• 제목/요약/키워드: block groups

검색결과 775건 처리시간 0.041초

PS-b-PHEA 디블록 공중합체와 폴리비닐알콜을 이용한 수소이온 전도성 가교형 전해질막의 제조 (Preparation of Proton Conducting Crosslinked Membranes From PS-b-PHEA Diblock Copolymer and Poly(vinyl alcohol))

  • 김종학;서진아;노동규;박정태;고주환;산지브 마켄
    • 멤브레인
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    • 제18권3호
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    • pp.234-240
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    • 2008
  • 폴리스티렌-폴리히드록시에틸 아크릴레이트(PS-b-PHEA) 디블록 공중합체와 폴리비닐알콜(PVA)을 1 : 1 무게비로 블렌딩하여 수소 이온 전도성 가교형 고분자 전해질막을 개발하였다. 특히 술포석시닉산(SA)를 사용하여 디블록 공중합체의 PHEA 블록과 PVA와 가교반응을 시켰고, 이를 FT-IR 분광법을 이용하여 분석하였다. 이온교환능(IEC)은 SA 함량이 증가함에 따라 계속하여 증가하여 0.95 meq/g까지 도달하였고, 이는 전해질막에 이온 그룹수가 증가하기 때문이다. 하지만, 함수율은 SA 함량이 20 wt%까지는 증가하다 그 이상에서는 감소하였다. 또한 수소 이온 전도도도 SA 함량에 따라 증가하여 20 wt% SA농도에서 0.024 S/cm의 최대값을 나타내었다. 함수율과 수소이온전도도의 이러한 경향은 SA 함량이 증가함에 따라 이온 그룹의 수가 증가하는 효과와 가교가 증가하는 효과가 서로 경쟁적으로 일어나기 때문으로 생각된다.

보튤리눔 톡신-A가 백서의 임의 피판 생존율에 미치는 영향 (The Effect of Botulinum Toxin-A on the Survival of Random-Pattern Cutaneous Flap in Rat)

  • 김영석;이재수;유원민;탁관철
    • Archives of Plastic Surgery
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    • 제35권4호
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    • pp.360-366
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    • 2008
  • Purpose: Botulinum toxin type A(BoTA) can block the release of vasoconstriction cotransmitters as well as acetylcholine in nerve terminal. The authors observed that BoTA increases flap survival by preventing sympathetic collapse of peripheral vessels. Methods: 10 Sprague Dawley rats were divided into control(n=5), and BoTA group(n=5). $3{\times}10cm$ sized random pattern cutaneous flaps were elevated on the dorsal side in both groups. In BoTA group, BoTA was injected into the flap via intradermal to subdermal route, 7 days before the flap elevation. Flap survival rates (survival area/total area) were measured 7 days after the elevation. Cutaneous blood flow was measured in proximal, middle and distal compartments of the flap using laser Doppler flowmetry initially, preoperatively, at immediate postoperation, and 7 days after flap elevation, respectively. Histological examination was performed 7 days after the flap elevation. The number and shape of the vessels were evaluated under microscope. Results: Mean flap survival was $53.18{\pm}6.58%$ in control group and $93.79{\pm}6.06%$ in BoTA group, displaying statistically significant difference(p=0.0008, p<0.05). In the control group, blood flow to the middle and distal compartments of the flap decreased significantly immediately after flap elevation. In the BoTA group, blood flow to the middle compartment did not decrease(p=0.002) and slightly decreased in the distal compartment(p=0.001). Cutaneous blood flow was significantly higher in all compartments of the flap in BoTA group than in control group, 7 days after the flap elevation. In histopathologic examination, greater number of vessels were noted in the BoTA group than in the control group. Conclusion: Botulinum toxin A can increase the survival of the random pattern cutaneous flap in rats by preventing the sympathetic collapse of peripheral vessels.

