Role of Madden-Julian Oscillation in predicting the 2020 East Asian summer precipitation in subseasonal-to-seasonal models.

The 2020 summer monsoon season in East Asia was unusually long and intense, and the Madden-Julian Oscillation (MJO) has been proposed as an underlying reason. This study analyzes the role of the MJO in the 2020 East Asian precipitation forecasts of the subseasonal-to-seasonal (S2S) model. The S2S models underestimated the cumulative precipitation over East Asia, and the models with good forecast performance yielded a distinct precipitation band over East Asia and a western pacific subtropical high (WPSH) during the analysis period. East Asian precipitation forecast performance was more closely related to the location of the center than the strength of the WPSH, with precipitation increasing with a decrease in the latitude at the center. MJO Phases 1-3 activation intensified the WPSH and shifted the center of WPSH to lower latitudes. Our results confirm that the strong East Asian precipitation in summer 2020 was partly due to changes in the characteristics of the MJO and indicate the importance of accurately estimating the MJO-WPSH coupling for reliable East Asian precipitation forecasts.

Age-related changes in the electrophoresis pattern of serum proteins in Korean indigenous calves.

This study aimed to investigate changes in the serum protein profiles of healthy newborn Korean calves and provide a reference index for these changes during growth. The serum protein composition of 15 healthy bovine calves aged 1 week to 4 months was analyzed using electrophoresis. The albumin to globulin (A/G) ratio increased until calves reached 2 months (1.3 ± 0.2) and then decreased until they reached 4 months (1.1 ± 0.1). Albumin concentrations increased up to month 2 (3.4 ± 0.1) and decreased until month 4 (3.2 ± 0.2). α-1 globulin concentrations decreased up to week 4 (0.4 ± 0.1) and then increased until month 2 (0.6 ± 0.1). γ globulin decreased until month 2 (0.7 ± 0.2) and then increased until month 4 (1.1 ± 0.3). These age-related changes in protein concentrations indicate the importance of considering age in calf blood tests. The γ globulin concentration was at its highest in the first week, due to colostrum intake, and decreased to reach its lowest at 2 months, when passive maternal immunity is also at its lowest. Therefore, provision of sufficient passive immunity through the colostrum in neonatal calves might enable healthy growth.

Cette étude visait à examiner les changements dans les profils de protéines sériques de veaux coréens nouveau-nés et de fournir un index de référence pour ces changements durant la croissance. La composition des protéines sériques de 15 veaux en santé âgés de 1 semaine à 4 mois a été analysée par électrophorèse. Le ratio albumine:globuline (A/G) a augmenté jusqu'à ce que les veaux atteignent l'âge de 2 mois (1,3 ± 0,2) et diminuait par la suite jusqu'à ce qu'ils aient 4 mois (1,1 ± 0,1). Les concentrations d'albumine augmentèrent jusqu'au mois 2 (3,4 ± 0,1) et diminuèrent ensuite jusqu'au mois 4 (3,2 ± 0,2). Les concentrations de α-1 globuline ont diminué jusqu'à la semaine 4 (0,4 ± 0,1) et ont par la suite augmenté jusqu'au mois 2 (0,6 ± 0,1). Les concentrations de γ globuline ont diminué jusqu'au mois 2 (0,7 ± 0,2) et ont par la suite augmenté jusqu'au mois 4 (1,1 ± 0,3). Ces changements dans les concentrations de protéines en fonction de l'âge démontrent l'importance de considérer l'âge lors des tests sanguins chez les veaux. La concentration de γ globuline était à son maximum durant la première semaine, due à l'ingestion de colostrum, et diminua par la suite pour atteindre un minimum à 2 mois, alors que l'immunité maternelle passive est à son plus bas. Ainsi, le fait de fournir suffisamment d'immunité passive via le colostrum chez les veaux nouveau-nés peut permettre une saine croissance.(Traduit par Docteur Serge Messier).

