bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion of a racemate into a single enantiomer in one step by chiral liquid chromatography: Studies with rac‐2,2′‐diiodobiphenyl
Authors: Wolf Christian , Köunig Wilfried A. , Roussel Christian 
Published: January 2005

AbstractThe enantiomers of rac‐2,2′‐diiodobiphenyl were separated by liquid chromatography on microcrystalline triacetylcellulose. The conformational lability, a large separation factor α, and a suitable capacity factor k′(+) of this biphenyl allowed us to convert the racemate into 90% of enantiomerically pure (‐)‐2,2′‐diiodobiphenyl and 10% of pure (+)‐2,2′‐diiodobiphenyl, respectively, by a series of in situ racemization‐elution cycles. The much better retained (+)‐enantiomer was racemized on the chromatographic column at 50°C after the less retained (‐)‐enantiomer has already been eluted at 8°C. © 1995 Wiley‐Liss, Inc.
Three‐year recurrence‐free survival in a patient with recurrent medulloblastoma after resection, high‐dose chemotherapy, and intrathecal Yttrium‐90‐labeled DOTA0‐D‐Phe1‐Tyr3‐octreotide radiopeptide brachytherapy
Authors: Beutler Daniel , Avoledo Pierino , Reubi Jean‐Claude , Mäcke Helmut R. , Müller‐Brand Jan , Merlo Adrian , Kühne Thomas 
Published: January 2005

AbstractBACKGROUNDMost medulloblastomas express high levels of somatostatin type 2 receptors (sst2). DOTA0‐D‐Phe1‐Tyr3‐octreotide (DOTATOC) specifically binds sst2 in the low nanomolar range. The cytotoxic effect is mediated by the chelated, β‐emitting, metallic radionuclide Yttrium 90 (90Y). The authors applied this innovative treatment option in a boy age 8 years who presented with a recurrent medulloblastoma of the cauda equina: a prognostically poor condition. Targeted radiotherapy was administered to treat minimal sst2‐expressing tumor remnants, which persisted despite conventional and high‐dose chemotherapy and intercurrent resection of the lesion.METHODSA medulloblastoma arising from the floor of the fourth ventricle had been removed surgically; then, the patient was treated with standard adjuvant chemotherapy and craniospinal irradiation according to the prospective HIT '91 protocol. Complete remission was achieved for 20 months, when a drop metastasis of the cauda equina manifested with sensorimotor lumbosacral deficits and urinary incontinence. After four cycles of neoadjuvant chemotherapy (which consisted of combined ifosfamide, carboplatinum and etoposide), two cycles of high‐dose chemotherapy and autologous stem cell transplantation were performed; in between, the responding residual tumor within the lumbosacral nerve fibers was microscopically removed. Thereafter, an Indium‐111‐DOTATOC test injection indicated sst2‐expressing tumor remnants within the cauda equina. Con‐ sequently, 4 cycles of [90Y]‐DOTATOC (4 × 562.5 megabecquerels) were injected directly into the cerebrospinal fluid in monthly intervals.RESULTSThe consolidating intrathecal brachytherapy using [90Y]‐DOTATOC was tolerated well. A complete remission was achieved for a 3‐year period. The only remaining deficit was urinary incontinence.CONCLUSIONSIntrathecal administration of targeted radiopeptide brachytherapy in combination with conventional and high‐dose chemotherapy and surgical removal represents a promising new option to treat recurrent medulloblastoma and should be explored further. Cancer 2005. © 2005 American Cancer Society.
Residual tumor uptake of [99mTc]‐sestamibi after neoadjuvant chemotherapy for locally advanced breast carcinoma predicts survival
Authors: Dunnwald Lisa K. , Gralow Julie R. , Ellis Georgiana K. , Livingston Robert B. , Linden Hannah M. , Lawton Thomas J. , Barlow William E. , Schubert Erin K. , Mankoff David A. 
Published: January 2005

