Optimal Coverage of Full Frequency Reuse in FFR Networks in Relation to Power Scaling of a Base Station.

As a strategy to coordinate inter-cell interference in cellular networks, a fractional frequency reuse (FFR) system is proposed, in which the frequency bandwidth is split into two orthogonal bands; users staying near the center of a FFR cell use the band with a frequency reuse (FR) factor of one (i.e., full FR), and users located close to the cell edge utilize the band with a FR factor greater than one (i.e., partial FR). Full FR coverage, which identifies full FR and partial FR regions (that is, near-center and near-edge regions) within a FFR cell, has a crucial effect on system performance. Some of the authors of this paper recently investigated the optimization of full FR coverage to maximize system throughput. They analytically showed that under the constraint of satisfying a specified target outage probability, the optimal full FR coverage is a non-increasing function of base station power when all base station powers in the cellular network are scaled at an equal rate. Interestingly, in this paper, it is proven that as the power of a single base station is scaled, the optimal full FR coverage in that cell is a non-decreasing function of base station power. Our results provide useful insight into the design of full FR coverage in relation to the transmit power of a base station. It gives a deeper understanding of the intricate relationship between important FFR system parameters of base station power and full FR coverage.

Synthetic Glabridin Derivatives Inhibit LPS-Induced Inflammation via MAPKs and NF-κB Pathways in RAW264.7 Macrophages.

Glabridin is a polyphenolic compound with reported anti-inflammatory and anti-oxidative effects. In the previous study, we synthesized glabridin derivatives-HSG4112, (S)-HSG4112, and HGR4113-based on the structure-activity relationship study of glabridin to improve its biological efficacy and chemical stability. In the present study, we investigated the anti-inflammatory effects of the glabridin derivatives in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We found that the synthetic glabridin derivatives significantly and dose-dependently suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2), and decreased the level of inducible nitric oxygen synthase (iNOS) and cyclooxygenase-2 (COX-2) and the expression of pro-inflammatory cytokines interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor alpha (TNF-α). The synthetic glabridin derivatives inhibited the nuclear translocation of the NF-κB by inhibiting phosphorylation of the inhibitor of κB alpha (IκB-α), and distinctively inhibited the phosphorylation of ERK, JNK, and p38 MAPKs. In addition, the compounds increased the expression of antioxidant protein heme oxygenase (HO-1) by inducing nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) through ERK and p38 MAPKs. Taken together, these results indicate that the synthetic glabridin derivatives exert strong anti-inflammatory effects in LPS-stimulated macrophages through MAPKs and NF-κB pathways, and support their development as potential therapeutics against inflammatory diseases.

A novel laboratory method to simulate climatic stress with successful application to experiments with medically relevant ticks.

Ticks are the most important vectors of zoonotic disease-causing pathogens in North America and Europe. Many tick species are expanding their geographic range. Although correlational evidence suggests that climate change is driving the range expansion of ticks, experimental evidence is necessary to develop a mechanistic understanding of ticks' response to a range of climatic conditions. Previous experiments used simulated microclimates, but these protocols require hazardous salts or expensive laboratory equipment to manipulate humidity. We developed a novel, safe, stable, convenient, and economical method to isolate individual ticks and manipulate their microclimates. The protocol involves placing individual ticks in plastic tubes, and placing six tubes along with a commercial two-way humidity control pack in an airtight container. We successfully used this method to investigate how humidity affects survival and host-seeking (questing) behavior of three tick species: the lone star tick (Amblyomma americanum), American dog tick (Dermacentor variabilis), and black-legged tick (Ixodes scapularis). We placed 72 adult females of each species individually into plastic tubes and separated them into three experimental relative humidity (RH) treatments representing distinct climates: 32% RH, 58% RH, and 84% RH. We assessed the survival and questing behavior of each tick for 30 days. In all three species, survivorship significantly declined in drier conditions. Questing height was negatively associated with RH in Amblyomma, positively associated with RH in Dermacentor, and not associated with RH in Ixodes. The frequency of questing behavior increased significantly with drier conditions for Dermacentor but not for Amblyomma or Ixodes. This report demonstrates an effective method for assessing the viability and host-seeking behavior of tick vectors of zoonotic diseases under different climatic conditions.

