145 research outputs found
Dynamic evaluation of the loop technique using the U-Clip
13301甲第3921号博士(医学)金沢大学博士論文要旨Abstract 以下に掲載:Asian Cardiovascular and Thoracic Annals 22(2) pp.160-164 2014. SAGE Publications. 共著者:Hideki Moriyama, Shigeyuki Tomita, Go Watanab
Handedness manipulation of propagating antiferromagnetic magnons
Antiferromagnetic magnons possess a distinctive feature absent in their
ferromagnetic counterparts: the presence of two distinct handedness modes, the
right-handed (RH) and left-handed (LH) precession modes. The magnon handedness
determines the sign of spin polarization carried by the propagating magnon,
which is indispensable for harnessing the diverse functionalities. However, the
control of coherently propagating magnon handedness in antiferromagnets has
remained elusive so far. Here we demonstrate the manipulation and electrical
readout of propagating magnon handedness in perpendicularly magnetized
synthetic antiferromagnets (SAF). We find that the antiferromagnetic magnon
handedness can be directly identified by measuring the inverse spin Hall effect
(ISHE) voltage, which arises from the spin pumping effect caused by the
propagating antiferromagnetic magnons in the SAF structure. The RH and LH modes
of the magnon can be distinguishable particularly when the SAF structure is
sandwiched by heavy metals with the same sign of spin Hall angle. Moreover, we
succeed in controlling the handedness of propagating antiferromagnetic magnons
by tuning the excitation microwave frequency. This work unveils promising
avenues for harnessing magnon unique properties in antiferromagnet-based
magnonic applications
Advances in distraction techniques for craniofacial surgery
Distraction osteogenesis has been applied to the craniofacial skeleton as well as the long bones of the extremities. This technique does not require bone grafting and allows correction of craniofacial deformities with less invasion. Moreover, the distraction procedures can expand the overlying soft tissues simultaneously. We determined the indications of distraction osteogenesis, analyzed the types of devices available, and examined patients treated with distraction for the mandible, midface, and cranium. In all three sites, the devices tended to be the buried type and made of absorbable materials. Administration of some cytokines for shortening the consolidation period may be considered. Among disorders indicated for distraction osteogenesis, there are several syndromic craniosynostoses, which involve mutations in the fibroblast growth factor receptor (FGFR) 2 gene. The FGFR2 mutation was suggested to clinically accelerate osteogenesis at the distraction site. The usefulness and appropriateness of the distraction protocol must be assessed for each individual disorder. Although distraction osteogenesis in the craniofacial skeleton has advanced technologically, all possible risks must be discussed with the patient and family members when obtaining preoperative informed consent, especially until establishment of fully safe distraction procedures
Effect of activated protein C on plasma plasminogen activator inhibitor activity in patients with acute myocardial infarction treated with alteplase Comparison with unfractionated heparin
AbstractObjectivesWe examined whether activated protein C (APC) is an effective conjunctive therapy to thrombolysis in patients with ST-segment–elevated acute myocardial infarction (AMl).BackgroundActivated protein C possesses both systemic anticoagulant and anti-inflammatory properties. It has been also shown to enhance fibrinolysis by inhibiting plasminogen activator inhibitor (PAI) activity in vitro.MethodsAfter successful thrombolysis with alteplase, study patients were assigned to receive one of the two conjunctive therapies for 48 h intravenously: human plasma-derived APC at 0.06 mg/kg per day (APC group, n = 9) or unfractionated heparin at 100 to 400 U/kg per day, adjusted to maintain an activated partial thromboplastin time at 1.5 to 2 times of the control level (heparin group, n = 10).ResultsAdverse events, including reocclusion of the recanalized infarct-related coronary artery and major or minor hemorrhagic complications, occurred more frequently in the heparin group (4 of 10 cases) than in the APC group (none of 9 cases) (p = 0.033). In the heparin group, plasma PAI activity (IU/ml, median value [range]) was increased continuously from 8 to 24 h after thrombolysis and peaked at 24 h (30.9 [11.3 to 38.5]); on the other hand, it was not increased in the APC group at 24 h after thrombolysis (11.3 [0.0 to 31.0], p < 0.01 vs. heparin group).ConclusionsAdministration of APC suppressed increasing of plasma PAI activity observed after thrombolysis in patients with AMI. The effect of APC could be more eligible, compared with heparin, as a conjunctive regimen to thrombolysis in AMI patients
Laparoscopic pancreaticoduodenectomy after endovascular repair for abdominal aortic aneurysm
INTRODUCTION Most gastroenterological surgeries, even pancreatic surgery, can now be performed laparoscopically. However, the management of concomitant abdominal aortic aneurysm (AAA) and intra-abdominal malignancy is controversial. The performance of endovascular repair (EVAR) for AAA has been increasing; however, there is no report of laparoscopic pancreaticoduodenectomy after EVAR. PRESENTATION OF CASE A pancreatic tumor was detected during follow-up after EVAR for AAA. The enlarging tumor was diagnosed as an intraductal papillary mucinous tumor with a nodule. Laparoscopic pancreaticoduodenectomy was safely performed. After laparoscopic dissection around the pancreas head, an additional incision was made in the upper abdomen, and pancreatic reconstruction was performed through the incision. In spite of grade B pancreatic fistulae, the patient recovered with medical therapy. The pathological diagnosis was intraductal papillary mucinous adenoma with small foci of carcinoma in situ. The patient has been well with neither recurrence of the tumor nor any cardiovascular events for 18 months. DISCUSSION The management of concomitant malignancy and AAA is challenging, especially in patients with a pancreatic tumor. The reasons for the rarity of treatment include prognosis, anatomical vicinity, and postoperative complications. EVAR reduces retroperitoneal adhesions. A laparoscopic approach provides a small operative field and decreases mutual interference with AAA. Moreover, reconstruction is performed through an upper abdominal incision apart from the AAA. Hand-sewing provides more reliable stability of the anastomosis. CONCLUSION The increasing frequency of performance of EVAR for AAA and subsequent computed tomography may help to detect malignancy. Laparoscopic surgery appears to be a valid approach to malignancy after EVAR. © 2013 The Authors
