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Kraemer T, Mark M, Waldburger P, Danzl JG, Chin C, Engeser B, Lange AD, Pilch K, Jaakkola A, Nägerl HC, Grimm R. Evidence for Efimov quantum states in an ultracold gas of caesium atoms. Nature 2006; 440:315-8. [PMID: 16541068 DOI: 10.1038/nature04626] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Accepted: 02/02/2006] [Indexed: 11/09/2022]
Abstract
Systems of three interacting particles are notorious for their complex physical behaviour. A landmark theoretical result in few-body quantum physics is Efimov's prediction of a universal set of bound trimer states appearing for three identical bosons with a resonant two-body interaction. Counterintuitively, these states even exist in the absence of a corresponding two-body bound state. Since the formulation of Efimov's problem in the context of nuclear physics 35 years ago, it has attracted great interest in many areas of physics. However, the observation of Efimov quantum states has remained an elusive goal. Here we report the observation of an Efimov resonance in an ultracold gas of caesium atoms. The resonance occurs in the range of large negative two-body scattering lengths, arising from the coupling of three free atoms to an Efimov trimer. Experimentally, we observe its signature as a giant three-body recombination loss when the strength of the two-body interaction is varied. We also detect a minimum in the recombination loss for positive scattering lengths, indicating destructive interference of decay pathways. Our results confirm central theoretical predictions of Efimov physics and represent a starting point with which to explore the universal properties of resonantly interacting few-body systems. While Feshbach resonances have provided the key to control quantum-mechanical interactions on the two-body level, Efimov resonances connect ultracold matter to the world of few-body quantum phenomena.
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230 |
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Jochim S, Bartenstein M, Altmeyer A, Hendl G, Riedl S, Chin C, Hecker Denschlag J, Grimm R. Bose-Einstein Condensation of Molecules. Science 2003; 302:2101-3. [PMID: 14615548 DOI: 10.1126/science.1093280] [Citation(s) in RCA: 225] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report on the Bose-Einstein condensation of more than 10(5) Li2 molecules in an optical trap starting from a spin mixture of fermionic lithium atoms. During forced evaporative cooling, the molecules are formed by three-body recombination near a Feshbach resonance and finally condense in a long-lived thermal equilibrium state. We measured the characteristic frequency of a collective excitation mode and demonstrated the magnetic field-dependent mean field by controlled condensate spilling.
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Bernstein D, Naftel D, Chin C, Addonizio LJ, Gamberg P, Blume ED, Hsu D, Canter CE, Kirklin JK, Morrow WR. Outcome of listing for cardiac transplantation for failed Fontan: a multi-institutional study. Circulation 2006; 114:273-80. [PMID: 16847155 DOI: 10.1161/circulationaha.105.548016] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND The Fontan procedure is a successful palliation for children with single-ventricle physiology; however, many will eventually require heart transplantation. The purpose of this study was to determine risk factors for death awaiting transplantation and to examine results after transplantation in Fontan patients. METHODS AND RESULTS A retrospective, multi-institutional review was performed of 97 Fontan patients <18 years of age listed at 17 Pediatric Heart Transplant Study centers from 1993 to 2001. Mean age at listing was 9.7 years (0.5 to 17.9 years); 25% were <4 years old; 53% were United Network for Organ Sharing status 1; 18% required ventilator support. Pretransplantation survival was 78% at 6 months and 74% at 12 months and was similar to 243 children with other congenital heart disease (CHD) and 747 children without congenital heart disease (No-CHD), who were also awaiting transplantation. Patients who were younger, status 1, had shorter interval since Fontan, or were on a ventilator were more likely to die while waiting. At 6 months, the probability of receiving a transplant was similar for status 1 and 2 (65% versus 68%); however, the probability of death was higher for status 1 (22% versus 5%). Seventy patients underwent transplantation. Survival was 76% at 1 year, 70% at 3 years, and 68% at 5 years, slightly less than CHD and No-CHD patients. Causes of death included infection (30%), graft failure (17%), rejection (13%), sudden death (13%), and graft coronary artery disease (9%). Protein-losing enteropathy (present in 34 patients) resolved in all who survived >30 days after transplantation. CONCLUSIONS Heart transplantation is an effective therapy for pediatric patients with a failed Fontan. Although early posttransplantation survival is slightly lower than other patients with CHD, long-term results are encouraging, and protein-losing enteropathy can be expected to resolve.
