bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding base‐assisted desulfurization using a variety of disulfide‐bridged peptides
Authors: Galande Amit K. , Trent John O. , Spatola Arno F. 
Published: November 2003

AbstractA recently rediscovered reaction of base‐assisted lanthionine formation has been applied to several systems of disulfide‐bridged peptides. In addition to previously described nonapeptides consisting of i, i+3 cystine linkages, the reaction has now been extended to systems consisting of shorter (i, i+2) and longer (i, i+4) disulfide bridges. The desulfurization reaction is also compatible with disulfide bridges formed through homocysteines and penicillamines, yielding unusual amino acids such as cystathionine and β,β‐dimethyl lanthionine (referred to as “penthionine”) in a peptide chain, respectively. Systematic study of this transformation has provided several new insights into its mechanism. We have observed formation of dehydroalanine and dehydrovaline residues resulting from i, i+2‐bridged cysteines and i, i+3‐bridged cysteine/penicillamine peptides, respectively, thereby supporting a β‐elimination/Michael‐addition mechanism for this transformation. Amino acid analysis and NMR data from total correlation spectroscopy (TOCSY) and 1H‐13C heteronuclear single quantum correlation (HSQC) experiments show three diastereomeric lanthionine‐bridged peptides in the product mixture. But in the case of desulfurization of a cysteine/homocysteine containing disulfide‐bridged peptide, Michael addition appears to be stereoselective, yielding a single stereoisomer of cystathionine within the peptide. According to molecular modeling and CD spectroscopy, constrained peptides such as those containing penicillamine are less likely to undergo facile desulfurization. Flexibility of the torsional angles (CαH—Cα—Cβ—S) corresponding to the cysteine residues and temperature appear to be contributing factors determining the extent of desulfurization. © 2003 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 71: 534–551, 2003
Relative Energies of Dioxo μ‐Oxo Molybdenum Complexes from Various Fragmentation Strategies
Authors: Pellegatti Alain , Arzoumanian Henri , Blaive Bruno 
Published: November 2003

AbstractA thiocyanatomolybdenum(VI) dioxo μ‐oxo complex dimer bearing 4,4′‐di‐tBu‐2,2′‐bipyridine ligands has shown exceptional oxidizing ability. It exists as amesoform (symmetrical) and ad,lpair (unsymmetrical) in the crystal unit cell and also in equilibrium in solution. Which oxygen atom and which configuration are predominantly involved in the process of oxygen atom transfer is a question whose answer would certainly help experimentalists. From ab initio theoretical calculations we analyzed the electronic differences between the two configurations. The large number of atoms (101) restricts the choice of theoretical methods. We give results for second‐order Møller–Plesset (MP2) and DFT with the hybrid functional B3LYP, with and without pseudopotentials, with double‐ζbasis sets plus polarization functions. Although the structures of the two types of configurations are quite different, we show they have practically the same energy. Similarly, no significant differences were found for electronic atomic populations on oxygen and surrounding atoms. To facilitate future studies on the process of oxygen atom transfer, we compare the entire molecules to smaller entities obtained by fragmentations or by so‐called hybrid methods. We show that thetBu groups, and even sometimes the pyridyl rings, play only a minor role in determining the electronic structure. Concerning the energy difference between the two configurations, the MP2 results appear more consistent than the B3LYP results.
The Silica‐Like Extended Polymorphism of Cobalt(II) Imidazolate Three‐Dimensional Frameworks: X‐ray Single‐Crystal Structures and Magnetic Properties
Authors: Tian Yun‐Qi , Cai Chen‐Xin , Ren Xiao‐Ming , Duan Chun‐Ying , Xu Yan , Gao Song , You Xiao‐Zeng 
Published: November 2003

