Search

Experiences of contact between adopted persons and birth family members have implications for psychological adjustment of adopted persons. The current study utilizes four contact trajectory groups, spanning from middle childhood to young adulthood and encompassing three aspects of birth family contact in predicting psychological adjustment and adoption-related outcomes in adopted young adults. Data come from a longitudinal study of adoptive families in which adopted persons were domestically adopted in infancy by same-race parents in the United States. Adopted young adults in the group characterized by sustained high levels of contact and satisfaction with contact over time (“Extended Contact”) displayed lower levels of psychological distress and higher levels of psychological well-being than adopted persons in the group characterized by contact that increased over time but remained limited (“Limited Contact”). Generally, adopted persons within the group characterized by consistent lack of contact (“No Contact”) and the group characterized by contact that was initially present but ended (“Stopped Contact”) did not differ in distress and well-being from those in the “Extended Contact” group. No group differences were found on adoption dynamics and identity; however, young adults in the “Extended Contact” group generally reported more positive relationships with their birth mothers than those in the other groups. Findings are discussed in the context of heterogeneity in contact experiences and implications for policy and practice.

OBJECTIVE: Adoptive parents’ acknowledgement of differences is defined as the propensity to think that adoptive and nonadoptive families are different in important ways. Few studies have examined the implications of such cognitions for the parent-child bond. DESIGN: Structural equation modeling was utilized to examine the relation between adoptive parents’ acknowledgement of differences and adolescents’ later attachment to their parents in a sample of within-race domestic infant adoptions. Data from 189 adoptive families were drawn from two waves (middle childhood, adolescence) of the Minnesota/Texas Adoption Research Project, a longitudinal study of openness in adoption. RESULTS: Levels of acknowledgement of differences displayed by the adoptive mother and adoptive father during middle childhood positively predicted adopted adolescents’ feelings of attachment towards the respective parent 8 years later. This relation depended on adopted adolescents’ attitude toward adoption-related communication during middle childhood as well as the adoptive family’s level of openness during middle childhood. CONCLUSIONS: Acknowledgement of differences in adoptive families has positive implications for the parent-child bond.

The military strength of German National Socialism was based on the collaboration of large corporations with the Nazi state. Business provided capital, loans, taxes, managerial expertise and production for war industries. I elaborate four ideal-typical modes of business collaboration. Each mode is illustrated by a case study of a German corporation that acquires an Austrian firm: Krupp (traditional mode); the Reichswerke state conglomerate (coercive); Deutsche Bank (managerial nationalist); and IG Farben (competitive investment mode). The first and the last modes occurred when the state was highly dependent on large businesses for the economic requisites of war. The acquired firms in the Austrian semiperiphery contributed to Nazi war mobilization, as they exploited labor and resources from the peripheral regions of southeastern Europe. Patterns of the state's resource dependency on business led to bargaining interactions between state and business, over time shaping the mix between state and private ownership of war industry.La force militaire du socialisme national allemand reposait sur la collaboration commerciale avec l’État nazi. Les grandes entreprises fournissaient le capital, les prêts, les impôts, ainsi que l'expertise en gestion. J’élabore quatre modes types idéaux de collaboration commerciale. Chacun d'entre eux est illustré par une étude de cas d'une firme autrichienne acquise par une entreprise allemande : Krupp (mode traditionnel), le conglomérat d'État Reichswerke (coercitif), la Deutsche Bank (nationaliste directoriale) et IG Farben (mode de placement concurrentiel). Les premier et dernier modes ont vu le jour lorsque l’État dépendait fortement des grandes entreprises pour ses conditions économiques préalables de guerre. Les firmes acquises dans la semi-périphérie autrichienne ont contribué à la machine de guerre nazie, car elles permettaient d'accroître le recours aux ressources et à la main-d’œuvre des régions périphériques de l'Europe du Sud-Est. Les structures de la dépendance de l’État aux ressources commerciales ont donné lieu à des interactions de négociation entre l’État et les entreprises qui, avec le temps, ont façonné la répartition entre la propriété publique et privée de l'industrie.

