• Title/Summary/Keyword: PVP

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Size-dependent toxicity of silver nanoparticles to Glyptotendipes tokunagai

  • Choi, Seona;Kim, Soyoun;Bae, Yeon-Jae;Park, June-Woo;Jung, Jinho
    • Environmental Analysis Health and Toxicology
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    • v.30
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    • pp.3.1-3.6
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    • 2015
  • Objectives This study aims to evaluate the size-dependent toxicity of spherical silver nanoparticles (Ag NPs) to an endemic benthic organism, Glyptotendipes tokunagai. Methods Ag nanoparticles of three nominal sizes (50, 100, and 150 nm) capped with polyvinyl pyrrolidone (PVP-Ag NPs) were used. Their physicochemical properties, acute toxicity (48 hours), and bioaccumulation were measured using third instar larvae of G. tokunagai. Results The aggregation and dissolution of PVP-Ag NPs increased with exposure time and concentration, respectively, particularly for 50 nm PVP-Ag NPs. However, the dissolved concentration of Ag ions was not significant compared with the median lethal concentration value for $AgNO_3$ (3.51 mg/L). The acute toxicity of PVP-Ag NPs was highest for the smallest particles (50 nm), whereas bioaccumulation was greatest for the largest particles (150 nm). However, larger PVP-Ag NPs were absorbed and excreted rapidly, resulting in shorter stays in G. tokunagai than the smaller ones. Conclusions The size of PVP-Ag NPs significantly affects their acute toxicity to G. tokunagai. In particular, smaller PVP-Ag NPs have a higher solubility and stay longer in the body of G. tokunagai, resulting in higher toxicity than larger PVP-Ag NPs.

The Retrial of Percutaneous Vertebroplasty for the Treatment of Vertebral Compression Fracture

  • Kim, Han-Woong;Kwon, Austin;Lee, Min-Cheol;Song, Jae-Wook;Kim, Sang-Kyu;Kim, In-Hwan
    • Journal of Korean Neurosurgical Society
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    • v.47 no.4
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    • pp.278-281
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    • 2010
  • Objective : For the treatment of osteoporotic vertebral compression fracture, percutaneous vertebroplasty (PVP) is currently widely used as an effective and relatively safe procedure. However, some patients do not experience pain relief after PVP. We performed several additional PVP procedures in those patients who did not have any improvement of pain after their initial PVP and we obtained good results. Our purpose is to demonstrate the effective results of an additional PVP procedure at the same previously treated level. Methods : We reviewed the medical records and the radiologic data of the PVP procedures that were performed at our hospital from November 2005 to May 2008 to determine the patients who had undergone additional PVP. We identified ten patients and we measured the clinical outcomes according to the visual analogue scale (VAS) score and the radiologic parameters, including the anterior body height and the kyphotic angulation. Results : The mean volume of polymethylmethacrylate injected into each vertebrae was 4.3 mL (range: 2-8 mL). The mean VAS score was reduced from 8 to 2.32. The anterior body height was increased from 1.7 cm to 2.32 cm. The kyphotic angulation was restored from 10.14 degrees to 2.32 degrees. There were no complications noted. Conclusion : The clinical and radiologic outcomes suggest that additional PVP is effective for relieving pain and restoring the vertebral body in patients who have unrelieved pain after their initial PVP. Our study demonstrates that additional PVP performed at the previously-treated vertebral levels could provide therapeutic benefit.

Effects of Development and Viability of Pig Oocytes Matured in Defined Medium Containing PVA, PVP and pFF (PVA, PVP 및 pFF를 첨가한 체외성숙 한정배지가 미성숙 돼지 난포란의 성숙과 배발달에 미치는 영향)

  • Kim I. D.;Kim S. N.;Han S. K.;Seok H. B.
    • Journal of Embryo Transfer
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    • v.19 no.3
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    • pp.219-227
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    • 2004
  • This study was conducted to develop a serum-free, defined medium of IVM of pig oocytes. The TCM-199 with supplemented with polyvinylalcohol(PVA), polyvinylpyrrollidone(PVP) and porcine follicular fluid(pFF) were used as basal medium. The effects of the these additives on the rates of maturity and development under in-vitro fertilization and in vitro culture were examined and subsequently considered on the possibilities be sustituted for the bovine serum albumin(BSA). Maturation rate of pig oocytes in IVM media containing PVA(82.4%), pFF(89.4%) and BSA(90.0%) were significantly higher(P<0.05) than that of PVP(78.6%). Cleavage rate after IVF of PVP(64%) was significantly lower(P<0.05) than these of PVA(73%), pFF(77%) and BSA(73%) supplements. in vitro development rates to morulae and blastocyst on PVP(54%) were also significantly lower(P<0.05) than these of the supplements of PVA(63%), pFF(69%) and BSA(65%). In comparison of maturation and fertilization rates of pig oocytes in each supplements, the maturity rates of PVA(82.4%), pFF(89.4%) and BSA(90.0%) were significantly lower(P<0.05) than that of PVP(72.4%) and while, the fertilization rates of pFF(87.1%) and BSA(89.1%) were significantly higher(P<0.05) than these of PVA(78.0%) and PVP(70.6%). It may be concluded that PVA and pFF can be substituted far BSA in medium for culturing pig oocytes; however, it may be considered that PVP were limited to for BSA in the in vitro culture of the embryos.