AbstractFive polymorphous frameworks of cobalt(II) imidazolates (1–5) have been prepared by solvatothermal syntheses. Of these, compound 3 has already been synthesized in a gas‐phase reaction by Seel et al. in 1969 and structurally characterized by Sturm et al. in 1975. The new synthetic strategy affords four polymorphous frameworks of cobalt(II) imidazolates (1, 2, 4, 5) of crystalline substances, of which the compound 4 (a = b = 23.450(3), c = 12.460(3) Å, tetragonal, I41cd, Z = 16) is an isomorphous compound of [Zn(im)2]∞, which was also synthesized in a gas‐phase reaction in 1980. The frameworks of compounds 1 and 2 are porous and isostructural; they have the same framework topology that represents a novel uninodal (6,4)‐net: 1: a = 18.513(4), b = 24.368(5), c = 9.2940(19) Å, orthorhombic, Fdd2, Z = 16; 2: a = 17.635(4), b = 27.706(6), c = 9.0810(18) Å, orthorhombic, Fdd2, Z = 16. The framework of compound 5 exhibits a topology of zeolitic structure with the unit‐cell parameters: a = 24.3406(8), b = 9.4526(3), c = 24.8470(8) Å, β = 91.977(1)°, monoclinic, P21/n, Z = 4. All polymorphous frameworks of cobalt(II) imidazolates reflect the structural features of silica (SiO2) and also exhibit different magnetic behaviors, although the imidazolates transmit the antiferromagnetic coupling between the cobalt(II) ions in all cases. However, the uncompensated antiferromagnetic couplings arise from spin‐canting are sensitive to the structures: compound 1 is an antiferromagnet with TN = 13.11 K; compounds 2–4 are weak ferromagnets (canted antiferromagnets): 2 shows a very weak ferromagnetism below 15 K, 3 exhibits a relatively strong ferromagnetism below 11.5 K and a coercive field (HC) of 1800 Oe at 1.8 K, and 4 displays the strongest ferromagnetism of the three cobalt imidazolates and demonstrates a TC of 15.5 K with a coercive field, HC, of 7300 Oe at 1.8 K. However, compound 5 seems to be a hidden canted antiferromagnet with a magnetic ordering temperature of 10.6 K.
Spiroconjugation in Spirodicorrolato‐Dinickel(II)
Authors: Hohlneicher Georg , Bremm Dominik , Wytko Jennifer , Bley‐Escrich Jordi , Gisselbrecht Jean‐Paul , Gross Maurice , Michels Martin , Lex Johann , Vogel Emanuel 
Published: November 2003

AbstractIn the present work the effect of spiroconjugation on the electronic spectrum of the recently synthesized metal complex hexadecaethylspirodicorrolato–dinickel(II) (5) (the corrole units in5are isoforms) is investigated. To have a suitable reference compound at our disposal, tetraethylhexamethylisocorrolato nickel(II) (7) has been prepared. On comparing the electronic spectra of this reference compound and the spiro‐complex, bathochromic shifts of all absorption bands in the NIR/Vis‐region are observed for the latter as well as marked changes in the spectral intensities. A detailed analysis of the spectra supported by semiempirical calculations reveals that at least part of the observed changes can be unambiguously attributed to the spiro effect. This effect is further affirmed by electrochemically measured redox potentials.
Pattern of disease recurrence and prognostic factors in patients with osteosarcoma treated with contemporary chemotherapy
Authors: Hawkins Douglas S. , Arndt Carola A. S. 
Published: November 2003

AbstractBACKGROUNDThe goal of the current study was to define the clinical features and outcome of recurrent osteosarcoma (OS) in children and young adults initially treated with contemporary chemotherapy.METHODSThe authors reviewed the clinical features, therapy, and outcome for 59 patients from the Mayo Clinic (Rochester, MN) and Children's Hospital and Regional Medical Center (Seattle, WA). They were diagnosed initially with OS between January 1990 and December 2000, received multiagent chemotherapy (most frequently cisplatin, doxorubicin, high‐dose methotrexate, and ifosfamide), and developed disease recurrence after achieving an initial complete response (CR).RESULTSThe most common site of initial disease recurrence was the lung only (n = 36 patients), followed by distant bone (n =8 patients), combined lung and other sites (n =7 patients), and other sites (n =8 patients). The median time to first disease recurrence was 15 months (range, 2–92 months) from the initial diagnosis. Thirty patients with isolated pulmonary recurrence achieved a second CR, either with surgery alone (n =15 patients) or surgery and salvage chemotherapy (n =15 patients). For this group, the 4‐year disease‐free survival (DFS) and overall survival rates were 7% (95% confidence interval [95% CI], 0–16%) and 28% (95% CI, 11–45%), respectively. For all 59 patients with recurrent OS, the 4‐year DFS and overall survival rates were 6% (95% CI, 0–12%) and 23% (95% CI, 10–36%), respectively. The only factors associated with improved DFS and overall survival rates were unilateral pulmonary recurrence, solitary pulmonary nodule at recurrence, more than 24 months between the initial diagnosis and first disease recurrence, and achievement of a second CR.CONCLUSIONSThe DFS and overall survival rates for recurrent OS after contemporary therapy remained poor even for patients with isolated pulmonary recurrence. Therefore, new treatment strategies are needed. Cancer 2003. © 2003 American Cancer Society.
Clinicopathologic features of metastasis in nonsentinel lymph nodes of breast carcinoma patients
Authors: Degnim Amy C. , Griffith Kent A. , Sabel Michael S. , Hayes Daniel F. , Cimmino Vincent M. , Diehl Kathleen M. , Lucas Peter C. , Snyder Matthew L. , Chang Alfred E. , Newman Lisa A. 
Published: November 2003