Emotional distance regulation theory (Broderick, 1993; Grotevant, 2009) guided this examination of the changes in family structure and process in adoptive kinship networks experiencing different arrangements of contact between birth and adoptive family members. Group-based trajectory modeling was used to reveal four trajectories of postadoption contact experienced between adoptive and birth family members in adoptive kinship networks of same-race, domestic infant adoptions. Data were drawn from the Minnesota Texas Adoption Research Project, a study of 190 adoptive families and 169 birth mothers followed across four longitudinal waves (middle childhood, adolescence, emerging adulthood, young adulthood). Three aspects of the birth family adoptive family relationship measured at four times were used to create the groups: frequency of contact between the adopted person and birth mother, satisfaction of the adopted person with the openness arrangements, and number of adoptive and birth family members involved in the contact. Four trajectory groups emerged: no contact (41.6% of sample), stopped contact (13.7%), limited contact (26.3%), and extended contact (18.4%). Group membership was validated by coders who matched interview transcripts with group descriptions at levels significantly above chance. Knowledge of trajectories will assist professionals providing postadoption services. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Adopted persons face special challenges in the development of identity, as aspects of their histories may be unknown, making it difficult to construct a coherent narrative linking past, present, and future. Extensive literature on adjustment outcomes for adopted persons indicates an elevated risk for adjustment problems. In this study, a low-risk sample of adopted youth is involved to examine, longitudinally, connections between adoptive identity and adjustment. Participants included 145 adopted youth who participated in Waves 2 (W2: adolescence: mean age = 15.7) and 3 (W3: emerging adulthood: mean age = 25.0) of a longitudinal study with a nationwide sample. Children were placed with same-race adoptive families (over 95% White) as infants through domestic private adoption agencies in the U.S. Internalizing and externalizing behaviors were assessed by the Youth Self Report (W2) and the Adult Self Report (W3). Adoptive identity was assessed by ratings of 6 dimensions coded from interviews which, using cluster analysis, revealed 4 adoptive identity subgroups: unexamined, limited, unsettled, and integrated. Factorial ANCOVA examined mean differences in W3 internalizing problems across identity clusters while controlling for W2 internalizing. The main effect for adoptive identity cluster was significant: F(3, 840.72) = 3.724, p = .011. Adopted adolescents in the unsettled group had significantly higher levels of internalizing problems in emerging adulthood than persons in the unexamined and limited categories. A similar ANCOVA for W3 externalizing behavior was not significant. Identity profiles high in negative affect may be at particular risk of increased levels of internalizing problems. (PsycINFO Database Record

The flicker noise of source follower transistors is the dominant noise source in image sensors. This paper reports a systematic study of the shallow trench isolation effect in transistors with different sizes under high temperature conditions that correspond to the quantity of empty defect sites. The effects of shallow trench isolation sidewall defects on flicker noise characteristics are investigated. In addition, the low-frequency noise and subthreshold swing degrade simultaneously in accordance to the device gate width scaling. Both serious subthreshold leakage and considerable noise can be attributed to the high trap density near the STI edge. Consequently, we propose a coincidental relationship between the noise level and the subthreshold characteristic; its trend is identical to the experiments and simulation results.

The primary aim of this study is to show the non-inferiority of 15mg intraoperative dose of ketorolac as compared to the standard 30mg ketorolac by looking at the visual analog scale pain (VAS) scores 4h after an adult spine surgery.The study design is a prospective randomized non-inferiority clinical trial looking at non-inferiority of intraoperative 15mg ketorolac from the standard 30mg dose.Quaternary care center.50 adult (18-65years of age) undergoing lumbar decompression spine surgery.Group A received a single intraoperative dose of 15mg ketorolac at the end of surgery and group B received single intraoperative dose of 30mg ketorolac.The primary outcome was the visual analog scale (VAS) pain scores 4h after an adult spine surgery. Secondary measures were morphine usage in the first 8 and 24h postoperatively, numeric rating scores (NRS) up to 24h, sedation, nausea, vomiting, respiratory depression, pruritus and bleeding complications.Intention to treat analysis showed a mean increase in 4h VAS pain score of 7.9mm (95% CI: -4.5mm to 20.4mm) in patients administered 15mg ketorolac. This difference was neither statistically (P=0.207) nor clinically significant (18mm on VAS scale). A similar increase in the 15mg group was noted through a per protocol analysis, 6.9mm (95% CI: -6.6mm to 20.5mm, P=0.307) greater in the 15mg group. Non-inferiority of 15mg was not confirmed. No significant difference was found in secondary endpoints.Ketorolac 30mg intravenous was not superior to 15mg intravenous for post-operative pain management after spine surgery. However, 15mg failed to meet the pre-specified criteria for non-inferiority to the 30mg dose.