AbstractBACKGROUNDStudies utilizing serial [99mTc]‐sestamibi (MIBI) scintimammography have reported accurate prediction of tumor response in patients with locally advanced breast carcinoma (LABC) undergoing neoadjuvant chemotherapy. The pathologic response of LABC to presurgical treatment regimens is a prognostic indicator of survival. The authors tested whether MIBI uptake posttherapy predicted survival.METHODSSixty‐two patients with LABC underwent MIBI scintimammography just before chemotherapy and 2 months after treatment initiation. An additional MIBI scan was performed if treatment lasted > 3 months. The affected breast was imaged within 10 minutes after injection to reflect early uptake, which the authors have shown to be related to tumor blood flow. MIBI uptake was quantified using the lesion‐to‐normal breast (L:N) ratio. Most patients (93%) received weekly dose‐intensive doxorubicin‐based treatment. Disease‐free survival (DFS) and overall survival (OS) were compared with posttherapy primary MIBI uptake and with other established prognostic factors for neoadjuvantly treated LABC, namely, primary tumor pathologic response and posttherapy axillary lymph node status.RESULTSPatients with high uptake on the last observed MIBI scan (i.e., the L:N ratio was greater than the median value) had poorer DFS and OS (P < 0.01 and P = 0.01, respectively). Residual MIBI uptake retained independent prognostic significance in preliminary multivariate analysis that included other established prognostic markers.CONCLUSIONSHigh primary breast tumor MIBI uptake after neoadjuvant chemotherapy predicted poor survival, suggesting serial MIBI imaging may provide a useful quantitative surrogate end point for neoadjuvant chemotherapy trials. Given the association between MIBI uptake and tumor blood flow, this prognostic capability may be related to retained tumor vascularity after treatment. Cancer 2005. © 2005 American Cancer Society.
Abdominal computed tomography scans in the selection of patients with malignant peritoneal mesothelioma for comprehensive treatment with cytoreductive surgery and perioperative intraperitoneal chemotherapy
Authors: Yan Tristan D. , Haveric Namic , Carmignani Carlos P. , Chang David , Sugarbaker Paul H. 
Published: January 2005

AbstractBACKGROUNDMalignant peritoneal mesothelioma is a rare and fatal disease. Until recently, the treatment options were very limited and ineffective. The new comprehensive approach of cytoreductive surgery with perioperative intraperitoneal chemotherapy offers improved survival rates at a cost of considerable morbidity and mortality as in other peritoneal surface malignancies. The outcome after these treatments is predominantly dependent on adequate cytoreduction. The aim of the current study was to identify computed tomography (CT) scan images that are useful in patient selection for this comprehensive approach.METHODSAn analysis of the preoperative CT scans of 30 patients with peritoneal mesothelioma treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy at a single institution was performed. Based on the size of residual tumor nodules after cytoreductive surgery, patients were divided into 2 groups: those with residual lesions ≤ 2.5 cm (adequate cytoreduction) and those with residual lesions > 2.5 cm (suboptimal cytoreduction). The CT scans for each patient were evaluated by a standardized scoring system with the reader blinded to the operative findings. Thirty‐nine CT scan parameters were obtained and statistically analyzed to determine their association with the study outcome variables, namely, adequacy of cytoreduction.RESULTSSeven patients (64%) in the suboptimal cytoreduction group and 2 patients (11%) in the adequate cytoreduction group had a > 5‐cm tumor mass in the epigastric region (P = 0.004). Nine patients (82%) in the suboptimal group and 2 patients (11%) in the adequate cytoreduction group had CT scans that showed loss of normal architecture of the small bowel and its mesentery (P < 0.001). In a composite analysis of these 2 radiologic features, none of the patients with a > 5‐cm tumor mass in the epigastric region and loss of normal architecture of the small bowel and its mesentery had an adequate cytoreduction. Patients who lacked these two preoperative CT scan findings had a 94% probability of an adequate cytoreduction.CONCLUSIONSCT scans effectively identified large peritoneal mesothelioma tumors at crucial anatomic sites. Because adequate cytoreduction is necessary to achieve prolonged survival, CT scans became an accurate prognostic radiologic test for patient selection for comprehensive treatment. Cancer 2005. © 2005 American Cancer Society.
Evaluation of the CD34 and CD10 immunostains using a two‐color staining protocol in liver fine‐needle aspiration biopsies
Authors: Zimmerman Robert L. , Logani Sanjay , Baloch Zubair 
Published: January 2005

