From field-induced to zero-field SMMs associated with open/closed structures of bis(ZnDy) tetranuclear complexes: a combined magnetic, theoretical and optical study.

We have prepared a bis(compartmental) Mannich base ligand H4L (1,4,8,11-tetraaza-1,4,8,11-tetrakis(2-hydroxy-3-methoxy-5-methylbenzyl)cyclotetradecane) specifically designed to obtain bis(TMIILnIII) tetranuclear complexes (TM = transition metal). In this regard, we have succeeded in obtaining three new complexes of the formula [Zn2(µ-L)(µ-OAc)Dy2(NO3)2]·[Zn2(µ-L)(µ-OAc)Dy2(NO3)(OAc)]·4CHCl3·2MeOH (1) and [TM2(µ-H2L)2(µ-succinate)Ln2(NO3)2] (NO3)2·2H2O·6MeOH (TMII = Zn, LnIII = Dy (2); TMII = Co, LnIII = Dy (3)). Compound 1 contains two different bis(ZnDy) tetranuclear molecules that cocrystallize in the structure, in which acetato bridging ligands connect the ZnII and DyIII ions within each ZnDy subunit. This compound does not exhibit slow magnetic relaxation at zero field, but it is activated in the presence of an applied dc magnetic field and/or by Dy/Y magnetic dilution, showing two relaxation processes corresponding to each of the two different bis(ZnDy) units found in the structure. As revealed by the theoretical calculations, magnetic relaxation in 1 is single-ion in origin and takes place through the first excited state of each DyIII ion. When using the succinato dicarboxylate bridging ligand instead of acetate, compounds 2 and 3 were serendipitously formed, which have a closed structure with the succinate anion bridging two ZnDy subunits belonging to two different ligands. It should be noted that only compound 2 exhibits slow relaxation of magnetization in the absence of an external magnetic field. According to experimental and theoretical data, 2 relaxes through the second excited Kramers doublet (Ueff = 342 K). In contrast, 3 displays field-induced SMM behaviour (Ueff = 203 K). However, the Co/Zn diluted version of this compound 3Zn shows slow relaxation at zero field (Ueff = 347 K). Ab initio theoretical calculations clearly show that the weak ferromagnetic coupling between CoII and DyIII ions is at the origin of the lack of slow relaxation of this compound at zero field. Compound 2 and its diluted analogues 2Y and 3Zn show hysteresis loops at very low temperature, thus confirming their SMM behaviour. Finally, compounds 1 and 2 show DyIII based emission even at room temperature that, in the case of 2, allows us to extract the splitting of the ground 6H15/2 term, which matches reasonably well with theoretical calculations.

Zero-Field SMM Behavior Triggered by Magnetic Exchange Interactions and a Collinear Arrangement of Local Anisotropy Axes in a Linear Co3II Complex.

A new linear trinuclear Co(II)3 complex with a formula of [{Co(µ-L)}2Co] has been prepared by self-assembly of Co(II) ions and the N3O3-tripodal Schiff base ligand H3L, which is obtained from the condensation of 1,1,1-tris(aminomethyl)ethane and salicylaldehyde. Single X-ray diffraction shows that this compound is centrosymmetric with triple-phenolate bridging groups connecting neighboring Co(II) ions, leading to a paddle-wheel-like structure with a pseudo-C3 axis lying in the Co-Co-Co direction. The Co(II) ions at both ends of the Co(II)3 molecule exhibit distorted trigonal prismatic CoN3O3 geometry, whereas the Co(II) at the middle presents an elongated trigonal antiprismatic CoO6 geometry. The combined analysis of the magnetic data and theoretical calculations reveal strong easy-axis magnetic anisotropy for both types of Co(II) ions (|D| values higher than 115 cm-1) with the local anisotropic axes lying on the pseudo-C3 axis of the molecule. The magnetic exchange interaction between the middle and ends Co(II) ions, extracted by using either a Hamiltonian accounting for the isotropic magnetic coupling and ZFS or the Lines' model, was found to be medium to strong and antiferromagnetic in nature, whereas the interaction between the external Co(II) ions is weak antiferromagnetic. Interestingly, the compound exhibits slow relaxation of magnetization and open hysteresis at zero field and therefore SMM behavior. The significant magnetic exchange coupling found for [{Co(µ-L)}2Co] is mainly responsible for the quenching of QTM, which combined with the easy-axis local anisotropy of the CoII ions and the collinearity of their local anisotropy axes with the pseudo-C3 axis favors the observation of SMM behavior at zero field.