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Multicenter Study |
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Chin C, Bartenstein M, Altmeyer A, Riedl S, Jochim S, Denschlag JH, Grimm R. Observation of the Pairing Gap in a Strongly Interacting Fermi Gas. Science 2004; 305:1128-30. [PMID: 15272125 DOI: 10.1126/science.1100818] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We studied fermionic pairing in an ultracold two-component gas of 6Li atoms by observing an energy gap in the radio-frequency excitation spectra. With control of the two-body interactions through a Feshbach resonance, we demonstrated the dependence of the pairing gap on coupling strength, temperature, and Fermi energy. The appearance of an energy gap with moderate evaporative cooling suggests that our full evaporation brought the strongly interacting system deep into a superfluid state.
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Graves EE, Nelson SJ, Vigneron DB, Chin C, Verhey L, McDermott M, Larson D, Sneed PK, Chang S, Prados MD, Lamborn K, Dillon WP. A preliminary study of the prognostic value of proton magnetic resonance spectroscopic imaging in gamma knife radiosurgery of recurrent malignant gliomas. Neurosurgery 2000; 46:319-26; discussion 326-8. [PMID: 10690720 DOI: 10.1097/00006123-200002000-00011] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE The goal of this study was to investigate the use of proton magnetic resonance spectroscopic imaging as a prognostic indicator in gamma knife radiosurgery of recurrent gliomas. METHODS Thirty-six patients with recurrent gliomas were studied with proton magnetic resonance spectroscopic imaging at the time of radiosurgery, and with conventional magnetic resonance imaging examinations at regular time intervals until the initiation of a new treatment strategy. Patients were categorized on the basis of their initial spectroscopic results, and their performance was assessed in terms of change in contrast-enhancing volume, time to further treatment, and survival. RESULTS The trends in the overall population were toward more extensive increase in the percent contrast-enhancing volume, a decreased time to further treatment, and a reduced survival time for patients with more extensive initial metabolic abnormalities. Statistical analysis of the subpopulation of patients with glioblastoma multiforme found a significant increase in relative contrast-enhancing volume (P < 0.01, Wilcoxon signed-rank test), a decrease in time to further treatment (P < 0.01, log-rank test), and a reduction in survival time (P < 0.01, log-rank test) for patients with regions containing tumor-suggestive spectra outside the gamma knife target, compared with patients exhibiting spectral abnormalities restricted to the gamma knife target. Further studies are needed to establish statistical significance for patients with lower-grade lesions and to confirm the results observed in this study. CONCLUSION The pretreatment spectroscopic results provided information that was predictive of outcome for this patient pool, both in local control (change in contrast-enhancing volume) and global outcome (time to further treatment and survival). This modality may have an important role in improving the selection, planning, and treatment process for glioma patients.
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Sigfússon G, Fricker FJ, Bernstein D, Addonizio LJ, Baum D, Hsu DT, Chin C, Miller SA, Boyle GJ, Miller J, Lawrence KS, Douglas JF, Griffith BP, Reitz BA, Michler RE, Rose EA, Webber SA. Long-term survivors of pediatric heart transplantation: a multicenter report of sixty-eight children who have survived longer than five years. J Pediatr 1997; 130:862-71. [PMID: 9202606 DOI: 10.1016/s0022-3476(97)70270-1] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Short-term survival after pediatric heart transplantation is now excellent, but ultimately the efficacy of this procedure will depend on duration and quality of survival. We sought to evaluate the clinical course of long-term survivors of heart transplantation in childhood. METHODS Patients who had undergone heart transplantation at the university hospitals of Stanford, Columbia, and Pittsburgh between 1975 and 1989 and survived longer than 5 years from transplantation were identified and their clinical courses retrospectively reviewed. RESULTS Sixty eight children have survived more than 5 years from transplantation, and 60 (88%) are currently alive with a median follow-up of 6.8 years (5 to 17.9 years). Thirteen have survived more than 10 years from transplantation. Renal dysfunction caused by immunosuppressive agents was common, and two patients required late renal transplantation. Lymphoproliferative disease or other neoplasm occurred in 12 patients, but none resulted in death. Coronary artery disease was diagnosed in 13 patients (19%), leading to retransplantation in eight. Death after 5 years was related to acute or chronic rejection in 5 of 8 cases. Two of the deaths were directly related to noncompliance with immunosuppressive medication. All survivors are in New York Heart Association class 1. CONCLUSIONS Long-term survival with good quality of life can be achieved after heart transplantation in childhood, though complications of immunosuppression remain common. Posttransplantation coronary artery disease is emerging as the main factor limiting long term graft and patient survival.
