bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nocturnal calcium, phosphorus and parathyroid hormone in the diagnosis of concealed and subclinical hypoparathyroidism
Authors: Even Leah , Bader Tarif , Hochberg Ze’ev 
Published: January 2007

Context: Circadian rhythms of plasma parathyroid hormone (PTH) show peak values at night, whereas serum calcium levels peak in the evening and display a nadir at night.
Hypotheses: Subclinical hypoparathyroidism (HPT) can be detected by utilizing the knowledge of diurnal variations. Thalassemia major (TM) may provide a model system of subclinical HPT.
Design: Nocturnal plasma PTH and serum calcium values were determined in 13 TM patients with normal morning serum calcium levels as compared with the corresponding values in eight healthy control subjects.
Results: Six patients with TM presented a nadir serum calcium level of 8.3 mg/dl or lower (hypoCa TM) at 0200 h, whereas the remaining seven showed nadir levels of 8.4 mg/dl or higher (normoCa TM). Patients with hypoCa TM displayed a drop between peak and nadir of 1.2 ± 0.5 mg/dl as compared with a considerably smaller fall of 0.3 ± 0.7 mg/dl in control subjects (P < 0.05). NormoCa TM patients experienced comparable nocturnal variation to that of control subjects. Patients from both the hypoCa and normoCa TM groups presented significantly lower nocturnal PTH levels than those of control subjects and lost the nocturnal PTH variation characteristic of healthy subjects. A plot of all serum calcium against plasma PTH levels provides a clear distinction of the three groups.
Conclusions: All 13 daytime normocalcemic TM patients presented a certain degree of HPT. The hypoCa TM group displayed a concealed HPT detected in all, except the morning sampling, whereas normoCa TM patients experienced sub clinical HPT observed in the absence of nocturnal HPT variation. Nocturnal measurements of serum minerals thus enhance the sensitivity of HPT diagnosis.
Adiposity, estradiol, and genetic variants of steroid-metabolizing enzymes as determinants of bone mineral density
Authors: Zarrabeitia Maria T , Hernandez Jose L , Valero Carmen , Zarrabeitia Ana , Amado Jose A , Gonzalez-Macias Jesus , Riancho Jose A 
Published: January 2007

Objectives: Bone mineral density (BMD) is a complex trait resulting from the interplay of genetic and acquired factors. The objective of this study was to explore the influence of several anthropometric, lifestyle, genetic, and hormonal factors on BMD and analyze the possible differences in men and women.Methods: We studied 572 individuals over 50 years of age (381 postmenopausal women and 191 men). Lumbar spine and femoral neck BMD were measured by dual energy x-ray absorptiometry. The free estrogen index (FEI) was calculated as the ratio of serum estradiol to sex hormone binding globulin in 241 individuals. Three polymorphisms in the genes coding for 17-hydroxylase/liase, sulfotransferase, and 5α-reductase were studied in DNA isolated from blood cells.Results: Body mass index was strongly correlated to spine and femoral BMD both in women and in men (r= 0.32–0.49;P< 0.001). FEI was also independently correlated with spine BMD in both sexes (r= 0.23 and 0.34,P< 0.01), and with femoral neck in women (r= 0.30). Women with G alleles of the sulfotransferase gene tended to have higher spine BMD than those with C alleles (P= 0.025). No other genotype-related differences in BMD were found.Conclusions: In conclusion, the results of this study point toward body weight and estradiol levels as major factors determining BMD both in women and in men. A common polymorphism of the sulfotransferase gene also appears to be associated to spine BMD in women.
Catalytic Asymmetric Epoxidation of α,β‐Unsaturated Esters with Chiral Yttrium–Biaryldiol Complexes
Authors: Kakei Hiroyuki , Tsuji Riichiro , Ohshima Takashi , Morimoto Hiroyuki , Matsunaga Shigeki , Shibasaki Masakatsu 
Published: January 2007

AbstractThe full details of the asymmetric epoxidation of α,β‐unsaturated esters catalyzed by yttrium complexes with biaryldiol ligands are described. An yttrium–biphenyldiol catalyst, generated from Y(OiPr)3–biphenyldiol ligand–triphenylarsine oxide (1:1:1), is suitable for the epoxidation of various α,β‐unsaturated esters. With this catalyst, β‐aryl α,β‐unsaturated esters gave high enantioselectivities and good yields (≤99 % ee). The reactivity of this catalyst is good, and the catalyst loading could be decreased to as little as 0.5–2 mol % (the turnover number was up to 116), while high enantiomeric excesses were maintained. For β‐alkyl α,β‐unsaturated esters, an yttrium–binol catalyst, generated from Y(OiPr)3–binol ligand–triphenylphosphine oxide (1:1:2), gave the best enantioselectivities (≤97 % ee). The utility of the epoxidation reaction was demonstrated in an efficient synthesis of (−)‐ragaglitazar, a potential antidiabetes agent.
Supramolecular Tilt Chirality Derived from Symmetrical Benzene Molecules: Handedness of the 21 Helical Assembly
Authors: Tanaka Akira , Hisaki Ichiro , Tohnai Norimitsu , Miyata Mikiji 
Published: January 2007