Changes in serum protein electrophoresis profiles and acute phase proteins in calves with diarrhea.

Calf diarrhea leads to substantial economic losses in the livestock industry worldwide due to medical treatment costs, retarded growth performance, and even death. The objective of this study was to investigate changes in serum protein profiles and acute phase proteins in calves with diarrhea and identify the association between these changes and diarrhea. A total of 185 Korean beef calves were used and divided into 3 groups by age: 1 to 10 days (n = 46), 11 to 20 days (n = 65), and 21 to 30 days (n = 74). Blood and fecal samples were collected from each calf. Serum concentrations of total protein, protein fractions (albumin, α1-globulin, α2-globulin, ß-globulin, and γ-globulin), haptoglobin (Hp), and serum amyloid A (SAA) were analyzed. Compared to calves without diarrhea, calves with diarrhea had significantly lower albumin concentrations at 11 to 20 days and 21 to 30 days of age (P = 0.017 and P = 0.000, respectively) and significantly higher α1-globulin fractions at 21 to 30 days of age (P = 0.01). Interestingly, α2-globulin fractions were significantly higher in diarrheic calves in all age groups, whereas γ-globulin fractions were significantly lower in calves with diarrhea aged 1 to 10 days, compared with normal animals. In calves with diarrhea, the concentration of Hp was significantly higher, whereas SAA levels were not different between normal and diarrheic calves. In addition, a positive correlation was found between α2-globulin and Hp (P = 0.0004). Taken together, these results provide useful information about the use of serum protein profiles and Hp as prognostic and diagnostic markers for animal health status.

La diarrhée des veaux entraîne des pertes économiques substantielles dans l'industrie de l'élevage dans le monde entier en raison des coûts des traitements médicaux, du retard de croissance et même de la mort. L'objectif de cette étude était d'étudier les changements dans les profils des protéines sériques et les protéines de la phase aiguë chez les veaux souffrant de diarrhée et d'identifier l'association entre ces changements et la diarrhée. Un total de 185 veaux de boucherie coréens ont été utilisés et répartis en trois groupes par âge : 1 à 10 jours (n = 46), 11 à 20 jours (n = 65) et 21 à 30 jours (n = 74). Des échantillons de sang et de matières fécales ont été prélevés sur chaque veau. Les concentrations sériques de protéines totales, les fractions protéiques (albumine, α1-globuline, α2-globuline, ß-globuline et γ-globuline), d'haptoglobine (Hp) et d'amyloïde sérique A (SAA) ont été analysées. Par rapport aux veaux sans diarrhée, les veaux souffrant de diarrhée avaient des concentrations d'albumine significativement plus faibles à 11 à 20 jours et 21 à 30 jours d'âge (P = 0,017 et P = 0,000, respectivement) et des fractions d'α1-globuline significativement plus élevées à 21 à 30 jours d'âge (P = 0,01). Il est intéressant de noter que les fractions d'α2-globuline étaient significativement plus élevées chez les veaux diarrhéiques de tous les groupes d'âge, tandis que les fractions de γ-globuline étaient significativement plus faibles chez les veaux souffrant de diarrhée âgés de 1 à 10 jours, par rapport aux animaux témoins. Chez les veaux souffrant de diarrhée, la concentration de Hp était significativement plus élevée, tandis que les niveaux de SAA n'étaient pas différents entre les veaux normaux et diarrhéiques. De plus, une corrélation positive a été trouvée entre l'α2-globuline et Hp (P = 0,0004). Pris ensemble, ces résultats fournissent des informations utiles sur l'utilisation des profils de protéines sériques et de Hp comme marqueurs pronostiques et diagnostiques de l'état de santé des animaux.(Traduit par Docteur Serge Messier).

Alterations in serum protein electrophoresis profiles during the acute phase response in dogs with acute pancreatitis.

