A 28 GHz GaN 6-Bit Phase Shifter MMIC with Continuous Tuning Calibration Technique.

A 28 GHz digitally controlled 6-bit phase shifter with a precision calibration technique in GaN high-electron mobility transistor (HEMT) technology is presented for Ka-band phased-array systems and applications. It comprises six stages, in which stages 1 and 2 for 5.625° and 11.25° are designed in the form of a switched-line circuit, and stages 3, 4, and 5 for 22.5°, 45°, and 90° are designed in the form of a switched-filter circuit. The final stage 6 for 180° is designed in a single-to-differential balun followed by a single-pole double-throw (SPDT) switch for achieving an efficient phase inversion. A novel continuous tuning calibration technique is proposed to improve the phase accuracy. It controls the gate bias voltage of off-state HEMTs at the stage 6 SPDT switch for fine calibration of the output phase. Fabricated in a 0.15 µm GaN HEMT process using a die size of 1.75 mm2, the circuit produces 64 phase states at 28 GHz with a 5.625° step. The experimental results show that the Root-Mean-Square (RMS) phase error is significantly improved from 8.56° before calibration to 1.08° after calibration. It is also found that the calibration does not induce significant changes for other performances such as the insertion loss, RMS amplitude error, and input-referred P1dB. This work successfully demonstrates that the GaN technology can be applied to millimeter-wave high-power phased-array transceiver systems.

NPR1 Translocation from Chloroplast to Nucleus Activates Plant Tolerance to Salt Stress.

Chloroplasts play crucial roles in biotic and abiotic stress responses, regulated by nuclear gene expression through changes in the cellular redox state. Despite lacking the N-terminal chloroplast transit peptide (cTP), nonexpressor of pathogenesis-related genes 1 (NPR1), a redox-sensitive transcriptional coactivator was consistently found in the tobacco chloroplasts. Under salt stress and after exogenous application of H2O2 or aminocyclopropane-1-carboxylic acid, an ethylene precursor, transgenic tobacco plants expressing green fluorescent protein (GFP)-tagged NPR1 (NPR1-GFP) showed significant accumulation of monomeric nuclear NPR1, irrespective of the presence of cTP. Immunoblotting and fluorescence image analyses indicated that NPR1-GFP, with and without cTP, had similar molecular weights, suggesting that the chloroplast-targeted NPR1-GFP is likely translocated from the chloroplasts to the nucleus after processing in the stroma. Translation in the chloroplast is essential for nuclear NPR1 accumulation and stress-related expression of nuclear genes. An overexpression of chloroplast-targeted NPR1 enhanced stress tolerance and photosynthetic capacity. In addition, compared to the wild-type lines, several genes encoding retrograde signaling-related proteins were severely impaired in the Arabidopsis npr1-1 mutant, but were enhanced in NPR1 overexpression (NPR1-Ox) transgenic tobacco line. Taken together, chloroplast NPR1 acts as a retrograding signal that enhances the adaptability of plants to adverse environments.

Measurement of serum anti-Müllerian hormone by revised Gen II or automated assay: Reproducibility under various blood/serum storage conditions.

OBJECTIVE: We investigated the agreement between anti-Müllerian hormone (AMH) levels measured with revised Gen II (rev-Gen II) and automated AMH (Access) assays and evaluated the reproducibility of each method under various blood/serum storage conditions. METHODS: AMH levels in blood samples from 74 volunteers were measured by rev-Gen II and Access assays under various conditions: immediate serum separation and AMH measurement (fresh control); serum stored at -20 °C and AMH measured after 48 hours, 1 week, and 2 years; serum stored at 0 to 4 °C and AMH measured after 48 hours and 1 week; and blood kept at room temperature and delayed serum separation after 48 hours and 1 week, with immediate AMH measurement. RESULTS: In fresh controls, all rev-Gen II-AMH values were higher than comparable Access-AMH values (difference, 8.3% to 19.7%). AMH levels measured with the two methods were strongly correlated for all sample conditions (r=0.977 to 0.995, all p<0.001). For sera stored at -20 °C or 0 to 4 °C for 48 hours, Access-AMH values were comparable to control measurements, but rev-Gen II-AMH values were significantly lower. AMH levels in sera stored at -20 °C or 0 to 4 °C for 1 week were significantly lower than in fresh controls, irrespective of method. Across methods, long-term storage at -20 °C for 2 years yielded AMH measurements significantly higher than control values. When serum separation was delayed, rev-Gen II-AMH values were significantly lower than control measurements, but Access-AMH values varied. CONCLUSION: The rev-Gen II and Access-AMH assays showed varying reproducibility across blood/serum storage conditions, but automated Access yielded superior stability to rev-Gen II.

Fat3 regulates neural progenitor cells by promoting Yap activity during spinal cord development.