On Training Neural Network Decoders of Rate Compatible Polar Codes via Transfer Learning.

Neural network decoders (NNDs) for rate-compatible polar codes are studied in this paper. We consider a family of rate-compatible polar codes which are constructed from a single polar coding sequence as defined by 5G new radios. We propose a transfer learning technique for training multiple NNDs of the rate-compatible polar codes utilizing their inclusion property. The trained NND for a low rate code is taken as the initial state of NND training for the next smallest rate code. The proposed method provides quicker training as compared to separate learning of the NNDs according to numerical results. We additionally show that an underfitting problem of NND training due to low model complexity can be solved by transfer learning techniques.

Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks.

In this paper, a new non-orthogonal multiple-access scheme, trellis tone modulation multiple-access (TTMMA), is proposed for peer discovery of distributed device-to-device (D2D) communication. The range and capacity of discovery are important performance metrics in peer discovery. The proposed trellis tone modulation uses single-tone transmission and achieves a long discovery range due to its low Peak-to-Average Power Ratio (PAPR). The TTMMA also exploits non-orthogonal resource assignment to increase the discovery capacity. For the multi-user detection of superposed multiple-access signals, a message-passing algorithm with supplementary schemes are proposed. With TTMMA and its message-passing demodulation, approximately 1.5 times the number of devices are discovered compared to the conventional frequency division multiple-access (FDMA)-based discovery.

Analysis of the Shear Behavior of Stubby Y-Type Perfobond Rib Shear Connectors for a Composite Frame Structure.

Shear connectors are used in steel beam-concrete slabs of composite frame and bridge structures to transfer shear force according to design loads. The existing Y-type perfobond rib shear connectors are designed for girder slabs of composite bridges. Therefore, the rib and transverse rebars of the conventional Y-type perfobond rib shear connectors are extremely large for the composite frames of building structures. Thus, this paper proposes stubby Y-type perfobond rib shear connectors, redefining the existing connectors, for composite frames of building structures; these were used to perform push-out tests. These shear connectors have relatively small ribs compared to the conventional Y-type perfobond rib shear connectors. To confirm the shear resistance of these stubby shear connectors, we performed an experiment by using transverse rebars D13 and D16. The results indicate that these shear connectors have suitable shear strength and ductility for application in composite frame structures. The shear strengths obtained using D13 and D16 were not significantly different. However, the ductility of the shear connectors with D16 was 45.1% higher than that of the shear connectors with D13.

Development of a Skewed Pipe Shear Connector for Precast Concrete Structures.

Joint connection methods, such as shear key and loop bar, improve the structural performance of precast concrete structures; consequently, there is usually decreased workability or constructional efficiency. This paper proposes a high-efficiency skewed pipe shear connector. To resist shear and pull-out forces, the proposed connectors are placed diagonally between precast concrete segments and a cast-in-place concrete joint part on a girder. Design variables (such as the pipe diameter, length, and insertion angle) have been examined to investigate the connection performance of the proposed connector. The results of our testing indicate that the skewed pipe shear connectors have 50% higher ductility and a 15% higher ratio of maximum load to yield strength as compared to the corresponding parameters of the loop bar. Finite element analysis was used for validation. The resulting validation indicates that, compared to the loop bar, the skewed pipe shear connector has a higher ultimate shear and pull-out resistance. These results indicate that the skewed pipe shear connector demonstrates more idealized behavior than the loop bar in precast concrete structures.

Sonographically based diagnosis of contralateral malignancy in preoperative patients with papillary thyroid microcarcinoma.