Pushing up the easy-axis magnetic anisotropy and relaxation times in trigonal prismatic CoII mononuclear SMMs by molecular structure design.

The replacement of pyridine by 1-methyl-imidazol in the arms of a N6-tripodal ligand allows preparing two new CoII complexes with quasi-ideal triangular prismatic geometry, which behave as SIMs (Single Ion Magnets) at zero dc field with enhanced axial magnetic anisotropy, magnetic relaxation times and magnetic hysteresis.

Multicenter study of the evolution of different types of avulsion over the 12 months after delivery.

OBJECTIVE: To perform a multicenter study of muscle recovery in levator ani muscle (LAM) avulsion during the first 12 months postpartum according to the type of LAM avulsion suffered. METHODS: This was a multicenter prospective observational study including 242 primiparas. Transperineal ultrasound was performed at 6 months and 12 months after delivery. Type I LAM avulsion was present when most of the lateral fibers of the pubovisceral muscle were observed at the muscle's insertion at the pubic level. Type II LAM avulsion was defined as complete detachment of the pubovisceral muscle from its insertion at the pubic level. RESULTS: Among the 56 patients who completed the study (with ultrasound at 6 and 12 months after delivery), 76 avulsions (10 cases of bilateral avulsion) were identified at 6 months after delivery, and the total number of avulsions had decreased to 58 at 12 months after delivery (P < 0.001; 95% confidence interval [CI] 13.9%-33.5%). This decrease was due to the disappearance of 69.2% of the cases of Type I LAM avulsions (P < 0.001; 95% CI: 50.2%-88.2%). However, the number of Type II LAM avulsions remained constant at 6 months and 12 months after delivery. CONCLUSION: The spontaneous resolution of LAM avulsion during the first 12 months postpartum occurs in cases of Type I LAM avulsion but is not observed in Type II LAM avulsion.

Photo-generation of H2 by heterometallic complexes.

Multiple and different metals in a complex can accomplish single and sequential multi-step reactions, providing valuable procedures to obtain chemicals in one-pot synthetic routes. Biology has shown how cooperative catalysis is a powerful method for the synthesis of complicated molecules. One of the most attractive targets for current chemists is the synthesis of H2 by a simple and economical procedure, mainly if it is produced from water using visible light as the energy source. This review aims to show how heterometallic complexes have been recently used to catalyze the photochemical production of H2.

DFT Study of the Formation of Atmospheric Aerosol Precursors from the Interaction between Sulfuric Acid and Benzenedicarboxylic Acid Molecules.

Dicarboxylic acids are ubiquitous products of the photooxidation of volatile organic compounds which are believed to play a significant role in the formation of secondary organic aerosols in the atmosphere. In this paper, we report high-level quantum investigations of the clustering properties of sulfuric acid and benzenedicarboxylic acid molecules. Up to four molecules have been considered in the calculations, and the behavior of the three isomers of the organic diacid species have been compared. The most stable geometries have been characterized together with the corresponding thermodynamic data. From an atmospheric point of view, the results of the DFT calculations show that the organic diacid molecules may significantly enhance the nucleation of small atmospheric clusters, at least from an energetic point of view. In this respect, the phthalic acid isomer seems more efficient than the two other isomers of the benzenedicarboxylic acid, in particular because the internal distance between the two carboxyl groups in the organic diacids appears to play an important role in the stabilization of the H-bond network inside the corresponding heterocluster formed with sulfuric acid molecules.

2D ultrasound diagnosis of middle compartment prolapse: a multicenter study.

