Simultaneous Correlative Interferometer Technique for Direction Finding of Signal Sources.

In this paper, we propose a novel simultaneous Correlative Interferometer (CI) technique that elaborately estimates the Direction of Arrival (DOA) of multiple source signals incident on an antenna array. The basic idea of the proposed technique is that the antenna-array-based receiver compares the phase of the received signal with one of the candidates at each time sample and jointly exploits these multiple time samples to estimate the DOAs of multiple signal sources. The proposed simultaneous CI-based DOA estimation technique collectively utilizes multiple time-domain samples and can be regarded as a generalized version of the conventional CI algorithm for the case of multiple time-domain samples. We first thoroughly review the conventional CI algorithm to comprehensively explain the procedure of the direction-finding algorithm that adopts the phase information of received signals. We also discuss several technical issues of conventional CI-based DOA estimation techniques that are originally proposed for the case of a single time-domain sample. Then, we propose a simultaneous CI-based DOA estimation technique with multi-sample diversity as a novel solution for the case of multiple time-domain samples. We clearly compare the proposed simultaneous CI technique with the conventional CI technique and we compare the existing Multiple Signal Classification (MUSIC)-based DOA estimation technique with the conventional CI-based technique by using the DOA spectrum as well. To the best of our knowledge, the simultaneous CI-based DOA estimation technique that effectively utilizes the characteristics of multiple signal sources over multiple time-domain samples has not been reported in the literature. Through extensive computer simulations, we show that the proposed simultaneous CI technique significantly outperforms both the conventional CI technique in terms of DOA estimation even in harsh environments and with various antenna array structures. It is worth noting that the proposed simultaneous CI technique results in much better performance than the classical MUSIC algorithm, which is one of the most representative subspace-based DOA estimation techniques.

Functional evaluation of parathyroid adenoma using 99mTc-MIBI parathyroid SPECT/CT: correlation with functional markers and disease severity.

OBJECTIVES: In parathyroid adenoma, uptake of technetium-99m-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been suggested to have a correlation with functional markers. The purpose of this study was to evaluate the feasibility of (99m)Tc-MIBI parathyroid single photon emission computed tomography/computed tomography (SPECT/CT) in evaluating the function and disease severity of parathyroid adenoma. PATIENTS AND METHODS: Twenty-three patients with surgically confirmed parathyroid adenoma were retrospectively enrolled. A parathyroid planar scan and SPECT/CT were performed before parathyroidectomy. Functional and clinical makers reflecting the disease severity of parathyroid adenoma were also evaluated, including serum intact parathyroid hormone, calcium, bone mineral density, and creatinine clearance. The pathologic volume (V(P)) of the adenoma was measured after parathyroidectomy. On parathyroid SPECT/CT, metabolic volume (V(M)) was measured using an isocontour method. Maximum uptakes of parathyroid adenoma and mean uptakes of contralateral thyroid tissue were measured to calculate the parathyroid adenoma-to-background ratio on parathyroid SPECT/CT (PBR(SCT)) and planar scan (PBR(PL)). RESULTS: V(M) significantly correlated with V(P) (r=0.669, P=0.0005). Serum intact parathyroid hormone level significantly correlated with PBR(PL), PBR(SCT), V(M), and V(P) (P=0.0004, 0.005, 0.003, and 0.025, respectively). However, serum calcium level correlated only with V(M) (P=0.012). Regarding the surgical indication criteria, PBR(SCT) and PBR(PL) were significantly higher in the young-aged group (P=0.0004 and 0.024, respectively) and V(M) was significantly higher in the high calcium level group (P=0.049), whereas V(P) was not different between groups on the basis of any criteria. CONCLUSION: Quantitative indices of parathyroid SPECT/CT closely correlate with laboratory functional markers and disease severity of parathyroid adenoma. Thus, parathyroid SPECT/CT could be used for evaluation of the underlying functional state and disease severity of parathyroid adenoma, particularly for decision pertaining to surgical treatment.

Effects of orally administered Actinidia arguta (Hardy Kiwi) fruit extract on 2-chloro-1,3,5-trinitrobenzene-induced atopic dermatitis-like skin lesions in NC/Nga mice.