AbstractAchiral molecules can form aggregates with chirality. This depends on the relative position of the molecules, in other words, the tilt of the molecules (so‐called supramolecular tilt chirality). In this paper, we describe supramolecular chirality appearing in a 21 column composed of symmetrical benzene molecules, which is formed in the host cavity of inclusion crystals of cholic acid. Moreover, we determined the handedness, that is, right or left, of the 21 helical column of benzene on the basis of the molecular tilt. Determination of the 21 helical handedness was performed on assemblies of other benzene derivatives in cholic acid crystals and benzene assemblies in other host frameworks selected from the Cambridge Structural Database. Finally, we demonstrated complementarity of the handedness between the 21 symmetrical host framework of cholic acid and the benzene column.
Ruthenium‐Catalyzed Sequential Reactions: Deracemization of Secondary Benzylic Alcohols
Authors: Shimada Yusuke , Miyake Yoshihiro , Matsuzawa Hiroshi , Nishibayashi Yoshiaki 
Published: January 2007

AbstractThe deracemization of secondary benzylic alcohols proceeds successfully by a two‐step process with the appropriate combination of two different ruthenium complexes for catalysis in the first oxidation and second reduction steps. The sequential catalytic system provides a novel approach to obtaining optically active alcohols, including diols, in high yields with excellent enantioselectivity (up to 95 % ee), in contrast to the conventional kinetic resolution of racemic alcohols.
Construction of Robust Ruthenium(salen)(CO) Complexes and Asymmetric Aziridination with Nitrene Precursors in the Form of Azide Compounds That Bear Easily Removable N‐Sulfonyl Groups
Authors: Kawabata Hirotoshi , Omura Kazufumi , Uchida Tatsuya , Katsuki Tsutomu 
Published: January 2007

AbstractWe synthesized new Ru(salen)(CO) complexes of high durability and achieved aziridination with good to excellent enantioselectivity by using azide compounds that contain an easily removable N‐sulfonyl group, such as the 2‐(trimethylsilyl)ethanesulfonyl group, as a nitrene precursor. Aziridination of less‐reactive α,β‐unsaturated esters (and amides) proceeded with excellent enantioselectivities, from which it is inferred that an electrophilic species is the active species of this reaction. The present asymmetric aziridination provides a useful tool for introducing optically active nonprotected amine groups.
A Novel Environmentally Benign Method for the Selective Oxidation of Alcohols to Aldehydes and Ketones
Authors: Shi Feng , Tse Man Kin , Beller Matthias 
Published: January 2007

AbstractIn the presence of [Ru(terpyridine)(2,6‐pyridinedicarboxylate)], aliphatic and benzylic alcohols are oxidized to the corresponding aldehydes or ketones with high selectivity by using hydrogen peroxide as the oxidant. There is no need for the addition of co‐catalysts or organic solvents. By applying an optimized reaction protocol, high catalyst productivity (turnover number>10 000) and activity (turnover frequency up to 14 800 h−1) has been achieved.
Analysis of the products from enzymatic scouring of cotton
Authors: Sae‐be Porntip , Sangwatanaroj Usa , Punnapayak Hunsa 
Published: January 2007

