Bis Groups Research Articles

Synthesis of 2,3-Bis(halomethyl)quinoxaline Derivatives and Evaluation of Their Antibacterial and Antifungal Activities

Quinoxaline derivatives having bis(fluoromethyl), bis(chloromethyl), or bis(iodomethyl) groups at the 2- and 3-positions, and various electron-donating/withdrawing substituents at the 6- and/or 7-positions, were synthesized. Their antibacterial and antifungal activities were evaluated by means of minimum inhibitory concentration assays. The relationships between the substituents and the antimicrobial activities of the quinoxaline derivatives indicate that the electrophilicity of the halomethyl units plays an important role in generating the antimicrobial activity.

Evaluation of the depth of sedation in an intensive care unit based on the photo motor reflex variations measured by video pupillometry

BackgroundEvaluating depth of sedation in the intensive care unit (ICU) is crucial for the management of mechanically ventilated patients but can be challenging in some situations. Because the depth of hypnosis is correlated with the decrease in photomotor reflex (PMR), we suggest using pupillometric video as an automated, noninvasive, simple, and reproducible technique to evaluate the depth of sedation in ICU patients. We compare the effectiveness of this procedure to the bispectral index (BIS).MethodsThirty-one patients requiring sedation and ventilation were included in this monocentric, observational study. The posology of hypnotics and morphinics were based on the Richmond Agitation and Sedation Scale (RASS). PMR was measured by the Neurolight® (IDMED) system and BIS value by BIS Vista® (Anandic Medical Systems). RASS, PMR, and BIS were measured three times daily in all patients. Data acquired by pupillometric video included variation in pupillary diameter (ΔPD), latency time (LT), and maximal speed of pupillary constriction (Vmax). These parameters were analyzed after having classified BIS values in three groups (<40 heavy sedation; 40 ≤ BIS ≤ 60 acceptable sedation; >60 light sedation). Exclusion criteria were neurological or ophthalmologic pathologies that could interfere with PMR.ResultsThere was a significant difference in Vmax and ΔPD between the BIS < 40 group and 40 ≤ BIS ≤ 60 groups (p < 0.0001 for each) and between the BIS < 40 and BIS > 60 groups (p < 0.0001 for each). There were no significant differences in Vmax and ΔPD between the 40 ≤ BIS ≤ 60 and BIS > 60 groups. There was no correlation between any of the BIS groups and LT.ConclusionsVmax and ΔPD seem to be relevant criteria compared with the BIS and the RASS. Pupillometric video monitoring of depth of sedation could be beneficial in ICU patients, especially for those under myorelaxant drugs, where no clinical evaluation of sedation is possible.

Proton dissociation and transfer in proton exchange membrane ionomers with multiple and distinct pendant acid groups: An ab initio study

The role of the separation of the protogenic groups and side chain chemistry on proton dissociation and the energetics of proton transfer is compared on single side chain fragments of 3M multi acid side chain (MASC) ionomers. Three ionomers were considered each containing a bis(sulfonyl imide) group and a sulfonic acid group with structural and chemical differences mediating protogenic group separation: two structural isomers with protogenic group separation determined by the location of the sulfonic acid group on an aromatic ring (side chains: O(CF2)4SO2(NH)SO2C6H4SO3H) with the sulfonic acid group located in either the meta or the ortho position) and a perfluorinated ionomer (PFIA) with protogenic groups separated by CF2 groups (side chain: O(CF2)4SO2(NH)SO2(CF2)3SO3H). Optimized (B3LYP/6-311G**) geometries on isolated fragments revealed that differences in side chain chemistry and proximity of the protogenic groups resulted in charge delocalization effects that facilitated proton dissociation at low hydration levels. Specifically, direct hydrogen bonding between the acid groups in the ortho bis acid and electron withdrawing CF2 groups in PFIA allowed for first proton dissociation at a lower hydration than the meta bis acid which lacked these effects. However, the tightly held intramolecular hydrogen bond in the ortho bis acid promoted interactions between water molecules and precluded dissociation of the second proton which required more water molecules to occur than the other MASC ionomers with more widely spread distribution of charge and hydrogen bonding. This was also realized through potential energy surface scans of proton transfer for second proton dissociation where the energetic penalty associated with proton transfer was found to be considerably higher in the ortho bis acid than the other MASC ionomers. The calculations reveal that the electron withdrawing CF2 units between protogenic groups in the PFIA not only promote proton dissociation but also do not sterically fix the protogenic group separation, as with the aromatic-based MASC ionomers, allowing for the development of a hydrogen bond network that readily adjusts for the transfer of charge at low hydration levels.