The quantification of serum proteins is a useful tool for diagnosing and monitoring various diseases that involve changes in the concentrations of these proteins. As canine acute pancreatitis (AP) accompanies the systemic inflammatory response syndrome, serum proteins such as C-reactive protein (CRP) have been used as inflammatory markers for dogs with AP. The goal of this study was to investigate the overall profiles of serum proteins by serum protein electrophoresis (SPE) and to determine the concentration of acute phase proteins (APPs) in dogs with AP in order to better understand serum protein profiles as diagnostic markers in these dogs. Decreased levels of albumin and increased levels of alpha-2 globulin were observed in dogs with AP by SPE. Among APPs, elevated concentrations of CRP, serum amyloid A (SAA), and haptoglobin were detected. The concentration of SAA was positively correlated with that of CRP, which suggests that SAA could be a sensitive marker of inflammation in dogs with AP, similar to CRP.

La quantification des protéines sériques est un outil utile pour diagnostiquer et suivre différentes pathologies qui impliquent des changements dans les concentrations de ces protéines. Comme la pancréatite aiguë (AP) accompagne le syndrome de réponse inflammatoire systémique, les protéines sériques telles que la protéine C-réactive (CRP) ont été utilisées comme marqueurs d'inflammation chez les chiens avec AP. L'objectif de la présente étude était d'examiner les profils globaux des protéines sériques par électrophorèse des protéines sériques (SPE) et de déterminer les concentrations des protéines de phase aiguë (APPs) chez les chiens avec AP afin de mieux comprendre les profils de protéines sériques comme marqueurs diagnostiques chez ces chiens. Des niveaux diminués d'albumine et des niveaux augmentés de globuline alpha-2 furent observés par SPE chez des chiens avec AP. Parmi les APPs, des concentrations élevées de CRP, d'amyloïde sérique A (SAA), et d'haptoglobine furent détectées. La concentration de SAA était corrélée positivement avec celle de CRP, ce qui suggère que SAA pourrait être un marqueur sensible d'inflammation chez les chiens avec AP, de manière similaire à la CRP.(Traduit par Docteur Serge Messier).

Acute phase response in bovine coronavirus positive post-weaned calves with diarrhea.

Bovine coronavirus (BCoV) is associated with severe diarrhea in calves, winter dysentery in adult cattle, and respiratory diseases in cattle of all ages. This study aimed to investigate the relationship between white blood cell counts and haptoglobin (Hp) and serum amyloid A (SAA) levels in post-weaned calves with diarrhea caused by BCoV and those that recovered from diarrhea. Blood and fecal samples were collected twice from the same animals; 17 post-weaned calves with diarrhea (first) and 15 post-weaned calves that recovered from diarrhea (second). Real-time polymerase chain reaction revealed that all 17 fecal samples from post-weaned calves with diarrhea and one out of 15 from diarrhea-recovered calves were positive for BCoV and negative for Cryptosporidium spp., Escherichia coli K99, Salmonella spp., bovine rotavirus, and bovine viral diarrhea virus. No Eimeria oocysts were detected using the flotation method. In comparison with post-weaned calves with diarrhea, in diarrhea-recovered calves, the lymphocyte count was significantly higher (P = 0.018), and the monocyte count was significantly lower (P = 0.001); however, the number of monocytes was still high. Post-weaned calves with diarrhea had a significantly higher Hp concentration (P < 0.001) compared with diarrhea-recovered calves. The results indicated that increased Hp concentration and monocytosis but not SAA may be associated with diarrhea caused by BCoV. The present study suggests that the monitoring of Hp concentration and monocyte count is useful in the diagnosis of post-weaned calves with diarrhea caused by BCoV in this field.

Experiences of Mothers' Attachment in a Follow-Up Program Using Early Intervention for Low-Birth-Weight Infants.