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Clinical Trial |
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Chen LK, Lin YL, Liao CL, Lin CG, Huang YL, Yeh CT, Lai SC, Jan JT, Chin C. Generation and characterization of organ-tropism mutants of Japanese encephalitis virus in vivo and in vitro. Virology 1996; 223:79-88. [PMID: 8806542 DOI: 10.1006/viro.1996.0457] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Using gamma-ray irradiation, a pair of virulent (RP-9) and attenuated (RP-2ms) variants of Japanese encephalitis virus (JEV) were generated from a Taiwanese isolate, NT109. The two variants differed in plaque morphology, virus adsorption, and growth properties in BHK-21 cells: (i) RP-2ms produced smaller plaques than RP-9; (ii) RP-2ms adsorbed less efficiently to host cells but yielded a higher virus titer (burst size); and (iii) RP-2ms virions were mostly accumulated intracellularly, whereas RP-9 was released extracellularly. In addition, in an in vitro binding assay, the envelope (E) protein of RP-9, but not that of RP-2ms, bound specifically to a cellular protein of 57-kDa derived from BHK-21 cells. When injected into mice intracerebrally, RP-2ms was much less virulent than RP-9, with 50% lethal doses of > 10(7) and 0.4 plaque forming units, respectively. Moreover, when inoculated intraperitoneally, their organ tropism differed in that the main target organ for RP-2ms was liver, whereas that for RP-9 was brain. These results suggest that RP-2ms was less neurovirulent and less neuroinvasive from peripheral routes. Molecular analysis of the virus structural proteins detected only two differences between RP-9 and RP-2ms: one in E protein, Glu-138 in RP-9 and Lys-138 in RP-2ms, and the other in prM, Tyr-43 in RP-9 and His-43 in RP-2ms. Since the N-terminal 92 amino acids of prM are cleaved and not present in mature JEV virions, the single-amino-acid change of the E protein at position 138 may account for the difference between the mutants in the in vitro binding assay. Such mutation in E protein, or perhaps in conjunction with the prM mutation, may be responsible, in part, for the phenotypic differences observed in vitro and in vivo between the two mutants.
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Taplin SH, Barlow WE, Ludman E, MacLehos R, Meyer DM, Seger D, Herta D, Chin C, Curry S. Testing reminder and motivational telephone calls to increase screening mammography: a randomized study. J Natl Cancer Inst 2000; 92:233-42. [PMID: 10655440 DOI: 10.1093/jnci/92.3.233] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Prospective randomized trials have demonstrated that motivational telephone calls increase adherence to screening mammography. To better understand the effects of motivational calls and to maximize adherence, we conducted a randomized trial among women aged 50-79 years. METHODS We created a stratified random sample of 5062 women due for mammograms within the Group Health Cooperative of Puget Sound, including 4099 women with prior mammography and 963 without it. We recruited and surveyed 3743 (74%) of the women before mailing a recommendation. After 2 months, 1765 (47%) of the 3743 women had not scheduled a mammogram and were randomly assigned to one of three intervention groups: a reminder post-card group (n = 590), a reminder telephone call group (n = 585), and a motivational telephone call addressing barriers group (n = 590). The telephone callers could schedule mammography. We used Cox proportional hazards models to estimate the hazard ratio (HR) and 95% confidence interval (CI) for documented mammography use by 1 year. RESULTS Women who received reminder calls were more likely to get mammograms (HR = 1.9; 95% CI = 1.6-2.4) than women who were mailed postcards. The motivational and reminder calls (average length, 8.5 and 3.1 minutes, respectively) had equivalent effects (HR = 0.97; 95% CI = 0.8-1.2). After we controlled for the intervention effect, women with prior mammography (n = 1277) were much more likely to get a mammogram (HR = 3.4; 95% CI = 2.7-4.3) than women without prior use (n = 488). Higher income, but not race or more education, was associated with higher adherence. CONCLUSIONS Reminding women to schedule an appointment was as efficacious as addressing barriers. Simple intervention groups should be included as comparison groups in randomized trials so that we better understand more complex intervention effects.
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Clinical Trial |
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9
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Abadji V, Lucas-Lenard JM, Chin C, Kendall DA. Involvement of the carboxyl terminus of the third intracellular loop of the cannabinoid CB1 receptor in constitutive activation of Gs. J Neurochem 1999; 72:2032-8. [PMID: 10217281 DOI: 10.1046/j.1471-4159.1999.0722032.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The human cannabinoid receptor CB1 functionally couples primarily to Gi-, but also to Gs-mediated pathways to modulate intracellular cyclic AMP (cAMP) levels. To probe the features of the receptor that may be involved in promoting interactions with one G protein type over another, we generated the L341A/A342L mutant CB1 receptor. The double mutation involved the swap in position of two adjacent residues in the carboxyl-terminal segment of the third intracellular loop of CB1. This resulted in partial constitutive activation of the receptor and an agonist-independent enhancement in cAMP levels. Characterization following treatment with either pertussis or cholera toxin indicated that the constitutive activity is selective for a Gs- and not a Gi-mediated pathway. Treatment with the CB1-specific inverse agonist SR141716A inhibited the basal accumulation of cAMP in the presence of pertussis toxin, establishing that the effect is CB1 mediated. The binding of the agonist CP-55,940 to the L341A/A342L receptor was not markedly different from that for the wild-type receptor despite the constitutive Gs activity. This may reflect a preference of this ligand for an activated receptor state associated with the Gi coupling form and underscores the potential for developing therapeutics that selectively activate one pathway over another.
