131 research outputs found
Adaptive path finding algorithm in dynamic environment for warehouse robot
Warehouse robots have been widely used by manufacturers and online retailer to automate good delivery process. One of the fundamental components when designing a warehouse robot is path finding algorithm. In the past, many path finding algorithms had been proposed to identify the optimal path and improve the efficiency in different conditions. For example, A* path finding algorithm is developed to obtain the shortest path, while D* obtains a complete coverage path from source to destination. Although these algorithms improved the efficiency in path finding, dynamic obstacle that may exist in warehouse environment was not considered. This paper presents AD* algorithm, a path finding algorithm that works in dynamic environment for warehouse robot. AD* algorithm is able to detect not only static obstacle but also dynamic obstacles while operating in warehouse environment. In dynamic obstacle path prediction, image of the warehouse environment is processed to identify and track obstacles in the path. The image is pre-processed using perspective transformation, dilation and erosion. Once obstacle has been identified using background subtraction, the server will track and predict future path of the dynamic object to avoid the obstacle
Suppression of STAT3 and HIF-1 Alpha Mediates Anti-Angiogenic Activity of Betulinic Acid in Hypoxic PC-3 Prostate Cancer Cells
Background: Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that betulinic acid (BA), a triterpene from the bark of white birch, had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells. Methodology/Principal Findings: BA inhibited the protein expression and the transcriptional activities of hypoxia-inducible factor-1a (HIF-1a) under hypoxic condition. Consistently, BA blocked hypoxia-induced phosphorylation, DNA binding activity and nuclear accumulation of STAT3. In addition, BA significantly reduced cellular and secreted levels of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Furthermore, BA prevented in vitro capillary tube formation in human umbilical vein endothelial cells (HUVECs) maintained in conditioned medium of hypoxic PC-3 cells, implying anti-angiogenic activity of BA under hypoxic condition. Of note, chromatin immunoprecipitation (ChiP) assay revealed that BA inhibited binding of HIF-1a and STAT3 to VEGF promoter. Furthermore, silencing STAT3 using siRNA transfection effectively enhanced the reduced VEGF production induced by BA treatment under hypoxia. Conclusions/Significance: Taken together, our results suggest that BA has anti-angiogenic activity by disturbing th
A mid-infrared Brillouin laser using ultra-high-Q on-chip resonators
Ultra-high-Q optical resonators have facilitated recent advancements in
on-chip photonics by effectively harnessing nonlinear phenomena providing
useful functionalities. While these breakthroughs, primarily focused on the
near-infrared region, have extended interest to longer wavelengths holding
importance for monitoring and manipulating molecules, the absence of
ultra-high-Q resonators in this region remains a significant challenge. Here,
we have developed on-chip microresonators with a remarkable Q-factor of 38
million, surpassing previous mid-infrared records by over 30 times. Employing
innovative fabrication techniques, including the spontaneous formation of
light-guiding geometries during material deposition, resonators with internal
multilayer structures have been seamlessly created and passivated with
chalcogenide glasses within a single chamber. Major loss factors, especially
airborne-chemical absorption, were thoroughly investigated and mitigated by
extensive optimization of resonator geometries and fabrication procedures. This
allowed us to access the fundamental loss performance offered by doubly
purified chalcogenide glass sources, as demonstrated in their fiber form.