We review the benefits of using 29 Si and 1 H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy for probing the local structures of both bulk and surface portions of mesoporous bioactive glasses (MBGs) of the CaO–SiO 2 −(P 2 O 5 ) system. These mesoporous materials exhibit an ordered pore arrangement, and are promising candidates for improved bone and tooth implants. We discuss experimental MAS NMR results from three MBGs displaying different Ca, Si and P contents: the 29 Si NMR spectra were recorded either directly by employing radio-frequency pulses to 29 Si, or by magnetization transfers from neighbouring protons using cross polarization, thereby providing quantitative information about the silicate speciation present in the pore wall and at the MBG surface, respectively. The surface modifications were monitored for the three MBGs during their immersion in a simulated body fluid (SBF) for intervals between 30 min and one week. The results were formulated as a reaction sequence describing the interconversions between the distinct silicate species. We generally observed a depletion of Ca 2+ ions at the MBG surface, and a minor condensation of the silicate-surface network over one week of SBF soaking.

An array of magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy experiments is applied to explore the surface reactions of a mesoporous bioactive glass (MBG) of composition Ca0.10Si0.85P0.04O1.90 when subjected to a simulated body fluid (SBF) for variable intervals. Powder X-ray diffraction and 31P NMR techniques are employed to quantitatively monitor the formation of an initially amorphous calcium phosphate surface layer and its subsequent crystallization into hydroxycarbonate apatite (HCA). Prior to the onset of HCA formation, 1H → 29Si cross-polarization (CP) NMR evidence dissolution of calcium ions; a slightly increased connectivity of the speciation of silicate ions is observed at the MBG surface over 1 week of SBF exposure. The incorporation of carbonate and sodium ions into the bioactive orthophosphate surface layer is explored by 1H → 13C CPMAS and 23Na NMR, respectively. We discuss similarities and distinctions in composition−bioactivity relationships established for traditio...

A comprehensive multinuclear solid-state magnetic resonance study of In(I)- and Ag(I)bis(imino)pyridine systems is presented. Solid-state 115 In and 109 Ag NMR experiments are utilized to probe the metal cation centers, which are very weakly coordinated to the bis(imino)pyridine ligands. Along with solid-state 15 N NMR data, it is shown that the metal cations interact with the N atoms within the "pocket" of the ligands. Reasonable agreement between the measured and calculated 115 InNMR(electricfieldgradientandchemicalshift)tensorsisobtained. The relationship between the electric field gradient tensor and the arrangement of the metal center relative to the encumbered ligand is explored. The insights obtained aid in understanding the structure and bonding in these kinetically stable complexes of unstable metal ions and may assist in the rational design of other encumbered ligands for capturing reactive species. SECTION Kinetics, Spectroscopy

Using average Hamiltonian (AH) theory, we analyze recently introduced homonuclear dipolar recoupling pulse sequences for exciting central-transition double-quantum coherences (2QC) between half-integer spin quadrupolar nuclei undergoing magic-angle-spinning. Several previously observed differences among the recoupling schemes concerning their compensation to resonance offsets and radio-frequency (rf) inhomogeneity may qualitatively be rationalized by an AH analysis up to third perturbation order, despite its omission of first-order quadrupolar interactions. General aspects of the engineering of 2Q-recoupling pulse sequences applicable to half-integer spins are discussed, emphasizing the improvements offered from a diversity of supercycles providing enhanced suppression of undesirable AH cross-terms between resonance offsets and rf amplitude errors.