PURPOSE: Mothers who give birth prematurely experience parenting stress after their babies are discharged and find it difficult to emotionally bond with them. Forming an emotional bond with a baby promotes the baby's growth and development, helps the mother cope with parenting stress after discharge, and is important for maintaining family functioning. This study aimed to identify the attachment experiences of mothers with low-birth-weight infants (LBWIs) in a follow-up program using early intervention. METHODS: A phenomenological perspective was used for this qualitative research. Data were collected from in-depth interviews with twelve mothers who participated in a follow-up program using early intervention for mothers with LBWIs from September 2017 to December 2017. Colaizzi's method was used to analyze the data. RESULTS: The experience of mothers' attachment was investigated on the basis of three categories: 'beginning of changes in parenting methods,' 'forming an intimate mother-child bond,' and 'concerns and expectation about the child's development.' CONCLUSION: The results indicate that the follow-up program using an early intervention designed to increase mothers' confidence in their parenting skills can promote mother' attachment and the quality of life of families with LBWIs.

Characteristic study on the chemical components of Korean curved ginseng products.

Dried ginseng (DG) is in fact the representing ginseng product in the worldwide market. Although it is made in various packages depending on the processing method, size and age of DG, basic scientific data reporting the chemical components are limited. In this study, 4-year-old curved ginseng (CG), one of the domestic DG products, was selected for further investigation. Eighty-six samples of 30 and 50 piece-grade CG, which are the most widely distributed in the market, were collected for 5 yr. Their major components, such as moisture, total sugar, acidic polysaccharides, total phenolic compounds, and saponins, were analyzed to figure out the standard quality characteristics. The moisture content of all CG samples was less than 15%. The total water-soluble sugar contents were 22.9% to 47.8% and 23.2% to 49.5% in the 30 and 50 piece-grade CG, respectively. The acidic polysaccharide contents were 3.6% to 6.7% and 2.9% to 6.9% in the 30 and 50 piece-grade CG, respectively. The total phenolic compound content was 0.4% to 0.5% in CG, regardless of the piece-grade. The crude saponin content, which represents the active component of ginseng, was over 2% in all samples. In 30 piece-grade CG samples, the contents of major ginsenosides, Rb1, Rf, and Rg1, were 2.2 to 4.7 mg/g, 0.4 to 1.3 mg/g, and 1.6 to 4.0 mg/g, respectively. The ginsenoside contents in 50 piece-grade CG samples were 2.1 to 3.9 mg/g (Rb1), 0.5 to 1.2 mg/g (Rf), and 1.3 to 3.4 mg/g (Rg1). Overall, since there were relatively high standard deviation and coefficient of variation in all the chemical component contents that were assessed, we found some difficulties in showing the CG standard chemical component characteristics by average, standard deviation, and other statistical analysis factors.

Antiferromagnetic ordering through a hydrogen-bonded network in the molecular solid CuF2(H2O)2(3-chloropyridine).

CuF(2)(H(2)O)(2)(3-chloropyridine) possesses a five-coordinate Cu(2+) center with a slightly distorted trigonal bypyramidal coordination geometry. Strong intermolecular F···H-O hydrogen bonds enable the formation of 2D layers and provide the primary magnetic exchange path that leads to the stabilization of long-range antiferromagnetic (AFM) order below T(N) = 2.1 K.

[Ni(HF2)(3-Clpy)4]BF4 (py = pyridine): evidence for spin exchange along strongly distorted F···H···F- bridges in a one-dimensional polymeric chain.

[Ni(HF(2))(3-Clpy)(4)]BF(4) (py = pyridine) is a simple one-dimensional (1D) coordination polymer composed of compressed NiN(4)F(2) octahedra that form chains with bridging HF(2)(-) ligands. In spite of significant distortion of the HF(2)(-) bridge, a quasi-1D antiferromagnetic (AFM) behavior was observed with J(FHF) = 4.86 K.

Prognostic factors for treatment outcomes in transient tachypnea of the newborn.