OBJECTIVES: We aimed to assess the usefulness of sonographically based diagnosis to predict whether contralaterally located dominant thyroid nodules are malignant or benign in patients with known papillary thyroid microcarcinoma. METHODS: We studied 143 patients with primary papillary thyroid microcarcinoma who underwent preoperative thyroid sonography. Each dominant thyroid nodule was prospectively classified into 1 of 5 diagnostic categories by a single radiologist: benign, probably benign, borderline, possibly malignant, and malignant. We calculated the efficacy of sonographic diagnosis for contralateral malignancy by using histopathologic or long-term sonographic follow-up results as reference standards. RESULTS: Of the 143 primary papillary thyroid microcarcinomas, 17 showed satellite carcinomas; hence, the bilaterality rate in all patients was 11.9% (17 of 143). Real-time sonography of the contralateral thyroid yielded no thyroid nodules (n = 55) and benign (n = 52), probably benign (n = 10), borderline (n = 13), possibly malignant (n = 4), and malignant (n = 9) nodules. When the borderline sonographic class was excluded, the sensitivity, specificity, positive and negative predictive values, and accuracy of sonographic diagnosis for detecting contralateral malignancy were 86.7%, 100%, 100%, 98.3%, and 98.5%, respectively. Within individual sonographic classes for the dominant thyroid nodules, the diagnostic accuracy rates for classes IV and V (possibly malignant and malignant) were higher than those for other classes. CONCLUSIONS: Sonographically based diagnosis may be helpful for detection of contralateral malignancy in preoperative patients with papillary thyroid microcarcinoma.

Analysis of the risk factors for development of post-operative extradural hematoma after intracranial surgery.

OBJECTIVE: Post-operative extradural hematoma (EDH) is a relatively common complication in patients undergoing intracranial operations. The risk factors associated with the occurrence of EDH are not well described in the literature. The objective of this study was to identify the risk factors and the incidence of post-operative EDH adjacent and regional to the craniotomy or the craniectomy site. METHOD: This was a retrospective study of 24 (2.6% of total) patients who underwent extradural hematoma evacuation after primary intracranial supratentorial surgery between January 2005 and December 2011. During this period, 941 intracranial operations were performed. The control group (72 patients) was selected on the basis of having undergone the same pre-operative diagnosis and treatment within 2 months of the operations for the 24 hematoma patients. The Glasgow Coma Scale score and operation character (emergency or elective) of the hematoma and control group were individually matched to minimize pre-operative conditional bias. The ages of both groups were individually matched with similar ages within 10 years of each other to minimize age bias. RESULT: Univariate analysis showed that the significant pre-operative and intra-operative factors associated with post-operative EDH were an intra-operative blood loss of greater than 800 mL (p=0.007), maximal craniotomy length of greater than or equal to 100 mm (p=0.001), and craniotomy area of greater than or equal to 71.53 cm2 (p=0.018). In multivariate analysis, intra-operative blood loss exceeding 800 mL (median of total patients) placed a patient at significantly increased risk for post-operative EDH. CONCLUSION: The data did not examine established risk factors for post-operative hematoma, such as thrombocytopenia, anti-coagulant and anti-platelet therapy, and a history of heavy alcohol consumption and/or tobacco intake. Recognizing the limitations of the study, large intra-operative blood loss and wide craniotomy area are implicated with an increased risk of post-operative EDH after intracranial surgery.

Brain Metastases of Papillary Thyroid Carcinoma with Horner's Syndrome.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy and has relatively favorable prognosis. Blood-borne metastases of PTC are very rare among the thyroid malignancies. Moreover a case of blood-borne central nervous system metastasized PTC with only unilateral Horner's syndrome, and without any abnormalities in laboratory or physical examinations has not been described before. A 53-year-old female patient had been managed in ophthalmologic clinic due to vague symptoms of right monocular blurred vision with eye dryness for 3 months, but showed no signs of improvement. So it was performed a magnetic resonance imaging and magnetic resonance angiography to evaluate the possibilities of cerebral lesion. And a left frontal mass was incidentally found, and the tumor turned out to be a PTC that had metastasized to brain, regional lymph node, cervical, thoracic spine, and lung. We describe a PTC with extraordinary initial symptoms that metastasized to an unusual site. We recommend that if a papillary thyroid tumor with unusual symptoms or at an advanced stage is found, further investigation should be performed for distant metastasis.