AbstractThis article discusses the analysis of the hydrolysis products from one‐step scouring of cotton using pectinase and two‐step scouring of cotton using lipase then cellulase, protease then cellulase, or lipase/protease then cellulase, to improve water absorbency of cotton. UV spectrophotometric analysis indicated that the pectinase scouring process produced approximately 18‐fold higher amounts of reducing sugars and galacturonic acid than any of the two‐step scouring processes. The production rate of reducing sugars and galacturonic acid from most of the scouring processes showed a decrease with an increase in time. HPLC analysis revealed that the lipase/protease/cellulase scouring processes produced approximately 5‐fold higher amounts of 17 amino acids than the pectinase scouring process. GC analysis for 18 fatty acids (C8‐C24) revealed that three major fatty acids, palmitic acid, stearic acid, and behenic acid, were found on both the scoured and the unscoured fabrics. Scoured fabrics were tested for content of proteins, extractable components, waxes, and anionic components including pectins, and some differences among the fabric scoured with different enzyme combinations were found.
The Complete Structure and Pro‐inflammatory Activity of the Lipooligosaccharide of the Highly Epidemic and Virulent Gram‐Negative Bacterium Burkholderia cenocepacia ET‐12 (Strain J2315)
Authors: Silipo Alba , Molinaro Antonio , Ieranò Teresa , De Soyza Anthony , Sturiale Luisa , Garozzo Domenico , Aldridge Christine , Corris Paul A. , Khan C. M. Anjam , Lanzetta Rosa , Parrilli Michelangelo 
Published: January 2007

AbstractMembers of genus Burkholderia include opportunistic Gram‐negative bacteria that are responsible for serious infections in immunocompromised and cystic fibrosis (CF) patients. The Burkholderia cepacia complex is a group of microorganisms composed of at least nine closely related genomovars. Among these, B. cenocepacia is widely recognized to cause epidemics associated with excessive mortality. Species that belong to this strain are problematic CF pathogens because of their high resistance to antibiotics, which makes respiratory infections difficult to treat and impossible to eradicate. Infection by these bacteria is associated with higher mortality in CF and poor outcomes following lung transplantation. One virulence factor contributing to this is the pro‐inflammatory lipopolysaccharide (LPS) molecules. Thus, the knowledge of the lipopolysaccharide structure is an essential prerequisite to the understanding of the molecular mechanisms involved in the inflammatory process. Such data are instrumental in aiding the design of antimicrobial compounds and for developing therapeutic strategies against the inflammatory cascade. In particular, defining the structure of the LPS from B. cenocepacia ET‐12 clone LMG 16656 (also known as J2315) is extremely important given the recent completion of the sequencing project at the Sanger Centre using this specific strain. In this paper we address this issue by defining the pro‐inflammatory activity of the pure lipopolysaccharide, and by describing its full primary structure. The activity of the lipopolysaccharide was tested as a stimulant in human myelomonocytic U937 cells. The structural analysis was carried out by compositional analysis, mass spectrometry and 2D NMR spectroscopy on the intact lipooligosacchride (LOS) and its fragments, which were obtained by selective chemical degradations.
Expression of Concern: Inactivation of human mutL homolog 1 and mutS homolog 2 genes in head and neck squamous cell carcinoma tumors and leukoplakia samples by promoter hypermethylation and its relation with microsatellite instability phenotype
Authors: Sengupta Shiladitya , Chakrabarti Susmita , Roy Anup , Panda Chinmay K. , Roychoudhury Susanta 
Published: January 2007

AbstractBACKGROUND.A subset of head and neck squamous cell carcinoma (HNSCC) exhibits a microsatellite instability (MIN) phenotype. The authors correlated alterations in the mismatch‐repair genes human mutL homolog 1 (hMLH1) and human mutS homolog 2 (hMSH2) in primary head and neck squamous cell carcinoma (HNSCC) tumors and in samples of leukoplakia with the MIN phenotype.METHODS.One hundred twenty‐three paired HNSCC normal and tumor tissues and 27 leukoplakia samples were examined for hypermethylation of hMLH1 and hMSH2 promoters. The hypermethylation status of the tissues was confirmed by expression studies. Sixty‐three of 123 randomly selected tumors and all 27 leukplakia samples were genotyped with 8 microsatellite markers to determine MIN.RESULTS.Fifty percent of HNSCC tumors and 63% of leukoplakia samples harbored hypermethylation at either or both hMLH1 and hMSH2 promoters. Normal tissues adjacent to methylation‐positive tumors also demonstrated hypermethylation of both promoters at a high frequency (25%). A positive correlation between tobacco habit and promoter hypermethylation was observed (P = .001). A correlation was observed between MIN and the frequency of promoter hypermethylation in the leukoplakia samples, but no such trend was observed in the HNSCC tumors. It is noteworthy that patients who had a high frequency of MIN‐positive tumors exhibited hypermethylation in both the affected tissues and the adjacent normal tissues (P = .007). Patients with a tobacco habit who had promoter hypermethylation at both the affected tissues and the adjacent normal tissues had tumors that mostly were MIN positive (P = .047).CONCLUSIONS.The current results suggested that tobacco‐addicted individuals are more susceptible to promoter hypermethylation of hMLH1 and hMSH2 and that, if such hypermethylation occurs in the normal squamous epithelium of the head and neck region, then those tissues are likely to develop into tumors that involve the MIN pathway. Cancer 2007;109:703–12. © 2007 American Cancer Society.
Adjuvant and neoadjuvant chemotherapy for Ewing sarcoma family tumors in patients aged between 40 and 60
Authors: Bacci Gaetano , Balladelli Alba , Forni Cristiana , Ferrari Stefano , Longhi Alessandra , Bacchini Patrizia , Alberghini Marco , Fabbri Nicola , Benassi MariaSerena , Briccoli Antonio , Picci Piero 
Published: January 2007