Percutaneous Vertebroplasty versus Conservative Treatment Using a Transdermal Fentanyl Patch for Osteoporotic Vertebral Compression Fractures

  • Oh, Younggyu;Lee, Byungjou;Lee, Subum;Kim, Junghwan;Park, Jinhoon
    • Journal of Korean Neurosurgical Society
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    • v.62 no.5
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    • pp.594-602
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    • 2019
  • Objective : Although surgical intervention, such as percutaneous vertebroplasty (PVP), is the standard treatment for osteoporotic vertebral compression fractures (OVCFs), its effectiveness and safety are unclear. Therefore, this study compared the safety and efficacy of conservative treatment with that of PVP for acute OVCFs. Methods : Patients with single-level OVCFs who were treated conservatively with a transdermal fentanyl patch (TFP) or with PVP between March 2013 and December 2017 and followed-up for more than 1 year were retrospectively evaluated. Patients with pathologic fractures, fractures of more than two columns, or a history of PVP were excluded. Clinical outcomes (visual analog scale [VAS] scores) and radiographic factors were evaluated, including changes in the compression rate of the corresponding vertebral body at onset and after 12 months, sagittal Cobb angle at onset and after 6 and 12 months, and the incidence of adjacent compression fractures. Results : Of the 131 patients evaluated, 75 were treated conservatively using TFPs and 56 underwent PVP. We divided the patients into TFP and PVP groups. Their baseline characteristics (including sex, level of fracture, and bone mineral density T-scores) were similar, but the TFP group was significantly younger. The overall VAS score for pain showed a greater decrease during the first month (1 week after PVP) in the PVP group but remained similar in the two groups thereafter. The compression rate after 12 months increased in the TFP group but decreased in the PVP group. Five patients in the PVP group, but none in the TFP group, experienced adjacent compression fractures within 12 months. Conclusion : We compared clinical and radiological outcomes between the TFP and PVP groups. The immediate pain reduction effect was superior in the PVP group, but the final clinical outcome was similar. Although the PVP group had a better-preserved compression rate than the TFP group for 1 year, the development of adjacent fractures was significantly higher. Although TFPs seemed to be beneficial in reducing the failure rate of conservative treatment, the possibility of side effects (22.6%, 17 out of 75 patients, in this study) should be carefully monitored.

Preparation of Porous Separators for Zn Air Batteries through Phase Inversions of Polyetherimide-PVP Solutions (Polyetherimide-PVP 용액의 상전이를 통한 아연공기전지의 다공성 분리막 제조)

  • Cho, Yu Song;Kim, Young Kyoung;Koo, Ja-Kyung
    • Membrane Journal
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    • v.24 no.3
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    • pp.231-239
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    • 2014
  • Polyetherimide (PEI) membranes for separators in Zn air batteries were prepared via phase inversion process from casting solution composed of PEI, n-methylpyrolidone (NMP), and polyvinylpurrolidone (PVP). Furthermore, Zn air batteries were fabricated with the separators. The effects of PEI content and PVP addition in the casting solution on the morphology, mechanical strength, ionic conductivity were investigated through SEM, stress-strain test and ac impedance test. The elelctrochemical performances of the batteries were evaluated through galvanostatic discharge analysis. The mechanical strength of the membrane increased with increasing PEI composition in the casting solution. Little effect of PVP addition into the solution on the mechanical strength of the membrane was investigated. The ionic conductivity value decreased with increasing PEI composition in the solution. With addition of PVP, ionic conductivity of membrane increased until 10 wt% to show the maximum value of 0.1 S/cm. In the higher range of PVP addition over 10%, the ionic conductivity decreased with increasing PVP addition. Ionic conductivity of separator strongly affected the capacity of Zn air battery, and the battery assembled with the separator which showed high ionic conductivity showed high capacity.