BACKGROUND: Transient tachypnea of the newborn (TTN) is a clinical syndrome associated with respiratory distress usually seen shortly after delivery in infants. This study aims to determine the risk factors predicting treatment outcomes in infants with TTN. METHODS: Data from 236 infants diagnosed with TTN during the study period were evaluated retrospectively. Logistic regression analyses were performed to select significant risk factor for prognosis (prolonged oxygen therapy, application of mechanical ventilator, and prolonged hospital stay) of TTN among components of clinical variables. RESULTS: Of the 236 TTN infants, 111 (47.0%) infants were delivered via cesarean section (CS) without labor, 29 (12.3%) infants were delivered via CS with labor, and 96 (40.7%) were delivered via vaginal birth. Lower Apgar score at 1 min (OR: 3.03; 95%CI: 1.25-7.36) and lower umbilical artery pH (OR: 4.00; 95%CI 1.55-10.49) were associated with a significantly increased risk for mechanical ventilator care. Also, late-preterm delivery (OR: 4.70; 95%CI: 2.11-10.49) was independently associated with risk of prolonged duration of hospital stay. CONCLUSIONS: Late-preterm delivery, lower initial umbilical artery pH (<7.25), and lower Apgar score at 1 min were independently associated with poor prognostic treatment outcomes in infants with TTN.

Influence of HF2- geometry on magnetic interactions elucidated from polymorphs of the metal-organic framework [Ni(HF2)(pyz)2]PF6 (pyz = pyrazine).

A tetragonal polymorph of [Ni(HF(2))(pyz)(2)]PF(6) (designated ß) is isomorphic to its SbF(6)-congener at 295 K and features linear Ni-FHF-Ni pillars. Enhancements in the spin exchange (J(FHF) = 7.7 K), Néel temperature (T(N) = 7 K), and critical field (B(c) = 24 T) were found relative to monoclinic α-PF(6). DFT reveals that the HF(2)(-) bridges are significantly better mediators of magnetic exchange than pyz (J(pyz)), where J(FHF) ≈ 3J(pyz), thus leading to quasi-1D behavior. Spin density resides on all atoms of the HF(2)(-) bridge whereas N-donor atoms of the pyz ring bear most of the density.

Importance of halogen···halogen contacts for the structural and magnetic properties of CuX2(pyrazine-N,N'-dioxide)(H2O)2 (X = Cl and Br).

The structural and magnetic properties of the newly crystallized CuX(2)(pyzO)(H(2)O)(2) (X = Cl, Br; pyzO = pyrazine-N,N'-dioxide) coordination polymers are reported. These isostructural compounds crystallize in the monoclinic space group C2/c with, at 150 K, a = 17.0515(7) Å, b = 5.5560(2) Å, c = 10.4254(5) Å, ß = 115.400(2)°, and V = 892.21(7) Å(3) for X = Cl and a = 17.3457(8) Å, b = 5.6766(3) Å, c = 10.6979(5) Å, ß = 115.593(2)°, and V = 950.01(8) Å(3) for X = Br. Their crystal structure is characterized by one-dimensional chains of Cu(2+) ions linked through bidentate pyzO ligands. These chains are joined together through OH···O hydrogen bonds between the water ligands and pyzO oxygen atoms and Cu-X···X-Cu contacts. Bulk magnetic susceptibility measurements at ambient pressure show a broad maximum at 7 (Cl) and 28 K (Br) that is indicative of short-range magnetic correlations. The dominant spin exchange is the Cu-X···X-Cu supersuperexchange because the magnetic orbital of the Cu(2+) ion is contained in the CuX(2)(H(2)O)(2) plane and the X···X contact distances are short. The magnetic data were fitted to a Heisenberg 1D uniform antiferromagnetic chain model with J(1D)/k(B) = -11.1(1) (Cl) and -45.9(1) K (Br). Magnetization saturates at fields of 16.1(3) (Cl) and 66.7(5) T (Br), from which J(1D) is determined to be -11.5(2) (Cl) and -46.4(5) K (Br). For the Br analog the pressure dependence of the magnetic susceptibility indicates a gradual increase in the magnitude of J(1D)/k(B) up to -51.2 K at 0.84 GPa, suggesting a shortening of the Br···Br contact distance under pressure. At higher pressure X-ray powder diffraction data indicates a structural phase transition at ∼3.5 GPa. Muon-spin relaxation measurements indicate that CuCl(2)(pyzO)(H(2)O)(2) is magnetically ordered with T(N) = 1.06(1) K, while the signature for long-range magnetic order in CuBr(2)(pyzO)(H(2)O)(2) was much less definitive down to 0.26 K. The results for the CuX(2)(pyzO)(H(2)O)(2) complexes are compared to the related CuX(2)(pyrazine) materials.