BACKGROUND: Recently, a specific methodology has been defined, using transperineal ultrasound, for the differential diagnosis of middle compartment prolapse [uterine prolapse (UP) or cervical elongation (CE) without UP] based on the difference in the pubis-uterine fundus distance at rest and with the Valsalva maneuver, with a cutoff point of 15 mm. The objective of this study was to validate the diagnostic utility of a ≥15 mm difference between the pubis-uterine fundus distance at rest and during the Valsalva maneuver to define UP in a multicenter study. METHODS: This prospective multicenter observational study included 94 patients (UP =51; CE without UP =43). The clinical examination was based on the International Continence Society Pelvic Organ Prolapse Quantification (ICS POP-Q) system for assessing pelvic organ prolapse (POP) and patients were candidates for corrective surgery of the middle compartment of the pelvic floor (correction of UP or CE without UP). The ultrasound study was performed by transperineal ultrasound (B-mode) with the patient undergoing dorsal lithotomy. The distance evaluation was performed in relation to the posteroinferior pubic margin in the midsagittal plane, with reference to the uterine fundus (established as the most distal hyperechogenic) line from the pubis to the uterine fundus at rest and with the Valsalva maneuver. We defined UP detected using UP as a difference of ≥15 mm between the pubis-uterine fundus distance at rest and with the Valsalva maneuver. Agreement between the clinical and ultrasound diagnosis of UP was assessed using the Cohen kappa coefficient of agreement and its 95% CIs. RESULTS: The ultrasound diagnosis of global UP at the three centers showed very good agreement, with a kappa index of 0.826 (0.71, 0.94). The agreement of ultrasound with the clinical diagnosis of UP using the ICS POP-Q system was very good for each of the hospitals [Hospital 1: 0.814 (0.64, 0.98), Hospital 2: 0.847 (0.64, 1) and Hospital 3: 0.824 (0.59, 1)]. CONCLUSIONS: A difference of ≥15 mm between the pubis-uterine fundus distance at rest and during the Valsalva maneuver for the diagnosis of UP presents very good agreement with the results of clinical evaluation with the ICS POP-Q system.

Monitoring spin-crossover phenomena via Re(I) luminescence in hybrid Fe(II) silica coated nanoparticles.

Bare (1) and silica coated (1@SiO2) spin crossover (SCO) nanoparticles based on the polymer {[Fe(NH2Trz)3](BF4)2}n have been prepared following a water-in-oil synthetic procedure. For 1, the critical temperatures of the spin transition are TC↓ = 214.6 K and TC↑ = 220.9 K. For 1@SiO2, the abruptness of the transition is enhanced and the critical temperatures are centred at room temperature (TC↓ = 292.1 K and TC↑ = 296.3 K). An inert Re(I) complex of formula [Re(phen)(CO)3(PETES)](PF6) (phen = 1, 10-phenanthroline; PETES = 2(4-pyridylethyl)triethoxysilane) (Re) was also synthesized yielding intense green emission centred at λem = 560 nm. The grafting of this complex on the silica shell of 1@SiO2 led to a bifunctional SCO-luminescence composite (1@SiO2/Re) whose luminescence properties were tuned by the spin state switching. Temperature-variable photophysical studies showed that luminescence and spin transition were synchronized through a radiative (trivial) energy transfer mechanism between the Re(I) and the Fe(II)-LS (LS, Low Spin) centres.

Rotational forceps: a retrospective study evaluating anatomical and functional consequences for the pelvic floor.

INTRODUCTION AND HYPOTHESIS: The use of Kielland's rotational forceps is considered to involve greater technical difficulty and may be associated with a higher rate of pelvic floor trauma. Our main objective was to evaluate the association between avulsion of the levator muscle and rotational and non-rotational forceps. METHODS: This was an observational study carried out at a tertiary hospital that recruited singleton cephalic vaginally primiparous women with previous Kielland's forceps delivery between March 2012 and May 2017. Patients were retrieved from a local database, contacted consecutively and blinded to all clinical data. Power calculations determined a sample of n = 160 patients. All women underwent a urogynecological interview, clinical examination and 4D translabial ultrasound (TLUS). The 4D TLUS volumes were stored and analyzed offline by an experienced ultrasound examiner who was blinded to all clinical data. RESULTS: A total of 165 patients were available for analysis. Rotational forceps accounted for 27.3% (45 out of 165) of the study sample. Avulsion was present in 41.8% (69 out of 165) of all forceps deliveries. On multivariate analysis, rotational forceps was associated with avulsion, with an adjusted odds ratio (OR) of 2.57 (CI 95% 1.20-5.62, p = 0.016). Body mass index at the beginning of gestation was found to be a protective factor, with an adjusted OR of 0.918 (CI 95% 0.847-0.986, p = 0.025). CONCLUSION: Rotational forceps is associated with a higher avulsion rate than non-rotational forceps, with an adjusted OR of over 2.5. Obstetricians need to consider the potential long-term consequences of performing a rotational forceps for mothers.