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10
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Bartenstein M, Altmeyer A, Riedl S, Jochim S, Chin C, Denschlag JH, Grimm R. Collective excitations of a degenerate gas at the BEC-BCS crossover. PHYSICAL REVIEW LETTERS 2004; 92:203201. [PMID: 15169351 DOI: 10.1103/physrevlett.92.203201] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Indexed: 05/24/2023]
Abstract
We study collective excitation modes of a fermionic gas of (6)Li atoms in the BEC-BCS crossover regime. While measurements of the axial compression mode in the cigar-shaped trap close to a Feshbach resonance confirm theoretical expectations, the radial compression mode shows surprising features. In the strongly interacting molecular BEC regime, we observe a negative frequency shift with increasing coupling strength. In the regime of a strongly interacting Fermi gas, an abrupt change in the collective excitation frequency occurs, which may be a signature for a transition from a superfluid to a collisionless phase.
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Chin C, Zhang ZP, Karnes HT. A study of matrix effects on an LC/MS/MS assay for olanzapine and desmethyl olanzapine. J Pharm Biomed Anal 2005; 35:1149-67. [PMID: 15336361 DOI: 10.1016/j.jpba.2004.01.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2003] [Accepted: 01/06/2004] [Indexed: 11/19/2022]
Abstract
The purpose of this research project was to investigate potential matrix effects of anticoagulant and lipemia on the response of olanzapine, desmethyl olanzapine, olanzapine-D(3) and desmethyl olanzapine-D(8) in an LC/MS/MS assay. Blank human serum and sodium heparin, sodium citrate, and K(3)EDTA plasma with various degrees of lipemia were fortified with olanzapine, desmethyl olanzapine, olanzapine-D(3) and desmethyl olanzapine-D(8). Six replicates of each sample were extracted using Waters Oasis MCX cartridges and analyzed using electrospray LC/MS/MS. The analytes were separated on a Phenomenex LUNA phenyl hexyl, 2 mm x 50 mm, 5 microm, analytical column and a gradient rising from 2 to 85% mobile phase B. Mobile phase A consisted of acetonitrile-ammonium acetate (20 mM) (52:48 v/v) and mobile phase B was formic acid-acetonitrile (0.1:100 v/v). Ion suppression was investigated through post column infusion experiments. The degree of lipemia of each sample, indicated by turbidity, was ranked into categories from least to greatest and used for statistical analyses. The results from analysis of variance testing indicated that lipemia, anticoagulant and their interaction significantly influenced mass spectral matrix effects and extraction matrix effects. Differential behavior between the analytes and labeled internal standards contributed to variability. The most significant source of variability however, was ion suppression due to co-eluting matrix components.
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Research Support, Non-U.S. Gov't |
20 |
72 |
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Lofters WS, Pater JL, Zee B, Dempsey E, Walde D, Moquin JP, Wilson K, Hoskins P, Guevin RM, Verma S, Navari R, Krook JE, Hainsworth J, Palmer M, Chin C. Phase III double-blind comparison of dolasetron mesylate and ondansetron and an evaluation of the additive role of dexamethasone in the prevention of acute and delayed nausea and vomiting due to moderately emetogenic chemotherapy. J Clin Oncol 1997; 15:2966-73. [PMID: 9256141 DOI: 10.1200/jco.1997.15.8.2966] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To compare the efficacy of dolasetron and ondansetron in controlling nausea and vomiting in the first 24 hours; to evaluate the efficacy when dexamethasone is added to either drug in the first 24 hours; and to extend these comparisons over 7 days in patients receiving moderately emetogenic chemotherapy. PATIENTS AND METHODS This was a multicenter, double-blind, randomized study with six parallel arms that used a 2 x 2 factorial design in chemotherapy-naive patients. In arm 1, dolasetron (2.4 mg/kg) was given intravenously (I.V.) prechemotherapy, followed 24 hours later by oral dolasetron (200 mg once daily) for 6 days. Arms 2 and 3 consisted of dolasetron and dexamethasone 8 mg I.V., followed 24 hours later by oral dexamethasone (8 mg once daily) in one arm, and oral dexamethasone and dolasetron in the other, also for 6 days. In arms 4, 5, and 6, ondansetron (32 mg I.V. or 8 mg orally twice daily) was administered in a similar manner to arms 1, 2, and 3 before and 24 hours after chemotherapy. Mean nausea severity (MNS) was assessed on a visual analog scale (VAS) in a daily diary. RESULTS Of 703 patients enrolled, 696 were eligible. There were 343 dolasetron- and 353 ondansetron-treated patients; 57% of dolasetron-treated patients had complete protection in the first 24 hours versus 67% of patients who received ondansetron (P = .013). MNS was also more pronounced on the dolasetron arm (P = .051). Sixty-seven percent of patients who received added dexamethasone in the first 24 hours had complete protection, compared with 55% without dexamethasone (P < .001). MNS was significantly reduced with the addition of dexamethasone (P < .001). At 7 days, dolasetron and ondansetron had equivalent complete protection rates (36% and 39%, respectively). With the addition of dexamethasone, 48% of patients compared with 28% had complete protection (P < .001). MNS was significantly improved with added dexamethasone (P < .001). CONCLUSION At the doses used, dolasetron was significantly less effective than ondansetron at controlling nausea and vomiting in the first 24 hours in patients receiving moderately emetogenic chemotherapy, but there was no demonstrable difference between both drugs over 7 days. The addition of dexamethasone significantly improved the efficacy of both drugs in the first 24 hours and over 7 days.