Multinuclear solid-state NMR spectroscopy and powder X-ray diffraction (XRD) experiments are applied to comprehensively characterize a series of pure and lanthanide-doped LaF3 nanoparticles (NPs) that are capped with di-n-octadectyldithiophosphate ligands (Ln3+ = diamagnetic Y3+ and Sc3+ and paramagnetic Yb3+ ions), as well as correlated bulk microcrystalline materials (LaF3, YF3, and ScF3). Solid-state 139La and 19F NMR spectroscopy of bulk LaF3 and the LaF3 NPs reveal that the inorganic core of the NP retains the LaF3 structure at the molecular level; however, inhomogeneous broadening of the NMR powder patterns arises from distributions of 139La and 19F NMR interactions, confirming a gradual change in the La and F site environments from the NP core to the surface. 139La and 19F NMR experiments also indicate that low levels (5 and 10 mol %) of Ln3+ doping do not significantly change the LaF3 structure in the NP core. Similar doping levels of paramagnetic Yb3+ ions severely broaden 19F resonances, but only marginally effect 139La powder patterns, suggesting that the dopant ions are uniformly distributed throughout the NP core and occupy vacant La sites. Measurements of 139La T1 and T2 relaxation constants are seen to vary between the bulk material and NPs and between samples with diamagnetic and paramagnetic dopants. 45Sc NMR experiments confirm that the dopants are integrated into the La sites of the LaF3 core. Solid-state 1H and 31P magic-angle spinning (MAS) NMR spectra aid in probing the nature of the capping ligands and their interactions at the NP surface. 31P cross-polarization (CP)/MAS NMR experiments identify not only the dithiophosphate head groups but also thiophosphate and phosphate species which may form during NP synthesis. Finally, 19F-31P CP/MAS and 1H MAS experiments confirm that ligands are coordinated to the NP surface.

In this chapter, the detection principles and fabrication methods of optofluidic devices are discussed. Optofluidic devices enable synergistic operations of optics and microfluidics over a unified platform, resulting in precise and quantitative examination of biological samples such as cells, proteins, and nucleic acids. To address the emerging needs for point-of-care in vitro diagnostics, a variety of optofluidic devices have been developed to isolate, detect, or image cells and molecules. Lab-on-a-chip devices based on optofluidic technologies are adept for personalized healthcare, holding promise for reduced cost and improved efficacy. Very recently, incorporation of portable optofluidic devices into mobile devices such as smart phones has presented particularly promising opportunities for telemedicine and point-of-care clinics for low- and medium-income countries.

Mesoporous titanium oxide synthesized using a dodecylamine template was treated with 0.2, 0.6, and 1.0 equiv of Li- or Na-naphthalene. The composite materials were characterized by nitrogen adsorption, powder X-ray diffraction, X-ray photoelectron spectroscopy, elemental analysis, thermogravimetric analysis, and solid-state 23Na and 7Li NMR spectroscopy. In all cases the wormhole mesoporosity was retained as evidenced by BET surface areas from 400 to 700 m(2)/g, Horvath-Kawazoe pore sizes in the 20 Angstroms range, and a lack of hysteresis in the nitrogen adsorption isotherms. Variable-temperature conductivity studies show that the Li-reduced materials are semiconductors, with conductivity values 3 orders of magnitude higher than those of the Na-reduced materials. Electrochemical measurements demonstrate reversible intercalation/deintercalation of Li+ ions into pristine mesoporous Ti oxides with good cycling capacity. Solid-state 23Na NMR reveals two distinct Na environments: one corresponding to sodium ions in the mesoporous channels and the other corresponding to sodium ions intercalated into the metal framework. 23Na NMR spectra also indicate that the relative population of the framework site increases with increased reduction levels. Solid-state 7Li NMR spectra display a single broad resonance, which increases in breadth with increased reduction levels, though individual resonances inferring the presence of channel and framework Li species are not resolved. Comparisons of the lithium chemical shifts with published values suggests an "anatase-like structure" with no long-range order in the least-reduced samples but a "lithium titanate-like structure" with no long-range order in the higher reduced materials.

