bluuebunny/crossref_metadata_2025 huggingface dataset:
Fetal cerebral venous Doppler velocimetry in normal and high‐risk pregnancy
Authors: Cheema R. , Dubiel M. , Breborowicz G. , Gudmundsson S.
Published: July 2004

Objective

In previous pilot studies, fetal vein of Galen (GV) blood velocity has been shown to be non‐pulsatile in normal pregnancies. A pulsating pattern in high‐risk pregnancies has been related to adverse outcome of pregnancy. The aim of this study was to establish reference ranges for fetal cerebral venous blood flow and compare them to the recordings in high‐risk pregnancies in terms of predicting adverse perinatal outcome.

Methods

The GV, straight sinus (SS) and transverse sinus (TS) were located by color Doppler ultrasound in 189 normal pregnancies between 23 and 43 weeks of gestation. Recordings were also made in 102 pregnancies complicated by pregnancy‐induced hypertension and/or intrauterine growth restriction. The following parameters were measured: peak systolic velocity, minimum diastolic velocity, time‐averaged maximum velocity, pulsatility index for veins (PIV) and preload index (PLI). GV pulsations were noted. In high‐risk pregnancies, Doppler measurements were correlated to pregnancy outcome, including emergency operative intervention and/or neonatal distress. Umbilical vein and umbilical, uterine and middle cerebral artery blood velocities were also recorded at the same time.

Results

In normal pregnancy, pulsating venous blood velocity was observed in GV in 8% of cases, in SS in 79% of cases and in TS in 100% of cases. GV and SS maximum velocity increased with gestational age and TS‐PIV showed linear decreasing values and TS‐PLI showed increasing values with gestational age. In high‐risk pregnancies, pulsating blood velocity in the GV was found in 59 (58%) cases and was related to adverse outcome of pregnancy including mortality. Abnormal values for TS‐PIV and PLI and SS maximum velocity were found in nine, six and five cases, respectively and were only related to perinatal mortality. GV pulsations were more frequent than umbilical venous pulsations.

Conclusions

Of the fetal cerebral veins studied, the presence of pulsations in the GV seems to be the best predictor of adverse outcome of high‐risk pregnancy. Pulsations in the GV are more frequent than in the umbilical vein and might therefore appear earlier during worsening fetal condition, and thus be of potential value for fetal surveillance in high‐risk pregnancies. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Fetoscopic tracheal occlusion (FETO) for severe congenital diaphragmatic hernia: evolution of a technique and preliminary results
Authors: Deprest J. , Gratacos E. , Nicolaides K. H.
Published: July 2004

Background

Congenital diaphragmatic hernia (CDH) with liver herniation and a lung area to head circumference ratio (LHR) > 1 is associated with a high rate of neonatal death due to pulmonary hypoplasia.

Methods

We report the development of a minimally invasive and reversible fetoscopic tracheal occlusion (FETO) with a balloon, carried out in 21 consecutive fetuses with severe CDH.

Results

Endotracheal placement of the balloon was successfully performed in all 21 cases and the mean duration of the operation was 20 (range, 5–54) min. The median gestation at FETO was 26 (range, 25–33) weeks. There were no maternal complications such as hemorrhage, placental abruption or pulmonary edema. In 11 (52.4%) patients there was postoperative prelabor amniorrhexis, which occurred within 2 weeks in five patients and after 2 weeks in six patients. Ultrasound scans after FETO demonstrated an increase in the echogenicity of the lungs within 48 h and improvement in the LHR from a median 0.7 (range, 0.4–0.9) before FETO to 1.8 (range, 1.1–2.9) within 2 weeks following surgery. The median gestation at delivery was 34 (range, 27–38) weeks and in 17 (77.3%) patients delivery occurred after 32 weeks. Nine babies died in the neonatal period due to complications from pulmonary hypoplasia. Surgical repair of the diaphragmatic hernia was carried out in 12 babies and in all but one the defect was extensive and required the insertion of a patch. Ten of these babies survived, and at the time of writing were aged 6–25 (median, 18) months and were developing normally. Survival was 30% in the first group of 10 fetuses and 63.6% in the second group of 11 fetuses. The total number of cases was too small for definite conclusions to be drawn as to the causes of this apparent improvement in survival. Nevertheless, improved survival coincided with a shift in the timing of FETO from the third to the second trimester, the administration of epidural rather than general anesthesia, reduced incidence of postoperative amniorrhexis and a change in the policy on the timing of removal of the balloon from the intrapartum to the prenatal period. During the same period of study there were 17 cases examined in the participating centers that met the criteria for FETO but which declined prenatal therapy. In all cases there was isolated left‐sided CDH with liver in the thorax and LHR of 0.4–0.9 (mean, 0.7). In five cases the parents elected to terminate the pregnancy. In the 12 cases with expectant management all babies were liveborn but 11 died in the neonatal period due to pulmonary hypoplasia and only one (8.3%) survived.

Conclusion

Severe CDH can be successfully treated with FETO, which is minimally invasive and may improve postnatal survival. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Polysulfonylamine. CLXVIII [1]. Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 16 [2]. Ein lineares Koordinationspolymer aus isolierten quadratischen Röhren: Tetragonales Na4[(MeSO2)2N]4·3H2O
Authors: Zerbe Eva‐Maria , Jones Peter G. , Moers Oliver , Blaschette Armand
Published: July 2004

Das hydratisierte Natrium‐dimesylamid Na4[(MeSO2)2N]4·3 H2O wurde durch Zufall entdeckt. Die Kristallstruktur (tetragonal, seltene Raumgruppe I41cd, Z′ = 1) enthält eindimensionale quadratische Röhren auf der Grundlage von Na—O‐ und Na—N‐Wechselwirkungen und veranschaulicht, daß auch ein unelegantes Koordinationsnetzwerk zu einer hochästhetischen Kristallsymmetrie führen kann. Jede Röhre wird von vier parallelen Ketten gebildet, die sich durch z‐Translation fortpflanzen. Als isolierte Einheiten würden diese Ketten aus drei μ3‐O, N, O‐verbrückenden Anionen, einem μ2‐O, N‐verbrückenden Anion, drei μ2‐verbrückenden Wassermolekülen und vier Natriumionen mit den Koordinationszahlen 5, 5, 4 und 3 bestehen; bei der Röhrenbildung verhalten sich ein μ3‐ und das einzelne μ2‐Anion passiv („äußere Liganden”︁), die anderen μ3‐Anionen („innere Liganden”︁) erhöhen ihren Verbrückungsmodus auf μ4‐O, O, N, O bzw. μ5‐O, O, N, O, O, und die niedriger koordinierten Kationen gelangen zur Koordinationszahl 5. Bei den Koordinationspolyedern handelt es sich um zwei verzerrte trigonale (O3N2)‐Bipyramiden, eine verzerrte quadratische (O5)‐Pyramide und ein (O5)‐Polyeder zwischen trigonaler Bipyramide und quadratischer Pyramide. Die in koordinationschemischer Hinsicht mangelhaft konstruierten Röhren umhüllen die zweizähligen Drehachsen, wobei benachbarte Ketten in der Röhre durch c‐Gleitspiegelung miteinander in Beziehung stehen. Außerdem finden sich benachbarte Röhren von den vierzähligen Schraubenachsen in der Weise transformiert, daß aufeinanderstoßende Stapel von äußeren Liganden zu Mischstapeln verschmelzen und dichte Packung der Röhren gewährleistet ist. Ein dreidimensionales Netzwerk aus sechs Wasserstoffbrücken O(W)—H···O=S und zahlreichen schwachen H‐Brücken des Typs C—H···O=S verstärkt die Kohäsion des Kristalls; bemerkenswert ist dabei, daß die starken O—H‐Donoren spezifisch mit den sechs nichtkoordinierenden Sulfonyl‐Sauerstoffatomen in Wechselwirkung treten.
Bimetallic Copper(I)‐Mercury(II) and Copper(I)‐Potassium(I) Coordination Polymers with Bridging Di‐ and Trithiacrown Ethers
Authors: Heller M. , Sheldrick W. S.
Published: July 2004