AbstractBACKGROUNDIn breast carcinoma patients with a positive sentinel lymph node (SN), the value of complete axillary lymph node dissection has been questioned. Multiple published reports have attempted to identify clinicopathologic characteristics of the primary tumor and SN that are associated with an increased likelihood of positive nonsentinel lymph nodes (NSN). Because of differences in lymph node evaluation techniques and limited patient numbers in each study, the authors performed a meta‐analysis to assess the regularity and relative strength of association between various characteristics and the risk of NSN metastasis.METHODSA MEDLINE search identified 15 candidate studies, 11 of which met the criteria for analysis. General elements of the studies, the pathologic characteristics evaluated, and the results for selected characteristics were compared. Original data were abstracted from each study and used to calculate odds ratios. The Mantel–Haenszel common odds ratios were calculated to determine the relative strength of the associations.RESULTSDespite methodologic differences, the correlation between positive NSNs and certain pathologic characteristics was found to be remarkably similar among studies. The 5 individual characteristics found to be associated with the highest likelihood of NSN metastasis are SN metastasis > 2 mm in size, extranodal extension in the SN, tumor size > 2 cm, > 1 positive SN, and lymphovascular invasion in the primary tumor.CONCLUSIONSThere is general concordance among studies regarding the association between pathologic characteristics and NSN metastasis in breast carcinoma patients with a positive SN. The pooled analysis identified those factors with the strongest associations that should be evaluated routinely in SN specimens and included in prospective databases for the development of a predictive model. Cancer 2003. © 2003 American Cancer Society.
Hormone therapy adjuvant to external beam radiotherapy for locally advanced prostate carcinoma
Authors: Jani Ashesh B. , Kao Johnny , Hellman Samuel 
Published: November 2003

AbstractBACKGROUNDHormone therapy commonly is used to treat metastatic, locally advanced, and localized prostate carcinoma. The objective of the current investigation was to determine, using the number‐needed‐to‐treat (NNT) method, the effect of using hormone therapy to treat locally advanced disease, with consideration given to both the complications and the known advantages associated with hormone therapy.METHODSA literature review was performed to determine 1) the absolute benefit, based on available clinical endpoints, associated with the addition of hormone therapy to external beam radiotherapy for locally advanced prostate carcinoma; 2) the incidence of side effects of short‐term and long‐term hormone therapy; and 3) the stepwise progression from biochemical failure to death. A model was constructed to estimate the complication/utility‐adjusted survival detriment resulting from the side effects of short‐term (≤ 6 months) and long‐term (> 6 months) hormone therapy, and the absolute/unadjusted and complication‐adjusted NNTs for the addition of short‐term and long‐term hormone therapy were computed. In all cases, the magnitudes and signs of the NNTs obtained were used to gauge the effect of hormone therapy.RESULTSThe unadjusted NNTs were positive and in most cases had relatively small magnitudes (the greater the NNT, the smaller the benefit) for both short‐term and long‐term hormone therapy; these results were expected, and they suggested that there is a strong benefit associated with the use of hormones adjuvant to radiotherapy for locally advanced disease. Adjusted NNTs remained positive and had relatively small magnitudes even after the introduction into the analysis of complications of short‐term and long‐term hormone therapy. This finding, although weak with respect to the effect of short‐term hormone therapy on cause‐specific survival, remained robust over the range of values for utility impairment expected from short‐term and long‐term hormone therapy.CONCLUSIONSThe benefits of short‐term and long‐term hormone therapy for locally advanced prostate carcinoma appear to be significant and to outweigh the associated side effects. Long‐term therapy appears to be better than short‐term therapy in terms of virtually all endpoints studied, even when the increased incidence of side effects is considered. The current investigation was successful in the use of the complication‐adjusted NNT method for oncologic and radiotherapeutic scenarios in which the results of randomized trials could be summarized, adjusted for treatment toxicity, and individualized to a given patient. Cancer 2003. © 2003 American Cancer Society.
Microscopic analysis of chromium accumulation in the bronchi and lung of chromate workers
Authors: Kondo Kazuya , Takahashi Yuji , Ishikawa Sumiyo , Uchihara Hiroshi , Hirose Yukiko , Yoshizawa Kiyoshi , Tsuyuguchi Masaru , Takizawa Hiromitsu , Miyoshi Takanori , Sakiyama Shoji , Monden Yasumasa 
Published: November 2003