With the increasing computational speed of PC processors, lowering hardware prices, and the increasing accessibility of open source software, PC clusters have become an attractive option for exploring budgetary high performance computation on high resolution environment modelling. This paper documents the implementation and operation of a Beowulf-class PC cluster called DOBSON built in the Atmospheric Modelling Laboratory at National Central University in Taiwan. Based on our current configuration, the DOBSON cluster achieves a 4.4-8.7 times of speedup with 8 and 14 CPUs, respectively, compared with a 1 CPU in simulations of the Antarctic vortex. The potential impacts of running a high resolution environmental modelling system on the DOBSON cluster were examined by case simulations of Typhoon Haiyan with a nested five-domain configuration. These results show that the complicated topographical flow in the Taipei Basin can only be properly resolved when model grid resolutions less than 9km were used.

Solid-state 93Nb and 13C NMR experiments, in combination with theoretical calculations of NMR tensors, and single-crystal and powder X-ray diffraction experiments, are applied for the comprehensive characterization of structure and dynamics in a series of organometallic niobium complexes. Half-sandwich niobium metallocenes of the forms Cp'Nb(I)(CO)4 and CpNb(V)Cl4 are investigated, where Cp = C5H5- and Cp' = C5H4R- with R = COMe, CO2Me, CO2Et, and COCH2Ph. Anisotropic quadrupolar and chemical shielding (CS) parameters are extracted from 93Nb MAS and static NMR spectra for seven different complexes. It is demonstrated that 93Nb NMR parameters are sensitive to changes in temperature and Cp' ring substitution in the Cp'Nb(I)(CO)4 complexes. There are dramatic differences in the 93Nb quadrupolar coupling constants (C(Q)) between the Nb(I) and Nb(V) complexes, with C(Q) between 1.0 and 12.0 MHz for Cp'Nb(CO)4 and C(Q) = 54.5 MHz for CpNbCl4. The quadrupolar Carr-Purcell Meiboom-Gill (QCPMG) pulse sequence is applied to rapidly acquire, in a piecewise fashion, a high signal-to-noise ultra-wide-line 93Nb NMR spectrum of CpNbCl4, which has a breadth of ca. 400 kHz. Solid-state 93Nb and 13C NMR spectra and powder XRD data are used to identify a new metallocene adduct coordinated at the axial position of the metal site by a THF molecule: CpNb(V)Cl4.THF. 13C MAS and CP/MAS NMR experiments are used to assess the purity of samples, as well as for measuring carbon CS tensors and the rare instance of one-bond 93Nb, 13C J-coupling, 1J(93Nb,13C). Theoretically calculated CS and electric field gradient (EFG) tensors are utilized to determine relationships between tensor orientations, the principal components, and molecular structures.

A series of P/As mixed pnicogen phases of composition (CuI)(8)P(12-x)As(x), in which x = 2.4, 4.2, 4.8, 5.4, and 6.6, have been synthesized and characterized by X-ray single crystal and powder diffraction, solid-state NMR spectroscopy, thermal gravimetric analysis, and impedance spectroscopy. These materials are isostructural to (CuI)(8)P(12) and consist of neutral, tubular P/As mixed pnicogen chains associated with Cu(I) and I(-) ions. The As is distributed throughout the pnicogen chains; however, the "roof" sites of the [P8] cage show preferred occupation by As relative to the other sites. Accordingly, the change in cell volume is not a linear function of the As incorporation. Solid-state (31)P NMR spectroscopy of the 40 % As incorporated sample are consistent with the X-ray structural model, with extensive broadening due to (31)P-(75)As coupling and site disorder, and a change in the chemical shifts of the resonances due to the As substitution into the lattice. The degree of copper ion site disorder, probed by single-crystal X-ray diffraction, increases with increasing As content. Although very little change is observed in the copper ionic conductivity of polycrystalline samples, which ranges from 1.8-5.1 x 10(-6) S cm(-1) for (CuI)(8)P(12-x)As(x), x = 0, 4.2, 5.4; a single crystal (x = 4.8) measured along the needle axis has a conductivity of 1.7 x 10(-3) S cm(-1) at 128 degrees C. This represents an order of magnitude improvement in conductivity over (CuI)(8)P(12) at the same temperature.

