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1.
Thorac Cardiovasc Surg ; 69(4): 362-365, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32898891

RESUMO

The frozen elephant trunk (FET) procedure enables easier replacement of the entire aortic arch because it does not require reaching the distal part of the left subclavian artery (LSCA). However, it requires additional management for reconstruction of the LSCA, which is associated with bleeding events. However, the fenestrated FET technique confers a risk of endoleakage from the fenestration site. We report our unique novel technique in which the proximal side of the hybrid stent graft is cut into V-shape around the subclavian artery and sutured continuously around the orifice of the subclavian artery during aortic stump fixation.


Assuntos
Aorta Torácica/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Dissecção Aórtica/cirurgia , Implante de Prótese Vascular , Procedimentos Endovasculares , Artéria Subclávia/cirurgia , Técnicas de Sutura , Idoso , Dissecção Aórtica/diagnóstico por imagem , Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico por imagem , Prótese Vascular , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Stents , Artéria Subclávia/diagnóstico por imagem , Resultado do Tratamento
2.
Surg Today ; 45(8): 1067-70, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25016369

RESUMO

A persistent sciatic artery is a rare vascular anomaly in which the sciatic artery, which involutes in the embryonic stage, persists as the blood supply to the lower limb. This vascular anomaly is often associated with aneurysm formation. A persistent sciatic artery aneurysm is a rare cause of peripheral arterial embolic disease. We herein describe the case of a 72-year-old female with a free-floating thrombus in a persistent sciatic artery aneurysm. She underwent iliac-popliteal artery bypass and exclusion of the aneurysm to prevent an embolic event.


Assuntos
Aneurisma/cirurgia , Implante de Prótese Vascular/métodos , Artéria Ilíaca/cirurgia , Extremidade Inferior/irrigação sanguínea , Artéria Poplítea/cirurgia , Tromboembolia/cirurgia , Trombose/cirurgia , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Aneurisma/complicações , Aneurisma/diagnóstico por imagem , Feminino , Humanos , Artéria Poplítea/diagnóstico por imagem , Tromboembolia/diagnóstico por imagem , Tromboembolia/etiologia , Trombose/diagnóstico por imagem , Trombose/etiologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
3.
Medicine (Baltimore) ; 102(43): e35657, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37904351

RESUMO

RATIONALE: The symptoms of impaired consciousness and unilateral motor impairments are a perfect scenario for cerebral infarction, and a physician can easily miss the findings of limb ischemia on the patient paralyzed side even if acute limb ischemia (ALI) occurs on that side. The purpose of this case report is to reiterate the need to suspect ALI in patients with impaired consciousness who cannot complain of symptoms such as abnormal limb paresthesia or pain. PATIENT CONCERNS: An 89-year-old woman with impaired consciousness and motor impairment of the left upper and lower extremities was transported to our hospital. DIAGNOSES: Brain magnetic resonance imaging showed a suspected cerebral infarction in the posterior circulation; contrast-enhanced computed tomography showed occlusion of the left axillary artery and left femoral artery; and ultrasonography showed occlusion of the right popliteal artery. INTERVENTIONS: Cerebral angiography was performed simultaneously with surgical thrombectomy to treat the ALI. Mechanical thrombectomy was not performed for cerebral infarction. OUTCOMES: Although motor impairment of the left upper and lower extremities persisted, the patient successfully underwent limb salvage. LESSONS: Both cerebral infarction and ALI require early diagnosis and treatment. This rare case of cerebral infarction complicated by ALI emphasizes the need to avoid missing the signs of ALI in patients with impaired consciousness.


Assuntos
Arteriopatias Oclusivas , Doenças Vasculares Periféricas , Feminino , Humanos , Idoso de 80 Anos ou mais , Estado de Consciência , Isquemia/etiologia , Arteriopatias Oclusivas/complicações , Imageamento por Ressonância Magnética/efeitos adversos , Infarto Cerebral/complicações , Doenças Vasculares Periféricas/complicações
4.
Chem Commun (Camb) ; (28): 2953-5, 2007 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-17622442

RESUMO

15-Crown-5-appended metalloporphyrin causes a K(+)-driven self-organization to bind a bifunctional guest ditopically, thereby allowing the circular dichroism (CD) detection of chirality induced in the ensemble when chiral amines are employed as the guest; the chiroptical properties are discussed.