AbstractFine‐needle aspiration (FNA) biopsies of liver masses may need immunohistochemistry to resolve difficult cases. We examined liver FNAs with CD10 and CD34 using a two‐color staining protocol. Fifty‐one cases of hepatocellular carcinoma (HCC) and 23 cases of liver metastases were stained first with CD10 using diaminobenzidine as a chromogen and then with CD34 using Fast Red. All cases were reviewed in a blinded fashion by two of the authors (R.I.Z. and Z.B.). Diagnoses were unblinded and staining patterns evaluated. Forty‐eight of 51 cases of HCC stained for CD34 in a peripheral pattern and no cases of metastases stained for CD34 Seven of 23 cases of metastatic disease stained for CD10 in a diffuse cytoplasmic distribution and 29 of 51 HCCs stained in a canalicular pattern. Overall, the sensitivity of the CD10/CD34 combination was 98% and the specificity was 100% for HCC when appropriate staining patterns were observed. Two‐color immunostaining with CD10 and CD34 may prove useful in distinguishing HCC from metastases. Diagn. Cytopathol. 2005;32:88–91. © 2005 Wiley‐Liss, Inc.
Solvothermal Synthesis of NiS 3D Nanostructures
Authors: Zhang Wanqun , Xu Liqiang , Tang Kaibin , Li Fanqing , Qian Yitai 
Published: January 2005

AbstractHighly uniform urchin‐like nanostructures (in the structures, nanoneedles or nanobelts grow radially from the core particles) of NiS (millerite) were successfully prepared by a solvothermal synthetic route using Ni(Ac)2·6H2O and dithizone as reagents and ethylenediamine as solvent in the temperature range of 220−240 °C. The prepared nickel sulfides with urchin‐like 3D architectures were characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM) and high‐resolution transmission electron microscopy (HRTEM). The reaction temperature, sulfur sources, and solvent are of great importance on the final urchin‐like structures. On the basis of the experimental results, a possible growth mechanism of the urchin‐like NiS crystals is proposed, which is supported by the technical characterizations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Enhanced residual‐free bubble method for convection–diffusion problems
Authors: Cangiani A. , Süli E. 
Published: January 2005

AbstractWe analyse the performance of the enhanced residual‐free bubble (RFBe) method for the solution of elliptic convection‐dominated convection–diffusion problems in 2‐D, and compare the present method with the standard residual‐free bubble (RFB) method. The advantages of the RFBe method are two‐fold: it has better stability properties and it can be used to resolve boundary layers with high accuracy on globally coarse meshes. Copyright © 2005 John Wiley & Sons, Ltd.
(1‐Methoxyvinyl)boronic and (1‐chlorovinyl)boronic esters
Authors: Matteson Donald S. , Beedle Ellen C. 
Published: January 2005

Abstract(s)‐Pinanediol (1‐methoxyvinyl)boronate (1) was prepared from (1‐methoxyvinyl)‐lithium and triisopropyl borate followed by (s)‐pinanediol. Attempted reaction with (dichloromethyl)lithium failed, and reaction with butylmagnesium chloride followed by acetic acid yielded a mixture of diastereomers of (s)‐pinanediol (1‐methoxy‐1‐methyl‐pentyl)boronate (2). (s)‐Pinanediol (1‐chlorovinyl)boronate (4) has been prepared by dehydrochlorination of (s)‐pinanediol 1,1‐dichloroethylboronate (3) with lithium chloride in dimethylformamide. Reaction of 4 with (dichloromethyl)lithium yielded (s)‐pinanediol (1S)‐(1,2‐dichloroallyl)boronate (5) in 92% diastereomeric excess. Reaction of 5 with RMgX resulted in a 3 : 1 ratio of displacement of the 1‐Cl from carbon by R to displacement of the entire 1,2‐dichloroallyl group from boron by R. With lithium benzyl oxide, displacement of the 1‐Cl from 5 failed entirely. Reaction of 4 with (dibromomethyl)lithium was inefficient and yielded a gross mixture of diastereomers.
Reactions involving selenium metal as an electrophile: Scope and limitations of the enolate‐selenolate transformation
Authors: Swiss Kevin , Choi Woo‐Baeg , Mohan Julie , Barnum Christopher , Saindane Manohar , Zima George , Liotta Dennis 
Published: January 2005