Mesoporous tantalum oxide rubidium fulleride composites were synthesized by solution impregnation and characterized by elemental analysis, X-ray diffraction, Raman spectroscopy, nitrogen adsorption/ desorption, X-ray photoelectron spectroscopy, superconducting quantum interference device magnetometry, room- and variable-temperature electron transport measurements, and solid-state 8 7 Rb and 1 3 C NMR. The room-temperature conductivity pattern, as a function of the oxidation state of C 6 0 n - , displayed a conductivity minimum at n = 3.0 and a single maximum at n = 4.0, while variable-temperature conductivity measurements indicated that the n = 1.0 composite is a semiconductor and the n = 4.0 material is a narrow band gap semiconductor or a semimetal. Solid-state 8 7 Rb NMR of the composite materials indicated the presence of two Rb environments associated with the walls or channels of the mesostructure as well as several resonances associated with various fulleride species. The n = 3.0 and n = 4.0 samples showed a substantial increase of Rb ions confined into the walls of mesostructure as well as the buildup of a Rb environment associated with a fulleride species. Solid-state 1 3 C NMR experiments showed the presence of multiple fulleride species as well as pure fullerene, depending on the level of reduction.

By employing a reactive low temperature wafer bonding technique, we have demonstrated oxide-defined 850 nm vertical-cavity surface-emitting lasers (VCSEL's) on Si substrates. Devices reach a differential quantum efficiency of 53% and a light output power of 7.1 mW under room temperature and continuous-wave operation without a heat sink.

Mesoporous titanium oxide was treated with bis(toluene) titanium under nitrogen at room temperature in toluene, leading to a new blue black material possessing conductivity values of up to 10-2 Ω-1 cm-1. XRD and nitrogen adsorption showed that the mesostructure was fully retained. Elemental analysis indicated that the material absorbed Ti from the organometallic, without any incorporation of the toluene ligand. There was also an increase of nitrogen from below the detection limit to 1.16%. XPS studies showed that the Ti framework was reduced by the organometallic and that the material had reduced nitride on the surface. There was also an emission at the Fermi level, suggesting metallic behavior. This was confirmed by variable-temperature conductivity studies, which showed a gradual decrease of resistivity with temperature. SQUID magnetometer studies revealed spin glass behavior with a degree of temperature independent paramagnetism, consistent with metallic properties. Solid-state 15N NMR studies on mater...

Silver-containing layered networks of the form [Ag(L)] (L = 4-pyridinesulfonate or p-toluenesulfonate) were treated with primary amines in different ratios. The structures of the parent supramolecular networks are well-known; however, their interactions with primary amines lead to the formation of new layered materials for which single-crystal X-ray structures cannot be obtained. Solid-state (109)Ag, (15)N, and (13)C cross-polarization magic-angle spinning (CP/MAS) NMR experiments, in combination with powder X-ray diffraction experiments and ab initio calculations, are utilized to investigate the interactions between the primary amines and the parent materials, and to propose structural models for the new materials. (109)Ag chemical shift (CS) tensor parameters are extremely sensitive to changes in silver environments; hence, (1)H-(109)Ag CP/MAS NMR experiments are used to distinguish and characterize silver sites. The combination of (109)Ag and (15)N NMR experiments on starting materials and samples prepared with both (15)N-labeled and unlabeled amines permits the accurate measurements of indirect (1)J((109)Ag,(15)N) and (1)J((109)Ag,(14)N) spin-spin coupling constants, providing further information on structure and bonding in these systems. First principles calculations of silver CS tensors and (1)J((109)Ag,(14)N) coupling constants in model complexes aid in formulating the proposed structural models for the new materials, which are largely comprised of layers of silver-diamine cations.