Prevalence of levator hiatal overdistension after vacuum and forceps deliveries.

INTRODUCTION: Levator ani avulsion rates after assisted vaginal delivery have been reported in the literature. However, there are no definitive data regarding the association between overdistention and assisted vaginal delivery. Therefore, our aim is to report overdistention rates after assisted vaginal delivery with a postpartum ultrasound examination. MATERIALS AND METHODS: This multicenter study involved a retrospective analysis of data from primiparous women (n = 602) who had previously been recruited at three tertiary hospitals between January 2015 and January 2017. Overdistention was assessed at 6 months postpartum using three-/four-dimensional transperineal ultrasound. Patients with levator ani muscle avulsion were excluded. Overdistention was defined as a levator hiatal area ≥ 25 cm2 on Valsalva. RESULTS: Of the 602 primiparous patients, 250 patients who satisfied the inclusion criteria (139 patients who underwent forceps delivery and 111 patients who underwent vacuum delivery) were evaluated. Overdistention occurred in 20% (50 of 250) of these patients. Overdistention was observed for 1% (1/111) of vacuum deliveries and 35.3% (49 of 139) of forceps deliveries. We found an increased risk of overdistention following forceps delivery compared to vacuum delivery, with a crude odds ratio (OR) of 59.9 (95% confidence interval [CI]: 8.1, 442.2) and an adjusted OR (adjusted for maternal age, second-stage duration, and head circumference) of 17.6 (95% CI: 2.3, 136.7). CONCLUSIONS: Postpartum overdistention occurred for 20% of assisted vaginal deliveries, with an increased risk of overdistention following forceps delivery compared to vacuum delivery.

Are there differences in the damage to the pelvic floor between malmstrom's and kiwi omnicup vacuums? A multicenter study.

OBJECTIVES: The objective of this study is to investigate a multicenter study to establish if differences exist in the levator ani muscle avulsion (LAM) rates between deliveries performed with Malmstrom's vacuum and the Kiwi vacuum. STUDY DESIGN: A prospective, multicenter observational study with 199 primiparous subjects was performed. All patients had undergone vaginal delivery by vacuum (Malmstrom's or Kiwi). Avulsion was defined as an abnormal insertion of LAM in the lower pubic branch in the multiplanar mode, as identified in the three central sections by transperineal 3/4D echography 6 months after delivery. The area of ​​the levator hiatus was measured in the plane of minimum dimensions at rest, during the Valsalva maneuver and during contraction. RESULTS: LAM avulsion occurred in 33.1% of cases in which Malmstrom's vacuum was used and in 29.4% of cases in which the Kiwi vacuum was used (the difference was not statistically significant), which resulted in a crude odds ratio (OR) of 0.977 (0.426, 2.241; P = .957) and an adjusted OR of 2.90 (0.691; 12.20; P = .146). Women in the Malmstrom's vacuum group had a larger LHA at rest 14.77 vs 12.64 cm2 ; P = .001) and at maximum contraction (13.41 vs 10.83 cm2 ; P < 0.001) in comparison with the Kiwi group, although the difference did not reach statistical significance under Valsalva maneuver (18.71 vs 17.21 cm2 ; P = .051).Differences between both groups were detected in the measurements of the hiatus area levator at rest (14.77 vs 12.64 cm2 ), during the Valsalva maneuver (18.71 vs 17.21 cm2 ) and during maximum contraction (13.41 vs 10.83 cm2 ). CONCLUSIONS: In the present study, Malmstrom's vacuum was not associated with a higher risk of LAM in comparison with Kiwi's Omnicup.

An [FeIII 34 ] Molecular Metal Oxide.