Evaluation of energy and amino acids of brown rice and its effects on laying performance and egg quality of layers

  • An, Byoung-Ki;An, Su Hyun;Jeong, Han-Seul;Kim, Kwan-Eung;Kim, Eun Jip;Lee, Sang-Rak;Kong, Changsu
    • Journal of Animal Science and Technology
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    • 제62권3호
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    • pp.374-384
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    • 2020
  • Two experiments were conducted to determine apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and ileal digestible amino acid (AA) content of brown rice (BR) and to investigate the effect of dietary supplementation of BR on laying performance and egg quality of laying hens. In Exp. 1, 72 Hy-line Brown layers (49-week-old) were allocated to two treatments using a completely randomized block design, and each treatment included six cages per treatment and six hens per cage. A semi-purified diet was formulated to include BR as the sole source of AA and energy and an N-free diet was used to determine basal endogenous loss of AA. The hens were fed a commercial layer diet for adaptation to the experimental environment and diet for 7 days from d 0, and then fed experimental diets for 5 days from d 7. Excreta were collected from d 10 to 11 and ileal digesta were collected on d 12. On a dry matter (DM) basis, the AME and AMEn of BR was determined at 3,773 and 3,729 kcal/kg, respectively. The apparent ileal digestibility (AID) of BR ranged from 32.7% for Thr to 73.7% for Arg. The range of the standardized ileal digestibility (SID) value was between 79.4% for Met and 96.6% for Lys. In Exp. 2, 252 Hy-line Brown layers (44-week-old) were divided into four groups, comprising seven replicates of nine birds each and assigned to four experimental diets containing 0 (Control), 5%, 10%, or 15% BR for 5 weeks. The BR-containing diets were formulated to be equal in the content of AMEn and digestible AA to those of the diet without BR. No significant differences were observed in laying performances. Egg quality and blood profiles were not linearly or quadratically affected by dietary treatments. These results suggest that up to 15% BR can be included into layer feed without any adverse effects on laying performance and egg quality, if its energy and digestible AA values are well evaluated.

파노라마 방사선 사진을 이용한 한국인 소아의 하악공 위치에 대한 연구 (A STUDY ON THE POSITION OF THE MANDIBULAR FORAMEN IN KOREAN CHILDREN USING PANORAMIC RADIOGRAPHS)

  • 홍소이;정서영;마연주;정영정;안병덕
    • 대한소아치과학회지
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    • 제38권4호
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    • pp.368-375
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    • 2011
  • 본 연구는 소아에서의 성공적인 하치조신경 전달 마취를 위한 정보를 얻기 위해 파노라마 방사선 사진에서 한국인 소아의 하악공 위치를 분석하였다. 총 240명의 7-15세의 파노라마 방사선 사진을 수집하여, 연령에 따라 7-8세, 9-10세, 11-12세, 13-15세의 하위 그룹으로 나누었으며 각 그룹은 남녀 각 30명씩을 포함하였다. 좌우측의 하악공으로부터 하악절흔, 악각전절흔, 하악지 전연, 하악지 후연까지의 최단거리와 교합평면까지의 수직거리를 측정하였으며, 하악공으로부터 하악절흔과 악각전절흔의 거리의 비와 하악공으로부터 하악지 전연과 하악지 후연의 비를 계산하였다. 연구 결과는 다음과 같다. 1) 하악공의 하악지 내 상대적 위치는 남녀 모두에서 연령 증가에 따라 전방으로 이동하는 경향이 관찰되나, 수직적인 위치는 연령과 유의한 상관관계를 보이지 않았다. 2) 하악공의 교합평면과의 상대적인 위치는 연령 증가에 따라 교합평면 하방에서 상방으로 이동하였으며, 연령과 높은 상관관계를 나타내었다(p<0.05). 3) 여자보다 남자에서 하악공이 교합평면을 기준으로 더 상방에, 하악지 내 전후방 및 수직적으로는 하악지의 후상방에 위치하여 성별에 따른 차이를 보였다(p<0.05).