AbstractWhen lithium enolates are allowed to react with selenium metal, selenolate (selenide) ions are formed. Alkylation of these selenolate ions produces the corresponding α‐alkylselenenyl carbonyl derivatives. These derivatives can then be converted to their unsaturated counterparts using the same type of protocols that are employed with arylselenenyl derivatives.
A facile method for generation of carbon oxide sulfide
Authors: Mizuno Takumi , Nishiguchi Ikuzo , Hirashima Tsuneaki , Sonoda Noboru 
Published: January 2005

AbstractCarbon oxide sulfide was easily generated upon heating of amine salts of carbamothioic acids at 85°C which were produced in situ from amines, carbon monoxide, and elemental sulfur in the presence of a catalytic amount of selenium under mild conditions.
Some highly fluorinated acyclic, cyclic, and polycyclic derivatives of Cl2NCF2CF2NCl2 and Cl2CNCCl2CCl2NCCl2
Authors: Sarwar Ghulam , Kirchmeier Robert L. , Shreeve Jean'ne M. 
Published: January 2005

AbstractWhen Cl2NCF2CF2NCl2 is heated with CF2CFX (X = Cl, F) ClXCFCF2N(Cl)CF2CF2N(Cl)CF2CXClF (X = Cl, 2; F, 3) is formed. Mercury extracts chlorine fluoride from 2 and 3 to form new polyfluorobisazomethines, ClXCFCF2NCFCFNCF2CXClF (X = Cl, 4; F, 5). Photolysis of the product obtained from CCl2NCCl2CCl2NCCl2 with ClF, CF2ClN(Cl)CF ClCFClN(Cl)CF2Cl (6) gives another bisazomethine, CF2ClNCFCFNCF2Cl (7) with concomitant loss of Cl2. At 25°C, in the presence of CsF, 4 and 5 are cyclized to give (X = Cl, 8; F, 9), and 7 forms a bicyclic derivative at 100°C, (1). Addition of chlorine fluoride to 8 and to 1 produces (10) and (14), respectively. Photolysis of 10 results in the loss of CFCl3 to form (11), and 14 loses Cl2 and dimerizes to the hydrazine (15). The further addition of ClF to 11 gives rise to (12) which when photolyzed at 3000 Å forms a second cyclic hydrazine, (13).
Phosphate‐phosphonate conversion: Nucleophilic displacement reactions involving phosphoric esters and methyllithium
Authors: Savignac Philippe , Teulade Marie‐Paule , Patois Carl 
Published: January 2005

AbstractThe alkylation‐metalation reaction of phosphoric esters depends on the way the lithium reagent has been prepared. With salt‐containing methyllithium (LiBr or LiI), the alkylation is never complete. On the contrary, with salt‐free methyllithium, the alkylation is completed at – 10°C. This reaction is performed independently of the substituents at the phosphoryl group.
Easy access to bismuth catecholates
Authors: Guilhaume Nolven , Postel Michèle 
Published: January 2005

AbstractThe reaction of catechols with bismuth (III) acetate in acetic acid solution provides an easy access to the polymeric bismuth catecholate acetate (1), 4‐tert ˙ butylcatecholate hydroxide (2), and 3,5‐di‐tert ˙ butylcatecholate hydroxide (3).
One‐Pot synthesis of (2E)‐ and (2E, 4E)‐ unsaturated carboxylic acid amides via organotellurium reagents
Authors: Xiao Wen‐Juan , Shi Li‐Lan , Chen Zheng‐Qing , Huang Yao‐Zeng , Lang S. A. 
Published: January 2005

