of adsorbed bilirubin increases with an increase in the dispersibility of the adsorbent.

Fatigue strength of notched specimen and smooth specimen of Zr-based bulk metallic glass, Zr55Cu30Ni5Al10, were conducted under either plane-bending or axial-loading. Fatigue notch factor, Kf, for axial-loading was almost equal to the elastic stress concentration factor, Kt, and the value of Kf for plane-bending was 5% lower than the value of Kt. It indicates that the effect of stress gradient around notch root is negligible, and the fatigue limit of notched specimen is determined by the stress at the notch root. On the contrary, the fatigue strength and the fatigue limit were lower for axial-loading than plane-bending either for notched or smooth specimen. It is considered that the fatigue strength of BMG depends on the cooling rate in the casting pro cess of the material, which is different along the thickness direction, and the fatigue strength of plane-bending reflects the strength at the specimen surface while that of axial-loading is determined by the weakest strength in the thickness direction.

Previous molecular genetic analyses indicate that Opisthorchis viverrini is a complex of at least 2 cryptic species in Thailand and the Lao People's Democratic Republic (PDR). Opisthorchis viverrini sensu lato (s.l.) populations can be divided into 6 genetic groups, which correlate with 5 different river wetlands systems. The present study examines the infectivity, growth, fecundity, and body size of O. viverrini s.l. isolates from these systems. Worm recovery was lowest in the Songkhram River, which differed significantly from all other wetland systems. In addition, the Chi River and Nam Ngum River populations also differed significantly. A similar pattern was found for fecundity. These results support the genetic/molecular data indicating a subdivision of O. viverrini populations on the basis of watershed and that propose the existence of cryptic species in Thailand and the Lao PDR.