Nix protein is a BH3-only pro-apoptotic mitochondrial protein. Here we reported the 1H, 13C and 1... more Nix protein is a BH3-only pro-apoptotic mitochondrial protein. Here we reported the 1H, 13C and 15N resonance assignments of zebrafish Nix protein for further understanding the structure and function relationship.
13 C CP/MAS solid-state NMR spectroscopy has been utilized to analyze six steroid compounds, name... more 13 C CP/MAS solid-state NMR spectroscopy has been utilized to analyze six steroid compounds, namely testosterone (Tes), hydrocortisone (Cor), trans-dehydroandrosterone (Adr), prednisolone (Prd), prednisone (Pre) and estradiol (Est). Among them, Tes displays a doublet pattern for all residues, whereas Prd, Pre and Est, exhibit exclusively singlets. For Cor and Adr, the 13 C spectra contain both doublet and singlet patterns. The 13 C doublet signal, with splittings of 0.2-1.5 ppm, are ascribed to local differences in the ring conformations associated with polymorphism. We have assigned all of the 13 C resonances to the different residues in these steroid compounds on the basis of solution NMR data. The C-7, C-8, C-10, C-15 and C-16 residues of Tes, Cor and Adr consistently give rise to singlets or doublets with splittings of less than 0.5 ppm, indicating similar local conformations. Accompanying hydration and dehydration processes, a reversible phase transformation between δ-and α-crystal forms has been observed in Tes, corresponding to singlet and doublet 13 C patterns, respectively. To further characterize the ring conformations in the α-form, we have successfully extracted chemical shift tensor elements for the 13 C doublets. It is demonstrated that 13 C solid-state NMR spectroscopy provides a reliable and sensitive means of characterizing polymorphism in steroids.
The ratio R of the cross section for e + e - annihilation into hadronic final states to the QED c... more The ratio R of the cross section for e + e - annihilation into hadronic final states to the QED cross section for muon-pair production is measured to be 4.34±0.45±0.30 and 4.23±0.20±0.21 at cm energies of 50 and 52 GeV, respectively. From these values of R and an analysis of the ...
We present a study of the influence of the constant uniform electric field on the doubly excited ... more We present a study of the influence of the constant uniform electric field on the doubly excited resonances of the positronium negative ion associated with the Nϭ3 positronium threshold. The calculation is performed in the framework of the complex coordinate rotation method which obtains results both for the real part of the energy ͑position of the resonance͒ and for the imaginary part of the energy ͑related to the width of the resonance͒. Results are given for the M ϭ0
In the present work, we have carried out an investigation on the S-wave resonances of e + -H in p... more In the present work, we have carried out an investigation on the S-wave resonances of e + -H in plasma environments based on the Debye model for weakly coupled plasmas. We employ the complex-coordinaterotation method with highly correlated Hylleraas-type wave functions. For resonant states below the respective H͑n =2s͒ and Ps͑n =2s͒ thresholds, good agreement has been found with an earlier calculation using the stabilization method. Results for the other five S-wave autoionization states up to and below the H͑n =4s͒ threshold of the e + -H system immersed in a Debye plasma are reported here.
nonautoionizing states of helium atom with Coulomb and screened Coulomb ͑Yukawa͒ potentials in th... more nonautoionizing states of helium atom with Coulomb and screened Coulomb ͑Yukawa͒ potentials in the framework of Ritz variational principle. Highly accurate correlated exponential wave functions with exponents generated by a quasirandom process are used to represent the correlation effect. For the Coulomb case, the metastable bound-excited 2pnp 1 P e ͑3 Յ n Յ 5͒, 2pnp 3 P e ͑2 Յ n Յ 5͒, 2pnd 1,3 D o ͑3 Յ n Յ 9͒, and 2pnf 1,3 F e ͑4 Յ n Յ 9͒ states energies are reported. Our upper-bound results for the 2pnd 1 D o ͑3 Յ n Յ 7͒, 2pnf 1 F e ͑4 Յ n Յ 8͒, 3 D o and 3 F e states are the lowest values up to this date. For the screened Coulomb case, the lower-lying metastable bound states energies for different screening parameters and for each spin states are also reported.
Solid-state 13 Cf 1 Hg cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been uti... more Solid-state 13 Cf 1 Hg cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been utilized to extract the molecular structure information of Taxol, which is an anti-tumor therapeutic medicine extracted from the yew bark. The 13 C signals have chemical shift values quite consistent with those measured in solution phase, and the overall chemical shift range is over 200 ppm. Notably, most of the 13 C resonances of the taxane ring have two clearly resolved spectral components except the resonance peaks of C-15, C-16 and C-17, which are located at the central part of the taxane ring. On the basis of our NMR data, we propose that these doublets originate from two slightly different molecular conformations of the taxane ring and still the central part of the ring remains structurally similar. Furthermore, it is demonstrated that the 13 C chemical shift difference deduced from the doublet splittings can serve as a direct measure of the structural difference between the two conformations, which could possibly correlate with the anti-tumor activity of Taxol.
