25-GHz Spaced Spectrum-Sliced WDM PON Using 50-GHz AWGs

Manandhar, Dipen,Hyung Hwan Kim,Chul Han Kim,Jae Seung Lee IEEE 2015 IEEE photonics technology letters Vol.27 No.13

<P>We demonstrate a spectrum-sliced wavelength-division-multiplexed passive optical network with the channel spacing of 25 GHz, where even and odd channels are spectrum sliced separately using a pair of 50-GHz arrayed-waveguide gratings (AWGs). The 50-GHz AWGs have an offset of 25 GHz with respect to each other. Similarly, the demultiplexing is done using a pair of 50-GHz AWGs for even and odd channels separately. Our use of 50-GHz AWGs gives better bit-error rate performances than using 25-GHz AWGs in a conventional way. With 50-GHz AWGs, the channel bandwidth is increased about two times larger than using 25-GHz AWGs. Moreover, the increased spectral overlap between adjacent channels produces relatively small crosstalk since the channels are incoherent and their intensity noise is absorbed by reflective semiconductor amplifiers. The 25-GHz spaced spectrum-sliced WDM passive optical network can be realized more easily using 50-GHz AWGs since 50-GHz AWGs are more available in the market than 25-GHz AWGs.</P>

Effect of Stable Inhibition of NRF2 on Doxorubicin Sensitivity in Human Ovarian Carcinoma OV90 Cells

Manandhar, Sarala,Lee, Sang-Whan,Kwak, Mi-Kyoung 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

The transcription factor NRF2 defends the cell from oxidative stress by up-regulating a large number of antioxidant genes through its binding with antioxidant response element on gene promoters. Cancer cells are known to possess high levels of antioxidant genes that increases survival in cancer microenvironment of oxidative stress, particularly in the treatment with anticancer agents. In the current study we have examined the role of the NRF2 in doxorubicin sensitivity and tumor growth by establishing stable cell line expressing NRF2 shRNA in the human ovarian carcinoma cell line OV90. On knockdown of NRF2 through NRF2-specific shNRF2 expressing lentiviral plasmid, antioxidant response element-driven luciferase activity as well as the expression of NRF2-target genes were significantly suppressed compared to nonspecific scrambled RNA (scRNA) expressing cells. In addition, shNRF2 expressing OV90-shNRF2 cells showed a reduction in total GSH levels by 82% and cell growth was observed to be significantly retarded compared to scRNA control cells. Furthermore, stable inhibition of NRF2 sensitized OV90 cells were seen following doxorubicin treatment as shown by the analysis with MTT assay and propidium iodide-fluorescence-activated cell sorting. OV90-shNRF2 cells showed higher levels of cell death and apoptosis in response to doxorubicin than OV90-scRNA cells. While, when BALBc (nu/nu) mice with OV90 tumor xenograft in the flanks were injected with NRF2 shRNA containing viral particles and treated with doxorubicin a pattern of retardation in tumor growth was seen in shRNA group compared to scRNA group, but this difference was not statistically significant. In conclusion, we propose that the NRF2 signaling might be a molecular target to repress tumor growth and enhance cytotoxic effects of anticancer agent in cancer cells.

Controlled ionic complexation of positively charged phenylene‐based conjugated polymers by modulated backbone structures

Manandhar, Prakash,Vokatá,, Tereza,Lee, Sunyoung,Lee, Yejin,Jung, Hyun Min,Shim, Sangdeok,Moon, Joong Ho John Wiley Sons, Ltd 2018 Polymer international Vol.67 No.12

<P><B>Abstract</B></P><P>Understanding the role of the polymer backbone structure on the aggregation of conjugated polymers in an aqueous environment is of prime interest as the physical, photophysical and biophysical properties required for many applications are closely related to the nature of aggregation structures. We report unique and ordered aggregation behaviours of four positively charged conjugated polymers, which differ in backbone chemical structure and connectivity, upon complexation with a linear polyanion hyaluronic acid. Opposite signals of induced circular dichroism were observed from achiral poly(phenyleneethynylene) (PPE) and flexible linker containing poly(phenylenebutadiynylene) (PPB) with the same side chain structure, implying the formation of highly ordered ionic complexes. The intrinsic difference in the interpolymer interaction between PPE and PPB is probably the contributing factor for different aggregation structures upon complexation with hyaluronic acid. The structure–property relationship can be useful to design and fabricate highly ordered macromolecular materials exhibiting unique electrical, photophysical or biophysical properties. © 2018 Society of Chemical Industry</P>