Prevention of Intraoperative Awareness with Explicit Recall in an Unselected Surgical Population

Intraoperative awareness with explicit recall occurs in approximately 0.15% of all surgical cases. Efficacy trials based on the Bispectral Index® (BIS) monitor (Covidien, Boulder, CO) and anesthetic concentrations have focused on high-risk patients, but there are no effectiveness data applicable to an unselected surgical population. We conducted a randomized controlled trial of unselected surgical patients at three hospitals of a tertiary academic medical center. Surgical cases were randomized to alerting algorithms based on either BIS values or anesthetic concentrations. The primary outcome was the incidence of definite intraoperative awareness; prespecified secondary outcomes included postanesthetic recovery variables. The study was terminated because of futility. At interim analysis the incidence of definite awareness was 0.12% (11/9,376) (95% CI: 0.07-0.21%) in the anesthetic concentration group and 0.08% (8/9,460) (95% CI: 0.04-0.16%) in the BIS group (P = 0.48). There was no significant difference between the two groups in terms of meeting criteria for recovery room discharge or incidence of nausea and vomiting. By post hoc secondary analysis, the BIS protocol was associated with a 4.7-fold reduction in definite or possible awareness events compared with a cohort receiving no intervention (P = 0.001; 95% CI: 1.7-13.1). This negative trial could not detect a difference in the incidence of definite awareness or recovery variables between monitoring protocols based on either BIS values or anesthetic concentration. By post hoc analysis, a protocol based on BIS monitoring reduced the incidence of definite or possible intraoperative awareness compared with routine care.

Control of Conformations of Piperazidine-Bridged Bis(phenolato) Groups: Syntheses and Structures of Bimetallic and Monometallic Lanthanide Amides and Their Application in the Polymerization of Lactides

A series of bimetallic and monometallic lanthanide amides stabilized by a piperazidine-bridged bis(phenolato) ligand were successfully prepared, and the factors controlling the formation of these lanthanide amides were elucidated. Reactions of Ln[N(TMS)2]3(μ-Cl)Li(THF)3 (TMS = SiMe3; THF = tetrahydrofuran) with a piperazidine-bridged bis(phenol), H2[ONNO][4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazidine], in a 2:1 molar ratio in THF at 60 °C gave the anionic bimetallic bis(phenolato) lanthanide amido complexes [ONNO]{Ln[N(TMS)2]2(μ-Cl)Li(THF)}2 [Ln = Y (1), Er (2), Eu (3), Sm (4)], whereas the same reactions conducted at room temperature gave the monometallic bis(phenolato) lanthanide amides [ONNO]LnN(TMS)2(THF) [Ln = Y (5), Sm (6)]. Complex 1 can be transformed to a neutral bimetallic bis(phenolato) yttrium amido complex, [ONNO]{Y[N(TMS)2]2}2 (7), by heating a toluene solution to 80 °C. Complex 7 can also be conveniently prepared by the reaction of the yttrium amide Y[N(TMS)2]3 with H2[ONNO] in a 2:1...