AbstractBACKGROUND.The clinical and pathologic features of 46 patients 40 to 60 years old with Ewing sarcoma family tumor (ESFT) diagnosed at the authors' institute between 1972 and 2000 were reviewed.METHODS.Ten patients with metastatic tumors at presentation went elsewhere for treatment; 35 of 36 remaining cases with localized disease were treated at the authors' institution according to different chemotherapy protocols activated in successive years. In patients with nonmetastatic tumors local treatment was surgery in 9 patients, radiotherapy in 16, and surgery followed by radiotherapy in 10.RESULTS.At follow‐up times ranging from 6 and 34 years (mean, 17.8 years), 15 patients (42.9%) remained continuously disease‐free, 19 experienced recurrence, and 1 died of chemotherapy‐related toxicity. The 5‐ and 10‐year event‐free survivals were 42.9% and 35.2%, respectively, and the 5‐ and 10‐year overall survivals were 46.1% and 42.8%, respectively. Comparing this group of patients with 586 cases of younger patients seen in the same period at Rizzoli, the only difference between the 2 groups was a significantly higher rate of tumors located in the soft tissues with a larger volume in the older group. The results achieved were comparable in the 2 groups, although the older group had a lower chemotherapy dose‐intensity and a higher rate of WHO grade 4 hematologic toxicity.CONCLUSIONS.For patients with localized disease treated with adjuvant and neoadjuvant chemotherapy the results were essentially comparable in the 2 groups. It is concluded that patients 40 years or older with ESFT should be treated in the same way as younger patients and included in treatment trials for these tumors. Cancer 2007. © 2007 American Cancer Society.
Activity of decitabine, a hypomethylating agent, in chronic myelomonocytic leukemia
Authors: Aribi Ahmed , Borthakur Gautam , Ravandi Farhad , Shan Jianqin , Davisson Jan , Cortes Jorge , Kantarjian Hagop 
Published: January 2007

AbstractBACKGROUND.Hypomethylating agents have activity in myelodysplastic syndrome (MDS) and have received approval for the treatment of both MDS and chronic myelomonocytic leukemia (CMML). The specific efficacy in CMML has not been detailed in a large number of patients. The aim of the study was to evaluate the activity and safety of decitabine in CMML.METHODS.Nineteen adults with a diagnosis of CMML treated on decitabine studies were analyzed. Decitabine was given at 100 mg/m2 per course every 4 weeks. The median number of courses given was 9 (range, 1–18).RESULTS.Overall, 11 patients (58%) achieved complete response (CR) and 2 (11%) had hematologic improvement (HI), for an overall response rate of 69% according to the modified International Working Group (IWG) criteria. Median survival was 19 months. Severe (grade 3–4) extramedullary side effects were rare.CONCLUSIONS.Decitabine is active in CMML. Studies of combinations of decitabine with topoisomerase I inhibitors or other active anti‐CMML agents are indicated. Cancer 2007. © 2007 American Cancer Society.
Studies on the Growth Rates of Crystals
Authors: Dhanasekaran R. , Ramasamy P. 
Published: January 2007

AbstractThe crystal growth rates are calculated from the nucleation rate of two‐dimensional square shaped nucleus in four different models. In all these models, the growth is initiated by the birth of the critical nuclei. Two limiting values of the lateral spreading velocities perpendicular to the side of the growing island are considered in first two models and finite spreading velocities are treated in other two models.
Analysis of GaAs Growth Rate Anisotropy in Some CVD Systems
Authors: Lavrentieva L. G. 
Published: January 2007

AbstractGrowth rate anisotropy in the vicinity of singular faces is being analized for GaAs layers deposited in some chemical deposition systems. Classical crystal growth theory conceptions was being used. In accordance with them a linear connection between growth rate component in the direction of the normal to the singular face and the growth step density is shown to accur in the range of angle deviation 20, 10 and 6° from the faces (111)B, (001) and (111)A correspondingly. Step motion velocity has been calculated on the assumption that the atoms reaching the surface may be crystallized either by joining the step in echelon or by joining the interstep surface due to nucleation or normal growth mechanism. The discussion shows the model which takes into consideration the growth owing to nucleation and step echelon motion gives more selfconsistent results.
Inclined Dislocations in Synthetic Calcite Crystals
Authors: Desai C. C. , George K. V. 
Published: January 2007