Cryptophanes are molecular hosts having high binding affinities for small, neutral molecules in weakly polar solvents. We have previously studied dichloromethane as a guest inside the cavity of cryptophane-E (cryptophane-333), in solution as well as in the solid state. Here, we present a solution 13C relaxation study of dichloromethane as the guest molecule complexed in the cavity of two smaller hosts: cryptophane-A (cryptophane-222) and cryptophane-223. 13C relaxation measurements were performed for both guest and host molecules. Exchange kinetics have to be explicitly taken into consideration in order to derive 13C relaxation properties of the bound guest. Rate coefficients were measured using proton 1D-exchange experiments. We have also investigated dichloromethane complexed in the cavity of cryptophane-233 in the solid state, by estimating the motionally averaged 13C−1H dipolar interactions from recoupling experiments under magic angle spinning (MAS) conditions. The measurements for the three cryptoph...

A series of P/As mixed pnicogen phases of composition (CuI)8P12−xAsx, in which x=2.4, 4.2, 4.8, 5.4, and 6.6, have been synthesized and characterized by X-ray single crystal and powder diffraction, solid-state NMR spectroscopy, thermal gravimetric analysis, and impedance spectroscopy. These materials are isostructural to (CuI)8P12 and consist of neutral, tubular P/As mixed pnicogen chains associated with CuI and I− ions. The As is distributed throughout the pnicogen chains; however, the “roof” sites of the [P8] cage show preferred occupation by As relative to the other sites. Accordingly, the change in cell volume is not a linear function of the As incorporation. Solid-state 31P NMR spectroscopy of the 40 % As incorporated sample are consistent with the X-ray structural model, with extensive broadening due to 31P–75As coupling and site disorder, and a change in the chemical shifts of the resonances due to the As substitution into the lattice. The degree of copper ion site disorder, probed by single-crystal X-ray diffraction, increases with increasing As content. Although very little change is observed in the copper ionic conductivity of polycrystalline samples, which ranges from 1.8–5.1×10−6 S cm−1 for (CuI)8P12−xAsx, x=0, 4.2, 5.4; a single crystal (x=4.8) measured along the needle axis has a conductivity of 1.7×10−3 S cm−1 at 128 °C. This represents an order of magnitude improvement in conductivity over (CuI)8P12 at the same temperature.

New mesoporous niobium oxides with 5, 10, and 15 mol% vanadium(V) doped into the walls of the structure were synthesized by the ligand-assisted templating method with an octadecylamine template. These materials were characterized by XRD, XPS, EPR, elemental analysis, and nitrogen adsorption before being treated with excess bis(benzene)chromium to give new composites with an organometallic phase in the walls. All materials were also characterized by EPR, XRD, nitrogen adsorption, XPS, SQUID magnetometry, and elemental analysis. The materials with higher percentages of vanadium absorbed more bis(benzene)chromium, because this process depends largely on the electron transfer between the organometallic and the walls of the mesostructure and vanadium(V) is a stronger oxidant than niobium(V). Conductivity studies on these materials revealed that the ratio of Cr(0) to Cr(l) in the pores was more important than the absolute Cr loading level in governing electron transport properties but that increasing the V content led to more insulating behavior regardless of the Cr concentration. Solid-state 2H NMR studies on perdeuteriobenzene analogues of these composites showed the presence of the neutral and cationic Cr species in different ratios depending on the loading. Tumbling of these species was also slow on the NMR time scale, indicating that the charge-carrying Cr species are not rapidly moving through the pore channels of the mesostructure. This suggests that the walls of the structure may play a key role in charge transfer in these composites, contrary to what was previously believed.

Mesoporous titanium oxide was treated with bis(toluene) titanium under nitrogen at room temperature in toluene, leading to a new blue black material possessing conductivity values of up to 10(-)(2) Omega(-)(1) cm(-)(1). XRD and nitrogen adsorption showed that the mesostructure was fully retained. Elemental analysis indicated that the material absorbed Ti from the organometallic, without any incorporation of the toluene ligand. There was also an increase of nitrogen from below the detection limit to 1.16%. XPS studies showed that the Ti framework was reduced by the organometallic and that the material had reduced nitride on the surface. There was also an emission at the Fermi level, suggesting metallic behavior. This was confirmed by variable-temperature conductivity studies, which showed a gradual decrease of resistivity with temperature. SQUID magnetometer studies revealed spin glass behavior with a degree of temperature independent paramagnetism, consistent with metallic properties. Solid-state (15)N NMR studies on materials synthesized in the presence of labeled dinitrogen showed that the source of the nitride was the reaction atmosphere. IR and (15)N NMR demonstrated that this nitrogen species was surface ammonia, suggesting that the initially formed nitride species had reacted with moisture imbedded in the walls of the mesostructure. The direct conversion of dinitrogen to ammonia is a very rare process and this work represents the first example of this process mediated by a molecular sieve.