Effects of bispectral index monitoring on isoflurane consumption and recovery profiles for anesthesia in an elderly asian population

Background:Age related limited physiological reserves and associated co-morbidities in elderly patients require careful titration of inhalational anesthetic agents to minimize their side effects. The use of Bispectral index (BIS) monitoring may be helpful in this regard. The objectives of this study were to evaluate the effect of BIS monitoring on Isoflurane consumption during maintenance and recovery profile at the end of anesthesia. This Quasi experimental study was conducted for a 1 year period at the main operating units of a tertiary care hospital.Materials and Methods:Total 60 patients of age 60 years and above were enrolled in either standard practice (SP) or (BIS) group. In the SP group, the anesthesia depth was maintained as a routine clinical practice, while in BIS group it was maintained by monitoring the BIS score between 45 and 55. Standard anesthesia care was provided to all of the patients. Data including demographics, isoflurane consumption, hemodynamic variables and recovery profiles were recorded in both groups.Results:The mean isoflurane consumption was lower (P = 0.001) in the BIS group. The time to eye opening, extubation and ready to shift was shorter (P = 0.0001) in BIS group. The patients in BIS group had higher Post anesthesia recovery score (P = 0.0001) than the SP group.Conclusion:The use of BIS in an elderly Asian population resulted in 40% reduction of isoflurane usage. The patients having BIS monitoring awoke earlier and had better recovery profiles at the end of anesthesia.

Osteogenesis and osteoclast inhibition in rheumatoid arthritis patients treated with bisphosphonates alone or in combination with pitavastatin over an 18-month follow-up after more than 4 years of treatment with bisphosphonates

IntroductionTo investigate the effects of bisphosphonates (Bis) (etidronate, alendronate, and risedronate), alone and in combination with statin, on the BMD (bone mineral density) and bone metabolism of rheumatoid arthritis (RA) patients.MethodsSeventy-seven RA patients who had been receiving prednisolone (PSL) and Bis for over 4 years were divided into two groups: Bis and Bis + statin (n = 42 and 35; average age, 66.4 and 65.3 years; average disease duration, 24.9 and 20.8 years; average PSL dose, 2.4 and 2.7 mg, respectively). Serum levels of NTX (N-terminal telopeptide of type I collagen), TRACP-5b (tartrate-resistant acid phosphate-5b), PICP (C-terminal propeptide of type I procollagen), and RANKL (receptor activator of NF-κB ligand) were measured over an 18-month period of treatment and follow-up. The BMD levels of the two groups at the radius, lumbar spine, and femoral neck were compared using DXA (dual-energy x-ray absorptiometry).ResultsA significant increase was only observed in the BMD of the lumbar spine at 18-months, but the BMDs of the radius and femoral neck decreased during the follow-up period in the Bis group. Meanwhile, a significant increase was observed in the BMD of the lumbar spine in the Bis + statin group during administration and the BMDs of the radius and femoral neck stayed at baseline. Among the markers of bone metabolism, serum NTX was up-regulated after 6 months in the Bis + statin group. Serum TRACP-5b was significantly increased during the follow-up period in the Bis + statin group, but only at 18 months in the Bis group. Serum PICP recovered to base line in the Bis + statin group, whereas that in the Bis group did not observably recover during the post-administration follow-up, but rather decreased.ConclusionOur findings suggest that both bone resorption and bone formation were inhibited by long-term administration of Bis alone, whereas combination therapy with Bis + statin may be associated with a less marked inhibition of bone metabolism. Cardiovascular disease is highly prevalent in RA patients and some patients are prescribed statins and bisphosphonate. Bis + statin may confer more benefit to the bone metabolism of these patients compared to Bis alone.

Bispectral index monitoring as an adjunct to nurse-administered combined sedation during endoscopic retrograde cholangiopancreatography