The complex [Hg(SCN)2(1, 10DT18C6)] (1) contains discrete Hg(SCN)2 units, whose Hg atoms lie at the centre of a 1, 10‐dithia‐18‐crown‐6 (1, 10DT18C6) macrocycle. The essentially linear coordination of Hg in Hg(SCN)2 is extended to hexagonal bipyramidal by weak Hg—S bonds of length 3.003(2)Å to the thiacrown ether S atoms and by four additional secondary Hg—O interactions. Solvothermal reaction of CuCN and HgCl2 with 1, 10DT18C6 in acetonitrile at 100 °C affords [(CuCN)4{Hg(CN)2(1, 10DT18C6)}] (2). Zigzag CuCN chains in this complex are linked by 1, 10DT18C6 ligands in a μ‐S1, S10 bridging manner into layers. These, in their turn, are connected through μ‐[Hg(CN)2] units into interpenetrating 3D frameworks, in which the Hg atoms are surrounded by coordinating thiacrown ether macrocycles. [K(Cu3I4)(1, 7, 13TT18C6)]·CH3CN (3) can be prepared by treatment of KI and CuI with 1, 7, 3‐trithia‐18‐crown‐6 (1, 7, 13TT18C6) in acetonitrile at 100 °C and contains anionic layers in which broken cube [Cu3I4]— building units connect three adjacent thiacrown ether ligands. Individual layers are linked into a 3D network by the K+ counter cations.
(Fluoroorgano)fluoroboranes and ‐borates. 11 [1] The Electrochemical Oxidation of Polyfluorophenyltrifluoroborate Anions in Acetonitrile
Authors: Shundrin Leonid A. , Bardin Vadim V. , Frohn Hermann‐Josef
Published: July 2004

The potentials for the electrochemical oxidation of potassium polyfluorophenyltrifluoroborate salts K[C6H5—nFnBF3] (n = 0 — 5) were measured by cyclic voltammetry in CH3CN. In all cases the first oxidation peak corresponded to irreversible processes at the Pt electrode. The good correlation between the observed first oxidation peak potential values, Ep1, and the calculated (RHF, MNDO approximation) vertical ionisation potentials of the polyfluorophenyltrifluoroborate anions, [C6H5—nFnBF3]—, indicates an one‐electron step as first step of the oxidation. The formation of C6F5H and of the adduct BF3·NCCH3 in the potential controlled electrolysis of K[C6F5BF3] in CH3CN is in agreement with this assumption.
Synthesis and Crystal Stucture of a Long‐Chain Thiophosphinic Amide, Me2P(S)NH{C6H4‐p‐[OCO(C6H4‐p‐OC8H17)]}
Authors: Soulivong D. , Matt D. , Harrowfield J. , Toupet L.
Published: July 2004

The two long‐chain dimethylphosphinic amides Me2P(X)NH{C6H4‐p‐[OCO(C6H4‐p‐OC8H17)]} (X = S, O) were synthesized by reacting Me2PNEt2 with H2N{C6H4‐p‐[OCO(C6H4‐p‐OC8H17)]} and by subsequently achieving the appropriate oxidation step (with H2O2 or S8). The sulfido compound was characterized by X‐ray crystallography, proving to be triclinic, space group, P1¯, a = 6.056(2), b = 8.110(2), c = 25.016(5) Å, α = 97.04(2), β = 89.91(2), γ = 102.81(3), V = 1188.6(5) Å3 , Z = 2. In the solid state, the molecule adopts a bent structure with a length of ca. 24 Å.
Intramolekular stickstoffstabilisierte Organoaluminiumverbindungen mit Naphthyl‐, Benzyl‐ und Phenylliganden
Authors: Schumann Herbert , Dechert Sebastian , Hummert Markus , Lange Katharina C. H. , Schutte Stefan , Wassermann Birgit C. , Köhler Katrin , Eichhorn Jens
Published: July 2004

N, N‐Dimethylnaphthylamin (1) reagiert mit Butyllithium zu Li(Et2O)C10H6NMe2‐8 (2). Die Umsetzung von 2 mit Et2AlCl und EtAlCl2 führt zu Et2AlC10H6NMe2‐8 (3) bzw. EtAl(C10H6NMe2‐8)2 (5) und mit iBu2AlCl wird iBu2AlC10H6NMe2‐8 (4) gebildet. 1 reagiert mit Me3Al zum entsprechenden Addukt Me3Al←N(C10H7)Me2 (6). LiCH2C6H4NMe2‐2 (7) und LiC6H4CH2NR2‐2 (R = Me (10), Et (12)) reagieren mit Me2AlCl, Et2AlCl und iBu2AlCl unter Bildung von R2AlCH2C6H4NMe2‐2 (R = Me (8), Et (9)), iBu2AlC6H4CH2NMe2‐2 (11) und Et2AlC6H4CH2NEt2‐2 (13). Die neuen Verbindungen wurden durch Elementaranalysen, 1H‐, 13C‐ und 27Al‐NMR‐Untersuchungen sowie massenspektrometrisch, 3 (zwei Modifikationen), 5 und 6 darüberhinaus durch Einkristall‐Röntgenstrukturanalyse charakterisiert.
Hydrothermal Synthesis of Three New Transition Metal Complexes with Azido Ligands
Authors: He Xiang , Lu Can‐Zhong , Yu Ya‐Qin , Chen Shu‐Mei , Wu Xiao‐Yuan , Yan Ying
Published: July 2004