AbstractBACKGROUNDIt is known that chromium is an inhaled carcinogen and an important risk factor in the development of lung carcinoma.METHODSThe authors used a microscopic X‐ray fluorescence analyzer with transmitted X‐ray mapping imaging (Horiba, Kyoto, Japan) to measure the accumulation of chromium in 10 resected lung tissue specimens and 90 biopsy specimens from chromate workers.RESULTSThe maximum chromium accumulation (mean ± standard deviation) in 10 resected lung tissue specimens was 197 ± 238 counts per second (cps)/mili ampere (mA) (range, 4–649 cps/mA). Chromium accumulation was scattered in six tissue specimens and diffuse in one specimen. Chromium accumulation in the proximal bronchi was less than in the bronchioles or subpleural regions of the lung. Chromium accumulation was detectable in 63 (70%) of 90 biopsy specimens, and the mean accumulation was 6.5 ± 9.2 cps/mA (range, 0–46.5 cps/mA). Chromium detected in bronchial tissue specimens was deposited in the bronchial stroma but not in the epithelium. The maximum chromium accumulations in dysplasic (n = 3), squamous metaplastic (n = 10), and normal bronchial epithelia (n = 9) in chromate workers and in normal bronchial epithelia (n = 3) in non‐chromate workers were 20.2 ± 5.4, 18.3 ± 12.2, 13.2 ± 13.4, and 3.0 ± 1.8 cps/mA, respectively. The amount of chromium accumulation significantly increased according to the progression of malignant change of the bronchial epithelium (P = 0.003).CONCLUSIONSPrevious studies found that lung carcinoma with chromate exposure exhibited a variety of genetic abnormalities. Considering genetic aberrations and chromium accumulation in these premalignant lesions is useful for elucidating the process of carcinogenesis in chromium‐induced lung carcinoma. Cancer 2003. © 2003 American Cancer Society.
Risk and timing of hospitalization for febrile neutropenia in patients receiving CHOP, CHOP‐R, or CNOP chemotherapy for intermediate‐grade non‐Hodgkin lymphoma
Authors: Lyman Gary H. , Delgado David J. 
Published: November 2003

AbstractBACKGROUNDHospitalization for chemotherapy‐induced febrile neutropenia is associated with substantial cost and may negatively impact clinical outcome due to associated dose attenuation.METHODSMedical records of 1355 patients with intermediate‐grade non‐Hodgkin lymphoma receiving cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or similar chemotherapy were reviewed. The potential risk factors associated with first hospitalization for febrile neutropenia were evaluated.RESULTSIn the current study, 230 patients (17%) experienced 1 or more hospitalizations for febrile neutropenia and greater than one‐half of all initial hospitalizations for febrile neutropenia occurred in Cycles 1 or 2. Increased risk of hospitalization for febrile neutropenia, based on Cox proportional hazards models, was significantly associated with the following characteristics: age 65 years or older (hazard ratio [HR] = 1.79; 95% confidence interval [95% CI], 1.35–2.37), serum albumin level at presentation less than or equal to 3.5 g/dL (HR = 1.34; 95% CI, 1.01–1.78), planned average relative dose intensity greater than or equal to 80% (HR = 2.70; 95% CI, 1.47–4.98), baseline absolute neutrophil count less than 1500/mm3 (HR = 1.98; 95% CI, 1.28–3.06), and the presence of hepatic disease (HR = 2.18; 95% CI, 1.11–4.28). Lack of early granulocyte colony‐stimulating factor in Cycles 1 and 2 was also associated with increased risk of hospitalization for febrile neutropenia, but this did not reach statistical significance. A composite risk score based on these potential risk factors effectively distinguished patients at greater risk of hospitalization for febrile neutropenia (P < 0.001), the majority of which were observed during the first cycle of chemotherapy.CONCLUSIONSThe data from the current study demonstrated that the risk of initial hospitalization for febrile neutropenia occured early in the course of CHOP‐like chemotherapy. Identified risk factors for febrile neutropenia hospitalization may facilitate the use of targeted supportive care. Cancer 2003. © 2003 American Cancer Society.
A variable diffusion method for mesh smoothing
Authors: Hermansson J. , Hansbo P. 
Published: November 2003