Atopic dermatitis (AD) is characterized by highly pruritic, chronic, relapsing inflammatory skin lesions. Furthermore, therapeutic choices are limited, especially in long-standing cases, despite its increasing prevalence. This study was performed to examine the clinical efficacy and the therapeutic mechanism underlying the effects of Actinidia arguta (hardy kiwi) fruit extract in an animal model of AD. To examine the effects of A. arguta extract on AD, 2-chloro-1,3,5-trinitrobenzene-treated NC/Nga mice were orally administered A. arguta extract (100 mg/kg/day), tacrolimus (1 mg/kg/day), or dexamethasone (3 mg/kg/day) for 8 weeks. Skin severity scores, epidermal thickening, mast cell infiltration and degranulation, total serum immunoglobulin (Ig) isotypes (IgE, IgG(1)), and cytokine (interleukin [IL]-4 and interferon [IFN]-gamma) and Toll-like receptor (TLR) (TLR-2, TLR-4, and TLR-9) expressions were examined in each of the study groups. Orally administered A. arguta extract significantly reduced clinical dermatitis severity, epidermal thickness, mast cell dermal infiltration and degranulation, and total levels of serum IgE and IgG(1). Furthermore, this suppression of total serum IgE and IgG(1) levels was accompanied by a decrease in IL-4 and an increase in IFN-gamma expression in skin and splenocytes. Interestingly, TLR-9 expression was increased by oral A. arguta extract. This study confirms that A. arguta extract has potential as a dietary therapeutic agent for the treatment of AD. Furthermore, our findings suggest that its clinical efficacy and mode of action against AD are associated with the modulation of biphasic T-helper (Th) 1/Th2 cytokines, with the inhibition of Th2-mediated IgE overproduction, and possibly with the up-regulation of TLR-9.

Anti-diabetic effects of DA-11004, a synthetic IDPc inhibitor in high fat high sucrose diet-fed C57BL/6J mice.

DA-11004 is a synthetic, potent NADP-dependent isocitrate dehydrogenase (IDPc) inhibitor where IC50 for IDPc is 1.49 microM. The purpose of this study was to evaluate the effects of DA-11004 on the high fat high sucrose (HF)-induced obesity in male C57BL/6J mice. After completing a 8-week period of experimentation, the mice were sacrificed 1 hr after the last DA-11004 treatment and their blood, liver, and adipose tissues (epididymal and retroperitoneal fat) were collected. There was a significant difference in the pattern of increasing body weight between the HF control and the DA-11004 group. In the DA-11004 (100 mg/kg) treated group the increase in body weight significantly declined and a content of epididymal fat and retroperitoneal fat was also significantly decreased as opposed to the HF control. DA-11004 (100 mg/ kg) inhibited the IDPc activity, and thus, NADPH levels in plasma and the levels of free fatty acid (FFA) or glucose in plasma were less than the levels of the HF control group. In conclusion, DA-11004 inhibited the fatty acid synthesis in adipose tissues via IDPc inhibition, and it decreased the plasma glucose levels and FFA in HF diet-induced obesity of C57BL/6J mice.

DA-7911, 188Rhenium-tin colloid, as a new therapeutic agent of rheumatoid arthritis.

Radiation synovectomy is one of the most useful methods for treating patients with refractory synovitis because of its convenience, long-term effects, repeatability and the avoidance of surgery. In this study, we investigated the toxicity, stability and biodistribution of a rhenium-188 (188Re)-tin colloid to evaluate its suitability as a synovectomy agent. Twenty four hours after injecting the 188Re-tin colloids (74 KBq/0.1 mL) into the tail vein of ICR mice, most of the 188Retin colloidal particles was found in the lungs. In addition, there were no particle size changes at either room temperature or at 37 degrees C after injecting the 188Re-tin colloids in human plasma and synovial fluid. In vitro stability tests showed that the 188Re-tin colloid remained in a colloidal form without a critical size variation over a 2-day period. We investigated the leakage of 188Retin colloids from the intraarticular injection site with gamma counting in New Zealand white rabbits. The 188Re-tin colloids (55.5 MBq/0.15 mL) were injected at the cavum articular and the mean retention percentage of the 188Re-tin colloid was 98.7% for 1 day at the injection site, which suggests that there was neither change in the particle size nor leakage at the injection sites. In the biodistribution study with the SD rats, the liver showed the highest radioactivity (0.0427% ID/organ) except for the injected knees (99.49%). In the SD rats, mild toxicities including the skin or a synovium inflammation were observed as a result of a radioactivity of 15 mCi/kg at the intraarticular injection site. However, there was no systemic toxicity. In the Ovalbumin (OVA)-induced arthritic rabbits, the 188Re-tin colloid improved the macroscopic, the histological score and reduced the knee joint diameter when compared to the arthritic control. In conclusion, a 188Re-tin-colloid is considered as a strong candidate for radiation synovectomy with a superior efficacy and safety.