Author Correction: A frequency reconfigurable dipole antenna with solid-state plasma in silicon.

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A frequency reconfigurable dipole antenna with solid-state plasma in silicon.

A frequency reconfigurable dipole antenna based on a silicon radiator is presented. The silicon radiator is activated with the aid of highly dense solid-state plasma by injecting carriers into the intrinsic region of p-i-n diodes. The fabrication and design guideline of the reconfigurable dipole antenna with this plasma radiator are described. When the plasma radiator is activated or deactivated, the length of the dipole arm changes, which means that the operating frequency of the dipole antenna is reconfigurable. When all the channels in the plasma radiator are activated, the operating frequency is tuned from 6.3 GHz to 4.9 GHz. The measured tunable bandwidth of our fabricated dipole antenna is approximately 31%, which is a practical value in comparison to conventional frequency reconfigurable antennas whose tunable bandwidth is in a range from 20% to 50%. To further support the validity of our results, we provide the well-matched simulation results from an antenna simulation. These results demonstrate that silicon with its commercial technology, which has not attracted attention in comparison to a metal antennas, is a promising tunable material for a frequency reconfigurable antenna. This plasma-based reconfigurable antenna has great potential for use in the dynamic communication environment.

Cutoff fluorescence loss for the recovery of incipient carious lesions after fluoride application in primary teeth: A clinical study.

PURPOSE: Early detection and diagnosis of incipient caries are the keys to achieving a favorable prognosis. Monitoring of pathological changes based on clinical evidence leads to an accurate prognosis. Therefore, this clinical study investigated changes in minerals of incipient carious lesions using quantitative light-induced fluorescence-digital (QLF-D) after applying professional fluoride treatment to children, with improvement of the lesion severity assessed based on the fluorescence loss (ΔF) value obtained using QLF-D. METHODS: This study examined 90 incipient enamel lesions on the primary teeth of 27 children aged between 4 and 10 years. QLF-D images were obtained before and after the application of 1.23% acidulated phosphate fluoride gel for 1 min, and the ΔF values at 0 and 4 weeks (ΔF(0) and ΔF(4), respectively) and the recovery rates (RΔF) of the lesions were evaluated. Receiver operating characteristic curve analysis was used to calculate the cutoff ΔF(0) value at which recovery of the lesion with fluoride treatment remained feasible. RESULTS AND CONCLUSION: The recovery patterns of ΔF 4 weeks after fluoride application differed depending on the ΔF(0) values. The incipient lesions with ΔF(0) values of less than -13.00 recovered 4 weeks after fluoride application (P <  0.001) and had an average RΔF value of 19.27%. The results indicate that a ΔF(0) cutoff value can be determined for predicting the effects of remineralization after fluoride application and quantitative prognostic data can be provided to patients.

Reconfigurable Yagi-Uda antenna based on a silicon reflector with a solid-state plasma.

This paper describes the fabrication and characterization of a reconfigurable Yagi-Uda antenna based on a silicon reflector with a solid-state plasma. The silicon reflector, composed of serially connected p-i-n diodes, forms a highly dense solid-state plasma by injecting electrons and holes into the intrinsic region. When this plasma silicon reflector is turned on, the front-realized gain of the antenna increases by more than 2 dBi beyond 5.3 GHz. To achieve the large gain increment, the structure of the antenna is carefully designed with the aid of semiconductor device simulation and antenna simulation. By using an aluminum nitride (AlN) substrate with high thermal conductivity, self-heating effects from the high forward current in the p-i-n diode are efficiently suppressed. By comparing the antenna simulation data and the measurement data, we estimated the conductivity of the plasma silicon reflector in the on-state to be between 104 and 105 S/m. With these figures, silicon material with its technology is an attractive tunable material for a reconfigurable antenna, which has attracted substantial interest from many areas, such as internet of things (IoT) applications, wireless network security, cognitive radio, and mobile and satellite communications as well as from multiple-input-multiple-output (MIMO) systems.

Susceptibility of Escherichia coli from community-acquired urinary tract infection to fosfomycin, nitrofurantoin, and temocillin in Korea.

With increase of multi-drug resistant Escherichia coli in community-acquired urinary tract infections (CA-UTI), other treatment option with a therapeutic efficacy and a low antibiotic selective pressure is necessary. In this study, we evaluated in vitro susceptibility of E. coli isolates from CA-UTI to fosfomycin (FM), nitrofurantoin (NI), temocillin (TMO) as well as trimethoprim-sulfamethoxazole (SMX), ciprofloxacin (CIP) and cefepime (FEP). The minimal inhibitory concentrations were determined by E-test or agar dilution method according to the Clinical and Laboratory Standards Institute guidelines, using 346 E. coli collected in 12 Korean hospitals from March 2010 to February 2011. FM, NI and TMO showed an excellent susceptibility profile; FM 100% (346/346), TMO 96.8% (335/346), and NI 99.4% (344/346). Conversely, resistance rates of CIP and SMX were 22% (76/346) and 29.2% (101/349), respectively. FEP still retained an activity of 98.5%. In Korea, NI and TMO in addition to FM are a good therapeutic option for uncomplicated CA-UTI, especially for lower UTI.

Comparison of the clinical characteristics of diabetic and non-diabetic women with community-acquired acute pyelonephritis: a multicenter study.