AbstractIn this note we suggest a new approach to mesh smoothing, based on a combination of Laplacian smoothing and Winslow's method. Using our approach, we can avoid mesh folding and maintain/produce element stretch. We also make a comparison with a method due to Giuliani and show that the latter method cannot ensure that folding is avoided. Copyright © 2003 John Wiley & Sons, Ltd.
Explicit/implicit partitioning and a new explicit form of the generalized alpha method
Authors: Daniel W. J. T. 
Published: November 2003

Abstractabstract Most finite element packages use the Newmark algorithm for time integration of structural dynamics. Various algorithms have been proposed to better optimize the high frequency dissipation of this algorithm. Hulbert and Chung proposed both implicit and explicit forms of the generalized alpha method. The algorithms optimize high frequency dissipation effectively, and despite recent work on algorithms that possess momentum conserving/energy dissipative properties in a non‐linear context, the generalized alpha method remains an efficient way to solve many problems, especially with adaptive timestep control. However, the implicit and explicit algorithms use incompatible parameter sets and cannot be used together in a spatial partition, whereas this can be done for the Newmark algorithm, as Hughes and Liu demonstrated, and for the HHT‐αalgorithm developed from it. The present paper shows that the explicit generalized alpha method can be rewritten so that it becomes compatible with the implicit form. All four algorithmic parameters can be matched between the explicit and implicit forms. An element interface between implicit and explicit partitions can then be used, analogous to that devised by Hughes and Liu to extend the Newmark method. The stability of the explicit/implicit algorithm is examined in a linear context and found to exceed that of the explicit partition. The element partition is significantly less dissipative of intermediate frequencies than one using the HHT‐αmethod. The explicit algorithm can also be rewritten so that the discrete equation of motion evaluates forces from displacements and velocities found at the predicted mid‐point of a cycle. Copyright © 2003 John Wiley & Sons, Ltd.
An exploration of corporate attitudes to the significance of environmental information for stakeholders
Authors: Collison David , Lorraine Nathan , Power David 
Published: November 2003

AbstractThis paper reports on a questionnaire survey sent to environmental managers in quoted UK firms from environmentally sensitive sectors. A total of 58 usable responses was received, with most but not all being returned by environmental managers. While contextual information regarding perceptions of their companies' environmental sensitivity and management systems was sought, the main focus of the questionnaire was on respondents' views about stakeholder concerns. There was broad agreement that external stakeholders attached importance to environmental communications. The results indicate that respondents' perceptions of these issues were associated with the formality of their internal management systems and with the role of the respondents within their firms. It was also found that shareholders were thought to be the least interested stakeholder group. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Critical role of Vα14+ natural killer T cells in the innate phase of host protection against Streptococcus pneumoniae infection
Authors: Kawakami Kazuyoshi , Yamamoto Natsuo , Kinjo Yuki , Miyagi Kazuya , Nakasone Chikara , Uezu Kaori , Kinjo Takeshi , Nakayama Toshinori , Taniguchi Masaru , Saito Atsushi 
Published: November 2003

AbstractThe present study was designed to elucidate the role of Vα14+ NKT cells in the host defense against pulmonary infection with Streptococcus pneumoniae using Jα281 gene‐disrupted mice (Jα281KO mice) that lacked this lymphocyte subset. In these mice, pneumococcal infection was severely exacerbated, as shown by the shorter survival time and marked increase of live bacteria in the lung compared to wild‐type (WT) mice. The proportion of Vα14+ NKT cells, detected by an α‐galactosylceramide (α‐GalCer)‐loaded CD1d tetramer, increased in thelung after S. pneumoniae infection. This increase was significantly reduced in mice with a genetic disruption of monocyte chemotactic protein (MCP)‐1, which was produced in the early phaseof infection in WT mice. In the lungs of Jα281KO mice, the number of neutrophils was significantly lower at 12 h than that in WT mice. In support of this finding, macrophage inflammatory protein (MIP)‐2 and TNF‐α synthesis in infected lungs was significantly reduced at 3 h and at both 3 and 6 h, respectively, in Jα281KO mice, compared to WT mice. In addition, treatment of mice with α‐GalCer significantly improved the outcome of this infection. Our results demonstrated MCP‐1‐dependent recruitment of Vα14+ NKT cells and their critical role in early host protection against S. pneumoniae by promoting the trafficking of neutrophils to the site of infection.