혼합된 PVP-PVA 유기 게이트 절연막이 유기 박막 트랜지스터의 전기적 특성에 미치는 영향에 대한 연구

  • Jo, Byeong-Geun;Kim, Gi-Jung;No, Yong-Han
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.42-42
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    • 2009
  • To make up for the disadvantages of PVA gate, we blend PVP(20% wt) with PVA(5% wt) as a gate material. The best ratio for the mixture was 5:5, PVP-PVA blended gate used MIM structure showed better performance in leakage current and capacitance. PVP-PVA blended gate was fabricated by spin-coating process and pentacene was used as an organic TFT channel layer by thermal evaporation. Overall OTFT performance has also increased as PVP-PVA blended gate has relatively lower leakage current and higher capacitance than pure PVA gate has.

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Pentacene TFTs and Integrated Circuits with PVP as Gate Insulator

  • Xu, Yong-Xian;Byun, Hyun-Sook;Song, Chung-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1027-1029
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    • 2004
  • In this paper, we have fabricated pentacene thin film transistors (TFTs) using polyvinylphenol (PVP) copolymer and cross-linked PVP as gate insulator on glass and plastic (PET) substrate. Depending on the density of PVP and cross-link material the performance has been changed. We obtained the best device performance with the mobility of 0.32cm2/V${\cdot}$sec and the on/off current ratio of 1.19${\times}$106 for the case of 10wt% PVP copolymer mixed with 5wt% poly (melamine-co-formaldehyde). Additionally using pentacene TFTs with the above PVP gate insulator, we fabricated the integrated circuits including inverter which produced the gain of 9.7.

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Liquid Crystal Composite of Celloulose Acetate (셀룰로오스 아세테이트의 액정복합체)

  • 홍영근
    • Textile Science and Engineering
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    • v.28 no.5
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    • pp.31-36
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    • 1991
  • Mixtures of cellulose acetate(CA) with poly-4-vinyl pyridine(PVP), polymethyl methacrylate(PMMA) , and polyethylene oxide(PEO) in various weight proportions were prepared in a mixed solvent of trifluoroacetic acid : methylene chloride/6:4(v:v). The properties of the mixed solutions and the films cast from the solutions were examined. CA was not miscible with PEO, whereas, it was quite miscible with PVP and PMMA in that solvent system. The solutions of CA/PVP and CA/PMMA showed mesomorphic phases with cholesteric nature in a certain range of concentration. The phase behavior of the solutions was optically investigated by using a polarized light microscope. The films cast from liquid crystal solutions of CA/PVP and CA/PMMA were characterized by empolying IR, DSC, and SEM techniques. It was observed that CA was compatible with PVP and PMMA in soiled state as well. This indicated that CA was dispersed molecularly in the continuous phase of PVP or PMMA.

Membrane from Liquid Crystal Composite of Cellulose Acetate and Poly (4-vinyl pyridine) (셀룰로오스 아세테이트와 폴리비닐 피리딘 액정중합체의 박막에 관한 연구)

  • Hong, Young-Keun;Cho, Bong-Heuy
    • Textile Coloration and Finishing
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    • v.3 no.2
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    • pp.43-48
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    • 1991
  • Cellulose acetate (CA) and poly-4-vinyl pyridine (PVP) in various weight proportions were mixed in a mixed solvent of trifluoroacetic acid: methylene chloride/6:4 (v:v). CA was miscible with PVP in that solvent system. CA/PVP/solvent show liquid crystal in a certain range of concentration and the nature of that liquid crystal was cholesteric. Films of the liquid crystal composite cast from the liquid crystal solutions of CA/PVP were tested in a viewpoint of biomembrane. Results show that considering permselectivity CA/PVP membrane is better than that of CA and CA/PVP membrane is closer to cell membrane.

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Effect of PVP Binder Addition on Formation of SrZr$O_{3}$ Thin Films (SrZr$O_{3}$박막 제조에 미치는 PVP 결합제 첨가효과)

  • 이득용;이세종;예경환;송요승
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • pp.146-148
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    • 2003
  • SrZrO$_3$ resistive oxide barriers on Ag sheathed Bi2223 monocore tapes were prepared by the sol-gel and dip coating method to reduce AC coupling loss. The performance of the dip-coated SrZrO$_3$ thin films was evaluated in terms of bond strength and surface microstructure by varying the amount of PVP (polyvinylpyrrolidone) binder. Although bond strength and coating thickness increased as the PVP content rose, surface microcracking was more severe for the specimen containing higher content of PVP binder. It suggests that coating thickness and microcracking of the SrZrO$_3$ films on Bi2223 tapes was governed primarily by the amount of PVP binder.

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