Early embryonic development of the spinal cord requires tight coordination between proliferation of neural progenitors and their differentiation into distinct neuronal cell types to establish intricate neuronal circuits. The Hippo pathway is one of the well-known regulators to control cell proliferation and govern neural progenitor cell number, in which the downstream effector Yes-associated protein (Yap) promotes cell cycle progression. Here we show that an atypical cadherin Fat3, expressed highly in the neural tube, plays a critical role in maintaining proper number of proliferating progenitors. Knockdown of Fat3 in chick neural tube down-regulates expression of the proliferation markers but rather induces the expression of neural markers in the ventricular zone. We further show that deletion of Fat3 gene in mouse neural tube depletes neural progenitors, accompanied by neuronal gene expression in the ventral ventricular zone of the spinal cord. Finally, we found that Fat3 regulates the phosphorylation level of Lats1/2, the upstream kinase of Yap, resulting in dephosphorylation and stabilization of Yap, suggesting Yap as a key downstream effector of Fat3. Our study uncovers another layer of regulatory mechanisms in controlling the activity of Hippo signaling pathway to regulate the size of neural progenitor pools in the developing spinal cord.

Reference Values for the Revised Anti-Müllerian Hormone Generation II Assay: Infertile Population-based Study.

Anti-Müllerian hormone (AMH) is now accepted as an important clinical marker of ovarian reserve and is increasingly measured as an initial evaluation at infertility clinics. The aim of this study was to establish reference values for the revised second generation (Gen II) assay using population-based data. In this population-based cohort study, AMH data from unselected infertile women aged 25-45 years from June 2013 to June 2014 (n = 15,801) were collected. The AMH values were measured using the revised Gen II assay. We established and validated 5 AMH-age regression models. Based on the optimal AMH-age model, reference values and centile charts were obtained. The quadratic model (log AMH = 0.410 × age -0.008 × age² -3.791) was the most appropriate for describing the age-dependent decrease in AMH measured using the revised Gen II assay. This is the largest population-based study to establish age-specific reference values of AMH using the revised Gen II assay. These reference values may provide more specific information regarding the ovarian reserve estimation of infertile women.

Serologic screening of pregnant Korean women for primary human cytomegalovirus infection using IgG avidity test.

BACKGROUND: Primary human cytomegalovirus (CMV) infection during pregnancy is a major cause of congenital malformation. We detected primary CMV infection in pregnant Korean women by using an algorithm that comprises CMV IgG, IgM, and IgG avidity tests. METHODS: During a 2-month period, 744 pregnant women who were at 10-19 weeks of gestation were consecutively enrolled in this study. Human anti-CMV IgG and IgM levels in their sera were determined by chemiluminescence immunoassays. Serum samples from the women who were positive for CMV IgG and IgM were assayed by the ARCHITECT CMV IgG avidity test in order to distinguish primary from non-primary CMV infection. Gross examination of the neonates of the women who were positive for CMV IgM was conducted. RESULTS: The seroprevalence of CMV IgG and IgM was estimated to be 98.1% and 1.7%, respectively. The samples from all the women who were positive for CMV IgM or with grey zone results contained high avidity CMV IgG. Seven women with positive CMV IgG and IgM results who completed follow-up up to delivery showed no gross evidence of in utero CMV transmission. CONCLUSIONS: Maternal primary CMV infection was not detected in any of the pregnant women included in this study cohort. CMV IgG avidity test enabled the identification of women who were at a low risk of transmitting CMV infection and provided informative for subsequent pregnancy outcomes. Compared to previous studies, the seroprevalence of CMV IgG antibody across pregnant Korean women remained unchanged.

[Usefulness of NMP22 BladderChek for the diagnosis and monitoring of bladder cancer].

BACKGROUND: As bladder cancer is a superficial tumor with frequent recurrences, early detection and confirmation of recurrence are important. We evaluated the usefulness of NMP22 BladderChek (NMP22BC) for the diagnosis and monitoring of bladder cancer. METHODS: From July to December 2004, we enrolled in the study 670 patients who visited the urology clinic in Ewha Womans University, Dongdaemun Hospital with hematuria or dysuria and were tested with NMP22BC. We also performed the NMP22BC and BTA stat tests simultaneously in 21 patients and interference test in 10 patients. RESULTS: NMP22BC tests were negative in 97% of the patients who had been cured of bladder cancer and were positive in 95% of the patients with recurred bladder cancer. The diagnostic sensitivity, specificity, positive and negative predictive value, and efficiency were 95.0%, 91.5%, 25.7%, 99.8%, and 91.6%, respectively, with 8.5% false positive and 5% false negative rates. Fifty-five patients showed false positive in the NMP22BC test, the main cause of which was the presence of WBCs in urine. There was a good agreement between the NMP22BC and BTA stat tests (kappa agreement value, 0.5; P=0.008). According to the interference test, two patients with more than 3+ in leukocyte esterase results showed false positive in the NMP22BC test. CONCLUSIONS: NMP22BC test was simple to perform, rapid to produce the results, and useful in diagnosing a bladder cancer recurrence; the test shows a high efficiency with a high sensitivity, specificity, negative predictive value, and low false negative rate.