Adjoint method and inverse design for diffractive beam splitters

Diffractive optical elements with a large diffraction angle require feature sizes down to sub-wavelength dimensions, which require a rigorous electromagnetic computational model for calculation. However, the computational optimization of these diffractive elements is often limited by the large number of design parameters, making parametric optimization practically impossible due to large computation times. The adjoint method allows calculating the gradient of the target function with respect to all design variables with only two electromagnetic simulations, thus enabling gradient optimization. Here, we present the adjoint method for modeling wide-angle diffractive optical elements like 7x7 beam splitters with a maximum 53{\deg} diffraction angle and a non-square 5x7 array generating beam splitter. After optimization we obtained beam splitter designs with a uniformity error of 16.35% (7x7) and 6.98% (5x7), respectively. After reviewing the experimental results obtained from fabricated elements based on our designs, we found that the adjoint optimization method is an excellent and fast method to design wide-angle diffractive fan-out beam-splitters.Comment: 8 pages, 3 figures, submitted to SPIE LASE 202

The effect of heating insufflation gas on acid-base alterations and core temperature during laparoscopic major abdominal surgery

BACKGROUND: Carbon dioxide (CO(2)) has different biophysical properties under different thermal conditions, which may affect its rate of absorption in the blood and the related adverse events. The present study was aimed to investigate the effects of heating of CO(2) on acid-base balance using Stewart's physiochemical approach, and body temperature during laparoscopy. METHODS: Thirty adult patients undergoing laparoscopic major abdominal surgery were randomized to receive either room temperature CO(2) (control group, n = 15) or heated CO(2) (heated group, n = 15). The acid-base parameters were measured 10 min after the induction of anesthesia (T1), 40 min after pneumoperitoneum (T2), at the end of surgery (T3) and 1 h after surgery (T4). Body temperature was measured at 15-min intervals until the end of the surgery. RESULTS: There were no significant differences in pH, PaCO(2), the apparent strong ion difference, the strong ion gap, bicarbonate ion, or lactate between two groups throughout the whole investigation period. At T2, pH was decreased whereas PaCO(2) was increased in both groups compared with T1 but these changes were not significantly different. Body temperatures in the heated group were significantly higher than those in the control group from 30 to 90 min after pneumoperitoneum. CONCLUSIONS: The heating of insufflating CO(2) did not affect changes in the acid-base status and PaCO(2) in patients undergoing laparoscopic abdominal surgery when the ventilator was set to maintain constant end-tidal CO(2). However, the heated CO(2) reduced the decrease in the core body temperature 30 min after the pneumoperitoneum.ope

Sorbus alnifolia protects dopaminergic neurodegeneration in Caenorhabditis elegans

Context: The twigs of Sorbus alnifolia (Sieb. et Zucc.) K. Koch (Rosaceae) have been used to treat neuro- logical disorders as a traditional medicine in Korea. However, there are limited data describing the efficacy of S. alnifolia in Parkinson’s disease (PD). Objective: This study was conducted to identify the protective effects of the methanol extracts of S. alnifolia (MESA) on the dopaminergic (DA) neurodegeneration in Caenorhabditis elegans. Materials and methods: To test the neuroprotective action of MESA, viability assay was performed after 48 h exposure to 1-methyl-4-phenylpyridine (MMPþ) in PC12 cells and C. elegans (400 lM and 2 mM of MMPþ, respectively). Fluorescence intensity was quantified using transgenic mutants such as BZ555 (Pdat-1::GFP) and and UA57 (Pdat-1::GFP and Pdat-1::CAT-2) to determine MESA’s effects on DA neurode- generation in C. elegans. Aggregation of a-synuclein was observed using NL5901 strain (unc-54p::a- synuclein::YFP). MESA’s protective effects on the DA neuronal functions were examined by food-sensing assay. Lifespan assay was conducted to test the effects of MESA on the longevity. Results: MESA restored MPPþ-induced loss of viability in both PC12 cells and C. elegans (85.8% and 54.9%, respectively). In C. elegans, MESA provided protection against chemically and genetically-induced DA neurodegeneration, respectively. Moreover, food-sensing functions were increased 58.4% by MESA in the DA neuron degraded worms. MESA also prolonged the average lifespan by 25.6%. However, MESA failed to alter a-synuclein aggregation. Discussion and conclusions: These results revealed that MESA protects DA neurodegeneration and recov- ers diminished DA neuronal functions, thereby can be a valuable candidate for the treatment of PD

Construction of Bacillus thuringiensis simulant strains suitable for environmental release

For a surrogate bacterium to be used in outdoor studies, it is important to consider environmental and human safety and ease of detection. Recently, Bacillus thuringiensis, a popular bioinsecticide bacterium, has been gaining attention as a surrogate bacterium for use in biodefense. In this study, we constructed simulant strains of B. thuringiensis with enhanced characteristics for environmental studies. Through transposon mutagenesis, pigment genes were inserted into the chromosome, producing yellow-colored colonies for easy detection. To prevent persistence of spores in the environment, a genetic circuit was designed to produce a spore without sporulation capability. Two loxP sites were inserted, one on each side of the spo0A gene, which encodes a sporulation master regulator, and a sporulation-dependent Cre expression cassette was inserted into the chromosome. This genetic circuit successfully deleted spo0A during sporulation, producing spores that lacked the spo0A gene. In addition, two major α/β-type small acid-soluble spore protein (SASP) genes, predicted by synteny analysis, were deleted. The spores of the mutant strain showed increased UV-C sensitivity and quickly lost viability when tested in a solar simulator. When the spores of the mutant strain were administered to the lungs of BALB/c mice, cells were quickly removed from the body, suggesting enhanced in vivo safety. All strains constructed in this study contain no antibiotic resistance markers and all heterologous genes were inserted into the chromosome, which are useful features for simulants to be released into the environment