Exploiting this ultra-high-Q resonator, we successfully demonstrated Brillouin
lasing on a chip for the first time in the mid-infrared, with a threshold power
of 91.9 {\mu}W and a theoretical Schawlow-Townes linewidth of 83.45 Hz, far
surpassing carrier phase noise. Our results showcase the effective integration
of cavity-enhanced optical nonlinearities into on-chip mid-infrared photonics.Comment: 10 pages, 5 figures in main script, and 1 figure in method
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Direct Reprogramming of Rat Neural Precursor Cells and Fibroblasts into Pluripotent Stem Cells
Background: Given the usefulness of rats as an experimental system, an efficient method for generating rat induced pluripotent stem (iPS) cells would provide researchers with a powerful tool for studying human physiology and disease. Here, we report direct reprogramming of rat neural precursor (NP) cells and rat embryonic fibroblasts (REF) into iPS cells by retroviral transduction using either three (Oct3/4, Sox2, and Klf4), four (Oct3/4, Sox2, Klf4, and c-Myc), or five (Oct3/4, Sox2, Klf4, c-Myc, and Nanog) genes. Methodology and Principal Findings: iPS cells were generated from both NP and REF using only three (Oct3/4, Sox2, and Klf4) genes without c-Myc. Two factors were found to be critical for efficient derivation and maintenance of rat iPS cells: the use of rat instead of mouse feeders, and the use of small molecules specifically inhibiting mitogen-activated protein kinase and glycogen synthase kinase 3 pathways. In contrast, introduction of embryonic stem cell (ESC) extracts induced partial reprogramming, but failed to generate iPS cells. However, when combined with retroviral transduction, this method generated iPS cells with significantly higher efficiency. Morphology, gene expression, and epigenetic status confirmed that these rat iPS cells exhibited ESC-like properties, including the ability to differentiate into all three germ layers both in vitro and in teratomas. In particular, we found that these rat iPS cells could differentiate to midbrain-like dopamine neurons with a high efficiency. Conclusions/Significance: Given the usefulness of rats as an experimental system, our optimized method would be useful for generating rat iPS cells from diverse tissues and provide researchers with a powerful tool for studying human physiology and disease
Estrogen Receptor-1 Genetic Polymorphisms for the Risk of Premature Ovarian Failure and Early Menopause
Background: The aim of this study was to investigate the role of the estrogen receptor 1 (ESR1) genetic polymorphisms for early menopause that was classified as premature ovarian failure (POF) and early menopause (EM) and to examine whether the associations of ESR1 genetic variants are different for POF and EM. Methods: We selected 100 POF cases and matched 100 EM cases and 200 normal menopause (NM) controls from the Korean Multi-Center Cohort. Among them, we restricted idiopathic POF and EM cases vs NM controls by excluding POF/EM cases with medical/surgical causes. The XbaI (rs9340799) and PvuII (rs2234693) in the ESR1 gene were genotyped. The single-nucleotide polymorphism (SNP) and haplotype effects were analyzed by multivariate logistic regression and haplotype analysis. Also nominal polytomous logistic regression was used to find whether ESR1 genetic variants are differently associated with POF and EM. Results: The global p values for idiopathic POF and EM were 0.08 and 0.39 (SNP-based), and <0.001 and 0.12 (haplotype-based), respectively. The XbaI genetic variant containing the X allele was marginally significantly associated with a reduced risk of idiopathic POF (OR=0.6, 95% CI 0.3-1.0). The P-x haplotype and diplotypes significantly decreased the risk of idiopathic POF (OR=0.5, 95% CI 0.2-0.9; OR 0.4, 95% CI 0.2-0.9, respectively). In contrast from POF, the P-x haplotypes and diplotypes insignificantly increased the risk for both idiopathic EM (p(polytomous)=0.009 for P-x haplotype; p(polytomous)=0.02 for P-x diplotypes). Conclusion: Our results suggest that the ESR1 gene including PvuII and XbaI polymorphisms may modify the risk of idiopathic premature ovarian failure (POF) but not idiopathic early menopause (EM) risk.Bretherick KL, 2008, FERTIL STERIL, V89, P318, DOI 10.1016/j.fertnstert.2007.03.008Chang SH, 2007, MATURITAS, V58, P19, DOI 10.1016/j.maturitas.2007.04.001Kitamura I, 2007, BONE, V40, P1623, DOI 10.1016/j.bone.2007.02.016Molvarec A, 2007, HYPERTENS