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Clinical Trial |
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72 |
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al-Zahrani MA, Peters W, Evans DA, Chin C, Smith V, Lane RP. Phlebotomus sergenti, a vector of Leishmania tropica in Saudi Arabia. Trans R Soc Trop Med Hyg 1988; 82:416. [PMID: 3232175 DOI: 10.1016/0035-9203(88)90142-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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69 |
14
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Bartenstein M, Altmeyer A, Riedl S, Jochim S, Chin C, Denschlag JH, Grimm R. Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas. PHYSICAL REVIEW LETTERS 2004; 92:120401. [PMID: 15089653 DOI: 10.1103/physrevlett.92.120401] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2004] [Revised: 02/02/2004] [Indexed: 05/24/2023]
Abstract
We demonstrate a reversible conversion of a 6Li2 molecular Bose-Einstein condensate to a degenerate Fermi gas of atoms by adiabatically crossing a Feshbach resonance. By optical in situ imaging, we observe a smooth change of the cloud size in the crossover regime. On the Feshbach resonance, the ensemble is strongly interacting and the measured cloud size is 75(7)% of the one of a noninteracting zero-temperature Fermi gas. The high condensate fraction of more than 90% and the adiabatic crossover suggest our Fermi gas to be cold enough to form a superfluid.
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Biessmann H, Valgeirsdottir K, Lofsky A, Chin C, Ginther B, Levis RW, Pardue ML. HeT-A, a transposable element specifically involved in "healing" broken chromosome ends in Drosophila melanogaster. Mol Cell Biol 1992; 12:3910-8. [PMID: 1324409 PMCID: PMC360270 DOI: 10.1128/mcb.12.9.3910-3918.1992] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Eight terminally deleted Drosophila melanogaster chromosomes have now been found to be "healed." In each case, the healed chromosome end had acquired sequence from the HeT DNA family, a complex family of repeated sequences found only in telomeric and pericentric heterochromatin. The sequences were apparently added by transposition events involving no sequence homology. We now report that the sequences transposed in healing these chromosomes identify a novel transposable element, HeT-A, which makes up a subset of the HeT DNA family. Addition of HeT-A elements to broken chromosome ends appears to be polar. The proximal junction between each element and the broken chromosome end is an oligo(A) tract beginning 54 nucleotides downstream from a conserved AATAAA sequence on the strand running 5' to 3' from the chromosome end. The distal (telomeric) ends of HeT-A elements are variably truncated; however, we have not yet been able to determine the extreme distal sequence of a complete element. Our analysis covers approximately 2,600 nucleotides of the HeT-A element, beginning with the oligo(A) tract at one end. Sequence homology is strong (greater than 75% between all elements studied). Sequence may be conserved for DNA structure rather than for protein coding; even the most recently transposed HeT-A elements lack significant open reading frames in the region studied. Instead, the elements exhibit conserved short-range sequence repeats and periodic long-range variation in base composition. These conserved features suggest that HeT-A elements, although transposable elements, may have a structural role in telomere organization or maintenance.