Risk stratification of symptomatic brain metastases by clinical and FDG PET parameters for selective use of prophylactic cranial irradiation in patients with extensive disease of small cell lung cancer

Purpose: To identify risk factors for developing symptomatic brain metastases and evaluate the impact of prophylactic cranial irradiation (PCI) on brain metastasis-free survival (BMFS) and overall survival (OS) in extensive disease small cell lung cancer (ED-SCLC). Materials and methods: Among 190 patients diagnosed with ED-SCLC who underwent FDG PET/CT and brain Magnetic Resonance Imaging (MRI) prior to treatment, 53 (27.9%) received PCI while 137 (72.1%) did not. Prognostic index predicting a high risk of symptomatic brain metastases was calculated for the group without receiving PCI (observation group, n = 137) with Cox regression model. Results: Median follow-up time was 10.6 months. Multivariate Cox regression showed that the following three factors were associated with a high risk of symptomatic brain metastases: the presence of extrathoracic metastases (p = 0.004), hypermetabolism of bone marrow or spleen on FDG PET (p < 0.001), and high neutrophil-to-lymphocyte ratio (p = 0.018). PCI significantly improved BMFS in high-risk patients (1-year rate: 94.7% vs. 62.1%, p = 0.001), but not in low-risk patients (1-year rate: 100.0% vs. 87.7%, p = 0.943). However, PCI did not improve OS in patients at high risk for symptomatic brain metastases (1-year rate: 65.2% vs. 50.0%, p = 0.123). Conclusion: Three prognostic factors (the presence of extrathoracic metastases, hypermetabolism of bone marrow or spleen on FDG PET, and high neutrophil-to-lymphocyte ratio) were associated with a high risk of symptomatic brain metastases in ED-SCLC. PCI was beneficial for patients at a high risk of symptomatic brain metastases in terms of BMFS, but not OS. Thus, selective use of PCI in ED-SCLC according to the risk stratification is recommended. (C) 2020 Elsevier B.V. All rights reserved.

Association between Dopamine D4 Receptor Gene Polymorphism and Scores on a Continuous Performance Test in Korean Children with Attention Deficit Hyperactivity Disorder

OBJECTIVE: The aim of this study was to evaluate the association between a variable number of tandem repeats polymorphism at the dopamine D4 receptor gene (DRD4) and the performance of children with attention deficit hyperactivity disorder (ADHD) in a continuous performance test (CPT). METHODS: This study included 72 ADHD children (mean age=9.39+/-2.05 years) who were recruited from one child psychiatric clinic. The omission errors, commission errors, reaction time and reaction standardization in the CPT were computed. The number of 48-base pairs tandem repeats in the exon III of DRD4 was analyzed in a blind manner. RESULTS: The homozygosity of the 4-repeat allele at DRD4 was significantly associated with fewer commission errors (t=2.364, df=28.685, p=0.025) and standard deviation of reaction time (t=2.351, df=24.648, p=0.027) even after adjusting for age. The results of analyses of CPT measured values among three groups showed that the group with higher frequency of the 4-repeat allele showed a lower mean score of commission errors (F=4.268, df=2, p=0.018). CONCLUSION: These results suggest a protective role of 4-repeat allele of the DRD4 polymorphisms on commission errors in the CPT in children with ADHDope

Variability of Response Time as a Predictor of Methylphenidate Treatment Response in Korean Children with Attention Deficit Hyperactivity Disorder

PURPOSE: Methylphenidate (MPH) is an effective medication for the treatment of attention deficit hyperactivity disorder (ADHD). However, about 30% of patients do not respond to or are unable to tolerate MPH. Based on previous findings, we hypothesized that great variability in response time (RT) among Korean children with ADHD on a computerized continuous performance attention test would be related to poor MPH treatment response. MATERIALS AND METHODS: Children (ages 6-18 years) with ADHD were recruited for a prospective 12-week, open-labeled, multicenter study to examine optimal dosage of OROS methylphenidate. Of the 144 subjects selected, 28 dropped out due to adverse events, medication noncompliance, or follow-up loss, and an additional 26 subjects with comorbid disorders were excluded from statistical analyses. We defined 'responders' as subjects who received a score of less than 18 on the attention deficit hyperactivity disorder rating scale (ARS; Korean version, K-ARS) and a score of 1 or 2 on the Clinical Global Impression-Improvement scale (CGI-I). RT variability was assessed with the ADHD diagnostic system (ADS). RESULTS: Fifty-nine (67%) subjects responded to MPH treatment. The non-responders showed greater RT variability at baseline (Mann Whitney U = 577.0, p < 0.01). Baseline RT variability was a significant predictor of MPH response (Nagelkerke R(2) = 0.136, p < 0.01). It predicted 94.9% of responder, 17.2% of non-responder and 69.3% of overall group. CONCLUSION: High RT variability may predict poor response to MPH treatment in children with ADHDope