제왕절개 수술후 통증조절을 위해 PCA를 이용한 정맥과 경막외 Meperidine 투여효과의 비교 (A Comparative Effect of Meperidine between Intravenous and Epidural Patient-Controlled Analgesia for the Postoperative Pain Relief after Cesarean Section)

  • 이병호;채준석;정미영;변형진
    • The Korean Journal of Pain
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    • 제8권2호
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    • pp.257-265
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    • 1995
  • Patient-Controlled Analgesia (PCA) has been widely used for postoperative pain relief. Meperidine is useful for PCA and has efficient analgesia, rapid onset, and low incidence of adverse effect. To compare the analgesic effect, total dose and hourly dose, side effect and neonatal status of breast feeding with meperidine via intravenous or epidural PCA for 48 hours after Cesarean Section, 40 parturient women undergoing elective Cesarean Section were randomly divided into two groups. Each respective group of 20 parturient women received meperidine via one of the intravenous PCA after general anesthesia with enflurane (IVPCA group) and the epidural PCA after general anesthesia with enflurane (IVPCA group) and the epidural PCA after epidural block with 2% lidocaine 20ml combined with general anesthesia with only $N_2O$ and $O_2$ (EpiPCA group) when they first complained of pain in recovery room. Following the administration of analgesic initial dose, parturient women of IVPCA group were allowed intravenous meperidine 10 mg every 8 minutes when they felt pain. The EpiPCA group received additional bolus dose of meperidine 2 mg and bupivacaine 0.7 mg were administered every 8 minutes as requested the patients with hourly continuous infusion of meperidine 4 mg and bupivacaine 1.4 mg. Data was collected during the 48 hours observation period including visual analog scale (VAS) pain scores, total meperidine dose, hourly dose during 48 hours and each time interval, incidence of adverse effect, satisfaction, and neonatal status with breast feeding. VAS pain scores of analgesic effect in EpiPCA group was significantly lower than in IVPCA group at 2 hours after the initial pain after Cesarean Section. Total dose and hourly dose of meperidine significantly reduced in EpiPCA group. Hourly dose of meperidine at each time interval significantly reduced during first 6 hours and from 12 hours to 24 hours in EpiPCA group. The side effects in IVPCA group were mainly sedation, nausea, and local irritation of skin. And EpiPCA group experienced numbness and itching. The degree of satisfaction of parturient women was 88.2 % in IVPCA group and 85.7 % in EpiPCA group. We did not observe any sedation, abnormal behavior, or seizure like activity in any neonates of breast feeding. From the above results we conclude that epidural PCA was more efficiently analgesic, less sedative, and consumptional, and safer for neonate than intravenous PCA, and could be an alternative method to intravenous PCA.

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레진모형근관에서 엔진구동형 및 수동형 ProTaper 파일로 근관성형 후 근관형태 변화에 대한 비교연구 (A COMPARATIVE STUDY OF THE CANAL CONFIGURATION AFTER SHAPING BY PROTAPER ROTARY AND HAND FILES IN RESIN SIMULATED CANALS)

  • 양인석;강인철;황윤찬;황인남;오원만
    • Restorative Dentistry and Endodontics
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    • 제30권5호
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    • pp.393-401
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    • 2005
  • 본 연구는 형태 및 재질이 동일한 엔진구동형 ProTaper파일과 수동형 ProTaper파일을 이용하여 레진모형근관을 성형한 후 근관형태 변화를 비교 분석하고자 시행되었다. 본 연구에서는 레진모형근관으로 총 40개의 J자와 S자의 근관 형태가 재현된 ENDO-TRAINING BLOC을 사용하였다. 근관 성형 기구로는 엔진구동형 Ni-Ti 파일로 $ProTaper^{TM}$, 수동형 Ni-Ti 파일로 $ProTaper^{(R)}$ For Hand Use를 사용하였다. 사용된 레진모형근관과 파일의 종류에 따라 10개씩 4개의 그룹으로 나누어 근관성형을 시행하였다. 근관 성형 전$\cdot$후 이미지를 스캐너 (Color scanner, UMAX Technologies, Inc., USA)를 이용하여 얻은 후. Photoshop 7.0 프로그램 (Adobe System Inc., USA)을 이용하여 이미지를 중첩하였다. 이미지 분석 프로그램 (Image-$Pro^{(R)}$ Plus, Media Cybernetic, USA)을 이용하여 치근단 쪽에서부터 0, 1, 2, 3, 4, 5, 6 및 7 mm 수준에서 근관 성형에 따른 근관의 내측 및 외측 폭경의 변화량, 근관 총폭경의 변화량, 근관 중심축의 변위량을 측정하였다. 또한 근관 성형 시간을 기록하였다. 두 기구 사이의 유의성 검정을 위해 독립 표본 t-검정을 시행하여, 근관 성형 시 수동형 ProTaper 파일이 엔진구동형 ProTaper 파일에 비해 근관 중심축의 변위가 유의하게 덜 일어나며 근관의 원래 형태를 더욱 잘 유지할 수 있지만, 근관 성형시간은 길어질 수 있다는 결론을 얻었다.