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research-article |
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Shu PY, Chen LK, Chang SF, Yueh YY, Chow L, Chien LJ, Chin C, Lin TH, Huang JH. Dengue NS1-specific antibody responses: isotype distribution and serotyping in patients with Dengue fever and Dengue hemorrhagic fever. J Med Virol 2000; 62:224-32. [PMID: 11002252 DOI: 10.1002/1096-9071(200010)62:2<224::aid-jmv14>3.0.co;2-c] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To understand the antibody responses to dengue (DEN) nonstructural 1 (NS1) glycoprotein and their roles in protective immunity or pathogenesis of dengue fever (DF) and dengue hemorrhagic fever (DHF), we have analyzed the NS1-speccific IgM, IgA and IgG antibodies from patients with DF and DHF. An isotype-specific, indirect enzyme-linked immunosorbent assay (ELISA) was established by coating a NS1-specific monoclonal antibody (MAb), D2/8-1, to capture soluble NS1 antigens secreted in the culture supernatants of Vero cells infected with DEN virus. We observed strong anti-NS1 antibody responses in all of the convalescent sera of patients with DF and DHF. Similar NS1-specific isotypic and serotypic antibody responses were found in the sera from DF and DHF patients. The results showed that all DEN infections induced significant NS1-specific IgG, whereas 75% and 60% of primary DF patients vs. 40% and 90% of secondary DF patients produced IgM and IgA antibodies, respectively. Specificity analysis showed that DEN NS1-specific IgG and IgA antibodies cross-react strongly to Japanese encephalitis (JE) virus NS1 glycoprotein, whereas DEN NS1-specific IgM antibodies do not cross-react to JE virus NS1 glycoprotein at all. The serotype specificity of NS1-specific IgM, IgA and IgG were found to be 80%, 67% and 75% for primary infections, and 50%, 22% and 30% for secondary infections in positive samples of DF patients. Similar pattern was found in DHF patients. The results showed that all of the DF and DHF patients produced significant NS1-specific antibodies. We did not observe direct correlation between the anti-NS1 antibody responses and DHF because sera from patients with DF and DHF showed similar anti-NS1 antibody responses.
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Pater JL, Lofters WS, Zee B, Dempsey E, Walde D, Moquin JP, Wilson K, Hoskins P, Guevin RM, Verma S, Navari R, Krook JE, Hainsworth J, Palmer M, Chin C. The role of the 5-HT3 antagonists ondansetron and dolasetron in the control of delayed onset nausea and vomiting in patients receiving moderately emetogenic chemotherapy. Ann Oncol 1997; 8:181-5. [PMID: 9093728 DOI: 10.1023/a:1008247830641] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND 5-HT3 antagonists are effective in reducing the acute nausea and vomiting caused by cancer chemotherapy. However, it is not clear whether continuing these agents beyond twenty four hours is useful in controlling emesis on days two to seven after chemotherapy. PATIENTS AND METHODS Four hundred seven patients receiving moderately emetogenic chemotherapy who had been given dexamethasone 8 mg i.v. and either ondansetron 32 mg i.v. or dolasetron 2.4 mg/kg i.v. were randomized to continue either an oral form of their 5-HT3 antagonist (ondansetron 8 mg b.i.d. or dolasetron 200 mg daily) plus dexamethasone 8 mg p.o. daily or dexamethasone alone for days two to seven. Endpoints assessed by self-report were: 1) complete control (no vomiting, no rescue medications, no missing data) of emesis; 2) nausea severity; and 3) quality-of-life as measured by the EORTC QLQ-C30. RESULTS Continuation of 5-HT3 antagonists improved slightly, but not significantly, the complete control rate (47% vs. 41%: P = 0.24 one-sided) after chemotherapy. However, mean nausea severity was significantly (P = 0.015 one sided) reduced (by 3 mm on a 10 cm scale) on the combined arm. Minimal differences in quality of life were observed. CONCLUSION The benefit of continuing 5-HT3 antagonists beyond 24 hours is modest and the merits of routine use in these circumstances debatable.
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Clinical Trial |
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50 |
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Kuo MD, Chin C, Hsu SL, Shiao JY, Wang TM, Lin JH. Characterization of the NTPase activity of Japanese encephalitis virus NS3 protein. J Gen Virol 1996; 77 ( Pt 9):2077-84. [PMID: 8811006 DOI: 10.1099/0022-1317-77-9-2077] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Japanese encephalitis (JE) virus NS3 protein and two N-terminally truncated (delta 1-148 and delta 1-323) forms of NS3 were engineered and expressed in E. coli as fusion proteins with a histidine tag at the N terminus. The purified recombinant proteins his-NS3 and his-NS3(delta 1-148) were found to possess NTPase activity which was stimulated by single-stranded RNA, whereas NS3(delta 1-323) did not. The requirements for MgCl2 and MnCl2 and the salt and pH ranges necessary for optimal activity of the enzyme were determined and shown to be slightly different from those of the NTPases of other flaviviruses. Poly(U) and poly(C) were better than poly(A) at stimulating the NTPase activities, in contrast to other flaviviral NTPases. The substrate preference was in the order GTP > ATP >> UTP > CTP. Interestingly, we found that Ca2+ could not substitute for Mg2+; on the contrary, it inhibited NTPase activity. The removal of the N-terminal 148 amino acids enhanced NTPase activity, but further deletion of the region (amino acids 148-323) completely abolished the activity. Therefore, amino acids 148-323 contain a critical region required for NTPase activity.