5.
J Nanosci Nanotechnol ; 6(6): 1489-509, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17025049

RESUMO

Synthesis of many potentially useful molecular units by chemists promotes the development of methods for constructing supramolecular architectures. Indeed, programmed supramolecular interactions play crucial roles in the preparation of well-defined nanoscale assemblies. This review highlights successful approaches in designing for specific functions systematically. The incorporation and synergistic communication of conformation-switchable segments into molecules bears great promise. Allostery, which is often observed in naturally occurring proteins, provides a hint for molecular manipulation. In supramolecular chemistry crown ethers can serve not only as substrate-binding sites but also as function-tuning sites. With the combination of synthetic versatility and well-tailored design, diverse capabilities (molecular recognition, catalytic properties, chirality, actuation, and so on) become possible at the molecular or mesoscopic level. The synthetic preparation of advanced molecular units allows the systems to become smarter, and promise nanosystems with programmable functions. This review considers mainly the use of crown ethers which act as anchoring as well as allosteric sites, from the standpoint of design for molecular manipulation. It also gives a brief discussion of recent progress in molecular manipulation, based on related systems. The "synthetic systems" described in the present review should contribute to not only to more elaborate "chemical systems", but also to the evolving field of "molecular machinery", that can utilize these systems.


Assuntos
Éteres de Coroa/química , Nanotecnologia/métodos , Sítio Alostérico , Cátions/química , Desenho de Fármacos , Enzimas/química , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo
6.
Ann Thorac Cardiovasc Surg ; 22(5): 315-317, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26581497

RESUMO

PURPOSE: Cystic adventitial artery disease is an uncommon non-atherosclerotic peripheral vessel disease. Furthermore cystic adventitial disease of the common femoral artery is an extremely rare entity. We report the case of a 54 year-old man complaining of intermittent claudication who was referred to our vascular service. METHODS AND RESULTS: Doppler ultrasound and multidetector-row computed tomography (CT) with 3-dimensional volume rendering revealed severe stenosis with cystic an adventitial cyst in the common femoral artery. Intra-operative Doppler ultrasound showed the cyst to be multilocular type. Reversed great saphenous vein interposition was successfully placed. CONCLUSION: Removal of cyst together with artery and interposition using reversed great saphenous vein is the optimal treatment procedure to prevent recurrence.


Assuntos
Túnica Adventícia , Arteriopatias Oclusivas , Cistos , Artéria Femoral , Claudicação Intermitente , Túnica Adventícia/diagnóstico por imagem , Túnica Adventícia/cirurgia , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/fisiopatologia , Arteriopatias Oclusivas/cirurgia , Biópsia , Angiografia por Tomografia Computadorizada , Cistos/diagnóstico por imagem , Cistos/fisiopatologia , Cistos/cirurgia , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/fisiopatologia , Artéria Femoral/cirurgia , Humanos , Claudicação Intermitente/diagnóstico por imagem , Claudicação Intermitente/fisiopatologia , Claudicação Intermitente/cirurgia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores , Veia Safena/transplante , Resultado do Tratamento , Ultrassonografia Doppler em Cores
7.
Ann Thorac Cardiovasc Surg ; 22(4): 237-45, 2016 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-27025780

RESUMO

PURPOSE: Recently, performance of cardiac surgery in hemodialysis patients has increased, but the mortality rate is high. METHODS: We retrospectively examined the early and long-term outcomes in 128 dialysis patients who underwent cardiac surgery with or without carperitide infusion and were followed for 2 years. Sixty-three patients received carperitide infusion during surgery and 65 patients did not. RESULTS: The hospital mortality rate was 1.6% in the carperitide group and 12.3% in the non-carperitide group, being significantly lower in the carperitide group. The 2-year actuarial survival rate was 90.5% ± 3.7% in the carperitide group, and 76.9% ± 5.2% in the non-carperitide group, while the major adverse cardiovascular and cerebrovascular events (MACCE)-free rate at 2 years postoperatively was 90.5% ± 3.7% in the carperitide group and 67.7% ± 5.8% in the non-carperitide group. CONCLUSIONS: These findings suggest that carperitide improves the early postoperative outcome in dialysis patients undergoing cardiac surgery, as has already been demonstrated in non-dialysis patients. An early postoperative cardioprotective effect of carperitide and improvement of renal function in oliguric patients might have contributed to this outcome. However, this was a retrospective study, so a prospective investigation is required to demonstrate the mechanisms involved. In addition, further evaluation of the long-term results would be desirable.