Dielectric and piezoelectric properties of CeO2-added nonstoichiometric (Na0.5K0.5)0.97(Nb0.96Sb0.04)O3 ceramics for piezoelectric energy harvesting device applications.

In this study, nonstoichiometric (Na(0.5)K(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics were fabricated and their dielectric and piezoelectric properties were investigated according to the CeO(2) addition. In this ceramic composition, CeO(2) addition improved sinterability, electromechanical coupling factor k(p), mechanical quality factor Q(m), piezoelectric constant d(33), and g(33). At the sintering temperature of 1100°C, for the 0.2wt% CeO(2) added specimen, the optimum values of density = 4.359 g/cm(3), k(p) = 0.443, Q(m) = 588, ε(r) = 444, d(33) = 159 pC/N, and g(33) = 35 × 10(-3) V·m/N, were obtained. A piezoelectric energy harvesting device using 0.2 wt% CeO(2)- added lead-free (K(0.5)Na(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics and a rectifying circuit for energy harvesting were fabricated and their electrical characteristics were investigated. Under an external vibration acceleration of 0.7 g, when the mass, the frequency of vibration generator, and matching load resistance were 2.4 g, 70 Hz, and 721 Ω, respectively, output voltage and power of piezoelectric harvesting device indicated the optimum values of 24.6 mV(rms) and 0.839 µW, respectively-suitable for application as the electric power source of a ubiquitous sensor network (USN) sensor node.

Structural, electronic, and magnetic properties of quasi-1D quantum magnets [Ni(HF2)(pyz)2]X (pyz = pyrazine; X = PF6(-), SbF6(-)) exhibiting Ni-FHF-Ni and Ni-pyz-Ni spin interactions.

[Ni(HF(2))(pyz)(2)]X {pyz = pyrazine; X = PF(6)(-) (1), SbF(6)(-) (2)} were structurally characterized by synchrotron X-ray powder diffraction and found to possess axially compressed NiN(4)F(2) octahedra. At 298 K, 1 is monoclinic (C2/c) with unit cell parameters, a = 9.9481(3), b = 9.9421(3), c = 12.5953(4) Å, and ß = 81.610(3)° while 2 is tetragonal (P4/nmm) with a = b = 9.9359(3) and c = 6.4471(2) Å and is isomorphic with the Cu-analogue. Infinite one-dimensional (1D) Ni-FHF-Ni chains propagate along the c-axis which are linked via µ-pyz bridges in the ab-plane to afford three-dimensional polymeric frameworks with PF(6)(-) and SbF(6)(-) counterions occupying the interior sites. A major difference between 1 and 2 is that the Ni-F-H bonds are bent (∼157°) in 1 but are linear in 2. Ligand field calculations (LFT) based on an angular overlap model (AOM), with comparison to the electronic absorption spectra, indicate greater π-donation of the HF(2)(-) ligand in 1 owing to the bent Ni-F-H bonds. Magnetic susceptibility data for 1 and 2 exhibit broad maxima at 7.4 and 15 K, respectively, and λ-like peaks in dχT/dT at 6.2 and 12.2 K that are ascribed to transitions to long-range antiferromagnetic order (T(N)). Muon-spin relaxation and specific heat studies confirm these T(N)'s. A comparative analysis of χ vs T to various 1D Heisenberg/Ising models suggests moderate antiferromagnetic interactions, with the primary interaction strength determined to be 3.05/3.42 K (1) and 5.65/6.37 K (2). However, high critical fields of 19 and 37.4 T obtained from low temperature pulsed-field magnetization data indicate that a single exchange constant (J(1D)) alone is insufficient to explain the data and that residual terms in the spin Hamiltonian, which could include interchain magnetic couplings (J(⊥)), as mediated by Ni-pyz-Ni, and single-ion anisotropy (D), must be considered. While it is difficult to draw absolute conclusions regarding the magnitude (and sign) of J(⊥) and D based solely on powder data, further support offered by related Ni(II)-pyz compounds and our LFT and density-functional theory (DFT) results lead us to a consistent quasi-1D magnetic description for 1 and 2.