Generation of third-harmonic spin oscillation from strong spin precession induced by terahertz magnetic near fields
The ability to drive a spin system to state far from the equilibrium is
indispensable for investigating spin structures of antiferromagnets and their
functional nonlinearities for spintronics. While optical methods have been
considered for spin excitation, terahertz (THz) pulses appear to be a more
convenient means of direct spin excitation without requiring coupling between
spins and orbitals or phonons. However, room-temperature responses are usually
limited to small deviations from the equilibrium state because of the
relatively weak THz magnetic fields in common approaches. Here, we studied the
magnetization dynamics in a HoFeO3 crystal at room temperature. A custom-made
spiral-shaped microstructure was used to locally generate a strong multicycle
THz magnetic near field perpendicular to the crystal surface; the maximum
magnetic field amplitude of about 2 T was achieved. The observed time-resolved
change in the Faraday ellipticity clearly showed second- and third-order
harmonics of the magnetization oscillation and an asymmetric oscillation
behaviour. Not only the ferromagnetic vector M but also the antiferromagnetic
vector L plays an important role in the nonlinear dynamics of spin systems far
from equilibrium
Plasma Free Amino Acid Profiling of Five Types of Cancer Patients and Its Application for Early Detection
BACKGROUND: Recently, rapid advances have been made in metabolomics-based, easy-to-use early cancer detection methods using blood samples. Among metabolites, profiling of plasma free amino acids (PFAAs) is a promising approach because PFAAs link all organ systems and have important roles in metabolism. Furthermore, PFAA profiles are known to be influenced by specific diseases, including cancers. Therefore, the purpose of the present study was to determine the characteristics of the PFAA profiles in cancer patients and the possibility of using this information for early detection. METHODS AND FINDINGS: Plasma samples were collected from approximately 200 patients from multiple institutes, each diagnosed with one of the following five types of cancer: lung, gastric, colorectal, breast, or prostate cancer. Patients were compared to gender- and age- matched controls also used in this study. The PFAA levels were measured using high-performance liquid chromatography (HPLC)-electrospray ionization (ESI)-mass spectrometry (MS). Univariate analysis revealed significant differences in the PFAA profiles between the controls and the patients with any of the five types of cancer listed above, even those with asymptomatic early-stage disease. Furthermore, multivariate analysis clearly discriminated the cancer patients from the controls in terms of the area under the receiver-operator characteristics curve (AUC of ROC >0.75 for each cancer), regardless of cancer stage. Because this study was designed as case-control study, further investigations, including model construction and validation using cohorts with larger sample sizes, are necessary to determine the usefulness of PFAA profiling. CONCLUSIONS: These findings suggest that PFAA profiling has great potential for improving cancer screening and diagnosis and understanding disease pathogenesis. PFAA profiles can also be used to determine various disease diagnoses from a single blood sample, which involves a relatively simple plasma assay and imposes a lower physical burden on subjects when compared to existing screening methods
Comparison of performance of the 2016 ACR-EULAR classification criteria for primary Sjögren\u27s syndrome with other sets of criteria in Japanese patients
Objectives To compare the performance of the new 2016 American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria for primary Sjögren\u27s syndrome (SS) with 1999 revised Japanese Ministry of Health criteria for diagnosis of SS (JPN), 2002 American-European Consensus Group classification criteria for SS (AECG) and 2012 ACR classification criteria for SS (ACR) in Japanese patients.Methods The study subjects were 499 patients with primary SS (pSS) or suspected pSS who were followed up in June 2012 at 10 hospitals in Japan. All patients had been assessed for all four criteria of JPN (pathology, oral, ocular, anti-SS-A/SS-B antibodies). The clinical diagnosis by the physician in charge was set as the ‘gold standard’.Results pSS was diagnosed in 302 patients and ruled out in 197 patients by the physician in charge. The sensitivity of the ACR-EULAR criteria in the diagnosis of pSS (95.4%) was higher than those of the JPN, AECG and ACR (82.1%, 89.4% and 79.1%, respectively), while the specificity of the ACR-EULAR (72.1%) was lower than those of the three sets (90.9%, 84.3% and 84.8%, respectively). The differences of sensitivities and specificities between the ACR-EULAR and other three sets of criteria were statistically significant (p<0.001). Eight out of 302 patients with pSS and 11 cases out of 197 non-pSS cases satisfied only the ACR-EULAR criteria, compared with none of the other three sets.Conclusions The ACR-EULAR criteria had significantly higher sensitivity and lower specificity in diagnosis of pSS, compared with the currently available three sets of criteria
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