Hydrothermal reactions of NaN3, 1, 10‐phenanthroline or 2, 2′‐bipyridine and transition metal cations including ZnII or CoII in basified aqueous solutions yielded the three complexes, [Zn2(bipy)2(N3)4]n (1), [Zn(phen)(N3)2]n (2), and [Co(phen)2(N3)2] (3), which were characterized by X‐ray crystallography. All three complexes crystallize in the triclinic system, space group P1¯, with a = 6.5506(2), b = 10.8441(6), c = 16.893(2)Å, α = 96.333(5), β = 95.361(7), γ = 90.548(6)° for 1; a = 7.0302(10), b = 10.0590(14), c = 10.4550(15)Å, α = 109.372(2), β = 103.980(2), γ = 106.137(2)° for 2; and a = 8.1722(2), b = 11.0332(3), c = 12.5066(2)Å, α = 82.681(8), β = 82.457(9), γ = 72.991(7)° for 3, respectively. The photoluminescence spectra for compounds 1 and2 have also been studied.
Paramagnetic Octahedral p‐Methoxyphenyldithiophosphonato Nickel(II) Complexes: Crystal Structures of [Ni{S2P(OR)(p‐CH3O‐C6H4)‐κS, S′}2(L‐κN)2] (R = Et, 2, 4‐tBu2C6H3, L = 3‐acetylpyridine)
Authors: Karakus Mehmet , Lönnecke Peter , Hey‐Hawkins Evamarie
Published: July 2004

The square‐planar NiII complexes [Ni{S2P(OR)(p‐CH3O‐C6H4)‐κS, S′}2] react with 3‐acetylpyridine to give green crystals of the paramagnetic octahedral complexes [Ni{S2P(OR)(p‐CH3O‐C6H4)‐κS, S′}2(L‐κN)2] [R = Et (1), iPr (2), 2, 4‐tBu2C6H3 (3); L = 3‐acetylpyridine]. Complexes 1‐3 were characterized by IR, MS, and UV‐vis spectroscopy, and crystal structures were determined for 1 and 3. The magnetic moments for 1‐3 are 3.04‐3.15 B.M.
Zinc Complexes from Bromo Substituted Tris[(2‐pyridyl)methyl]amine Ligands. Influence of Sterically Demanding Substituents on Coordination Geometry
Authors: Schnieders David , Merkel Michael , Baldeau Sascha M. , Krebs Bernt
Published: July 2004

The reaction of zinc chloride with the tripodal tetradentate ligand [(6‐bromo‐2‐pyridyl)methyl]bis[(2‐pyridyl)methyl]amine (Brtpa), bis[(6‐bromo‐2‐pyridyl)methyl][(2‐pyridyl)methyl]amine (Br2tpa), or bis[(2‐pyridyl)methyl][(1‐methylimidazol‐2‐yl)methyl]amine (bpia) yields the new coordination compounds [Zn(Brtpa)Cl2] (1), [Zn(Br2tpa)Cl2] (2) and the first zinc compound derived from bpia [Zn(bpia)Cl]2[ZnCl4]·2CH3OH (3), respectively. 1 and 2 are the first zinc complexes with halogen substituted tripodal ligands of the tpa type. The bromine substitutions of the ligands have a strong effect on coordination and binding. The new compounds were isolated and characterized by single crystal X‐ray crystallography as well as infrared spectroscopy and elemental analyses. Compound 1 crystallizes in the triclinic space group P1¯ (No. 2) with a = 7.503(2) , b = 8.815(2) , c = 15.924(3)Å, α = 94.19(3)°, β = 92.33(3)°, γ = 112.32(3)°, V = 969.1(3)Å3, Z = 2. Compound 2 crystallizes in the monoclinic space group P21 (No. 4) with a = 8.357(1), b = 10.882(1), c = 11.286(1)Å, β = 99.04(1)°, V = 1013.7(2)Å3, Z = 2. Compound 3 crystallizes in the orthorhombic space group P212121 (No. 19) with a = 14.367(1), b = 17.269(1), c = 17.479(1)Å, V = 4336.5(2)Å3, Z = 4.
Beiträge zum Reaktionsverhalten von Phosphaalkinen gegenüber Übergangsmetallkomplexen — Synthese und Kristallstrukturanalyse von [(Ph3P)2Pt(η2‐PCMes)], [M(CO)3(η4‐P2C2Mes2)] (M = Fe, Ru), [Cp*Mo(CO)Cl(η4‐P2C2tBu2)] und [K(tol)2]2[Mn(CO)4{Mn(CO)3(η4‐P2C2tBu2)}2]2
Authors: Himmel Daniel , Seitz Markus , Scheer Manfred
Published: July 2004

Die Reaktion von MesC≡P (Mes = 2, 4, 6‐Me3C6H2) mit [(Ph3P)2Pt(η2‐C2H4)] führt zu [(Ph3P)2Pt(η2‐PCMes)] (1) während mit Fe2(CO)9 bzw. [Ru(CO)4(C2H4)] die 1, 3‐Diphosphetkomplexe [M(CO)3(η4‐P2C2Mes2)] (M = Fe(2), Ru(3)) und [Ru(CO)3(η4:η1‐P2C2Mes2){Ru(CO)2(η4‐P2C2Mes2)}] (4) gebildet werden. Weiterhin wurde das Reaktionsverhalten von t‐BuC≡P untersucht, wobei mit [Cp*Mo(CO)3Cl] der Komplex [Cp*Mo(CO)Cl(η4‐P2C2tBu2)] (6) erhalten wurde und mit K[Mn(CO)5], [K(tol)2]2[Mn(CO)4{Mn(CO)3(η4‐P2C2tBu2)}2]2 (7) (tol = Toluol) isoliert werden konnte. Die Reaktionsprodukte wurden durch Röntgenstrukturanalyse (außer 4) sowie mit spektroskopischen Methoden umfassend charakterisiert.
Crystal and Molecular Structures of the Pentafluorosulfanyl Compounds, SF5X (X = ‐NC, ‐CN, ‐NCO, ‐NCS and ‐NCCl2) by X‐ray Diffraction at Low Temperature
Authors: Buschmann Jürgen , Lentz Dieter , Luger Peter , Perpetuo Genivaldo , Preugschat Dagmar , Thrasher Joseph S. , Willner Helge , Wölk Hans‐Jörg
Published: July 2004

A new method for the synthesis of the unstable pentafluorosulfanyl isocyanide from N‐(pentafluorosulfanyl)(dichloromethanimine) was developed, thereby allowing for the study of its spectroscopic data. The structure of pentafluorosulfanyl isocyanide was determined by X‐ray crystallography at 113 K. The molecule possesses an almost linear S‐N‐C arrangement and an unexpectedly long S‐N bond. In addition, the structures of pentafluorosulfanyl cyanide, pentafluorosulfanyl isocyanate, pentafluorosulfanyl isothiocyanate, and N‐(pentafluorosulfanyl)(dichloro)methanimine were determined by single crystal X‐ray crystallography at low temperatures.
Dimeric Silsesquioxanes and Metallasilsesquioxanes — En route to large, welldefined Si‐O‐assemblies
Authors: Lorenz Volker , Edelmann Frank T.
Published: July 2004