Effect of bedrock stiffness and thickness of weathered rock on response spectrum in Korea

Manandhar, S.,Cho, H. I.,Kim, D. S. Springer Science + Business Media 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.7

<P>The Standard Penetration Test (SPT) is increasingly used to generate shear wave velocity (V (S) ) profile of a site for seismic hazard assessment. However, it is difficult to perform site investigation using the SPT for weathered rock and bedrock even at shallow depths in most cases. Consequently, the stiffness of bedrock (V (Sb) ) is assumed to be 760 m/s, and only partial thickness of weathered rock is used for site response assessment in Korea. The increase in V (Sb) and thickness of weathered rock (H (w) ) may affect the overall seismic response of a site, even though the site response is mostly governed by the upper soil layers. In this study, the effect of V (Sb) and H (w) on response spectrum in Korea was investigated by performing equivalent-linear site response analyses on three representative sites each of S (C) and S (D) soil categories as defined in the Korean seismic code based on the average shear wave velocity of top 30 m of a site (V-S30). The S (C) and S (D) categories are defined similar to that in the International Building Code (IBC). Further, the effect of increase in V-Sb and H-w on the selection of design response spectrum based on seismic codes was also investigated. An increase in V (Sb) resulted in an increase in spectral amplification, while the effect of increase in H-w was not substantial for the representative sites considered in this study. This means that the V (S) of bedrock needs to be assessed properly. On the other hand, it is possible to get a reliable seismic response even if the H-w cannot be determined accurately. The incorporation of V (Sb) in V (S30) for shallow bedrock sites (bedrock depth < 30 m) fails to consider the effect of increase in seismic amplification at large V (Sb) . Hence, it is preferable to consider the effect of V (Sb) separately on the design response spectrum. In addition, the effect on soil non-linearity due to variation in the V (Sb) and H (w) was found to be insignificant.</P>

Quality of Life among Breast Cancer Patients Undergoing Treatment in National Cancer Centers in Nepal

Manandhar, Sajani,Shrestha, Deepak Sundar,Taechaboonsermsk, Pimsurang,Siri, Sukhontha,Suparp, Jarueyporn Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Purpose: To study the quality of life and to identify associated factors among breast cancer patients undergoing treatment in national cancer centers in Nepal. Materials and Methods: One hundred breast cancer patients were selected and interviewed using a structured questionnaire. European Organization of Research and Treatment of Cancer EORTC-QLQ-C30 and EORTC-QLQ-BR23 were used to assess quality of life and modified Medical Outcome Study -Social Support survey(mMOS-SS) was used to assess social support. Only multi-item scales of EORTC C30 and BR23 were analyzed for relationships. Independent sample T-tests and ANOVA were applied to analyze differences in mean scores. Results: The score of global health status/quality of life (GHS/GQoL) was marginally above average (mean=52.8). The worst performed scales in C-30 were emotional and social function while best performed scales were physical and role function. In BR-23, most of the patients fell into the problematic group regarding sexual function and enjoyment. Almost 90% had financial difficulties. Symptom scales did not demonstrate many problems. Older individuals, patients with stage I breast cancer and thosewith good social support were found to have good GHS/GQoL. Of all the influencing factors, social support was established to have strong statistical associations with most of the functional scales: GHS/GQoL (0.003), emotional function (<0.001), cognitive function (0.020), social function (<0.001) and body image function (0.011). Body image was significantly associated with most of the influencing factors: monthly family income (0.003), type of treatment (<0.001), type of surgery (<0.001), stage of cancer (0.017) and social support (0.011). Conclusions: Strategies to improve social support of the patients undergoing treatment should be given priority and financial difficulties faced by breast cancer patients should be well addressed from a policy making level by initiating health financing system.