RES, V30, P205Hsieh YY, 2007, MOL HUM REPROD, V13, P117, DOI 10.1093/molehr/gal099Dvornyk V, 2006, MATURITAS, V54, P19, DOI 10.1016/j.maturitas.2005.08.005Onland-Moret NC, 2005, CANCER CAUSE CONTROL, V16, P1195, DOI 10.1007/s10552-005-0307-5Popat RA, 2005, NEUROLOGY, V65, P383Schuit SCE, 2005, EUR J ENDOCRINOL, V153, P327, DOI 10.1530/eje.1.01973Kok HS, 2005, HUM REPROD, V20, P536, DOI 10.1093/humrep/deh600Ioannidis JPA, 2004, JAMA-J AM MED ASSOC, V292, P2105van der Klift M, 2004, J BONE MINER RES, V19, P1172, DOI 10.1359/JBMR.040215Schuit SCE, 2004, JAMA-J AM MED ASSOC, V291, P2969Wasserman L, 2004, INT J OBESITY, V28, P49, DOI 10.1038/sj.ijo.0802481van Meurs JBJ, 2003, HUM MOL GENET, V12, P1745, DOI 10.1093/hmg/ddg176Gorai I, 2003, J CLIN ENDOCR METAB, V88, P799, DOI 10.1210/jc.2002-020353Laml T, 2002, HUM REPROD UPDATE, V8, P483Herrington DM, 2002, CIRCULATION, V105, P1879, DOI 10.1161/01.CIR.0000016173.98826.88Kobayashi N, 2002, MATURITAS, V41, P193YOO KY, 2002, ASIAN PAC J CANCER P, V3, P85de Bruin JP, 2001, HUM REPROD, V16, P2014Pelletier G, 2000, J CLIN ENDOCR METAB, V85, P4835Weiderpass E, 2000, CARCINOGENESIS, V21, P623Yan G, 2000, J WOMEN HEALTH GEN-B, V9, P275Lorentzon M, 1999, J CLIN ENDOCR METAB, V84, P4597Weel AEAM, 1999, J CLIN ENDOCR METAB, V84, P3146Drummond AE, 1999, MOL CELL ENDOCRINOL, V151, P57, DOI 10.1016/S0303-7207(99)00038-6Christin-Maitre S, 1998, MOL CELL ENDOCRINOL, V145, P75Torgerson DJ, 1997, EUR J OBSTET GYN R B, V74, P63vanderSchouw YT, 1996, LANCET, V347, P714Kobayashi S, 1996, J BONE MINER RES, V11, P306NELSON LM, 1996, REPROD ENDOCRINOLOGY, P1394KAPRIO J, 1995, HUM BIOL, V67, P739CRAMER DW, 1995, FERTIL STERIL, V64, P740EXCOFFIER L, 1995, MOL BIOL EVOL, V12, P921NELSON LM, 1994, J CLIN ENDOCR METAB, V79, P1470CAPLAN GA, 1994, J ROY SOC MED, V87, P200PALMER JR, 1992, AM J EPIDEMIOL, V136, P408BAGUR AC, 1992, CALCIFIED TISSUE INT, V51, P4FRANCESCHI S, 1991, INT J CANCER, V49, P57MEYER JM, 1991, AM J MED GENET, V39, P148TRELOAR SA, 1990, AM J HUM GENET, V47, P137SNOWDON DA, 1989, AM J PUBLIC HEALTH, V79, P709
Short-Term Efficacy of Enzyme Replacement Therapy in Korean Patients with Fabry Disease
Fabrazyme has been widely used for treatment of Fabry disease since its approval by the U.S. Food and Drug Administration in 2003. This study was undertaken to assess the short-term efficacy and safety of enzyme replacement therapy (ERT) for Fabry disease in Korea. Eight male patients and three female symptomatic carriers aged 13 to 48 yr were included. Fabrazyme was administered by intravenous infusion at a dose of 1 mg/kg every 2 weeks. Plasma and urine globotriaosylceramide (GL-3) levels, serum creatinine, creatinine clearance, and 24-hr urine protein levels were measured every 3 months. Kidney biopsies, ophthalmologic exams, and pure tone audiometry were performed before and 1 yr after ERT. Kidney function, including serum creatinine, creatinine clearance, and the 24-hr urine protein level, remained stable during ERT. Plasma and urine GL-3 levels were reduced within 3 to 6 months of ERT initiation. Microvascular endothelial deposits of GL-3 were decreased from renal biopsy specimens after 1 yr of treatment. The severity of sensorineural hearing loss and tinnitus did not improve after ERT. ERT is safe and effective in stabilizing renal function and clearing microvascular endothelial GL-3 from kidney biopsy specimen in Korean patients with Fabry disease
Oncogenic CagA Promotes Gastric Cancer Risk via Activating ERK Signaling Pathways: A Nested Case-Control Study
Background: CagA cellular interaction via activation of the ERK signaling pathway may be a starting point in the development of gastric cancer. This study aimed to evaluate whether genes involved in ERK downstream signaling pathways activated by CagA are susceptible genetic markers for gastric cancer. Methods: In the discovery phase, a total of 580 SNPs within +/-5 kbp of 30 candidate genes were genotyped to examine an association with gastric cancer risk in the Korean Multi-center Cancer Cohort (100 incident gastric cancer case-control sets). The most significant SNPs (raw or permutated p value??0.02) identified in the discovery analysis were re-evaluated in the extension phase using unconditional logistic regression model (400 gastric cancer case-control sets). Combined analyses including pooled-and meta-analysis were conducted to summarize all the results. Results: 24 SNPs in eight genes (ERK, Dock180, C3G, Rap1, Src, CrkL, Mek and Crk) were significantly associated with gastric cancer risk in the individual SNP analyses in the discovery phase (p??0.05). In the extension analyses, ERK rs5999749, Dock180 rs4635002 and C3G rs7853122 showed marginally significant gene-dose effects for gastric cancer. Consistently, final combined analysis presented the SNPs as significantly associated with gastric cancer risk (OR = 1.56, [95% CI: 1.19-2.06], OR = 0.61, [95% CI: 0.43-0.87], OR = 0.59, [95% CI: 0.54-0.76], respectively). Conclusions: Our findings suggest that ERK rs5999749, Dock180 rs4635002 and C3G rs7853122 are genetic determinants in gastric carcinogenesis