AbstractA large number of perfect (100) cleavages were obtained by cleaving the laboratory grown synthetic calcite crystals. By etching such cleavages in 20% ammonium chloride solution, it is established that the pits indicate the sites of dislocations in the crystals. This is further confirmed by comparing the etch patterns on matched cleavage surfaces. Eccentricity of the pits has been attributed to the inclined nature of dislocations. Existence of parallel dislocations seems to be due to the purity of the crystal. These observations are verified by comparing etch patterns produced on opposite faces of a thin flake (0.048 mm thick) and also by successive etching and polishing a cleavage surface. It is conjectured that curl‐bottomed pits nucleate at the sites of screw dislocations in the crystal. The implications are discussed.
On the Determination of the Size Distribution Functions of Spherical Precipitations in Al–Zn Alloys by Neutron Small‐angle Scattering
Authors: Schülbe R. , Schmidt U. , Schild L. , Eichhorn F. 
Published: January 2007

AbstractThe size distribution of approximately spherical incoherent precipitations of Zn in AlZn‐alloys is calculated and experimentally tested by means of neutron small angle scattering (NSAS) at a double‐crystal diffractometer (DCD). The scattering curves can be approximated by a Gaussian function, so that the size distribution is directly calculated for the experimentical scattering curves under application of a particular LAPLACE‐transformation. The size distributions of the α′m‐phase of AlZn(16)‐samples of different averaged radii of precipitations are calculated by means of FWHM which are determined by the fitting procedure of a computer programme and compared with TEM micrographs.
The Slow Precipitation of Sparingly‐soluble Metal Salt Powders from Aqueous Solution: Mathematical Relations for the Kinetics of the Crystal Growth Processes in Different Types of Precipitation
Authors: Packter A. 
Published: January 2007

AbstractThe following types of slow precipitation, of sparingly‐soluble metal salts from aqueous solution, have been analysed: precipitations without an induction period – (i) with very few microcrystallites or seeds, (ii) with microcrystallites and first/second order surface or diffusion rate‐controlled growth, (iii) with very many microcrystallites; precipitations with significant induction periods – (i) with very few microcrystallites or seeds, (ii) with microcrystallites and first/second order surface or diffusion rate‐controlled growth, (iii) with very many microcrystallites.Generally, in the early stages of precipitation, growth rates depend on the rate of addition of metal salt ions to the system and on the rate constant for crystal growth; in this stage, rates increase from low values to optimum values: in the later stages of precipitation, the metal salt ions are used up as rapidly as they are added to the system and growth rates then depend only on the rate of addition and on the number of microcrystallites or seeds; in this range, rates gradually decrease to low values.Mathematical relations, for the variation of crystal size with precipitation time at different stages of growth, have been derived for each of the above types of precipitation.
Calculation of the Suspension Volume of Crystallizers with Non‐ideally Mixed Suspension
Authors: Winter B. , Gramlich K. 
Published: January 2007

AbstractFor the calculation of the suspension volume of crystallizers with non‐ideally mixed suspension the material balance was derived. The model of complete segregation and the cell modell were used to describe the micro‐mixing of solid phase. Testing was carried out in a laboratory crystallizer. The residence time distribution and the weight increase of the crystals were measured. The results showed that the model of complete segregation is suitable for describing the flow behaviour of the solid phase in crystallizers.
Correlation between Light Microscopical and Electron Microscopical Images of Crystal Defects in GaP
Authors: Tempel A. , Löschke K. , Bartsch H. 
Published: January 2007

AbstractUltramicroscopy and dark‐field‐illumination basing on the scattering of photons are easily available, they are nondestructive light microscopical methods for real structure investigations of semiconducting materials. The observation of dislocations is possible because of photon scattering at precipitations adherent to the dislocation line. This work gives a direct correlation between light microscopical and electron microscopical images of dislocations and in this way some hints on the nature of scattering centres. The light scattering takes place at precipitations caused due to gettering of impurity atoms by the dislocation line. Besides elongated dislocations prismatic loops were observed. The loop density was found to be in the order of magnitude of about 1012 cm−3 which corresponds to a concentration of about 1017 atoms contained in the loops in good agreement with the concentration of impurities in the crystals.