To determine whether bispectral index (BIS) monitoring is useful for propofol administration for deep sedation during endoscopic retrograde cholangiopancreatography (ERCP). Fifty-nine consecutive patients with a variety of reasons for ERCP who underwent the procedure at least twice between 1 July 2010 and 30 November 2010. This was a randomized cross-over study, in which each patient underwent ERCP twice, once with BIS monitoring and once with control monitoring. Whether BIS monitoring was done during the first or second ERCP procedure was random. Patients were intermittently administered a mixed regimen including midazolam, pethidine, and propofol by trained nurses. The nurse used a routine practice to monitor sedation using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale or the BIS monitoring. The total amount of midazolam and propofol used and serious side effects were compared between the BIS and control groups. The mean total propofol dose administered was 53.1 ± 32.2 mg in the BIS group and 54.9 ± 30.8 mg in the control group (P = 0.673). The individual propofol dose received per minute during the ERCP procedure was 2.90 ± 1.83 mg/min in the BIS group and 3.44 ± 2.04 mg in the control group (P = 0.103). The median value of the MOAA/S score during the maintenance phase of sedation was comparable for the two groups. The mean BIS values throughout the procedure (from insertion to removal of the endoscope) were 76.5 ± 8.7 for all 59 patients in using the BIS monitor. No significant differences in the frequency of < 80% oxygen saturation, hypotension (< 80 mmHg), or bradycardia (< 50 beats/min) were observed between the two study groups. Four cases of poor cooperation occurred, in which the procedure should be stopped to add the propofol dose. After adding the propofol, the procedure could be conducted successfully (one case in the BIS group, three cases in the control group). The endoscopist rated patient sedation as excellent for all patients in both groups. All patients in both groups rated their level of satisfaction as high (no discomfort). During the post-procedural follow-up in the recovery area, no cases of clinically significant hypoxic episodes were recorded in either group. No other postoperative side effects related to sedation were observed in either group. BIS monitoring trend to slighlty reduce the mean propofol dose. Nurse-administered propofol sedation under the supervision of a gastroenterologist may be considered an alternative under anesthesiologist.

Encapsulated oligothiophenes having electron-affinity characteristics

Oligothiophenes composed of dioxocyclopenta[c]thiophene bearing bulky bis(di-t-butylphenyl) groups were designed and synthesized to develop molecular wires having electron-transporting characteristics. Their effective conjugation, electron affinity, and encapsulation effects were investigated by photophysical and electrochemical measurements.

Reduced cortical bone compositional heterogeneity with bisphosphonate treatment in postmenopausal women with intertrochanteric and subtrochanteric fractures.

Reduction of bone turnover with bisphosphonate treatment alters bone mineral and matrix properties. Our objective was to investigate the effect of bisphosphonate treatment on bone tissue properties near fragility fracture sites in the proximal femur in postmenopausal women with osteoporosis. The mineral and collagen properties of corticocancellous biopsies from the proximal femur were compared in bisphosphonate-naive (-BIS, n = 20) and bisphosphonate-treated (+BIS, n = 20, duration 7 ± 5 years) patients with intertrochanteric (IT) and subtrochanteric (ST) fractures using Fourier transform infrared imaging (FTIRI). The mean values of the FTIRI parameter distributions were similar across groups, but the widths of the parameter distributions tended to be reduced in the +BIS group relative to the -BIS group. Specifically, the widths of the cortical collagen maturity and crystallinity were reduced in the +BIS group relative to those of the -BIS group by 28% (+BIS 0.45 ± 0.18 versus -BIS 0.63 ± 0.28, p = 0.03) and 17% (+BIS 0.087 ± 0.012 versus -BIS 0.104 ± 0.036, p = 0.05), respectively. When the tissue properties were examined as a function of fracture morphology within the +BIS group, the FTIR parameters were generally similar regardless of fracture morphology. However, the cortical mineral:matrix ratio was 8% greater in tissue from patients with atypical ST fractures (n = 6) than that of patients with typical (IT or spiral ST) fractures (n = 14) (Atypical 5.6 ± 0.3 versus Typical 5.2 ± 0.5, p = 0.03). Thus, although the mean values of the FTIR properties were similar in both groups, the tissue in bisphosphonate-treated patients had a more uniform composition than that of bisphosphonate-naive patients. The observed reductions in mineral and matrix heterogeneity may diminish tissue-level toughening mechanisms.

Preparation of Polymeric Metal Complex Containing Azo Dye Rotaxane

In this article, we synthesized an azo dye rotaxane containing bis(8-hydroxyquinoline) group and its polymeric metal complex with zinc. The azo dye rotaxane exhibits high pH sensitivity, solvatochromism and zinc (II) ion sensings in aqueous solution. These behaviors came from the tautomeric equilibrium between azo-hydrazone tautomers and the formation of extended conjugation. The structure of polymeric zinc complexed dye rotaxane was confirmed with NMR and FT-IR measurements. The existence of CD rings, provided by dye rotaxane formation, was found to be very beneficial in improving aqueous solubility of polymeric metal complex.