The dissolution of anhydrous iron bromide in a mixture of pyridine and acetonitrile, in the presence of an organic amine, results in the formation of an [Fe34 ] metal oxide molecule, structurally characterised by alternate layers of tetrahedral and octahedral FeIII ions connected by oxide and hydroxide ions. The outer shell of the complex is capped by a combination of pyridine molecules and bromide ions. Magnetic data, measured at temperatures as low as 0.4 K and fields up to 35 T, reveal competing antiferromagnetic exchange interactions; DFT calculations showing that the magnitudes of the coupling constants are highly dependent on both the Fe-O-Fe angles and Fe-O distances. The simplicity of the synthetic methodology, and the structural similarity between [Fe34 ], bulk iron oxides, previous FeIII -oxo cages, and polyoxometalates (POMs), hints that much larger molecular FeIII oxides can be made.

Influence of the disengagement of the forceps on levator ani muscle injuries in instrumental delivery: A multicenter study.

INTRODUCTION: Forceps use is the main risk factor for levator ani muscle (LAM) injuries. We believe that the disengagement of the forceps branches before delivery of the fetal head could influence LAM injuries, so we aimed to determine the influence of the disengagement of the forceps on the occurrence of LAM avulsion during forceps delivery. MATERIAL AND METHODS: A prospective, observational, multicenter study was conducted with 261 women who underwent forceps delivery. The women were classified according to whether the branches of the forceps had been disengaged before delivery of the fetal head. LAM avulsion was defined using a multislice mode (3 central slices). RESULTS: In all, 255 women completed the study (160 without disengagement and 95 with disengagement). LAM avulsions were observed in 37.9% of women in the group with disengagement and in 41.9% of women in the group without disengagement. The crude OR (without disengagement vs with disengagement) for avulsion was 0.90 (95% CI 0.49-1.67, P = 0.757) and an adjusted OR of 0.82 (95% CI 0.40-1.69, P = 0.603). CONCLUSIONS: We did not observe a statistically significant reduction in the LAM avulsion rate with disengagement of the forceps branches before delivery of the fetal head.

A Chiral Bipyrimidine-Bridged Dy2 SMM: A Comparative Experimental and Theoretical Study of the Correlation Between the Distortion of the DyO6N2 Coordination Sphere and the Anisotropy Barrier.

Chiral bipyrimidine-bridged dinuclear LnIII complexes of general formula [(µ-bipym){((+)-tfacam)3Ln}2] and [(µ-bipym){((-)-tfacam)3Ln}2], have been prepared from the assembly of Ln(AcO)3·nH2O (LnIII = Dy, Gd), (+)/(-)-3-(trifluoroacetyl)camphor enantiopure ligands ((+)/(-)-Htfacam) and bipyrimidine (bipym). The structure and chirality of these complexes have been supported by single-crystal X-Ray diffraction and circular dichroism. The study of the magnetic properties of the GdIII complexes revealed a very weak antiferromagnetic interaction between the GdIII ions through the bipyrimidine bridging ligand. Ab initio CASSCF calculations indicated that the ground Kramers doublet (KD) of both DyIII centers is almost purely axial with the anisotropy axis located close to the two tfacam-ligands at opposite sides of each DyIIIatom, which create an axial crystal field. In keeping with this, ac dynamic measurements indicated slow relaxation of the magnetization at zero field with U eff = 55.1 K, a pre-exponential factor of τo = 2.17·10-6 s and τQTM = 8 µs. When an optimal dc field of 0.1 T is applied, QTM is quenched and U eff increases to 75.9 K with τo = 6.16 × 10-7 s. The DyN2O8 coordination spheres and SMM properties of [(µ-bipym){((+)-tfacam)3Ln}2] and their achiral [(Dy(ß-diketonate)3)2(µ-bpym)]analogous have been compared and a magneto-structural correlation has been established, which has been supported by theoretical calculations. In contrast to the GdIII compounds, the magnetic exchange interaction between the DyIII ions has been calculated to be very weak and, generally, ferromagnetic in nature. Relaxation mechanisms for [(µ-bipym){((+)-tfacam)3Ln}2] and previously reported analogous have been proposed from ab initio calculations. As the magnetic exchange interaction found to be very weak, the observed magnetization blockade in these systems are primarily dictated by the single ion anisotropy of DyIII ions.