개방 근첨 치아의 근관 충전방법에 따른 치근단 폐쇄효과에 관한 연구 (THE SEALING ABILITY OF OBTURATION TECHNIQUES IN OPEN APEX)

  • 소현;최호영;최경규;최기운
    • Restorative Dentistry and Endodontics
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    • 제25권3호
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    • pp.435-445
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    • 2000
  • The purpose of this study was to compare the leakage of four different obturation techniques in conjunction with immediate apical barrier of ${\beta}$-tricalcium phosphate(TCP) in teeth with open apex. Eighty single-rooted human premolar teeth were prepared and sectioned horizontally, so maximum diameter in apex was 4mm. Apical defects that were similar to open apex, were created with #1/2 round bur and SF104R bur. The apical foramen were opened to a size 80 file extended 3mm beyond the apex. The teeth were placed into the oasis block soaked saline to simulate periapical tissue often associated with pulpless teeth and received apical barriers consisting of TCP followed by obturation using lateral condensation technique, vertical condensation technique, continuous wave technique and thermoplasticized gutta-percha injection technique. Two unobturated teeth served as positive and negative controls. Teeth were immersed in resorcinol-formaldehyde resin for S days at $4^{\circ}C$, and the resin was allowed to polymerize completely for 4 days at room temperature. Teeth were then sectioned horizontally at 1.5mm(level 1), 2.5mm(level 2) and 3.5mm(level 3) from the apex, and examined under a stereomicroscope at ${\times}40$ magnification. The photographs were taken at ${\times}40$ magnification of the filling in each level and scanned. The leakage length in tooth/resin interface was measured at each of the three levels. Each ratio of leakage was obtained by calculating the ratio of the leakage length of canal wall infiltrated with resin to the total length of the canal and was analyzed statistically(One-way ANOVA and Scheffe test). The result were as follows : 1. At the level 1, there was the least leakage in the thermoplasticized gutta-percha injection technique group(group 4), but there was statistically significant(p<0.05). 2. At the level 2, there was the least leakage in the thermoplasticized gutta-percha injection technique group(group 4), and the most leakage in the continuous wave technique group(group 3). There was statistically significant difference between the thermoplasticized gutta-percha injection technique group and the continuous wave technique group(p<0.05). 3. At the level 3, there was the least leakage in the thermoplasticized gutta-percha injection technique group(group 4), but there were no statistically significant differences between other groups(p>0.05). These results suggest that thermoplasticized gutta-percha injection technique which had 1mm apical gutta-percha matrix after the formation of TCP apical barrier, can demonstrate favorable apical sealing.

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계면활성제가 담지된 메조포러스 실리케이트에 의한 수중 납이온 제거 (Removal of Pb2+ Ions from Water by Surfactant-templated Mesoporous Silicates)