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Lai CH, Wong WW, Chin C, Huang CK, Lin HH, Chen WF, Yu KW, Liu CY. Central venous catheter-related Stenotrophomonas maltophilia bacteraemia and associated relapsing bacteraemia in haematology and oncology patients. Clin Microbiol Infect 2006; 12:986-91. [PMID: 16961635 DOI: 10.1111/j.1469-0691.2006.01511.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This retrospective study investigated the clinical significance and impact of Stenotrophomonas maltophilia bacteraemia in 49 haematology and oncology patients at a tertiary referral medical centre in Taipei between July 1999 and December 2003. Sixteen patients had 24 episodes of central venous catheter (CVC)-related bacteraemia, with the main clinical characteristics being a nosocomial bacteraemia (100%), preceding antibiotic therapy (94%), bacteraemia developed in a general ward (87%), immunosuppressive therapy (75%), in-situ CVC-related bacteraemia (75%), and neutropenia (63%). Only four (25%) patients had inflammatory signs at the CVC site following diagnosis of bacteraemia. Five patients had recurrent bacteraemia, with risk-factors being long-lasting (>10 days) neutropenia (p 0.036) and an initial failure to remove the CVC (p 0.001). These cases did not involve re-infection, as the same S. maltophilia strain was identified following random amplified polymorphic DNA (RAPD) analysis of the initial and subsequent isolates. However, relapses could occur after long latency periods (maximum, 200 days). Most patients were cured after removal of the CVC, even without appropriate antibiotic treatment. Physicians should have a high index of suspicion for CVC-related bacteraemia with haematology and oncology patients with CVCs and S. maltophilia bacteraemia. In addition to appropriate antibiotic therapy, removal of the CVC is crucial for successful treatment of CVC-related S. maltophilia bacteraemia and prevention of relapses.
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Kerman AJ, Vuletic V, Chin C, Chu S. Beyond optical molasses: 3D raman sideband cooling of atomic cesium to high phase-space density. PHYSICAL REVIEW LETTERS 2000; 84:439-442. [PMID: 11015933 DOI: 10.1103/physrevlett.84.439] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/1999] [Indexed: 05/23/2023]
Abstract
We demonstrate a simple, general purpose method to cool neutral atoms. A sample containing 3x10(8) cesium atoms prepared in a magneto-optical trap is cooled and simultaneously spin polarized in 10 ms at a density of 1.1x10(11) cm (-3) to a phase space density nlambda(3)(dB) = 1/500, which is almost 3 orders of magnitude higher than attainable in free space with optical molasses. The technique is based on 3D degenerate Raman sideband cooling in optical lattices and remains efficient even at densities where the mean lattice site occupation is close to unity.
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Shu PY, Chen LK, Chang SF, Yueh YY, Chow L, Chien LJ, Chin C, Lin TH, Huang JH. Antibody to the nonstructural protein NS1 of Japanese encephalitis virus: potential application of mAb-based indirect ELISA to differentiate infection from vaccination. Vaccine 2001; 19:1753-63. [PMID: 11166901 DOI: 10.1016/s0264-410x(00)00391-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and differentiate the antibody responses to Japanese encephalitis (JE) virus nonstructural protein NS1 between infected and vaccinated individuals. The results showed that all convalescent sera from JE patients contained NS1-specific IgG antibodies, while 65 and 40% of these sera showed detectable NS1-specific IgM and IgA antibodies, respectively. Specificity analysis showed that NS1-specific IgM and IgA antibodies from JE patients do not cross-react to dengue virus NS1 glycoprotein, while IgG antibodies from 10% of JE patients showed significant cross-reaction to dengue virus NS1 glycoprotein. To differentiate infection from vaccination, the immune sera from 24 children vaccinated with inactivated JE vaccine were analyzed. The data showed that none of these immune sera had detectable NS1-specific IgG antibodies. The results demonstrated the potential application of JE NS1-specific indirect ELISA to differentiate infection from vaccination.