Assuntos
Fator Natriurético Atrial/administração & dosagem , Procedimentos Cirúrgicos Cardíacos , Complicações Pós-Operatórias/prevenção & controle , Substâncias Protetoras/administração & dosagem , Diálise Renal , Insuficiência Renal Crônica/terapia , Idoso , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/mortalidade , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Mortalidade Hospitalar , Humanos , Infusões Parenterais , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Diálise Renal/efeitos adversos , Diálise Renal/mortalidade , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/mortalidade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
8.
J Thorac Cardiovasc Surg ; 150(4): 957-64, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26254752

RESUMO

OBJECTIVES: We previously conducted a prospective study of landiolol hydrochloride (INN landiolol), an ultrashort-acting ß-blocker, and reported that it could prevent atrial fibrillation after cardiac surgery. This trial was performed to investigate the safety and efficacy of landiolol hydrochloride in patients with left ventricular dysfunction undergoing cardiac surgery. METHODS: Sixty patients with a preoperative left ventricular ejection fraction of less than 35% were randomly assigned to 2 groups before cardiac surgery and then received intravenous infusion with landiolol hydrochloride (landiolol group) or without landiolol (control group). The primary end point was occurrence of atrial fibrillation as much as 1 week postoperatively. The secondary end points were blood pressure, heart rate, intensive care unit and hospital stays, ventilation time, ejection fraction, biomarkers of ischemia, and brain natriuretic peptide. RESULTS: Atrial fibrillation occurred in 3 patients (10%) in the landiolol group versus 12 (40%) in the control group, and its frequency was significantly lower in the landiolol group (P = .002). During the early postoperative period, levels of brain natriuretic peptide and ischemic biomarkers were significantly lower in the landiolol group than the control group. The landiolol group also had a significantly shorter hospital stay (P = .019). Intravenous infusion was not discontinued for hypotension or bradycardia in either group. CONCLUSIONS: Low-dose infusion of landiolol hydrochloride prevented atrial fibrillation after cardiac surgery in patients with cardiac dysfunction and was safe, with no effect on blood pressure. This intravenous ß-blocker seems useful for perioperative management of cardiac surgical patients with left ventricular dysfunction.


Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/prevenção & controle , Morfolinas/uso terapêutico , Complicações Pós-Operatórias/prevenção & controle , Ureia/análogos & derivados , Disfunção Ventricular Esquerda/cirurgia , Idoso , Idoso de 80 Anos ou mais , Antiarrítmicos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos , Feminino , Humanos , Masculino , Morfolinas/efeitos adversos , Estudos Prospectivos , Ureia/efeitos adversos , Ureia/uso terapêutico
9.
Ann Thorac Cardiovasc Surg ; 21(3): 254-60, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26004117

RESUMO

BACKGROUND: Based on the revised AHA/ACC guidelines, it might be necessary to take into consideration the average life expectancy of Japanese people and revise the Japanese guidelines accordingly. Accordingly, we performed the present study to compare the long-term outcome in patients aged 65 years or older who underwent prosthetic valve replacement at our hospital using mechanical valves or biological valves. METHODS: We have performed valve replacement in 416 patients aged 65 years or older (mechanical: 157; biological: 244). RESULTS: There was no significant difference between the mechanical and biological valve for the actuarial survival rate. As for the valve-related complication free rate, in the mechanical valve group, the rates were significantly higher for all patients, aortic valve replacement (AVR) patients, and mitral valve replacement (MVR) patients. CONCLUSIONS: Following revision of the AHA/ACC guidelines for selection of prosthetic valves, it is necessary to investigate whether patients aged 60-70 represent the gray zone for selecting valves as in US and European guidelines, or whether a higher age is more appropriate in view of the longer average life expectancy in Japan. Accordingly, further evaluation of the long-term outcome for mechanical and biological valves in Japanese patients is needed to obtain evidence for preparation of original Japanese guidelines on prosthetic valve selection.