On the high magnetic-ordering temperature of the 5d magnetic oxide Ca3LiOsO6 crystallizing in a trigonal crystal structure: density functional analysis.

The 5d magnetic oxide Ca(3)LiOsO(6) has a trigonal arrangement of its LiOsO(6) chains parallel to the c-direction and hence has triangular arrangements of high-spin Os(5+) (d(3)) ions but exhibits no spin frustration and undergoes a long-range antiferromagnetic ordering at a high temperature. The origin of this apparently puzzling observation was examined by evaluating the nearest-neighbor Os-O···O-Os spin exchange interactions of Ca(3)LiOsO(6) on the basis of density functional calculations. Our study shows that, of the two nearest-neighbor interchain spin exchanges, one dominates over the other and that the intrachain spin exchange and the dominating interchain spin exchange are strong and form a three-dimensional antiferromagnetic spin lattice with no spin frustration, which is responsible for the long-range antiferromagnetic ordering of Ca(3)LiOsO(6) at high temperature. In determining the strengths of the Os-O···O-Os exchange interactions of Ca(3)LiOsO(6), the Li(+) and Ca(2+) ions of the O···Li(+)···O and O···Ca(2+)···O linkages are found to play only a minor role.

Symmetry-dependent strong reduction of the spin exchange interactions in Cs2CuCl4 by the 6p orbitals of Cs+ ions.

Despite a three-dimensional arrangement of its CuCl(4)(2-) ions, the magnetic properties of Cs(2)CuCl(4) are explained by a two-dimensional frustrated triangular antiferromagnetic spin-lattice. The origin of this low-dimensional magnetism was explored by evaluating the spin exchange interactions of A(2)CuCl(4) (A = Cs, Rb, K, Na) on the basis of first principles density functional calculations. The calculated spin exchange parameters agree with experiment only when the Cs(+) ions located between the CuCl(4)(2-) ions are not neglected. The antiferromagnetic spin exchange interaction between adjacent CuCl(4)(2-) ions is strongly reduced by the 6p orbitals of the intervening Cs(+) ions when the arrangement of the CuCl(4)(2-) and Cs(+) ions has either mirror-plane or inversion symmetry. The observed magnetism of Cs(2)CuCl(4) arises from this symmetry-dependent participation of the 6p orbitals of the Cs(+) ions in the spin exchange interactions between CuCl(4)(2-) ions.

Preferential site of attack on fullerene cations: frontier orbitals and rate coefficients.

An analysis of reaction efficiency is presented for reactions of carbonaceous ions and molecules. Our results show that the combination of experimental rate-coefficient measurements and computations of the condensed Fukui functions of frontier molecular orbitals and pyramidal angles of pi orbitals is very useful for elucidating the reactive sites on fullerene carbon clusters in the gas phase.