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Daly J, Elliott D, Cameron-Traub E, Salamonson Y, Davidson P, Jackson D, Chin C, Wade V. Health status, perceptions of coping, and social support immediately after discharge of survivors of acute myocardial infarction. Am J Crit Care 2000. [DOI: 10.4037/ajcc2000.9.1.62] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND: The period immediately after discharge from the hospital after an acute myocardial infarction is a stressful and vulnerable time about which little is known. OBJECTIVE: To explore health status, perceptions of coping, and social support among survivors of a recent myocardial infarction in the first 3 weeks after discharge from hospitals in southwestern Sydney, Australia. METHODS: A descriptive, exploratory approach with a triangulated methodology was used to assess the experiences of 38 survivors, detect patterns in these experiences, explore the health-support needs of survivors, and determine changes in health status in the first 3 weeks after discharge. Quantitative data were collected with the Medical Outcomes Study SF-36, New York Heart Association classification, Canadian Cardiovascular Society Angina Scale, and the Jalowiec Coping Scale. A semistructured interview schedule provided additional qualitative data about the experiences of the survivors. RESULTS: The health status of participants was relatively stable during the 3-week period; most had no activity limitation due to dyspnea or angina. However, the subjects' health status was considerably lower than that of their age-matched population. The most common and most effective coping strategies adopted during this period were confrontation, optimism, and self-reliance. In addition, the subjects experienced anxiety, depression, ambiguity and uncertainty, fear of recurrence of the infarction and of deterioration in health, of boredom and of inertia. CONCLUSION: These findings can help nurses in hospital and community settings assist survivors of acute myocardial infarction to prepare for and deal effectively with experiences during convalescence.
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Jackson D, Daly J, Davidson P, Elliott D, Cameron-Traub E, Wade V, Chin C, Salamonson Y. Women recovering from first-time myocardial infarction (MI): a feminist qualitative study. J Adv Nurs 2000; 32:1403-11. [PMID: 11136408 DOI: 10.1046/j.1365-2648.2000.01622.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although myocardial infarction (MI) is a leading cause of death and disablement for women internationally, little is known about women's recovery. This paper describes an exploratory descriptive study that was informed by feminist principles, and which aimed to explore the recovery experiences of a group of women survivors of first-time MI in the initial period following discharge from hospital. A total of 10 female survivors were interviewed using an open-ended semi-structured interview schedule administered at 7, 14 and 21 days post-hospital discharge. Findings revealed that recovery was experienced as a complex process, initially characterized by fear and uncertainty. Over the duration of the study these feelings were replaced with a more positive outlook, a return of energy, and a sense of confidence in the future. Participants identified an unmet need for reliable information which persisted over the duration of the study. The findings of this study have implications for nursing practice and research. Chief among these is the issue of effective provision of information to women following an acute MI. The importance of providing relevant information to be understood and retained by people experiencing crisis cannot be overstated. Equally important are the provision of opportunities for patients to have regular contact with health professionals to question and seek clarifying information. These findings should now be tested on larger populations.
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Fricker FJ, Addonizio L, Bernstein D, Boucek M, Boucek R, Canter C, Chinnock R, Chin C, Kichuk M, Lamour J, Pietra B, Morrow R, Rotundo K, Shaddy R, Schuette EP, Schowengerdt KO, Sondheimer H, Webber S. Heart transplantation in children: indications. Report of the Ad Hoc Subcommittee of the Pediatric Committee of the American Society of Transplantation (AST). Pediatr Transplant 1999; 3:333-42. [PMID: 10562980 DOI: 10.1034/j.1399-3046.1999.00045.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This review details the indications for heart transplantation in children. Contraindications have evolved from absolute to relative. Controversial issues remain and this paper represents a consensus of more than a dozen centers that have programs that remain active performing pediatric heart transplants.
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Review |
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Rosenthal DN, Dubin AM, Chin C, Falco D, Gamberg P, Bernstein D. Outcome while awaiting heart transplantation in children: a comparison of congenital heart disease and cardiomyopathy. J Heart Lung Transplant 2000; 19:751-5. [PMID: 10967268 DOI: 10.1016/s1053-2498(00)00135-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Outcomes for children who undergo heart transplantation differ for children with congenital heart disease as compared to those with structurally normal hearts. Similar data have not been reported for these groups of patients for the morbidity and mortality associated with waiting for a donor. We report these data. METHODS A retrospective review was performed for all pediatric patients who were listed for heart transplantation at Stanford from 1977 to 1996, comparing mortality and major morbidity for patients with congenital heart disease and those with cardiomyopathy and structurally normal hearts. RESULTS There were 96 patients who met study criteria, of whom 67 were successfully transplanted. The median waiting time was 23 days. Survival at 30 days was 93% and at 90 days was 81%, with no difference between groups. Major complications were identified in 38% of patients with structurally normal hearts, vs 9% of patients with congenital heart disease (p < 0.001). CONCLUSIONS Overall mortality is similar for patients with congenital heart disease and those with structurally normal hearts while listed for heart transplantation, but patients with congenital heart disease have fewer episodes of major morbidity during this time.
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