AbstractDi‐n‐butyl telluride, 2‐bromoacetylisobutylamide (or 2‐bromoacetylpiperidide) react directly with saturated or α,β‐unsaturated aldehydes at room temperature in the presence of potassium carbonate(s) to afford (2E)‐, or (2E, 4E)‐unsaturated carboxylic acid amides, respectively, in excellent yields with high E stereoselectivity.
Molecular modeling of oxaphosphetane intermediates of wittig olefination reactions
Authors: Marí Frank , Lahti Paul M. , McEwen William E. 
Published: January 2005

AbstractThe literature reveals that the structures of four unusual oxaphosphetanes have been established by x‐ray diffraction studies, and the structure of one mythical oxaphosphetane (6) has been deduced by theoretical calculations. We have used these known structures to calibrate the MMX87 force field, the only necessary modification being the stretching term for the P‐O bond. The bond length, 1o, was set at 1.80Å, which is an “average” of the P‐O axial bond distances of the stable oxaphosphetanes. The AMPAC (Ver. 1.0) molecular orbital package utilizing the MNDO hamiltonian was also applied to the same problem, starting with the minimized geometries of the modified MMX87 force field. Fixed bond lengths and full minimizations were performed. The computed geometries of the four‐member ring of each of the four oxaphosphetanes of known structures were found to be in very good agreement with the values obtained by x‐ray diffraction. Furthermore, the method was applied to the mythical oxaphosphetane, and the results of MMX87 and MNDO calculations were found to be in very good agreement with the results of ab initio calculations. The MMX force field and the MNDO semiempirical method have been used to calculate the geometries and the steric energies (or heats of formation) of diastereomeric oxaphosphetanes formed in a theoretically real Wittig reaction.
Second‐row anomeric interactions: The involvement of phosphorus
Authors: Juaristi Eusebio 
Published: January 2005

AbstractProton NMR spectroscopy and x‐ray crystallographic studies demonstrate the predominance of the axial conformer of 2‐(diphenylphosphinoyl)‐1,3‐dithiane (1). Chemical equilibration of anancomeric models (3 ⇌ 4) allows quantitative determination of the conformational free energy in 1, 1.0 kcal/mol, which corresponds to an anomeric effect of 2.64–3.74 kcal/mol, depending on the method used for estimating it. This value indicates that the anomeric effect operative in 1 may be among the largest yet measured.Five distinct rationalizations are considered to account for such a strong S‐C‐P(O) anomeric effect: (a) dipole‐dipole interactions, (b) electrostatic, attractive interaction between the phosphoryl oxygen and the syn‐axial hydrogens in 1‐axial, (c) delocalization of the lone pair on the endocyclic heteroatom into the antiperiplanar (axial) adjacent polar C‐P bond, (d) through‐space 3p‐3d electron donation from sulfur to phosphorus, and (e) repulsive interaction between the lone pairs on sulfur and on the phosphoryl oxygen. All these hypotheses have some experimental and/or the‐oretical support, but evidence contrary to expectation can be found also to argue against each one of them.The conformational preference of the diphenylthiophosphinoyl group in the 1,3‐dithian‐2‐yl ring was determined by nuclear magnetic resonance (NMR) analysis and by chemical equilibration of diastereomeric models. The slight predominance of axial 2‐(diphenylthiophosphinoyl)‐1,3‐dithiane (13‐ax) over 13‐eq reflects nonetheless the influence of a strong S‐C‐P anomeric interaction, worth ca. 2.3 kcal/mol.Spectroscopic evidence for the predominance of the equatorial conformers in 2‐(diphenylphosphinoyl)‐1,3‐oxathiane (19) and 2‐(diphenylphosphinoyl)‐1,3‐dioxane (22) was confirmed by the study of derivatives containing counterpoise substitutents, or by chemical equilibration on anancomeric models. ΔD°27°C [P(O)Ph2] = ‐3.23 kcal/mol was determined for the dioxane (chloroform solution), and ΔG°C55°C [P(O)Ph2] = ‐1.42 kcal/mol for the oxathiane (ethanolic solution). Nevertheless, evaluation of the different steric requirements in 1, 13 and 22 reveals that the magnitude of the O‐C‐P(O) and S‐C‐P(O) anomeric effects in the heterocycles is, in fact, quite similar, close to kcal/mol.
Vibration spectrum and normal coordinate analysis of the pyrothiophosphates Na4P2S7, Na2FeP2S7, and Ag4P2S7
Authors: Menzel Frank , Ohse Lothar , Brockner Wolfgang 
Published: January 2005

