Energy Velocity in Negative Group Index Structures

2008 ◽  
Author(s):  
Weiguo Yang ◽  
John O. Schenk ◽  
Michael A. Fiddy
Keyword(s):  
Group Index ◽  
Index Structures ◽  
Negative Group

Guided Modes of Positive and Negative Group Index in the Honeycomb Photonic Crystal Waveguides

2013 ◽  
Vol 717 ◽  
pp. 153-157
Author(s):  
W. Amorntep ◽  
P. Wanchai
Keyword(s):  
Photonic Crystal ◽  
Optical Communication ◽  
Photon Emission ◽  
Honeycomb Lattice ◽  
Group Index ◽  
Photonic Crystal Waveguide ◽  
Negative Group ◽  
Optical Communication System ◽  
Guided Modes ◽  
Photon Source

A guided mode of positive and negative group index structure is essential to quantum optics for design and development of high efficiency optical devices which are useful to security optical communication system and to diverse applications such as Optical Time-Division-Multiplexing, Optical Switch, Laser, LED, Entangled Photon Source and Single Photon Source. Thus, we proposed to develop an efficient photon emission along line defect of two-dimensional honeycomb photonic crystal waveguide in the silicon slab. The honeycomb lattice of circular air holes on a silicon plate is simulated to obtain two nearest guided modes between positive and negative group index regimes. This significant property shows the potential applied guided modes of photonic crystal waveguide enhancing spontaneous emission for controlling photon emission between two resonance frequencies. Significantly, this work is oriented to produce the novel optical devices for control photon emission in the optical communication system. In addition to the honeycomb lattice, it can easily be made on a Si on insulator (SOI) wafer.

scholarly journals Tunable negative group index in metamaterial structures with large form birefringence

2010 ◽  
Vol 18 (2) ◽  
pp. 463 ◽  
Author(s):  
Kirill Sinchuk ◽  
Richard Dudley ◽  
John D. Graham ◽  
Michael Clare ◽  
Mesfin Woldeyohannes ◽  
...  
Keyword(s):  
Group Index ◽  
Negative Group ◽  
Large Form ◽  
Form Birefringence

Processing of Social Identity Threats

2013 ◽  
Vol 44 (6) ◽  
pp. 361-372 ◽  
Author(s):  
Natascha de Hoog
Keyword(s):  
Social Identity ◽  
Social Identification ◽  
Negative Group ◽  
Identity Threat ◽  
Neutral Group ◽  
Threat Perceptions ◽  
Social Identity Threat ◽  
Identity Threats ◽  
Group Information ◽  
Source Study

The underlying process of reactions to social identity threat was examined from a defense motivation perspective. Two studies measured respondents’ social identification, after which they read threatening group information. Study 1 compared positive and negative group information, attributed to an ingroup or outgroup source. Study 2 compared negative and neutral group information to general negative information. It was expected that negative group information would induce defense motivation, which reveals itself in biased information processing and in turn affects the evaluation of the information. High identifiers should pay more attention to, have higher threat perceptions of, more defensive thoughts of, and more negative evaluations of negative group information than positive or neutral group information. Findings generally supported these predictions.

Linkage between H. pylori Infection and TNF-α polymorphism in The Pregnant Women

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Ghaidaa Raheem Lateef ◽  
Azhar Omaran Al-Thahab
Keyword(s):  
Pregnant Women ◽  
Serum Antibody ◽  
Rapid Test ◽  
Negative Group ◽  
Positive Group ◽  
Gynecology And Obstetrics ◽  
Tnf Α ◽  
Significant Difference ◽  
Pcr Products ◽  
H Pylori

A study was performed on 100 pregnant women in the outpatient department of gynecology and obstetrics of Maternity and Children Hospital in Al-Diwaniya City during the period between (March to September 2016). One hundred blood samples (50 for patients and 50 for control) were collected under the supervision of the treating gynecologist. The detection of Helicobacter. pylori was done by the use of the serum antibody Rapid test. The results showed that 50 (100%) were positive and 50 (100%) were negative for H. pylori in above method.All blood of patients and control samples were used for the extraction of genomic DNA,where the 107 bp PCR product size. Genotyping of the TNF-α-308 SNP (G/A)was performed by restriction fragment length polymorphism PCR (RFLP-PCR). PCR products were digested with restr NcoI iction enzyme. Individuals with the TNF-α-308(GG) homozygote produced digested DNA bands at 80,and 20 bp bp. A heterozygous genotype ofTNF-α-308 (GA)produced 107 bp,80 bp,and 20 bp bands. Individuals with the TNF-α-308 (AA) homozygote genotype had no amplicon digested and generated only one band of 107 bp. There was a significant difference in the frequency of the TNF-α-308(GG)genotype between H. pylori positive group and H. pylori negative group(72%,78% respectively). Also for GA genotype,there was a significant difference between H. pylori positive group and H. pylori negative group(24%,18% respectively). Concerning the frequency of the TNF-α-308 (AA)genotype between H. pylori positive group and H. pylori negative group,there was no significant difference between the two groups.