Arginine kinase (AK), a 42-kDa enzyme, reversibly catalyzes phosphoryl transfer between ATP and a... more Arginine kinase (AK), a 42-kDa enzyme, reversibly catalyzes phosphoryl transfer between ATP and arginine, regulating cellular ATP levels in invertebrates. Eight phosphagen kinases are known from the animal kingdom, the human orthologue is creatine kinase (Ellington, 2001). Conformational changes for this family of enzymes, not the chemistry, are rate limiting on the reaction (Yousef et al.,2003). As a first step towards investigating these conformational changes, main chain resonance assignments of recombinant AK from the horseshoe crab Limulus polyphemus are reported here. 2D and 3D heteronuclear NMR experiments on uniformly 2 H, 13 C, 15 N-labeled AK and 15 N-amino acid type specific labeled AK were recorded. Main chain resonance assignments are 95% complete and have been deposited (BMRB accession #6542).
Objective. This study has two purposes: (a) to compare the use of tumor cell suspensions and exci... more Objective. This study has two purposes: (a) to compare the use of tumor cell suspensions and excised tumor tissue for generating renal tumors suitable for radiofrequency ablation (RFA) studies and (b) to assess the efficacy of RFA for ablation of renal VX2 tumors in a rabbit model. Procedures. VX2 tumor masses were used to inoculate 17 rabbits. The renal VX2 tumors of 13 rabbits were subsequently treated with a cooled-tip RF system at a power of 15-30 W for 3-6 minutes, and 4 rabbits served as control. After RFA, rabbits were observed by contrast-enhanced CT to ascertain the ablative range. Rabbits were divided into three groups and sacrificed at 3, 7, and 14 days post-treatment for histopathological studies. Results. Both tumor implant methods had a 100% success rate in generating tumors. The average lesion produced was 1.3x1.8x1.5 cm. Complete tumor ablation occurred in 76.9%, and local tumor growth in 23.1%. Depending on the position of the tumors, the complications after RFA treatment included infarction, perirenal hematoma, hydronephrosis, and abscess. The over-all complication rate was 38.5%. In histopathological studies, a central needle track, tumor coagulation, renal tissue coagulation, peripheral hemorrhage, and an inflammatory layer could be observed. Conclusion and clinical relevance. Application of RFA to destroy renal VX2 tumors in this rabbit model has a relatively high cure rate. It can be used to destroy small renal tumors in a precise and non-invasive manner. Impact on human medicine. We hope to apply this procedure in selected human renal tumors in the future.
Nix protein is a BH3-only pro-apoptotic mitochondrial protein. Here we reported the 1H, 13C and 1... more Nix protein is a BH3-only pro-apoptotic mitochondrial protein. Here we reported the 1H, 13C and 15N resonance assignments of zebrafish Nix protein for further understanding the structure and function relationship.
13 C CP/MAS solid-state NMR spectroscopy has been utilized to analyze six steroid compounds, name... more 13 C CP/MAS solid-state NMR spectroscopy has been utilized to analyze six steroid compounds, namely testosterone (Tes), hydrocortisone (Cor), trans-dehydroandrosterone (Adr), prednisolone (Prd), prednisone (Pre) and estradiol (Est). Among them, Tes displays a doublet pattern for all residues, whereas Prd, Pre and Est, exhibit exclusively singlets. For Cor and Adr, the 13 C spectra contain both doublet and singlet patterns. The 13 C doublet signal, with splittings of 0.2-1.5 ppm, are ascribed to local differences in the ring conformations associated with polymorphism. We have assigned all of the 13 C resonances to the different residues in these steroid compounds on the basis of solution NMR data. The C-7, C-8, C-10, C-15 and C-16 residues of Tes, Cor and Adr consistently give rise to singlets or doublets with splittings of less than 0.5 ppm, indicating similar local conformations. Accompanying hydration and dehydration processes, a reversible phase transformation between δ-and α-crystal forms has been observed in Tes, corresponding to singlet and doublet 13 C patterns, respectively. To further characterize the ring conformations in the α-form, we have successfully extracted chemical shift tensor elements for the 13 C doublets. It is demonstrated that 13 C solid-state NMR spectroscopy provides a reliable and sensitive means of characterizing polymorphism in steroids.
The ratio R of the cross section for e + e - annihilation into hadronic final states to the QED c... more The ratio R of the cross section for e + e - annihilation into hadronic final states to the QED cross section for muon-pair production is measured to be 4.34±0.45±0.30 and 4.23±0.20±0.21 at cm energies of 50 and 52 GeV, respectively. From these values of R and an analysis of the ...