Assuntos
Povo Asiático , Bioprótese , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Valvas Cardíacas/cirurgia , Seleção de Pacientes , Guias de Prática Clínica como Assunto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Bioprótese/normas , Feminino , Doenças das Valvas Cardíacas/diagnóstico , Doenças das Valvas Cardíacas/etnologia , Doenças das Valvas Cardíacas/mortalidade , Próteses Valvulares Cardíacas/normas , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/mortalidade , Implante de Prótese de Valva Cardíaca/normas , Humanos , Japão/epidemiologia , Estimativa de Kaplan-Meier , Expectativa de Vida/etnologia , Masculino , Guias de Prática Clínica como Assunto/normas , Desenho de Prótese , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
10.
Ann Thorac Cardiovasc Surg ; 21(3): 247-53, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26004118

RESUMO

UNLABELLED: In this study, we investigated the early and long-term results of conventional aortic valve replacement (AVR) in very old patients. METHODS: Seventy-five patients with aortic stenosis underwent conventional AVR for patients aged 80 years.We examined early death and major adverse cardiovascular and cerebrovascular event (MACCE). RESULTS: The operative mortality was 0% for isolated AVR and 19.2% for concomitant surgery. The postoperative survival rate and MACCE free-rate were no significant differences between the isolated AVR and the concomitant surgery. Univariate analysis confirmed that cardiac dysfunction, severe chronic kidney disease (CKD), hemodialysis, + coronary artery bypass grafting, and norepinephrine use were risk factor of early death. Univariate analysis confirmed that severe CKD, BNP >1000 pg/ml, aortic cross clamping time (ACCT) >180 min, and non-use carperitide and multivariate analysis confirmed that ACCT >180 min, and non-use carperitide were risk factor of MACCE. CONCLUSIONS: This study showed that the results of conventional AVR in very old patients were not satisfactory. However, the results obtained with isolated AVR were favorable with no operative deaths. The present study demonstrated that preoperative cardiac function, preoperative renal function, and operative factors have an important impact on early mortality and MACCE.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca , Fatores Etários , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/mortalidade , Comorbidade , Intervalo Livre de Doença , Feminino , Cardiopatias/complicações , Cardiopatias/diagnóstico , Cardiopatias/fisiopatologia , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/mortalidade , Humanos , Japão , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Análise Multivariada , Razão de Chances , Complicações Pós-Operatórias/etiologia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/fisiopatologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
12.
J Cardiol ; 66(4): 298-303, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25649025

RESUMO

BACKGROUND: The NU-FLASH trial demonstrated that febuxostat was more effective for hyperuricemia than allopurinol. This time, we compared these medications in patients with chronic kidney disease (CKD) from the NU-FLASH trial. METHODS AND RESULTS: In the NU-FLASH trial, 141 cardiac surgery patients with hyperuricemia were randomized to a febuxostat group or an allopurinol group. This study analyzed 109 patients with an estimated glomerular filtration rate (eGFR) ≤60 mL/min/1.73 m(2), and also analyzed 87 patients with stage 3 CKD. The primary endpoint was the serum uric acid level. Secondary endpoints included serum creatinine, urinary albumin, cystatin-C, oxidized low-density lipoprotein, eicosapentaenoic acid/arachidonic acid ratio, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, and high-sensitivity C-reactive protein. Among patients with an eGFR≤60 mL/min/1.73 m(2), uric acid levels were significantly lower in the febuxostat group than the allopurinol group from 1 month of treatment onward. The serum creatinine, urinary albumin, cystatin-C, oxidized low-density lipoprotein, eicosapentaenoic acid/arachidonic acid ratio, and high-sensitivity C-reactive protein were also significantly lower in the febuxostat group. Similar results were obtained in the patients with stage 3 CKD. CONCLUSION: In cardiac surgery patients with renal dysfunction, febuxostat reduced uric acid earlier than allopurinol, had a stronger renoprotective effect than allopurinol, and also had superior antioxidant and anti-inflammatory effects.


Assuntos
Alopurinol/uso terapêutico , Febuxostat/uso terapêutico , Supressores da Gota/uso terapêutico , Hiperuricemia/tratamento farmacológico , Insuficiência Renal Crônica/complicações , Idoso , Albuminúria/urina , Proteína C-Reativa , Procedimentos Cirúrgicos Cardíacos , Colesterol , Creatinina/sangue , Cistatina C , Feminino , Humanos , Hiperuricemia/etiologia , Lipoproteínas HDL , Lipoproteínas LDL , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/urina , Triglicerídeos , Ácido Úrico/sangue
13.
Chem Commun (Camb) ; (12): 1394-5, 2004 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-15179481

RESUMO

The first rationalized crown ether-bis(porphyrin) conjugate with a large ring-based conformation flexibility 1 has been synthesized; the achiral-to-chiral transformation upon complexation with chiral diamines is assisted by K(+) accommodated in the crowned moiety, and it is possible to determine the chirality of carboxylates as potassium salts.