Recent advances in the chemistry of dimeric silsesquioxanes and metallasilsesquioxanes are reviewed. The number of metal‐free silsesquioxane dimers is still quite limited, although some promising synthetic routes have already been developed. In contrast, metallasilsesquioxanes containing two silsesquioxane ligands are known with numerous metals, including Li, K, Be, Al, In, Sc, Sm, Yb, U, Ti, Zr, V, Ta, Cr, and Cu. A major breakthrough in this chemistry was the successful synthesis of fully metalated silsesquioxane precursors such as (Cy7Si7O12)2Li6(THF)2 (15).
Über die Bildung von Trithiatetrazocin‐Derivaten aus bicyclischen Kohlenstoff‐Schwefel‐Stickstoff‐Heterocyclen, RCN5S3
Authors: Knapp Carsten , Lork Enno , Maggiulli Roberto , Watson Paul G. , Mews Rüdiger , Borrmann Tobias , Stohrer Wolf‐Dieter , Behrens Ulrich
Published: July 2004

F3CCN5S3 (1a) bildet mit AsF5 ein 1:1‐Addukt F3CCN5S3˙AsF5 (2), welches sich in CDCl3‐Lösung langsam zum kationischen, achtgliedrigem Ring [F3CCN4S3]+ [AsF6]— (3) zersetzt. Der Angriff des AsF5 erfolgt an dem verbrückenden Stickstoffatom, das die größte negative Partialladung trägt. Im Gegensatz dazu wird in der protonierten Verbindung [F3CCN5S3H]+ [AsF6]— (6) ein dem Ringkohlenstoff benachbartes Stickstoffatom angegriffen, was mit den unterschiedlichen Basizitäten der Stickstoffatome erklärt werden kann. Mit PPh3 und AsPh3 öffnen die Bicyclen RCN5S3 (1) zu den Phosphanimino‐ bzw. Arsaniminotetrazocin‐Derivaten RCN4S3N=EPh3 (R = F3C, E = P (endo), 4a; E = As (endo), 5a; R = Me2N, E = P (endo), 4c). Der dafür in der Literatur vorgeschlagene Reaktionsmechanismus wird durch die Isolierung von [TAS]+ [F3CCN5S3NC(NH2)CF3]— (7) gestützt. Die durch Röntgenbeugung bestimmten Strukturen von 2, 3, 4a, 4c, 5a, 6 und 7 werden diskutiert.
Manganese(II), Cobalt(II), and Nickel(II) Perchlorate Complexes Containing N, O Donor Macrocyclic Ligands
Authors: Lodeiro Carlos , Capelo Jose Luis , Bértolo Emilia , Bastida Rufina
Published: July 2004

Mononuclear macrocyclic complexes of manganese(II), cobalt(II) and nickel(II) perchlorate using 10 different oxaazamacrocyclic ligands (L1 — L10) have been prepared and characterized. The complexation reactions with the diiminic ligands were obtained by template condensation of the appropriate dialdehyde and diamine precursors; the reduced macrocycle complexes were synthesized using a direct route. The complexes have been characterized by elemental analyses, molar conductivity, mass spectrometry, IR, UV‐vis spectroscopy, diffuse reflectance and magnetic susceptibility measurements.
Tetranitratogoldsäure, (H5O2)[Au(NO3)4]·H2O: Synthese, Kristallstruktur und thermisches Verhalten des ersten sauren Nitrates des Goldes
Authors: Büchner Oliver , Wickleder Mathias S.
Published: July 2004

Gelbe Einkristalle von (H5O2)[Au(NO3)4]·H2O bilden sich beim Abkühlen einer Lösung von Au(OH)3 in konz. Salpetersäure. In der Kristallstruktur (monoklin, C2/c, Z = 4, a = 1214, 5(2), b = 854, 4(1), c = 1225, 7(2) pm, β = 117, 75(1)°, Rall = 0, 0331) wird Au3+ von vier einzähnig angreifenden NO3—‐Ionen umgeben. Die [Au(NO3)4]—‐Einheiten werden von H5O2+‐Ionen zusammengehalten, die mit den H2O‐Molekülen über starke Wasserstoffbrückenbindungen verknüpft sind. Die thermische Analyse läßt auf einen fünfstufigen Abbau schließen und führt zu elementarem Gold.
Reaktionsverhalten verschiedener Carbodiimide mit Ferrocen‐1, 1'‐dicarbonsäure
Authors: Schetter Bernd
Published: July 2004

1, 1'‐Bis‐(1, 3‐dicyclohexylureidocarbonyl)‐ferrocen (1), 1, 1'‐Bis‐(1, 3‐diisopropylureidocarbonyl)‐ferrocen (2) und Ferrocen‐1, 1'‐bis‐N‐p‐tolylcarboxamid (6) wurden bei kurzer Reaktionszeit durch lösungsmittelfreies Zusammenschmelzen von Ferrocen‐1, 1'‐dicarbonsäure (7) mit N, N'‐Dicyclohexylcarbodiimid (DCC), N, N'‐Diisopropylcarbodiimid (DIC) und N, N'‐Di‐p‐tolylcarbodiimid (8) erhalten. 1, 2, 1, 1'‐Bis‐(1‐ethyl‐3‐tert‐butylureidocarbonyl)‐ferrocen (3), 1‐(1‐tert‐butyl‐3‐ethylureidocarbonyl)‐1'(1‐ethyl‐3‐tert‐butylureidocarbonyl)‐ferrocen (4) und 1, 1'‐Bis(1‐tert‐butyl‐3‐ethylureidocarbonyl)‐ferrocen (5) wurden durch wochenlange Reaktion von 7 mit DCC, DIC, bzw. N‐tert‐Butyl‐N'‐ethylcarbodiimid (9) in Ethylacetat in hohen Ausbeuten erhalten. Transannulares Ferrocendicarbonsäureanhydrid (10) entsteht bei diesen Reaktionen nicht. Alle Verbindungen wurden durch 1H‐NMR‐, 13C‐NMR‐, IR‐Spektrometrie, MS und Elemantaranalyse charakterisiert. Für 1 wurde eine Röntgenstrukturanalyse durchgeführt.
Structural and Coordinative Variability in Zinc(II), Cadmium(II), and Mercury(II) Complexes of 2‐Pyridineformamide 3‐Hexamethyleneiminylthiosemicarbazone
Authors: Bermejo Elena , Castiñeiras Alfonso , García‐Santos Isabel , West Douglas X.
Published: July 2004