We present a study of the influence of the constant uniform electric field on the doubly excited ... more We present a study of the influence of the constant uniform electric field on the doubly excited resonances of the positronium negative ion associated with the Nϭ3 positronium threshold. The calculation is performed in the framework of the complex coordinate rotation method which obtains results both for the real part of the energy ͑position of the resonance͒ and for the imaginary part of the energy ͑related to the width of the resonance͒. Results are given for the M ϭ0
In the present work, we have carried out an investigation on the S-wave resonances of e + -H in p... more In the present work, we have carried out an investigation on the S-wave resonances of e + -H in plasma environments based on the Debye model for weakly coupled plasmas. We employ the complex-coordinaterotation method with highly correlated Hylleraas-type wave functions. For resonant states below the respective H͑n =2s͒ and Ps͑n =2s͒ thresholds, good agreement has been found with an earlier calculation using the stabilization method. Results for the other five S-wave autoionization states up to and below the H͑n =4s͒ threshold of the e + -H system immersed in a Debye plasma are reported here.
nonautoionizing states of helium atom with Coulomb and screened Coulomb ͑Yukawa͒ potentials in th... more nonautoionizing states of helium atom with Coulomb and screened Coulomb ͑Yukawa͒ potentials in the framework of Ritz variational principle. Highly accurate correlated exponential wave functions with exponents generated by a quasirandom process are used to represent the correlation effect. For the Coulomb case, the metastable bound-excited 2pnp 1 P e ͑3 Յ n Յ 5͒, 2pnp 3 P e ͑2 Յ n Յ 5͒, 2pnd 1,3 D o ͑3 Յ n Յ 9͒, and 2pnf 1,3 F e ͑4 Յ n Յ 9͒ states energies are reported. Our upper-bound results for the 2pnd 1 D o ͑3 Յ n Յ 7͒, 2pnf 1 F e ͑4 Յ n Յ 8͒, 3 D o and 3 F e states are the lowest values up to this date. For the screened Coulomb case, the lower-lying metastable bound states energies for different screening parameters and for each spin states are also reported.
Solid-state 13 Cf 1 Hg cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been uti... more Solid-state 13 Cf 1 Hg cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been utilized to extract the molecular structure information of Taxol, which is an anti-tumor therapeutic medicine extracted from the yew bark. The 13 C signals have chemical shift values quite consistent with those measured in solution phase, and the overall chemical shift range is over 200 ppm. Notably, most of the 13 C resonances of the taxane ring have two clearly resolved spectral components except the resonance peaks of C-15, C-16 and C-17, which are located at the central part of the taxane ring. On the basis of our NMR data, we propose that these doublets originate from two slightly different molecular conformations of the taxane ring and still the central part of the ring remains structurally similar. Furthermore, it is demonstrated that the 13 C chemical shift difference deduced from the doublet splittings can serve as a direct measure of the structural difference between the two conformations, which could possibly correlate with the anti-tumor activity of Taxol.
Arginine kinase (AK), a 42-kDa enzyme, reversibly catalyzes phosphoryl transfer between ATP and a... more Arginine kinase (AK), a 42-kDa enzyme, reversibly catalyzes phosphoryl transfer between ATP and arginine, regulating cellular ATP levels in invertebrates. Eight phosphagen kinases are known from the animal kingdom, the human orthologue is creatine kinase (Ellington, 2001). Conformational changes for this family of enzymes, not the chemistry, are rate limiting on the reaction (Yousef et al.,2003). As a first step towards investigating these conformational changes, main chain resonance assignments of recombinant AK from the horseshoe crab Limulus polyphemus are reported here. 2D and 3D heteronuclear NMR experiments on uniformly 2 H, 13 C, 15 N-labeled AK and 15 N-amino acid type specific labeled AK were recorded. Main chain resonance assignments are 95% complete and have been deposited (BMRB accession #6542).
Objective. This study has two purposes: (a) to compare the use of tumor cell suspensions and exci... more Objective. This study has two purposes: (a) to compare the use of tumor cell suspensions and excised tumor tissue for generating renal tumors suitable for radiofrequency ablation (RFA) studies and (b) to assess the efficacy of RFA for ablation of renal VX2 tumors in a rabbit model. Procedures. VX2 tumor masses were used to inoculate 17 rabbits. The renal VX2 tumors of 13 rabbits were subsequently treated with a cooled-tip RF system at a power of 15-30 W for 3-6 minutes, and 4 rabbits served as control. After RFA, rabbits were observed by contrast-enhanced CT to ascertain the ablative range. Rabbits were divided into three groups and sacrificed at 3, 7, and 14 days post-treatment for histopathological studies. Results. Both tumor implant methods had a 100% success rate in generating tumors. The average lesion produced was 1.3x1.8x1.5 cm. Complete tumor ablation occurred in 76.9%, and local tumor growth in 23.1%. Depending on the position of the tumors, the complications after RFA treatment included infarction, perirenal hematoma, hydronephrosis, and abscess. The over-all complication rate was 38.5%. In histopathological studies, a central needle track, tumor coagulation, renal tissue coagulation, peripheral hemorrhage, and an inflammatory layer could be observed. Conclusion and clinical relevance. Application of RFA to destroy renal VX2 tumors in this rabbit model has a relatively high cure rate. It can be used to destroy small renal tumors in a precise and non-invasive manner. Impact on human medicine. We hope to apply this procedure in selected human renal tumors in the future.
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