OBJECTIVES: Purpose of this study was to compare clinical characteristics and treatment outcomes in diabetic and non-diabetic women with community-acquired APN (CA-APN). METHODS: We prospectively collected and analyzed clinical data of women with CA-APN who attended 11 hospitals in South Korea from March 2010 to February 2012. RESULTS: Of a total of 775 patients, 246 (31.7%) were diabetic and 529 (68.3%) non-diabetic. Fewer of the diabetic patients had flank pain (27.6% vs. 37.2% P = 0.009), symptoms of lower urinary tract infection (57.3% vs. 69.6% P = 0.001) and costovertebral angle tenderness (54.9% vs. 72.2% P < 0.001). However, more of them had C-reactive protein ≥20 mg/dL (40.7% vs. 27.4% P < 0.001), azotemia (29.3% vs. 13.4% P < 0.001) and bacteremia (53.7% vs. 38.2% P < 0.001). Final clinical failure rates and deaths did not differ between the two groups: 6.9% vs. 4.5%, P = 0.169; 2.0% vs. 1.7%, P = 0.747. However, hospitalization was longer in the diabetics than the non-diabetics (median 9.0 days vs. 7.0 days, P < 0.001). In logistic regression, diabetes was independently associated with longer hospitalization (OR 1.7, CI 1.1-2.7, P = 0.011), together with nausea/vomiting, history of admission within 1 year, bacteremia, azotemia, and dementia, as well as extended-spectrum ß-lactamase (ESBL)-positivity and fluoroquinolone resistance of uropathogens. CONCLUSIONS: CA-APN patients with diabetes have more severe disease manifestations and require longer hospitalization than non-diabetic patients although their clinical findings are less clear than those of non-diabetic patients.

Fluoroquinolone resistance in uncomplicated acute pyelonephritis: epidemiology and clinical impact.

The objectives of this study were to investigate antibiotic resistance in urinary pathogens from Korean patients with uncomplicated acute pyelonephritis (UAPN), and to determine the effect of fluoroquinolone (FQ) resistance on clinical outcome in those patients with UAPN initially treated with FQ. Clinical and microbiologic data for all the APN patients attending 14 hospitals in South Korea in 2008 were collected retrospectively. Urinary pathogens were identified in 719 cases, and Escherichia coli was the most common pathogen (661/719, 91.9%). Antibiotic susceptibilities to several E. coli antibiotics were as follows: ciprofloxacin, 84.1%; trimethoprim-sulfamethoxazola (TMP-SMX), 67.2%; and extended-spectrum beta-lactamase-negative, 92.4%. FQ was the most frequent antibiotic prescribed for UAPN (45.3% intravenously and 53.9% by mouth). We compared clinical outcomes and hospital days in patients with FQ-resistant (32) and FQ-sensitive E. coli (173) who received FQ as initial empirical therapy. Clinical cure was higher in the FQ-sensitive group (78% vs. 91%, p=0.027), and hospital days were longer in the FQ-resistant group (9.6±5.5 days vs. 7±3.5 days, p=0.001). In conclusion, FQ-sensitivity of E. coli from UAPN was 84.1%. FQ treatment of UAPN caused by FQ-resistant E. coli has a lower cure rate and involves longer hospital stay than FQ treatment of cases caused by FQ-sensitive E. coli.

[Smoking and colorectal cancer risk in the Korean elderly].

OBJECTIVES: The incidence of colorectal cancer increased greatly among the elderly in Korea, but the relationship between smoking and colon cancer remains controversial. Few studies have targeted Asian elderly people. We analyzed the smoking status, the amount smoked, and the smoking duration as risk factors of colorectal cancer to determine their association and causality. METHODS: The cohort members (n = 14,103) consisted of 4,694 males and 9,409 females, and they were derived from the Korea Elderly Phamacepidemilogic Cohort (KEPEC), which was a population-based dynamic cohort. They were aged 65 years or more and they lived in Busan Metropolitan City between from 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). The baseline information was surveyed by a self-administered mailed questionnaire; after 8.7 person-years of mean follow up period, 100 cases of colorectal cancer occurred. The adjusted relative ratio (aRR) of smoking status, the smoking amount and the smoking duration were calculated from the Cox's proportional hazard model with the never-smokers as a reference group and the Cox model controlled for age, gender, precancerous lesions of CRC, medication history of NSAIDs and antibiotics, the alcohol drinking status and BMI. RESULTS: Compared with the never smokers, the aRRs were 2.03 (95% CI = 1.02-4.03) and 1.36 (95% CI = 0.80-2.32) for the ex-smokers and current smokers, respectively. Statistical significant trends were not observed for the dose-relationship among the elderly, either for the mean daily amount smoked (p for trend = 0.28) or for the total amount (p for trend = 0.15). Still, the aRRs were 1.51 (95% Cl = 0.97-2.34) for the elderly who smoked less than 40 years and 2.35 (95% CI = 1.16-4.74) for the elderly who had 40 years or more of smoking (p for trend = 0.06). Smokers who started smoking before the age 20 had an increased aRR of 2.15 (95% CI = 1.17-3.93) compared to the never smokers. CONCLUSIONS: After controlling for age, gender, precancerous lesion of CRC, medication history of NSAIDs and antibiotics, the alcohol drinking status and BMI, smoking increases the risk of colorectal cancer among elderly people. The age when starting smoking is also important.

A case infested with diphyllobothrium latum / 대한내과학회지

No abstract available.