Synthesis and self-organization of amphiphilic poly(N-vinylpyrrolidone-2,2,3,3-tetrafluoropropyl methacrylate) diblock copolymers in solution and bulk

It is shown that the amphiphilic diblock copolymers poly(N-vinylpyrrolidone-2,2,3,3-tetrafluoropropyl methacrylate) can be prepared through the reaction of chain transfer to bis(pentafluorophenyl)germane during the polymerization of N-vinylpyrrolidone and the subsequent postpolymerization of isolated functional polymers in 2,2,3,3-tetrafluoropropyl methacrylate. The dilute-solution behavior and self-organizing ability of functional polymers based on poly(N-vinylpyrrolidone) containing end bis(pentafluorophenyl) groups and of amphiphilic diblock copolymers formed on their basis are studied via the methods of static and dynamic light scattering and viscometry. Surface properties at the interface of the films are estimated through the wetting technique.

Emotional reactivity and force control: The influence of behavioral inhibition

Individual difference measures have been shown to alter emotional arousal and emotional arousal alters force production during force control tasks. In the current study we examined whether individual differences in behavioral inhibition influence force control during emotional image viewing. Subjects who scored high and low in behavioral inhibition (BIS) produced force with visual feedback for 5s. Feedback was then removed and replaced by a mutilation, attack, erotica, or neutral image for 6s. The magnitude and direction of error in force production during image presentation was compared between groups and across image type. The high BIS group displayed a relative increase in force production during exposure to attack and mutilation images compared to the low BIS group. Bias scores (i.e., comparison of unpleasant image to neutral or pleasant image) further confirmed these findings by demonstrating a relative increase in force for the high BIS group during attack and mutilation images as compared to erotica images, whereas the low BIS group displayed the reverse effect. Together these findings extend the premise of action readiness to demonstrate that dispositional differences in behavioral inhibition interact with emotional state to alter force production.

Efficacy of Bispectral Index Monitoring for Midazolam and Meperidine Induced Sedation during Endoscopic Submucosal Dissection: A Prospective, Randomized Controlled Study

Background/AimsPropofol induced sedation with bispectral index (BIS) monitoring has been reported to lead to higher satisfaction in patients and endoscopists during endoscopic submucosal dissection (ESD) procedures. There are no data, however, regarding the efficacy of midazolam and meperidine (M/M) induced sedation with BIS monitoring during ESD. The purpose of this study was to evaluate whether M/M induced sedation with BIS monitoring could improve satisfaction and reduce the dose of M/M required during ESD.MethodsBetween September 2009 and January 2010, 56 patients were prospectively enrolled and randomly assigned to a BIS group (n=28) and a non-BIS group (n=28). Patient and endoscopist satisfaction scores were assessed using the visual analog scale (0 to 100) following the ESD.ResultsThe mean satisfaction scores did not significantly differ between the BIS and non-BIS groups (92.3±16.3 vs 93.3±15.5, p=0.53) or endoscopists (83.1±15.4 vs 80.0±16.7, p=0.52). Although the mean meperidine dose did not differ (62.5±27.6 vs 51.0±17.3, p=0.18) between the two groups, the mean dose of midazolam in the non-BIS group was lower than in the BIS group (6.8±2.0 vs 5.4±2.1, p=0.01).ConclusionsBIS monitoring during ESD did not increase the satisfaction of endoscopists or patients and did not lead to an M/M dose reduction. These results demonstrate that BIS monitoring provides no additional benefit to M/M induced sedation during ESD.

Deproteinized dentin: A favorable substrate to self‐bonding resin cements?