UJI AKTIVITAS HEPATOPROTEKTOR KOMBINASI EKSTRAK ETANOL DAUN PANDAN WANGI (Pandanus amaryllifolius roxb) DAN KAYU MANIS (Cinnamomum burmanii) TERHADAP KADAR MDA YANG DIINDUKSI PARASETAMOL

2020 ◽  
pp. 68-73
Author(s):  
Yuni Asri Mulatsih Agami ◽  
Eka Wisnu Kusuma
Keyword(s):  
Oxidative Stress ◽  
Ethanol Extract ◽  
Optimal Dose ◽  
Experimental Methods ◽  
Positive Control ◽  
Negative Control ◽  
Male Rats ◽  
Negative Group ◽  
Ic50 Value ◽  
Dose Combination

Kasus penyakit hati semakin meningkat seiring penggunaan senyawa hepatotoksin salah satunya karena penggunaan parasetamol dengan dosis berlebih. Hal tersebut dapat meningkatkan produksi radikal bebas sehingga memicu terjadinya stress oksidatif yang dapat menimbulkan kerusakan jaringan yang ditandai dengan peningkatan kadar Malondialdehyde (MDA). Stress oksidatif dapat diatasi dengan antioksidan dari berbagai tanaman. Kulit kayu manis memiliki aktivitas antioksidan dengan nilai IC50 53ppm dan daun pandan wangi 39,7%  Penelitian ini bertujuan untuk mengetahui aktivitas kombinasi ekstrak etanol daun pandan wangi dan kayu manis dalam menurunkan kadar MDA. tikus yang diinduksi parasetamol. Penelitian menggunakan metode eksperimental, dilakukan selama 9 hari dengan 30 ekor tikus jantan dibagi menjadi 6 Kelompok, yaitu: Normal diberi aquadest, Kontrol Positif diberi silimarin 100 mg/kgBB, Kontrol Negatif diberi CMC-Na 0,05%, serta 3 kelompok lainnya diberi kombinasi ekstrak daun pandan wangi:kayu manis berturut-turut dosis I (25:75), dosis II (50:50), dosis III (75:25). Semua kelompok diinduksi parasetamol 2,5 g/kgBB pada hari ke-7  setelah 30 menit perlakuan, kecuali kelompok normal. Pada hari ke 9 dilakukan pengukuran kadar MDA dengan metode TBARs menggunakan spektrofotometri. Pemberian kombinasi ekstrak etanol daun pandan wangi dan kayu manis dapat menurunkan kadar MDA dengan kombinasi dosis yang paling optimal adalah 75:25 berdasarkan statistik dengan nilai signifikan 0,000<0,05 dibandingkan dengan kelompok negatif.    Cases of liver disease have increased with the use of hepatotoxin compounds, one of which is due to the use of paracetamol with excessive doses. This can increase the production of free radicals so that it triggers oxidative stress which can cause tissue damage which is characterized by increased levels of Malondialdehyde (MDA). Oxidative stress can be overcome with antioxidants from various plants. Cinnamomum burmanii has antioxidant activity with IC50 value of 53ppm and Pandanus amarrylifolius 39.7%. This study aims to determine the combined activity of ethanol extract of Pandanus amarrylifolius and Cinnamomum burmanii  in reducing MDA levels. Paracetamol-induced rats. Research using experimental methods, conducted for 9 days with 30 male rats divided into 6 groups, namely: Normal given aquadest, Positive Control were given silimarin 100 mg / kgBB, Negative Control was given CMC-Na 0.05%, and 3 other groups were given a combination of Pandanus amarrylifolius extract: Cinnamomum burmanii dose I (25:75), dose II (50:50), dose III (75:25). All groups induced paracetamol 2.5 g / kgBB on the 7th day after 30 minutes of treatment, except the normal group. On the 9th day MDA levels were measured using the TBARs method using spectrophotometry. Giving a combination of Pandanus amarrylifolius and Cinnamomum burmanii ethanol extract can reduce MDA levels with the most optimal dose combination is 75:25 based on statistics with a significant value of 0,000<0.05 compared with the negative group.