14.
Ann Thorac Cardiovasc Surg ; 20 Suppl: 754-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23364236

RESUMO

A 67-year-old man who had undergone substernal gastric tube interposition due to esophageal cancer showed ST changes on electrocardiography. Diagnosis was severe stenosis of the left anterior descending branch that required emergency coronary artery bypass grafting. Preoperative computed tomography (CT) showed the feeding arteries of the gastric tube were in contact with the left internal mammary artery. Therefore, we felt harvesting this artery could be dangerous and decided to perform a median sternotomy, approaching from the right side of the gastric tube. The pericardium was easily and safely reached. We undertook on-pump cardiac arrest single coronary artery bypass grafting of the left anterior descending artery with a saphenous vein graft. The postoperative course was uneventful without mediastinitis. Cardiac surgery after esophageal cancer is often performed from a left thoracotomy. But, we recommend a median sternotomy be performed as an option. Preoperative contrast-enhanced CT should be considered as it may indicate the need for a significant revision such as a median sternotomy.


Assuntos
Ponte de Artéria Coronária/métodos , Estenose Coronária/cirurgia , Neoplasias Esofágicas/cirurgia , Esternotomia , Idoso , Estenose Coronária/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Esofagectomia , Humanos , Masculino , Radiografia
15.
Ann Thorac Cardiovasc Surg ; 19(2): 158-61, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22850093

RESUMO

Relapsing polychondritis (RP) is a rare, inflammatory, multiorgan disorder affecting cartilaginous structure and other connective tissue. Cardiovascular complications occur in 10%-52% of patients. We report a case of emergency surgery for an acute aortic dissection in a patient with RP. A 45-year-old female who had been taking corticosteroids (10 mg/day) for 2 years for RP presented at another hospital with dyspnea and severe chest and back pain. Acute aortic dissection was diagnosed, and we performed emergency replacement of the ascending aorta. We could not control the bleeding from suture holes of the native aorta because the vessel was so fragile. Thus, we performed a delayed sternal closure. The day after surgery, bleeding had decreased, and we could close the chest wall. Infection was well controlled, and the patient suffered minimal additional complications. She was discharged to home by herself 29 days after surgery and returned to normal life.


Assuntos
Aneurisma Aórtico/cirurgia , Dissecção Aórtica/cirurgia , Implante de Prótese Vascular , Policondrite Recidivante/complicações , Doença Aguda , Corticosteroides/uso terapêutico , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/etiologia , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/etiologia , Aortografia/métodos , Biópsia , Emergências , Feminino , Humanos , Pessoa de Meia-Idade , Policondrite Recidivante/tratamento farmacológico , Esternotomia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Técnicas de Fechamento de Ferimentos
17.
Org Biomol Chem ; 5(8): 1210-7, 2007 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-17406719

RESUMO

In our program for developing chirality manipulation systems, we synthesized bis(zinc porphyrin) 1, with a dibenzodiaza-30-crown-10 as a linker unit. Two structural features were examined. The aza-crown segment exhibited an intermolecular interaction with the zinc(ii) of the porphyrin, capable of causing aggregation to form spherical nanostructures, as inferred by concentration-dependency of (1)H NMR as well as scanning electron microscopy (SEM) observation. We also consider the crown-based conformation flexibility, in which accommodated K(+) tunes the porphyrin orientation into the tweezers conformation, assisting chirality induction upon complexation with chiral diamine 2. The circular dichroism (CD) intensity change essentially reached a plateau at a [(1R,2R)-2] : [1] ratio of 2 : 1 for which a 45% enhancement in the amplitude of CD spectra was observed compared to the K(+)-free conditions. Use of the crown linker of is not limited to promoting chirality induction with diamines in the presence of K(+); chiroptical probing of unprotected amino acids (Lys, His, Trp, and Phe) using 1 was attained through liquid (1 in CH(2)Cl(2))-liquid (the amino acids in 1 N KOH) two-phase extraction. The amphiphilic properties of the crown segment, as well as the K(+)-assisted tweezers conformation, make it possible to explore a potent way to develop chirality sensors for amino acids in water.

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