Designing a Dy2 Single-Molecule Magnet with Two Well-Differentiated Relaxation Processes by Using a Nonsymmetric Bis-bidentate Bipyrimidine- N-Oxide Ligand: A Comparison with Mononuclear Counterparts.

Herein we report a dinuclear [(µ-mbpymNO){(tmh)3Dy}2] (1) single-molecule magnet (SMM) showing two nonequivalent DyIII centers, which was rationally prepared from the reaction of Dy(tmh)3 moieties (tmh = 2,2,6,6-tetramethyl-3,5-heptanedionate) and the asymmetric bis-bidentate bridging ligand 4-methylbipyrimidine (mbpymNO). Depending on whether the DyIII ions coordinate to the N^O or N^N bidentate donor sets, the DyIII sites present a NO7 ( D2 d geometry) or N2O6 ( D4 d) coordination sphere. As a consequence, two different thermally activated magnetic relaxation processes are observed with anisotropy barriers of 47.8 and 54.7 K. Ab initio calculations confirm the existence of two different relaxation phenomena and allow one to assign the 47.8 and 54.7 K energy barriers to the Dy(N2O6) and Dy(NO7) sites, respectively. Two mononuclear complexes, [Dy(tta)3(mbpymNO)] (2) and [Dy(tmh)3(phenNO)] (3), have also been prepared for comparative purposes. In both cases, the DyIII center shows a NO7 coordination sphere and SMM behavior is observed with Ueff values of 71.5 K (2) and 120.7 K (3). In all three cases, ab initio calculations indicate that relaxation of the magnetization takes place mainly via the first excited-state Kramers doublet through Orbach, Raman, and thermally assisted quantum-tunnelling mechanisms. Pulse magnetization measurements reveal that the dinuclear and mononuclear complexes exhibit hysteresis loops with double- and single-step structures, respectively, thus supporting their SMM behavior.

A comprehensive protocol for chemical analysis of flame combustion emissions by secondary ion mass spectrometry.

RATIONALE: Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is used to provide detailed information on the surface chemical composition of soot. An analytical protocol is proposed and tested on a laboratory flame, and the results are compared with our previous measurements provided by two-step laser mass spectrometry (L2MS). METHODS: This work details: (1) the development of a dedicated apparatus to sample combustion products from atmospheric flames and deposit them on substrates suitable for TOF-SIMS analysis; (2) the choice of the deposition substrate and the material of the sampling line, and their effect on the mass spectra; (3) a method to separate the contributions of soot and condensable gas based on impact deposition; and finally (4) post-acquisition data processing. RESULTS: Compounds produced during flame combustion are detected on the surface of different deposition substrates and attributed a molecular formula based on mass defect analysis. Silicon and titanium wafers perform similarly, while the surface roughness of glass microfiber filters results in a reduced mass resolution. The mass spectra obtained from the analysis of different locations of the deposits obtained by impaction show characteristic patterns that are attributed to soot/condensable gas. CONCLUSIONS: A working method for the analysis of soot samples and the extraction of useful data from mass spectra is proposed. This protocol should help to avoid common experimental issues like sample contamination, while optimizing the setup performance by maximizing the achievable mass resolution.

Digitation to Void: What Is the Significance of This Symptom?

OBJECTIVE: Digitation to void is defined as the need to apply manual pressure on the perineum or the vagina to assist with voiding. It has been associated with prolapse; however, there is little objective data concerning this symptom. Our aim was to determine the correlation between digitation to void, symptoms and signs of pelvic organ prolapse (POP), and urodynamic data. METHODS: This was a retrospective study that included a total of 1174 patients seen at a tertiary urogynecological unit. A standardized history was obtained from all patients followed by multichannel urodynamic testing, Pelvic Organ Prolapse Quantification scoring and 3-D/4-D translabial ultrasound. Stored 4-D translabial ultrasound volumes were obtained and analyzed at a later date. RESULTS: Digitation to void was present in 7% (n = 83) of our population. It is associated with primary symptoms of POP (odds ratio [OR], 25.75; confidence interval [CI], 8.08-82.05), clinically significant POP (OR, 5.62; CI, 2.25-14.02), and POP on ultrasound (OR, 5.39; CI, 2.67-10.88). Cystocele presented the strongest association, clinically (OR, 3.45; CI, 1.98-6.03) and on ultrasound (OR, 4.04; CI, 2.46-6.64). Digitation to void was also associated with symptoms of voiding dysfunction (OR, 6.38 [3.83-10.64]) and slower maximum urine flow rate centile (18.4 vs 24.9, P = 0.017). CONCLUSIONS: Digitation to void is strongly associated with primary symptoms of prolapse and of voiding dysfunction, clinically significant POP, and pelvic organ descent on ultrasound. It is also associated with objective voiding dysfunction. The strongest associations were found with cystocele, both clinically and on imaging.