Implication of minimal extrathyroidal extension as a prognostic factor in papillary thyroid carcinoma.

PURPOSE: Extrathyroidal extension (ETE) of papillary thyroid carcinoma (PTC) is a risk factor for tumor recurrence. By TNM Classification (7th edition), differentiated thyroid carcinoma with ETE is designated T3 (minimal invasion), T4a (extended invasion), or T4b (more extensive unresectable invasion), according to the degree of tumor involvement. We subsequently focused our investigation on minimal ETE (MEE), analyzing the clinicopathologic characteristics, recurrence rate, and recurrence-free survival (RFS) in this setting. METHODS: A retrospective study was conducted, based on 332 patients undergoing thyroidectomy for PTC between January 2005 and December 2006. RESULTS: The study population was stratified into two groups: PTC with MEE (103/332; 31.0%) and PTC without MEE (229/332; 69.0%). In patients with PTC, MEE correlated with gender, tumor size, multifocality, lymph node (LN) metastasis, underlying Hashimoto's thyroiditis, and the nature of the surgery. However, no significant intergroup differences were evident with respect to age, recurrence rate, and LN metastasis. In multivariate analysis, LN metastasis (odds ratio = 2.273; 95% confidence interval, 1.280-4.037) was recognized as an independent correlate of mETE (p = 0.005). However, recurrence-free survival did not differ significantly between the groups (p = 0.153), even when further stratified by the presence or absence of LN metastasis. CONCLUSION: In patients with PTC, MEE does not impact RFS. Thus, appropriate surgical intervention and postoperative follow up are mandatory in PTC, regardless of its extent.

Environmental impact assessment and eco-friendly decision-making in civil structures.

This study develops two useful procedures in performing an environmental-impact assessment. One is the advanced life-cycle assessment (LCA) method, which effectively tracks the flow of materials and considers the recycling and demolition of a civil structure. The other is an eco-friendly decision-making procedure, which may effectively apply when determining the prototype of a civil structure. The advanced LCA method differs from traditional LCA procedure, as it classifies the input material prior to the impact assessment. Classification work is performed to establish independent life-cycle stages for each material. The processes of recycling and demolition are appropriately added to the life-cycle stages. The impact assessment is performed separately for the materials, and results are aggregated at the end of the analysis. The eco-friendly decision-making procedure enables designers to choose an economical, and environmentally friendly, alternative during the planning phase of the construction project. This procedure rationally amalgamates economical value and environmental effects into a single indicator. The life cycle cost (LCC) of a structure can be analysed by using conventional LCC tools, whereas the environmental impact is estimated by LCA. The results from LCC and LCA are then integrated by using either a CO2 conversion method or an analytical hierarchy process (AHP). The CO2 conversion method presents the result as a monetary value, whereas the AHP presents the result as a non-dimensional value. A practical example using a steel box girder bridge and a pre-stressed concrete (PSC) box-girder bridge is also given in order to aid the understanding of the presented procedure.

Ultrasonography-guided fine-needle aspiration cytology for thyroid nodules: an emphasis on one-sampling and biopsy techniques.