Genetic Susceptibility on CagA-Interacting Molecules and Gene-Environment Interaction with Phytoestrogens: A Putative Risk Factor for Gastric Cancer
OBJECTIVES: To evaluate whether genes that encode CagA-interacting molecules (SRC, PTPN11, CRK, CRKL, CSK, c-MET and GRB2) are associated with gastric cancer risk and whether an interaction between these genes and phytoestrogens modify gastric cancer risk. METHODS: In the discovery phase, 137 candidate SNPs in seven genes were analyzed in 76 incident gastric cancer cases and 322 matched controls from the Korean Multi-Center Cancer Cohort. Five significant SNPs in three genes (SRC, c-MET and CRK) were re-evaluated in 386 cases and 348 controls in the extension phase. Odds ratios (ORs) for gastric cancer risk were estimated adjusted for age, smoking, H. pylori seropositivity and CagA strain positivity. Summarized ORs in the total study population (462 cases and 670 controls) were presented using pooled- and meta-analysis. Plasma concentrations of phytoestrogens (genistein, daidzein, equol and enterolactone) were measured using the time-resolved fluoroimmunoassay. RESULTS: SRC rs6122566, rs6124914, c-MET rs41739, and CRK rs7208768 showed significant genetic effects for gastric cancer in both the pooled and meta-analysis without heterogeneity (pooled OR = 3.96 [95% CI 2.05-7.65], 1.24 [95% CI = 1.01-1.53], 1.19 [95% CI = 1.01-1.41], and 1.37 [95% CI = 1.15-1.62], respectively; meta OR = 4.59 [95% CI 2.74-7.70], 1.36 [95% CI = 1.09-1.70], 1.20 [95% CI = 1.00-1.44], and 1.32 [95% CI = 1.10-1.57], respectively). Risk allele of CRK rs7208768 had a significantly increased risk for gastric cancer at low phytoestrogen levels (p interaction<0.05). CONCLUSIONS: Our findings suggest that SRC, c-MET and CRK play a key role in gastric carcinogenesis by modulating CagA signal transductions and interaction between CRK gene and phytoestrogens modify gastric cancer risk
The role of TNF genetic variants and the interaction with cigarette smoking for gastric cancer risk: a nested case-control study
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the role of <it>TNF </it>genetic variants and the combined effect between <it>TNF </it>gene and cigarette smoking in the development of gastric cancer in the Korean population.</p> <p>Methods</p> <p>We selected 84 incident gastric cancer cases and 336 matched controls nested within the Korean Multi-Center Cancer Cohort. Six SNPs on the <it>TNF </it>gene, <it>TNF</it>-α-238 G/A, -308 G/A, -857 C/T, -863 C/A, -1031 T/C, and <it>TNF</it>-β 252 A/G were genotyped. The ORs (95% CIs) were calculated using unconditional logistic regression model to detect each SNP and haplotype-pair effects for gastric cancer. The combined effects between the <it>TNF </it>gene and smoking on gastric cancer risk were also evaluated. Multi dimensionality reduction (MDR) analyses were performed to explore the potential <it>TNF </it>gene-gene interactions.</p> <p>Results</p> <p><it>TNF</it>-α-857 C/T containing the T allele was significantly associated with an increased risk of gastric cancer and a linear trend effect was observed in the additive model (OR = 1.6, 95% CI 1.0–2.5 for CT genotype; OR = 2.6, 95% CI 1.0–6.4 for TT genotype). All haplotype-pairs that contained TCT or CCC of <it>TNF</it>-α-1031 T/C, <it>TNF</it>-α-863 C/A, and <it>TNF</it>-α-857 C/T were associated with a significantly higher risk for gastric cancer only among smokers. In the MDR analysis, regardless of smoking status, <it>TNF</it>-α-857 C/T was included in the first list of SNPs with a significant main effect.</p> <p>Conclusion</p> <p><it>TNF</it>-α-857 C/T polymorphism may play an independent role in gastric carcinogenesis and the risk for gastric cancer by <it>TNF </it>genetic effect is pronounced by cigarette smoking.</p
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