Negative Group Velocity of Surface Polaritons in Metal Foil Nanostructure

2017 ◽  
Vol 9 (3) ◽  
pp. 03039-1-03039-4 ◽  
Author(s):  
Y. M. Aleksandrov ◽  
◽  
V. V. Yatsishen ◽  
Keyword(s):  
Group Velocity ◽  
Metal Foil ◽  
Negative Group ◽  
Surface Polaritons ◽  
Negative Group Velocity

Thiol/Disulfide Homeostasis as an Early Biomarker to Differentiate Sepsis from Pneumonia in Intensive Care Units

2020 ◽  
Vol 23 ◽  
Author(s):  
Esra Cakir ◽  
Gamze Gok ◽  
Ozcan Erel ◽  
Isil Ozkocak Turan
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Early Period ◽  
Sepsis Group ◽  
Group Index ◽  
Total Thiol ◽  
Potential Biomarker ◽  
Early Biomarker ◽  
Index 2 ◽  
Research Period

Background: It is possible that patients with pneumonia also may have sepsis and the separation of these two clinical entities may induce some trouble to clinicians Objective: In order to separate a patient with pneumonia and a patient with sepsis, we qualify thiol/disulfide homeostasis as a potential biomarker. Method: This study designed between February 2018 – February 2019 prospectively. All patients in the intensive care unit with pneumonia and sepsis were enrolled in the study. At the time of hospitalization, thiol/disulfide homeostasis was measured. Patients diagnosed with sepsis and pneumonia were compared, in regards to thiol/disulfide homeostasis. Conclusion: In this study, we showed that thiol/disulfide homeostasis can be used as new markers in the early period in order to separate patients with sepsis and patients with pneumonia. Results: During research period, 103 patients with sepsis and 120 patients with pneumonia were enrolled into the study. When we compared native-thiol, total-thiol, and disulfide levels in both sepsis and pneumonia patients, we had similar results (p>0.05). In sepsis group, index-1 (disulfide/native thiol ratio) and index-2 (disulfide/total thiol ratio) were found out to be statistically higher than the pneumonia group, and index-3 (native thiol/total thiol ratio) was statistically lower than the pneumonia group (p=0.020, p= 0.021, p=0.021, respectively).

Comparison of Mammography and Ultrasonography for Tumor Size of DCIS of Breast Cancer

2019 ◽  
Vol 15 (2) ◽  
pp. 209-213
Author(s):  
Yu Wang ◽  
Jiantao Wang ◽  
Haiping Wang ◽  
Xinyu Yang ◽  
Liming Chang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Correlation Coefficient ◽  
Tumor Size ◽  
Ductal Carcinoma ◽  
Pearson Correlation ◽  
Dense Breast ◽  
Pathological Examination ◽  
Negative Group ◽  
The Difference

Objective: Accurate assessment of breast tumor size preoperatively is important for the initial decision-making in surgical approach. Therefore, we aimed to compare efficacy of mammography and ultrasonography in ductal carcinoma in situ (DCIS) of breast cancer. Methods: Preoperative mammography and ultrasonography were performed on 104 women with DCIS of breast cancer. We compared the accuracy of each of the imaging modalities with pathological size by Pearson correlation. For each modality, it was considered concordant if the difference between imaging assessment and pathological measurement is less than 0.5cm. Results: At pathological examination tumor size ranged from 0.4cm to 7.2cm in largest diameter. For mammographically determined size versus pathological size, correlation coefficient of r was 0.786 and for ultrasonography it was 0.651. Grouped by breast composition, in almost entirely fatty and scattered areas of fibroglandular dense breast, correlation coefficient of r was 0.790 for mammography and 0.678 for ultrasonography; in heterogeneously dense and extremely dense breast, correlation coefficient of r was 0.770 for mammography and 0.548 for ultrasonography. In microcalcification positive group, coeffient of r was 0.772 for mammography and 0.570 for ultrasonography. In microcalcification negative group, coeffient of r was 0.806 for mammography and 0.783 for ultrasonography. Conclusion: Mammography was more accurate than ultrasonography in measuring the largest cancer diameter in DCIS of breast cancer. The correlation coefficient improved in the group of almost entirely fatty/ scattered areas of fibroglandular dense breast or in microcalcification negative group.

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