  • 최현석;이동규;조국진;이채영;정진석;유익근;신은우
    • Korean Chemical Engineering Research
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    • 제44권2호
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    • pp.172-178
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    • 2006
  • 메조포러스 실리케이트 물질은 포어 내에 thiol(-SH)기나 amine($-NH_2$)기 등의 관능기를 도입하여 수중의 중금속이온을 제거하는 흡착제로 많이 활용되어왔다. 본 연구는 메조포러스 실리케이트 합성에서 구조형성 전구체로 사용되는 계면활성제가 중금속 이온의 흡착활성점으로도 작용하는지를 조사하고자 하였다. 서로 다른 계면활성제를 사용하는 세가지 메조포러스 실리케이트(SBA-15, MCM-41, HMS)을 합성하여 소성 전 계면활성제가 담지되어 있는 경우와 소성되어 계면활성제가 사라진 경우에 이들의 수중 납이온의 흡착거동을 살펴보았다. 먼저, X선 회절분석 실험과 질소 기체 흡착 거동으로 메조포러스 실리케이트의 메조포어 구조를 확인하였고, FT-IR 분석을 통해 소성 전의 계면활성제의 존재와 소성 후에 계면활성제의 제거를 확인하였다. 중금속인 납이온을 사용하여 이들의 흡착능을 측정한 결과, 모든 소성된 메조포러스 실리케이트 물질과 공중합 고분자를 계면활성제로 이용하는 SBA-15는 수중에서 납이온에 대한 흡착능이 극히 미비한 반면에 각각 dodecylamine과 hexadecyltrimethylammoniumbromide(HDTMA)를 계면활성제로 사용하는 HMS, MCM-41은 소정의 흡착능을 보여주었다. 초기 납이온 농도가 50 ppm, 용액 pH가 5인 흡착 조건에서 얻은 흡착 키네틱 데이터를 pseudo second order kinetic model에 적용하여 계산한 결과, 계면활성제가 담지된 HMS는 115.16 mg/g, 계면활성제가 담지된 MCM-41은 26.60 mg/g의 납이온 흡착능을 나타내었다. 이러한 흡착능은 기존의 다른 메조포러스 실리케이트 흡착제의 흡착능과 유사하며, 그들과 비교하여 계면활성제가 담지된 흡착제는 전처리나 후처리 없이 흡착제로 활용할 수 있는 장점을 가지고 있다.

소 재조합 somatotropin 단백질을 이용한 한우 유량 증진 효과 (Effect of bovine recombinant somatotropin protein on milk yield in Hanwoo)

  • 우제석;이승환;이명식;박정용;김민규;홍성구
    • 농업과학연구
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    • 제38권4호
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    • pp.667-672
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    • 2011
  • This study was carried out to increase the breeding rate using sustained recombinant bovine somatotropin (bST) and examine the reproductive disorder and disease prevalencies of cow and calf, respectively. Sixty cows were allotted randomly to three groups in randomized complete block design; (1) No treatment, (2) 500 mg bST two times + 250 mg bST SC injection five times from 3 weeks before to 9 weeks after parturition every two weeks, (3) 500 mg bST two times before 3 weeks parturition + 250 mg bST SC injection three times from five to 9 weeks after parturition every two weeks. Developmental data of birth weight, weaning weight, total gain and average daily gain in control was $22.9{\mu}0.45$ kg, $88.0{\mu}1.13$ kg, $65.1{\mu}0.74$ kg and $0.54{\mu}0.08$ kg, respectively. There is no significant difference between Group 1 and 3 in the examined factors. However, there is significant difference between Group 1 and 2 in the birth weight ($24.4{\mu}0.88$ kg), weaning weight ($101.0{\mu}1.77$ kg), total gain ($76.7{\mu}0.9$ kg) and average daily gain ($76.7{\mu}0.9$ kg). Total gain was showed higher in Group 2 and 3 than Group 1 in the >2nd parity, and in Group 2 than Group 1 and 3 in the 1st parity. There is no significant difference in the BCS, no return days and disease occurrence of cow and calf by bST treatment. Number of service per conception was slightly increased in the Group 3 compared to Group 1 and 2. To increase the breeding ability of Hanwoo, it is recommended that 500 mg bST two times + 250 mg bST injection five times from 3 weeks before to 9 weeks after parturition every two weeks.

Octapeptide (Alanine Angiotensin) 의 合成 (Synthesis of an Octapeptide (Alanine Angiotensin))

  • 박원길
    • 대한화학회지
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    • 제5권1호
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    • pp.33-37
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    • 1961
  • We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

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