The aim of this study was to assess the adequacy and efficacy of ultrasonography (US)-guided fine-needle aspiration cytology (US-FNAC) with one-sampling technique (only one specimen through a single needle pass was obtained during the procedure on each thyroid nodule in each study patient) for the cytological diagnosis of thyroid nodules. In this study, US-FNAC techniques, including "free two-hand," "mixed sampling," "flipping-extraction," and "single-needle-pass" procedures were used to collect thyroid cells from July 2007 to June 2009. The cytopathology results and patients' complications were reviewed retrospectively. Of the 1456 thyroid-nodule samples obtained from 977 patients (1.49 per patient), the incidence of adequate and inadequate samplings was 88.5% (1289/1456) and 11.5% (167/1456), respectively. After thyroid surgery in 396 patients, 568 nodules were confirmed as 353 papillary thyroid carcinomas including one diffuse sclerosing variant, five follicular thyroid carcinomas, three medullary thyroid carcinomas, one anaplastic thyroid carcinoma, one metastatic renal cell carcinoma, two poorly differentiated carcinomas, 17 follicular adenomas, two nodular thyroiditis, two pseudonodules related to thyroiditis, and 182 cases of nodular hyperplasia. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, false-negative rate, and false-positive rate for the US-FNAC were 94.3%, 91.9%, 96.2%, 88.3%, 93.6%, 3.9%, and 2.6%, respectively. There were no significant patients' complications, but 87 patients (8.9%) reported mild pain during or after the procedure. This study showed a good adequacy and efficacy of US-FNAC for thyroid nodules despite one-sampling.

Differentiation between benign and malignant solid thyroid nodules using an US classification system.

OBJECTIVE: To evaluate the diagnostic accuracy of a new ultrasound (US) classification system for differentiating between benign and malignant solid thyroid nodules. MATERIALS AND METHODS: In this study, we enrolled 191 consecutive patients who received real-time US and subsequent US diagnoses for solid thyroid nodules, and underwent US-guided fine-needle aspiration. Each thyroid nodule was prospectively classified into 1 of 5 diagnostic categories by real-time US: "malignant," "suspicious for malignancy," "borderline," "probably benign," and "benign". We evaluated the diagnostic accuracy of thyroid US and the cut-off US criteria by comparing the US diagnoses of thyroid nodules with cytopathologic results. RESULTS: Of the 191 solid nodules, 103 were subjected to thyroid surgery. US categories for these 191 nodules were malignant (n = 52), suspicious for malignancy (n = 16), borderline (n = 23), probably benign (n = 18), and benign (n = 82). A receiver-operating characteristic curve analysis revealed that the US diagnosis for solid thyroid nodules using the 5-category US classification system was very good. The sensitivity, specificity, positive and negative predictive values, and accuracy of US diagnosis were 86%, 95%, 91%, 92%, and 92%, respectively, when benign, probably benign, and borderline categories were collectively classified as benign (negative). CONCLUSION: The diagnostic accuracy of thyroid US for solid thyroid nodules is high when the above-mentioned US classification system is applied.

Ultrasound-guided fine-needle aspiration biopsy of thyroid nodules smaller than 5 mm in the maximum diameter: assessment of efficacy and pathological findings.

OBJECTIVE: The aim of this study was to determine the efficacy of the use of an ultrasound-guided fine-needle aspiration biopsy (US-FNAB) to diagnose thyroid nodules smaller than 5 mm in the maximum diameter and to evaluate pathological findings of small thyroid malignancies. MATERIALS AND METHODS: From May 2007 to April 2008, we evaluated the findings of US-FNABs of small thyroid nodules less than 5 mm in the maximum diameter. The cytopathological findings were retrospectively reviewed and the diagnostic performance of the use of an US-FNAB was examined in all patients. RESULTS: Of 201 small thyroid nodules in 180 patients, there were 162 adequate specimens (81%). Among 180 patients, 75 patients underwent thyroid surgery and 50 malignant and 33 benign nodules were identified based on a pathological examination. All small malignant thyroid nodules were identified as papillary thyroid microcarcinomas (PTMCs). There were 34 (55%) true positive, 0 (0%) false positive, 23 (37%) true negative and five (8%) false negative results for malignancy after performing a first US-FNAB in 62 surgically confirmed nodules. The sensitivity (87%), specificity (100%), positive predictive value (100%), negative predictive value (82%), accuracy (92%), false positive rate (0%) and false negative rate (8%) for an US-FNAB were determined. In 23 patients with a primary PTMC, capsular invasion (9%, 2 of 23), a perithyroidal lymph node metastasis (30%, 7 of 23), the rate of multifocality (9%, 2 of 23) and bilaterality (4%, 1 of 23) were also determined. CONCLUSION: An US-FNAB of thyroid nodules smaller than 5 mm in the maximum diameter is an effective diagnostic procedure.