Sodium in dry methanol reduces 2‐cyanopyridine in the presence of 3‐hexamethyleneiminylthiosemicarbazide and produces 2‐pyridineformamide 3‐hexamethyleneiminylthiosemicarbazone, HAmhexim (1). Complexes with zinc(II), cadmium(II) and mercury(II) have been prepared and characterized by spectroscopic techniques. In addition, the crystal structures of HAmhexim (1), [Zn(Amhexim)(OAc)]2μ·μDMSO (2), [Cd(HAmhexim)Cl2]μ·μDMSO (7), [Cd(Amhexim)2] (8), [Cd(HAmhexim)Br2]μ·μDMSO (9), [Cd(HAmhexim)I2]μ·μEtOH (10), [Hg(HAmhexim)Cl2]μ·μDMSO (11), [Hg(Amhexim)Br]2 (13), [Hg3(HAmhexim)(Amhexim)Br5]μ·μH2O (14) and [Hg(Amhexim)I]2 (15) have been determined. Coordination of the anionic and neutral thiosemicarbazone ligand occurs through the pyridine nitrogen atom, imine nitrogen atom, and thiolato or thione sulfur atom. In [Zn(Amhexim)(OAc)]2 one of the bridging acetato ligands has monodentate coordination and the other bridges in a bidentate manner. [Cd(Amhexim)2] is a 6‐coordinate species while the other cadmium complexes are 5‐coordinate. In [Hg(Amhexim)Br]2 and [Hg(Amhexim)I]2 the thiolato sulfur atoms act as bridges between the Hg atoms to form dimeric compounds and [Hg3(HAmhexim)(Amhexim)Br5]μ·μH2O is a trinuclear complex with three different centers — two metallic centers have a 5‐coordination and the another one has 4‐coordination. In addition, [Hg(HAmhexim)Cl2]μ·μDMSO and [Hg3(HAmhexim)(Amhexim)Br5]μ·μH2O shown a supramolecular one‐dimensional hydrogen‐bonded self‐assembling.
Chemischer Transport fester Lösungen. 12 [1] Der Chemische Transport von Mischphasen im System ZnS/ZnTe
Authors: Rose C. , Binnewies M.
Published: July 2004

Mithilfe chemischer Transportreaktionen (Transportmittel Iod, 1000 → 900 °C) konnten im System ZnS/ZnTe, das eine breite Mischungslücke aufweist, schwefelreiche und tellurreiche Mischkristalle durch chemischen Transport erhalten werden. Während der Transport der tellurreichen Phasen ZnTe1‐xSx (x = 0 … ca. 0, 1) etwa kongruent erfolgt, kommt es beim Transport der schwefelreichen Mischkristalle ZnS1‐xTx (x = 0 … ca. 0, 1) zu einer deutlichen Schwefelanreicherung. Aus der Mischungslücke heraus wird nur die tellurreiche Mischphase transportiert, danach kommt der Transport zum Erliegen.
Chemischer Transport fester Lösungen. 13 [1] Bildung von Mischphasen im System ZnS/Zn3P2 im Temperaturgefälle
Authors: Locmelis S. , Binnewies M.
Published: July 2004

Erhitzt man ZnS und Zn3P2 gemeinsam mit Iod im Temperaturgefälle (z.B. 1000 → 900 °C), werden bei 900 °C die Mischphasen ZnS:P (0, 7 %) (ZnS1—xP0, 67x, x = 0 …0, 019) und Zn3P2:S (1, 2 %) (Zn3P2—xS1, 5x, x = 0 …0, 005) erhalten. Der Einbau von Sulfid‐Ionen in Zn3P2 führt zu einer Verkleinerung, der Einbau von Phosphid‐Ionen in ZnS zu einer Vergrößerung der Elementarzelle. Die ablaufenden Fest/Gas‐Reaktionen werden diskutiert.
Mono‐, Di‐ and Trinuclear Dioxo Complexes of Uranium Containing Hydrazonato and Azomethine Ligands
Authors: Gatto C. C. , Schulz Lang E. , Kupfer A. , Hagenbach A. , Abram Ulrich
Published: July 2004

Mono‐, di or trinuclear dioxouranium complexes with benzoylhydrazonato or azomethine ligands were prepared by reactions of common dioxouranium precursors such as UO2(NO3)2 · 6 H2O or [NBu4]2[UO2Cl4] with vanillin benzoylhydrazone (H2L4), salicylaldehyde benzoylhydrazone (H2L5), 2‐hydroxyacetylbenzene salicylhydrazone (H3L6) or N‐(2‐ethoxycarbonyl‐3‐oxo‐but‐1‐en(1)yl)‐2‐aminophenol (H2L7).

Spectroscopic and X‐ray crystallographic studies on the complexes [NBu4]2[UO2Cl4] · 2 H2L4, [UO2(HL5)(H2L5)2](NO3), [HNEt3]2[{UO2(L6)}2] and [HNEt3]2[{UO2(L7}3O] confirm that the individual donor atom constellation, the size of the potential chelate rings and the acidity of the OH and NH functionalities of the proligands have a strong influence on the structure of the products.
Neubestimmung der Ladungsdichte und topologische Analyse von β‐Diboran bei 94 K
Authors: Hübschle Christian B. , Messerschmidt Marc , Lentz Dieter , Luger Peter
Published: July 2004

Die experimentelle Ladungsdichte von β‐Diboran wurde aus 1779 Reflexen neu bestimmt, die bis (sinθ/λ)max = 1.11Å—1 mit MoKα‐Strahlung und CCD‐Flächendetektion bei 94(1) K gemessen wurden. Im Gradientenvektorfeld der Elektronendichte wurden die stark gebogenen Bindungspfade der B‐Hμ‐Bindungen verifiziert. Eine topologische Analyse ergab in Übereinstimmung mit theoretischen Ergebnissen keinen Hinweis auf einen bindungskritischen Punkt zwischen den beiden Boratomen.
Mass Spectrometric Investigations of Thermodynamic Properties of the RbCl/GdCl3 System
Authors: Rutkowska Iwona , Hilpert Klaus , Miller Mirosław
Published: July 2004

The vaporization of pure RbCl, GdCl3, and RbCl‐GdCl3 samples of different phase compositions was investigated in the temperature range between 666 K and 982 K by use of the Knudsen effusion mass spectrometry. The gaseous species RbCl, Rb2Cl2, GdCl3, and RbGdCl4 were identified in the equilibrium vapours and their partial pressures were determined. The enthalpy of dissociation of RbGdCl4(g), ΔdissH°(859 K) = 263.1 ± 7.7 kJ mol—1, was evaluated by second law treatment of the equilibrium partial pressures. The thermodynamic activities of RbCl and GdCl3 were obtained at 800 K in the two‐phase fields {Rb3GdCl6(s) + liquid} and {RbGd2Cl7(s) + GdCl3(s)}. The Gibbs free energies of formation of the pseudo‐binary phases Rb3GdCl6(s), ΔfG°(800 K) = —75.1 ± 2.5 kJ mol—1 and RbGd2Cl7(s), ΔfG°(800 K) = —40.6 ± 1.2 kJ mol—1, were evaluated from the thermodynamic activities of the components. The results are compared with the available literature data.
Trans‐bis(saccharinato)cadmium(II) Complexes with 2‐Aminomethylpyridine and 2‐Aminoethylpyridine — Synthesis, Crystal Structures, Spectral and Thermal Characterization of trans‐[Cd(sac)2(ampy)2] and trans‐[Cd(sac)2(aepy)2]
Authors: Yilmaz Veysel T. , Caglar Sema , Harrison William T. A.
Published: July 2004