GEO-REFERENCING OF MULTI-SENSOR RANGE DATA FOR VEHICLE-BORNE LASER MAPPING SYSTEM(VLMS)

Manandhar, Dinesh,Shibasaki, Ryosuke 대한원격탐사학회 2000 International Symposium on Remote Sensing Vol.16 No.1

Laser mapping has became quite popular in recent days due to it's capability of providing information directly in three dimension. However, the present laser mapping systems are either air-borne or ground-based (on a static platform). We cannot achieve detail information from air-borne system, though it has it's own suitability for applications like DEM generation. Ground based static systems are not suitable far larger area mapping purpose. The vehicle-borne laser mapping system (VLMS) use laser scanners for three dimensional data acquisition, CCD cameras for texture information, GPS, INS and odometer fax positioning information. The data obtained by this system could be a good resource for developing urban 3D database, which has numerous applications in the field of virtual reality, car navigation, computer games, planning and management. In this paper, we discuss about the system architecture of VLMS, calibration of sensors, integration of all these sensors and positioning devices far direct geo-referencing.

Site Classification System and Site Coefficients for Shallow Bedrock Sites in Korea

Manandhar, Satish,Cho, Hyung-Ik,Kim, Dong-Soo Informa UK (TaylorFrancis) 2018 Journal of earthquake engineering Vol.22 No.7

<P>Recent studies have shown that the site coefficients obtained from site response analyses of Korean soil sites are significantly different from those specified in the current Korean seismic code, especially in the short-period portion of site response. This difference is mainly attributed to the shallow bedrock conditions (bedrock depth usually less than 30 m) in Korea. This study proposes a new site classification system and site coefficients for shallow bedrock sites based on site response analyses of more than 300 sites. The proposed site classification scheme and site coefficients proposed in this study are an improvement over the current seismic code and previous studies.</P>

Properties of Heparinoids Premixed with Tumor-Derived Extracellular Vesicles

Manandhar, Sumeet,Park, Jooho,Kothandan, Vinoth K.,Lee, Joomin,Alam, Farzana,Jee, Jun-Pil,Hwang, Jinsu,Byun, Youngro,Hwang, Seung Rim American Chemical Society 2018 Bioconjugate chemistry Vol.29 No.11

<P>Tumor-derived exosomes are bound and internalized to organ-specific cells, affecting metastasis. Heparan sulfate proteoglycans mediate the interaction between cells and exosomes. Exosome transfer to the recipient cell can be competitively blocked by heparinoids, because heparin is structurally similar to heparan sulfate. It is hypothesized that there may be structural requirements of heparinoids to attenuate the cellular uptake and metastatic activity of tumor-derived exosomes. Here, we compared the properties of unfractionated heparin (UFH), glycol-split UFH, low-molecular-weight heparin (LMWH), glycol-split LMWH, and ultra-LMWH premixed with A549-derived exosomes. Uptake of A549-derived exosomes (0.1 mg/mL) into BEAS-2B cells was significantly blocked by 0.4 mg/mL of heparinoids. Heparinoids attenuated migration of BEAS-2B cells stimulated by A549-derived exosomes. Glycol-split LMWH with no antifactor Xa activity exhibited the strongest antimigratory effects than other heparinoids. Thus, heparinoids with proper molecular weight and structure can inhibit tumor-derived exosomes, not proportionally to the anticoagulant activity.</P> [FIG OMISSION]</BR>

Balancing North and South For a Harmonious Globe

Manandhar, Debendra 선문대학교 통일사상연구원 1997 통일사상 연구논총 Vol.3 No.-

Generally the term "North" and "South" are mainly understood in their geographic context meaning Northern and Southern hemispheres of the Globe. In the world of Development, these terms are more used to mean Developed and Developing countries, believing in an inherent assumption that the countries, the North have much more developed than the South. It means that they are economically rich, technically sophisticated and materially advanced. All these imply that the North is more powerful than the South.

A pharmaceutical investigation into exosomes

Manandhar, S.,Kothandan, V. K.,Oh, J.,Yoo, S. H.,Hwang, J.,Hwang, S. R. Springer Nature 2018 Journal of Pharmaceutical Investigation Vol.48 No.6