Design of a Family of Ln3 Triangles with the HAT Ligand (1,4,5,8,9,12-Hexaazatriphenylene): Single-Molecule Magnetism.

A series of trinuclear Ln3 complexes (LnIII = Yb (1), Er (2), Dy (3) and Gd (4)) were prepared from the tris-chelate bidentate ligand 1,4,5,8,9,12-hexaazatriphenylene (HAT). 1 and 2 exhibited field-induced single-molecule-magnet (SMM) behavior with estimated Ueff values of 21.30 and 13.86 K, respectively. Complex 3 behaved as a SMM even at zero field, and two different thermally assisted relaxation processes were detected with Ueff values of 29.6 K (fast relaxation process, FR) and 69 K (slow relaxation process, SR) due to the existence of two magnetically different DyIII centers in the molecule. Ab initio studies reveal that all the Dy3+ centers have almost an Ising ground state. The local anisotropy axes are not coplanar but form angles with the Dy3 plane in the range 58-78°. The magnetic interaction between the anisotropic Dy3+ ions is antiferromagnetic in nature and very weak in magnitude. However, due to the extreme feebleness of the magnetic interaction with regard to the local excitation energies, the magnetization blockade is most probably of single-ion origin. Calculations support the existence of two relaxation processes, which take place through the first excited state following an Orbach/Raman mechanism. Finally, for complex 4, the magnetocaloric effect was simulated using the magnetic parameters extracted from the fit of the magnetization and susceptibility data and demonstrated that the simulated -ΔSm values were almost coincident with those extracted from the integration of the field dependence of the magnetization. The simulated MCE value at 2 K and 5 T (20.46 J kg-1 K-1) makes complex 4 an attractive candidate for cryogenic magnetization.

Titanium dioxide food additive (E171) induces ROS formation and genotoxicity: contribution of micro and nano-sized fractions.

Since 1969, the European Union approves food-grade titanium dioxide (TiO2), also known as E171 colouring food additive. E171 is a mixture of micro-sized particles (MPs) and nano-sized particles (NPs). Previous studies have indicated adverse effects of oral exposure to E171, i.e. facilitation of colon tumour growth. This could potentially be partially mediated by the capacity to induce reactive oxygen species (ROS). The aim of the present study is to determine whether E171 exposure induces ROS formation and DNA damage in an in vitro model using human Caco-2 and HCT116 cells and to investigate the contribution of the separate MPs and NPs TiO2 fractions to these effects. After suspension of the particles in Hanks' balanced salt solution buffer and cell culture medium with either bovine serum albumin (BSA) or foetal bovine serum, characterization of the particles was performed by dynamic light scattering, ROS formation was determined by electron spin/paramagnetic resonance spectroscopy and DNA damage was determined by the comet and micronucleus assays. The results showed that E171, MPs and NPs are stable in cell culture medium with 0.05% BSA. The capacity for ROS generation in a cell-free environment was highest for E171, followed by NPs and MPs. Only MPs were capable to induce ROS formation in exposed Caco-2 cells. E171, MPs and NPs all induced single-strand DNA breaks. Chromosome damage was shown to be induced by E171, as tested with the micronucleus assay in HCT116 cells. In conclusion, E171 has the capability to induce ROS formation in a cell-free environment and E171, MPs and NPs have genotoxic potential. The capacity of E171 to induce ROS formation and DNA damage raises concerns about potential adverse effects associated with E171 (TiO2) in food.