Two trans‐bis(saccharinato) (sac) complexes of cadmium(II) with 2‐aminomethylpyridine (ampy) and 2‐aminoethylpyridine (aepy) were synthesized and characterized by means of elemental analysis, FT‐IR spectroscopy and thermal analysis. In addition, their solid‐state structures were determined by single crystal X‐ray diffraction studies. The [Cd(sac)2(ampy)2] (1) and [Cd(sac)2(aepy)] (2) complexes consist of neutral monomeric units and crystallize in the orthorhombic (Pbca) and monoclinic (P21/c) crystal systems, respectively. The cadmium(II) ions in 1 and 2 sit on inversion centres andexhibit distorted octahedral coordination by two sac anions and two aminopyridine ligands. The sac ligands in both complexes are N‐coordinated and located in trans positions, while the ampy and aepy ligands act as a bidentate ligand forming two symmetrically chelate rings around cadmium(II). IR spectra and thermal decompositions of the complexes are also discussed.
Formation of Carboxylato‐bridged Dipalladium(II) Complexes via Ligand Displacement with a Ferrocene Phosphanocarboxylate
Authors: Štěpnička Petr , Císařová Ivana
Published: July 2004

Racemic potassium [2‐(diphenylphosphano)ferrocenyl]acetate reacts with the dinuclear palladium(II) methyl‐phosphane complexes [{Pd(μ‐Cl)Me(PR3)}2] (1; R = Me (a), 2‐furyl (b), and Ph (c)) under formation of a dipalladium(II) complex with triply coordinated phosphanocarboxylate ligand: (Rp, Sp)‐[μ‐1κ2P, O: ‐2κO′‐{2‐(diphenylphosphano)ferrocenyl}acetato][μ‐1κO′:2κ2P, O{2‐(diphenylphosphano)ferrocenyl}acetato]bis{methylpalladium(II)} (2), exclusively as (Rp, Sp) diastereoizomer (meso‐form). The solid‐state structures of 1a and 2 have been determined by single‐crystal X‐ray diffraction.
Darstellung und Eigenschaften von dreizähnigen Schiff‐Basen‐Komplexen des Titans
Authors: Hecht Elmar , Rüffer Tobias , Lang Heinrich
Published: July 2004

Bis[iminoalkoxy]‐Komplexe des Titans wurden durch Umsetzung der entsprechenden Schiff‐Basen mit Titan‐tetraisopropoxid im Molverhältnis 2:1 in n‐Hexan erhalten. Selbst bei einer äquimolaren Umsetzung der Ausgangsstoffe konnten nur die disubstituierten Iminoalkoxy‐Komplexe erhalten werden. Die Schiff‐Basen‐Komplexe wurden mittels ihrer NMR‐Spektren und im Falle von 4 durch Einkristallstrukturanalyse charakterisiert. Als Folge von Ti—N und Ti—O Wechselwirkungen bildet 4 sechsfach koordinierte Ti‐Atome aus. Die Ti‐Atome sind von den entsprechenden Ligandatomen in Form eines verzerrten Oktadeders umgeben. 4: Raumgruppe C2/c, Z = 8, Gitterdimensionen bei 20 °C: a = 18.690(4), b = 16.281(3), c = 15.086(3) Å, b = 109.040(4)°, R1 = 0.0553, wR2 = 0.1598, GooF = 1.040.
Two Conformers in Solution and Solid State for a Novel Phosphoramidate — Synthesis, Characterization and Crystal Structures of C6H5C(O)NHP(O)[NH(tert‐C4H9)]2 and CCl3C(O)NHP(O)[NH(tert‐C4H9)]2
Authors: Gholivand Khodayar , Pourayoubi Mehrdad
Published: July 2004

Two new phosphoramidates with formula RC(O)NHP(O)[NH(tert‐C4H9)]2, R=C6H5, (1) and CCl3, (2) were synthesized and characterized by IR, 1H‐, 13C‐, 31P NMR, mass spectroscopy and elemental analysis. The structures confirmed by X‐ray single crystal determination. Compound 1 appears as two conformers (1a and 1b) in solid state as well as solution. Both compounds (1 and 2) exist in the polymeric chains in crystalline lattice produced by hydrogen bonding that for compound 1, there are two independent infinite chains; each of them composed of one of the two conformers.
Developmental stage dependent regulation of DNA methylation and chromatin modification in a immature astrocyte specific gene promoter
Authors: Namihira Masakazu , Nakashima Kinichi , Taga Tetsuya
Published: July 2004

Astrocytes are generated from neuroepithelial cells after neurons during brain development. However, the mechanism of this sequential generation is not fully understood. Here, we show that a particular cytosine residue in the promoter of the gene encoding the immature astrocyte marker, S100β, becomes demethylated, correlating with the time when the S100β expression commences at embryonic day (E) 14. In addition, astrocyte‐inducing cytokine, BMP2, increased histone acetylation around the CpG site in neuroepithelial cells at E14 but not E11 when S100β expressing astrocytes are absent. Furthermore, binding of a methyl DNA binding protein, MeCP2, to the S100β gene promoter in neuroepithelial cells was reduced at E14 compared to E11. Thus, demethylation of specific CpG site is suggested to be a critical determinant in regulating astrocyte differentiation in the developing brain.
Effect of vitamin E supplementation on neutrophil function, milk composition and plasmin activity in dairy cows in a commercial herd
Authors: Politis Ioannis , Bizelis Iosif , Tsiaras Anastasios , Baldi Antonella
Published: July 2004