AbstractNa4P2S7, Na2FeP2S7, and Ag4P2S7 were prepared by elemental synthesis at high temperatures and were characterized by vibration spectra and differential thermal analysis (DTA). A normal coordinate analysis was performed for P2S4−7. Additional vibration frequencies indicate the presence of the decathiotriphosphate anion P3S5−10. The formation of higher thiophosphates of the type PnS(n+2)‐3n+1 with n ≥ 4 cannot be excluded.
Phosphate–Phosphonate conversion: Nucleophilic displacement reactions involving phosphoric amides and alkyllithiums
Authors: Patois Carl , Savignac Philippe 
Published: January 2005

AbstractAlkylation at phosphorus with alkyllithiums of acyclic, 5‐membered, and 6‐membered cyclic phosphoric amides was investigated. The chlorinated derivatives reacted in all cases to afford stable α‐(lithioalkyl)phosphonamides. Only 2‐ethoxy‐2‐oxo‐1,3‐dimethyl‐1,3,2‐diazaphospholidine reacted similarly. The study has shown that steric hindrance at phosphorus is the main control of the reaction.
Substituted selenourea–tellurium tetrahalide adducts: Precursors to selenium–tellurium alloys
Authors: Pathirana Hema M. K. K. , Zingaro Ralph A. , Meyers Edward A. , Reibenspies Joseph H. , Dufner D. Carl 
Published: January 2005

AbstractN,N‐Dimethylselenourea (DMSeU) yields, with TeX4 (X = Cl or Br), a variety of compounds having bonds from selenium to tellurium. Excluding molecules of solvation these compounds display the following stoichiometries: [(DMSeU)4Te]X2, (DMSeU)3(TeX4)2, and (DMSeU)2Te2X6. Tetramethylselenourea (TMSeU) gives, with TeBr4, crystals of (TMSeU)2TeBr4. Both the carbon–selenium and tellurium–halogen bonds undergo hydrolysis under mild conditions to yield precipitates that are alloys of selenium and tellurium. Thus, this group of compounds affords a new approach to the synthesis of selenium–tellurium alloys. Some of the properties of these compounds, as well as the crystal structure of [(DMSeU)4Te]Cl2, are described in this article.
New fluorine derivatives of methylcyclohexasilane
Authors: Hengge Edwin F. , Hassler Karl , Schrank Franz 
Published: January 2005

Abstract1,1‐Difluorodecamethyl‐ and 1,1,4,4‐tetrafluorooctamethylcyclohexasilane were synthesized by the reaction of LiF with the corresponding trifluoromethanesulfonic derivatives and were characterized by spectroscopic methods, mainly by modern NMR techniques. The stability of the fluorinated cyclosilanes decreases with an increase of fluorine substituents. This seems to be the reason for the instability of perfluorinated cyclosilanes.
Polyhalogenalkoxy(aryloxy)chloro‐ and bromophosphoranes
Authors: Markovsky Leonid N. , Kozlov Ernest S. , Shermolovich Yury G. 
Published: January 2005

AbstractThe data on the synthesis, stereochemistry, and molecular dynamics of alkoxy(aryloxy)halogenphosphoranes of acyclic structure, as well as of halogenphosphoranes containing the pentacoordinate phosphorus atom in the 1,4,2‐dioxophospholane cycle and the node of bicyclo[2.2.2]octane system, are systematized. The influence of spatial properties of polyhalogenalkyl substituents on thermal stability and structure of adducts from tris(polyhalogenalkyl) phosphites with chlorine and bromine is ascertained. The effect of the phosphorus atom inclusion into the cycle and node of the bicyclooctane system on its pentacoordinate state stability is investigated.