The adhesive performance on deproteinized dentin of different self-adhesive resin cements was evaluated through microtensile bond strength (μTBS) analysis and scanning electron microscopy (SEM). Occlusal dentin of human molars were distributed into different groups, according to the categories: adhesive cementation with two-step bonding systems-control Groups (Adper Single Bond 2 + RelyX ARC/3M ESPE; One Step Plus + Duolink/Bisco; Excite + Variolink I/Ivoclar Vivadent) and self-adhesive cementation-experimental groups (Rely X Unicem/3M ESPE; Biscem/Bisco; MultiLink Sprint/Ivoclar Vivadent). Each group was subdivided according to the dentin approach to: α, maintenance of collagen fibers and β, deproteinization. The mean values were obtained, and submitted to ANOVA and Tukey test. Statistical differences were obtained to the RelyX Unicem groups (α = 13.59 MPa; β = 30.19 MPa). All the BIS Group specimens failed before the mechanical tests. Dentinal deproteinization provided an improved bond performance for the self-adhesive cement Rely X Unicem, and had no negative effect on the other cementing systems studied.

Modification of Nanocrystalline TiO2 with Phosphonate‐ and Bis(phosphonate)‐Bearing Macrocyclic Complexes: Sorption and Stability Studies

AbstractThe first systematic study of chemical adsorption/desorption of phosphonic acid and geminal bis(phosphonic acid) on/from the surface of anatase nanoparticles is reported. Stable TiO2 colloidal nanodispersions were used in the study. The colloidal stability is preserved upon nanoparticle modification. A macrocyclic lanthanide(III) complex, attached through a phosphonic/bis(phosphonic) group to the TiO2 surface allowed precise quantification of sorption parameters by means of inductively coupled plasma atomic emission spectroscopy (ICP‐AES). Results show different behavior of phosphonate and bis(phosphonate) groups. For phosphonate, a monomolecular layer formation was observed, and the desorption rate depends on the sorption conditions. It is probably caused by different phosphonate binding modes on the surface. Excess amounts of phosphate in the washing media accelerates the desorption rate of the phosphonate. The bis(phosphonate) is adsorbed on the surface in large quantities forming multilayers that resist desorption even in the presence of phosphate ions and, thus, the bis(phosphonate) moiety is a suitable group for anchoring other molecules on the TiO2 particle surface.

Novel bipolar carbazole-containing polyphenylquinoxalines: Synthesis and photophysical properties

39 In recent time, conjugated electroluminescent polymers have attracted much attention from both the scientific and practical viewpoint due to their application as electroactive materials for light emitting diodes [1–3]. It has been found that intense electroluminescence (EL) in polymer requires high electron–hole conduction of a medium related to the mobility of charge carriers and a balance of injection of carriers of both signs from opposite electrodes into the emission poly meric layer. However, the majority of EL polymers are hole transport materials, which leads to the imbalance of charge injection and a poor quantum yield. A search for new efficient electron transport polymers is required to improve performance of electrooptical devices, which is achieved in particu lar by introducing into macromolecules electron withdrawing fragments: triazole [4], oxadiazole [5], quinoline [6], and quinoxaline [7]. The latter is the least studied. One can suppose that polyphenylqui noxalines (PPQs) will show higher electron with drawing properties owing to the presence of four electron withdrawing heteroatoms. A promising approach to improve the quantum yield is provided not only by the balance of the electron and hole conduction but also by design of multilayer bipolar (donor–acceptor) emission polymers. In this work, to solve this problem, we have used a combination of carbazole and quinoxaline contain ing fragments in PPQ macromolecules. Such mole cules are known to show high thermal and oxidative stability, good mechanical and film forming proper ties, and solubility in organic solvents [8]. In continu ation of our studies [9–11], we have prepared and studied novel bipolar carbazole containing PPQs as efficient electron–hole and transport materials; for this purpose, we obtained previously unknown bis(α diketone) III. A common method for the synthesis of bis(α diketone)s is the oxidation of bis(phenylethy nyl)arenes obtainable from aromatic dibromides and arylacetylene. We have proposed a new method for the synthesis of bis(α diketone) III by the nucleophilic substitution reaction of fluorodiketone II, already containing bis(α dicarbonyl) groups, with dicarbazole I accord ing to Scheme 1. CHEMISTRY

The effect of cerebral monitoring on recovery after sevoflurane anesthesia in ambulatory setting in children: A comparison among bispectral index, A-line autoregressive index, and standard practice