Fifty-six Holstein dairy cows from a commercial dairy herd in the Northern part of Greece were used to determine the effect of vitamin E supplementation on immune parameters, milk composition and milk quality. Cows were assigned to one of two experimental groups: control (no vitamin E supplementation) and vitamin E supplementation. Supplementation of vitamin E started 4 weeks prior to and continued up to 12 weeks after parturition. Supplementation included daily oral administration of vitamin E at 3000 i.u./cow prepartum and was reduced to 1000 i.u./cow post partum. Blood samples were collected weekly for 8 weeks starting 4 weeks before parturition, neutrophils were isolated and the following parameters were determined in neutrophils activated by phorbol myristate acetate: total cell-associated and membrane-bound urokinase plasminogen activator (u-PA) activity and superoxide production. Milk samples were collected weekly and fat, protein, lactose, somatic cell count (SCC), plasmin and plasminogen-derived activity were determined. Activated neutrophils isolated from cows that received supplemental vitamin E had higher (P<0·01) total and membrane-bound u-PA activities during the first 3 weeks after parturition and higher (P<0·01) superoxide production during week 1 prepartum and week 1 post partum compared with the corresponding values of activated neutrophils isolated from control cows. Vitamin E supplementation had no effect (P=0·28) on plasminogen-derived activity in milk. Milk obtained from cows that received supplemental vitamin E had SCC lower by 25% (P<0·05) and plasmin lower by 30% (P<0·01) than corresponding values in milk obtained from control cows. The reduction in plasmin as a result of vitamin E supplementation is very beneficial to the dairy industry because plasmin reduces the cheese-yielding capacity of milk, affects the coagulating properties of milk and its overall ability to withstand processing during cheesemaking. In conclusion, vitamin E supplementation had positive effects on the function of bovine neutrophils and milk quality in a commercial dairy herd.
Changes in lipid fractions and sensory properties of Idiazabal cheese induced by lipase addition
Authors: Barron Luis JR , Hernández Igor , Bilbao Ainhoa , Flanagan Cristian E , Nájera Ana I , Virto Mailo , Pérez-Elortondo Francisco J , Albisu Marta , de Renobales Mertxe
Published: July 2004

This work studied the addition of an adequate lipase to enhance lipolysis reactions and the development of piquant flavour and sharp odour in Idiazabal cheese, as an alternative to the use of lamb rennet paste. Cheeses were manufactured from bulk raw ewes' milk in 50 l vats with commercial bovine rennet and 80 lipase units of pregastric or 180 lipase units of fungal lipase and ripened for 180 days. A higher lipolytic activity was induced by lipase addition promoting strong changes in odour and flavour attributes. Both fungal and pregastric lipases increased the content of total free fatty acids (FFA), but the fungal lipase released mainly medium- and long-chain FFA. In contrast, the pregastric lipase preferably released short-chain FFA. Diglyceride (DG) content was considerably higher in cheeses made with added pregastric lipase compared with those made with fungal lipase or with no lipase. Monoglycerides (MG) were detected only in cheeses made with either lipase added, reaching comparable concentrations after ripening for 180 days. The cheeses made with pregastric lipase had the highest scores for odour and flavour intensity, and sharp and rennet odours, desirable attributes for the Idiazabal cheese made with lamb rennet paste. None of the texture attributes were significantly influenced by the concentrations of MG and DG in the cheeses made with either lipase. Thus, the pregastric lipase was more appropriate than the fungal lipase to develop a more traditionally-flavoured Idiazabal cheese.
Controlled production of Camembert-type cheeses. Part II. Changes in the concentration of the more volatile compounds
Authors: Leclercq-Perlat Marie-Noëlle , Latrille Eric , Corrieu Georges , Spinnler Henry-Eric
Published: July 2004

Flavour generation in cheese is a major aspect of ripening. In order to enhance aromatic qualities it is necessary to better understand the chemical and microbiological changes. Experimental Camembert-type cheeses were prepared in duplicate from pasteurized milk inoculated with Kluyveromyces lactis, Geotrichum candidum, Penicillium camemberti and Brevibacterium linens under aseptic conditions. Two replicates performed under controlled conditions of temperature (12 °C), relative humidity (95±2%), and atmosphere showed similar ripening characteristics. The evolutions of metabolite concentrations were studied during ripening. The volatile components were extracted by dynamic headspace extraction, separated and quantified by gas chromatography and identified by mass spectrometry. For each cheese the volatile concentrations varied with the part considered (rind or core). Except for ethyl acetate and 2-pentanone, the volatile quantities observed were higher than their perception thresholds. The flavour component production was best correlated with the starter strains. During the first 10 days the ester formations (ethyl, butyl and isoamyl acetates) were associated with the concentrations of K. lactis and G. candidum. The rind quantity of esters was lower than that observed in core probably due to (1) a diffusion from the core to the surface and (2) evaporation from the surface to the chamber atmosphere. G. candidum and Brev. linens association produced 3 methyl butanol and methyl 3-butanal from leucine, respectively. DMDS came from the methionine catabolism due to Brev. linens. Styrene production was attributed to Pen. camemberti. 2-Pentanone evolution was associated with Pen. camemberti spores and G. candidum. 2-Heptanone changes were not directly related to flora activities while 2-octanone production was essentially due to G. candidum. This study also demonstrates the determining role of volatile component diffusion.
Volatile compounds in cheeses made from raw ewes' milk ripened with a lactic culture
Authors: Centeno Juan A , Fernández-García Estrella , Gaya Pilar , Tomillo Javier , Medina Margarita , Nuñez Manuel
Published: July 2004

In some European regions ewes' milk is transformed into cheese without a previous heat treatment. The microbiota and the native enzymes present in raw milk are considered to be responsible for the characteristic strong flavour of raw ewes' milk cheeses (Nuñez et al. 1989). Although pasteurization ensures a higher uniformity of the product, heat treatment of ewes' milk may impair the sensory characteristics of cheeses (Gaya et al. 1990).
The roles of disulphide and non-covalent bonding in the functional properties of heat-induced whey protein gels
Authors: Havea Palatasa , Carr Alistair J , Creamer Lawrence K
Published: July 2004

Heat-induced gelation (80 °C, 30 min or 85 °C, 60 min) of whey protein concentrate (WPC) solutions was studied using transmission electron microscopy (TEM), dynamic rheology and polyacrylamide gel electrophoresis (PAGE). The WPC solutions (150 g/kg, pH 6·9) were prepared by dispersing WPC powder in water (control), 10 g/kg sodium dodecyl sulphate (SDS) solution or 10 mM-dithiothreitol (DTT) solution. The WPC gels containing SDS were more translucent than the control gels, which were slightly more translucent than the gels containing DTT. TEM analyses showed that the SDS-gels had finer aggregate structure (≅10 nm) than the control gels (≅100 nm), whereas the DTT-gels had a more particulate structure (≅200 to 300 nm). Dynamic rheology measurements showed that the control WPC gels had storage modulus (G′) values (≅13500 Pa) that were ≅25 times higher than those of the SDS-gels (≅550 Pa) and less than half those of the DTT-gels after cooling. Compression tests showed that the DTT-gels were more rigid and more brittle than the control gels, whereas the SDS-gels were softer and more rubbery than either the control gels or the DTT-gels. PAGE analyses of WPC gel samples revealed that the control WPC solutions heated at 85 °C for 10 min contained both disulphide bonds and non-covalent linkages. In both the SDS-solutions and the DTT-solutions, the denatured whey protein molecules were in the form of monomers or small aggregates. It is likely that, on more extended heating, more disulphide linkages were formed in the SDS-gels whereas more hydrophobic aggregates were formed in the DTT-gels. These results demonstrate that the properties of heat-induced WPC gels are strongly influenced by non-covalent bonding. Intermolecular disulphide bonds appeared to give the rubbery nature of heat-induced WPC gels whereas non-covalent bonds their rigidity and brittle texture.
Selection of acid tolerant Bifidobacteria and evidence for a low-pH-inducible acid tolerance response in Bifidobacterium longum
Authors: Takahashi Noritoshi , Xiao Jin-Zhong , Miyaji Kazuhiro , Yaeshiima Tomoko , Hiramatsu Akinori , Iwatsuki Keiji , Kokubo Sadayuki , Hosono Akiyoshi
Published: July 2004