A preliminary set of solid-state 139La and 15N NMR data for lanthanum-containing metallocenes is presented, including (C5H5)3La, (C5Me4H)3La, [(C5Me5)2La]+[BPh4]-, and 15N-enriched [(C5Me4H)2La(THF)]215N2. Broad 139La NMR spectra, with breadths ranging from 600 kHz to 2.5 MHz, were acquired with piecewise QCPMG techniques at 9.4 T. Simulations of the spectra reveal 139La quadrupolar coupling constants (CQ) between 44 and 105 MHz. In addition, the first NMR measurement of a nitrogen chemical shift (CS) tensor for dinitrogen bound side-on to a metal atom is reported for [(C5Me4H)2La(THF)]215N2. The 139La NMR parameters show remarkable sensitivity to changes in metallocene structure and can be interpreted in an intuitive manner. Preliminary RHF and DFT calculations of 139La electric field gradient (EFG) and nitrogen CS tensors are used to provide tensor orientations and to rationalize the origin of the NMR parameters in terms of molecular structure and symmetry. The sensitivity of 139La and 15N NMR tensor parameters to changes in structure and bonding should prove invaluable in future studies of noncrystalline and disordered systems.

L-Amino acids are potent olfactory stimuli for Atlantic salmon. A plasma membrane fraction, previously shown to be rich in amino acid binding sites, was prepared from olfactory rosettes of Atlantic salmon (Salmo salar) and utilized to investigate the role of phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis in olfactory signal transduction. A cocktail of L-amino acids (Ser, Glu, Lys, and Gly) stimulated PIP2 hydrolysis by phospholipase C (PLC) in a dose-dependent manner with half-maximal stimulation when all amino acids were present at approximately 1 microM. Stimulation of PIP2 hydrolysis by amino acids required GTP gamma S, which alone had no effect on PLC activity. Unlike GTP gamma S, AlF4- and Ca2+ stimulated PIP2 breakdown. Preincubation with 1 mM GDP beta S eliminated the effect of amino acids and AlF4- on PIP2 hydrolysis, suggesting the involvement of G protein regulation. The lack of stimulation by GTP gamma S alone suggested that there was negligible exchange of GTP gamma S for GDP in the absence of odorant. There were no significant effects of amino acids on either adenylate cyclase or guanylate cyclase activities in the membrane preparation under these conditions. The effect of the amino acid cocktail was maximal at 1-10 nM free Ca2+. At or above 100 nM free Ca2+, no effect of amino acids on PIP2 hydrolysis was found. However, between 100 nM and 100 microM, Ca2+ directly stimulated PLC activity in a dose-dependent manner. This stimulation by Ca2+ appeared to be G protein independent because it did not require GTP gamma S and was not inhibited by GDP beta S.(ABSTRACT TRUNCATED AT 250 WORDS)

We report novel symmetry-based pulse sequences for exciting double-quantum (2Q) coherences between the central transitions of half-integer spin quadrupolar nuclei in the NMR of rotating solids. Compared to previous 2Q-recoupling techniques, numerical simulations and 23Na and 27Al NMR experiments on Na2SO4 and the open-framework aluminophosphate AlPO-CJ19 verify that the new dipolar recoupling schemes display higher robustness to both radio-frequency field inhomogeneity and to spreads in resonance frequencies. These advances allowed for the first demonstration of 2Q-recoupling in an amorphous solid for revealing its intermediate-range structural features, in the context of mapping 27Al-27Al connectivities between the aluminium polyhedra (AlO4, AlO5 and AlO6) of a lanthanum aluminate glass (La0.18Al0.82O1.5).