Ultrasound-guided fine-needle aspiration biopsy of thyroid nodules: comparison in efficacy according to nodule size.

BACKGROUND: The objective of this study was to compare the efficacy and procedure time of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) of thyroid nodules, according to the nodule size. METHODS: US-FNABs of thyroid nodules performed between June 2007 and December 2007 were studied. We divided these patients into three groups according to the largest diameter of their nodules. Group A consisted of patients with thyroid nodules less than or equal to 5 mm, group B of patients with thyroid nodules greater than 5 mm and less than or equal to 10 mm, and group C of patients with thyroid nodules greater than 10 mm. We retrospectively reviewed the cytopathology results and complications in all three patient groups and measured the separate, total US-FNAB procedure time for each of 20 randomly selected thyroid nodules. RESULTS: US-FNAB was performed on 438 thyroid nodules in 253 patients. In groups A, B, and C, the adequacy rates from the first US-FNAB were 79.6% (90/113), 90.6% (125/138), and 95.2% (178/187), respectively. In groups A, B, and C, 113, 138, and 187 thyroid nodules in 100, 120, and 169 patients, respectively, revealed 59, 75, and 126 benign; 12, 11, and 9 suspicious for malignancy; 9, 32, and 29 malignant; 10, 7, and 14 inderminate for malignancy; and 23, 13, and 9 inadequate on the first US-FNAB. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were determined to be 85.7%, 100%, 100%, 94.9%, and 96.1% in group A; 97.7%, 100%, 100%, 98.7%, and 99.1% in group B; and 100%, 99.2%, 97.1%, 100%, and 99.4% in group C. The mean procedure times in groups A, B, and C were 2 minutes 33 seconds, 1 minute 50 seconds, and 1 minute 32 seconds, respectively. There were no significant patient complications in any of the three patient groups. CONCLUSIONS: US-FNAB of thyroid nodules smaller than 5 mm in maximum diameter was less successful, and the sensitivity was lower than those of nodules larger than 5 mm. We considered, however, that the sampling adequacy and efficacy of US-FNAB of thyroid nodules less than 5 mm in maximum diameter was satisfactory in our series and should be similar in other centers with similar characteristics to ours.

Polyion complex micelles composed of all-trans retinoic acid and poly (ethylene glycol)-grafted-chitosan.

The goal of this study is to develop novel types of polyion complex micelles for the drug delivery to brain tumor. Methoxy poly(ethylene glycol) (mPEG)-grafted chitosan (CP) was synthesized in order to make polymeric micelles encapsulating all-trans retinoic acid (ATRA) based on polyion complex formation. Polyion complex micelles were found to have spherical shapes with sizes of about 50 approximately 200 nm. The loading efficiency of micelle was higher than 80% (w/w) for all formulations. 1H nuclear magnetic resonance (NMR) spectra confirmed the formation of polymeric micelles. The CP graft copolymer and ATRA have distinguishing peaks in their 1H NMR spectra. The specific peaks of ATRA disappeared in D2O or DMSO while it appeared at mixtures of D2O/DMSO, indicating that ATRA and chitosan formed ion complex inner-core. In the cell cytotoxicity study using U87MG cells in vitro, polyion complex micelles showed similar cytotoxicity to that of free ATRA. A migration test was performed to investigate the inhibition of tumor cell invasion in vitro. The results suggested that the polyion complex micelles was more effective at inhibiting tumor cell migration than free ATRA.