Acidity is an environmental condition commonly encountered by lactic acid bacteria and bifidobacteria in the gastrointestinal tract and fermented foods. In the present study, 22 strains of Bifidobacterium were screened for acid tolerance in artificial gastric juice (AGJ, pH 3·0) and fermented milk. AGJ tolerance was found to be strain-specific, with a pronounced variation among the strains. Several strains with a high survival rate in AGJ that belonged to Bifid. longum, Bifid. breve and Bifid. adolescentis were selected. Among them, only strain BL1 of Bifid longum was found to possess a high survival rate in fermented milk during refrigerated storage. Strain BL1 exhibited a survival rate of more than 25% in AGJ at pH 3·0 for 2 h and maintained a viable cfu level of more than 108 per gram of product in fermented milk (pH 4·6) under refrigerated conditions for 2 weeks. The acid tolerance of strain BL1 was found to depend on the final growth pH (<4·5). Rapid loss of acid tolerance was observed when the cells were shifted from acid to neutral conditions by addition of NaOH. Strain BL1 cells were able to maintain much higher intracellular pH under acid conditions, in comparison with those of AGJ sensitive mutant (BL1-S) or cells that lost acid tolerance following pH shifting from acid to neutral conditions. These results suggested that a cytoplasmic pH homeostasis system may function in the acid tolerance response in this strain.
Physical properties of mammary secretions in relation to chemical changes during transition from colostrum to milk
Authors: Madsen Birgitte D , Rasmussen Morten D , Nielsen Mette O , Wiking Lars , Larsen Lotte B
Published: July 2004

We examined the physical and chemical changes in milk during early lactation, and how these changes were affected by leaving one quarter unmilked in either the first or second milking, with the purpose of discriminating between colostrum and normal milk. Milk samples were collected from each quarter of 17 cows during the first 5 d after calving and then after about 7 d and 14 d. Samples were analysed for somatic cell count (SCC), fat, protein, casein, lactose, IgG1, colour, plasmin, pH and coagulation properties. Large variations occurred in both chemical and physical properties throughout the study period. Within six milkings, the concentration of casein decreased by 60%, IgG1 by 94%, and lactose increased by 34%. At milking number 6, rennet coagulation time was lowest and curd firmness was highest. The pH increased from 6·4 to 6·7 over the period of the experiment, and the colour changed from yellow (reddish) to white. Coagulation properties and the pH fell within the range of normal milk after five milkings. Measurement of colour and density appeared to be a potential method for detection of milk unsuitable for the dairy factory. Effects of omitting one quarter in one milking differed between milk components, but seemed to be of little importance to the physical properties.
Increasing magnesium intakes in relation to magnesium absorption in dry cows
Authors: Jittakhot Surasak , Schonewille J Thomas , Wouterse Hugo , Uijttewaal Anton WJ , Yuangklang Chalermpon , Beynen Anton C
Published: July 2004

Earlier studies with temporarily isolated rumen of heifers show saturation kinetics of Mg efflux across the rumen wall. Therefore, we hypothesized that high Mg intakes would not further increase the rate of Mg absorption in cows. To test our hypothesis, six ruminally fistulated non-pregnant dry cows were given diets with different Mg concentrations in a 6×6 Latin square design. Desired concentrations of Mg were attained by adding MgO to the basal diet and the Mg concentrations in the total rations were 3·8, 6·4, 9·1, 11·8, 14·1 and 17·3 g Mg/kg dry matter, which provided Mg intakes of 27·1, 44·6, 64·6, 83·5, 100·4 and 124·3 g/d, respectively. Increasing Mg intakes were associated with increased (P<0·001) faecal Mg excretion. However, apparent Mg absorption expressed as g/d was not significantly different for Mg intakes from 100·4 to 124·3 g/d while Mg absorption expressed as a proportion of intake was not significantly different for Mg intakes ranging from 64·6 to 124·3 g/d. Mg concentrations in rumen fluid after feeding increased (P<0·001) with increasing Mg intakes. Apparent absorption of Mg appeared to become saturated at a ruminal Mg concentration of 17·5 mM (Mg intake of 83·5 g/d). Group-mean post-feeding concentrations of Mg and Na in rumen fluid were significantly correlated (Pearson's r=−0·96; P=0·003, n=6). This study showed that under conditions of practical dairy cow feeding, Mg absorption was maximal at Mg intakes [ges ]84 g/d.
Effects of feeding or abomasal infusion of canola oil in Holstein cows 1. Nutrient digestion and milk composition
Authors: Chelikani Prasanth K , Bell John A , Kennelly John J
Published: July 2004

We determined the effects of feeding canola oil or infusing it into the abomasum on rumen fermentation, nutrient digestibility, duodenal flows of fatty acids, and milk composition in Holstein cows. Five ruminally and duodenally cannulated Holstein cows in late lactation were used in a 3×5 incomplete Latin square design. Treatments were 1) Control: basal diet (CON), 2) Control+supplementation of canola oil at 1 kg/d in the feed (FED), and 3) Control+abomasal infusion of canola oil at 1 kg/d (INF). Compared with CON, feed intake, ruminal fermentation characteristics, ruminal and total tract digestibilities of nutrients were not significantly affected by FED treatment but duodenal flows and milk concentrations of fatty acids (FA) such as trans-11 18[ratio ]1 and cis-9 trans-11 18[ratio ]2 (conjugated linoleic acid, CLA) were increased. In contrast to the effects of FED, INF reduced feed intake, total VFA production, intestinal flows of nutrients, FA digestibility and yields of milk and milk fat. Both FED and INF significantly reduced the proportions of saturated and medium-chain FA, and increased cis 18[ratio ]1 in milk. Concentrations of 18[ratio ]2n-6 and 18[ratio ]3n-3 in milk were increased nearly 2-fold with INF relative to CON. Dietary or postruminal supplementation of canola oil to late-lactation cows reduced saturated FA and increased unsaturated C18 in milk but nutrient digestion was adversely affected with abomasal infusion of canola oil.