Background The bispectral index (BIS) and A-line autoregressive index (AAI) are electroencephalogram-derived monitoring indices of anesthesia. This study evaluated the efficacy of BIS- and AAI-guided sevoflurane anesthesia in children receiving ambulatory urologic surgeries. Methods One hundred sixty children (aged 3–12 years) undergoing ambulatory urologic surgery were randomized to receive sevoflurane anesthesia controlled either solely by clinical parameters (standard practice group), BIS-guided group within the BIS range of 40–60 (BIS group), or AAI-guided group within the AAI range of 15–30 (AAI group). The primary outcome was the recovery time, and the secondary outcome was the quality of recovery, including the incidence of emergency delirium measured by Pediatric Anesthesia Emergence Delirium score, incidence of postoperative nausea and vomiting, and parental satisfaction. Results Compared with the standard practice group, patients with BIS or AAI monitoring had shortened recovery time and consumed less sevoflurane. There were no significant differences in the incidences of emergence delirium, postoperative nausea and vomiting, or parental satisfaction among the three groups. Conclusion BIS- and AAI- guided titration sevoflurane anesthesia could result in shortened recovery and reduced sevoflurane concentration and consumption without affecting the quality of recovery in children receiving ambulatory urologic surgery. The beneficial effects of AAI- and BIS-guided anesthesia in pediatric ambulatory surgeries are similar.

Bimetallic aluminum alkyl complexes as highly active initiators for the polymerization of ε-caprolactone

Two dinuclear aluminum alkyl complexes supported by a piperazidine-bridged bis(phenolato) group were prepared, and both complexes exhibited extremely high activity for the ring-opening polymerization of ε-caprolactone. In the presence of benzyl alcohol (BnOH), the polymerization accelerated dramatically.

Influence of the anions on the structure and magnetic properties of a series of bis(μ-diphenoxo)-bridged linear trinuclear copper(II) complexes: an experimental and theoretical study

The reaction of H(2)L (N,N'-dimethyl-N,N'-bis(2-hydroxy-3-methoxy-5-methylbenzyl)-ethylenediamine) with different copper salts, in methanol and using a H(2)L/Cu = 2 : 3 molar ratio, led to four new bis(μ-diphenoxo)-bridged Cu(3) complexes of general formula [{Cu(S)(μ-L)}(2)Cu(H(2)O)(2n)]X(2) (S = CH(3)OH, n = 1 and X = BF(4)(-) for (1) or ClO(4)(-) for (2); S = Br(3)(-) anion and n = 1 without any X species for (3); S = H(2)O, n = 0 and X = NO(3)(-) for (4)). The use in the same reaction conditions of 4,4'-bipyridine (4,4'-bipy) as connector led to the chain complex [{Cu(μ-4,4'-bipy)(0.5)(μ-L)}(2)Cu(H(2)O)(2n)](ClO(4))(2)·17H(2)O (5). The structure of the centrosymmetric trinuclear unit in (1)-(5) consists of two [Cu(L)] fragments connected through two phenoxo bridging groups to the central copper(II) ion giving rise to a linear arrangement of the copper(II) ions, where the ligand acts in a compartmental form wrapping the metal centre with a N(2)O(2) tetradentate bridging mode. The coordination polyhedron of the symmetrically related external copper atoms exhibits a geometry very close to square-pyramidal, whereas the central copper(II) atom displays either a tetragonally elongated octahedral geometry or a square-planar geometry. Owing to the steric hindrance promoted by the methoxy groups at the phenyl rings, the whole Cu(3) structure is not planar but folded along the line connecting the phenoxo bridging oxygen atoms of the same ligand. Temperature dependence of the magnetic susceptibility of complexes (1)-(5) was measured, showing strong antiferromagnetic interactions between the central and external atoms through the bis(μ-phenoxo) groups. DFT calculations were also performed (a) to support the experimental values of the coupling constant (J(1)) between the nearest-neighbouring copper atoms, (b) to determine the magnitude of the interactions between next-nearest copper(II) atoms (J(2)) and (c) to study magneto-structural correlations for this kind of bis(μ-diphenoxo) trinuclear copper(II) complex.