An accurate potential model for the a3Σu+ state of the lithium dimer.

An accurate Tang-Toennies (TT) model potential is introduced to describe the interatomic potential of the lithium dimer in the a3Σu+ state. With only one well-known parameter, the ionization energy, the new model potential compares favorably with the experimentally fitted Morse/Long-range (MLR) potential of Dattani and Le Roy [J. Mol. Spectrosc., 2011, 268, 199] and is in excellent agreement with the state-of-the-art ab initio potential of Lesiuk et al. [Phys. Rev. A, 2020, 102, 062806]. With the known dispersion coefficients and the ionization energy, the new potential requires only two experimental parameters, namely the depth of the potential well De and its location Re. The new potential can be extended to the region of zero separation by the united atom limit.

Correction: The development of a full range analytical interatomic potential.

Correction for 'The development of a full range analytical interatomic potential' by X. W. Sheng et al., Phys. Chem. Chem. Phys., 2021, DOI: 10.1039/d0cp04083e.

The development of a full range analytical interatomic potential.

A chronological account is given to the development of a full range interatomic potential. Starting with a simple phenomenological model, the terms in the model are gradually modified, so that they can carry some definite physical meaning. To gain insight, a systematic, order by order interaction potential theory is developed. Conversely, this theory suggests the functional form for the potential model. At present, we have a simple interaction model that is capable of describing the van der Waals potentials of many systems from R = 0 to R→∞.

Conformal Analytical Potential for All the Rare Gas Dimers over the Full Range of Internuclear Distances.

An analytical model for the potential between two rare gas atoms at distances between R=0 to R→∞ is assumed to be conformal with the previously published potential for He_{2} [J. Chem. Phys. 142, 131102 (2015)JCPSA60021-960610.1063/1.4916740]. The potential curves of the rare gas dimers all have the same shape and only depend on the well parameters D_{e} and R_{e}. The potentials and the vibrational levels for the 11 homonuclear and heteronuclear dimers for which recent ab initio calculations are available agree, within several percent, with the ab initio results. For the other rare gas dimers, the new potential provides the first realistic estimates for the potentials.

Ten-year fracture risk by FRAX and osteoporotic fractures in patients with systemic autoimmune diseases.

The Fracture Risk Assessment Tool (FRAX) has been used universally for the purpose of fracture risk assessment. However, the predictive capacity of FRAX for autoimmune diseases remains inconclusive. This study aimed to compare the applicability of FRAX for autoimmune disease patients. This retrospective study recruited rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and primary Sjögren syndrome (pSS) patients with bone mineral density (BMD) tests. Patients with any osteoporotic fractures were identified. Taiwan-specific FRAX with and without BMD were then calculated. In total, 802 patients (451 RA, 233 SLE and 118 pSS) were enrolled in this study. The cumulative incidences of osteoporotic fractures in the RA, SLE and pSS patients were 43.0%, 29.2% and 33.1%, respectively. For those with a previous osteoporotic fracture, T-scores were classified as low bone mass. Overall, the patients' 10-year probability of major fracture risk by FRAX without BMD was 15.8%, which then increased to 20.3% after incorporation of BMD measurement. When analyzed by disease group, the fracture risk in RA patients was accurately predicted by FRAX. In contrast, current FRAX, either with or without BMD measurement, underestimated the fracture risk both in SLE and pSS patients, even after stratification by age and glucocorticoid treatment. For pSS patients with major osteoporotic fractures, FRAX risks imputed by RA were comparable to major osteoporotic fracture risks of RA patients. Current FRAX accurately predicted fracture probability in RA patients, but not in SLE and pSS patients. RA-imputed FRAX risk scores could be used as a temporary substitute for SLE and pSS patients.

Ten-year clinical evaluation of posterior fixed-movable resin-bonded fixed partial dentures.

OBJECTIVES: Two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) offer long-term retention for anterior and premolar-sized spans. At this center, molar and longer spans have been restored with fixed-movable (FM) RBFPDs to overcome the lower retention rates of fixed-fixed RBFPDs. This retrospective study aimed to evaluate the long-term longevity and the patient-reported outcomes of posterior FM-RBFPDs. METHODS: Posterior FM-RBFPDs that had been inserted at least five years were reviewed. Survival was "retention of the original prosthesis in mouth" and success was "survival of prosthesis and absence of complications requiring treatment intervention". Prosthesis location, number of units, insertion year, tooth/teeth replaced and operator experience were collected. Patients' acceptance to FM-RBFPDs were assessed using prosthesis satisfaction questionnaire and Oral Health Impact Profile (OHIP-49). Results were analyzed using log-rank and cox-regression tests at significance level α = 0.05. RESULTS: One-hundred-and-one prostheses were examined. The mean observation time was 126.4 ±â€¯32.2 months. Thirty-six (35.6%) and 63 (62.4%) FM-RBFPDs were rated as success and survival respectively. Prostheses inserted after year 2001 (n = 69) experienced 42.0% (n = 29) success and 75.4% (n = 52) survival, and its survival rate was significantly better than those inserted in or before 2001 (p = 0.01). Five- and ten-year cumulative survival probability of FM-RBFPDs inserted after year 2001 were 82.3% and 74.1% respectively. The most frequent complications were debonding among 34 (33.7%) prostheses. Patients' acceptance were high. CONCLUSIONS: More recently inserted prostheses showed improved longevity and patients' acceptance to posterior FM-RBFPDs were high. CLINICAL SIGNIFICANCE: Fix-Movable RBFPDs are a viable tooth replacement option in the posterior region.

Combination immunosuppressant therapy and lupus nephritis outcome: a hospital-based study.

Lupus nephritis (LN) is the leading cause of mortality in lupus patients. This study aimed to investigate the treatment outcome and renal histological risk factors of LN in a tertiary referral center. Between 2006 and 2017, a retrospective observational study enrolled 148 biopsy-proven LN patients. After propensity score matching, 75 cases were included for further analysis. The classification and scoring of LN were assessed according to the International Society of Nephrology/Renal Pathology Society. Treatment response was evaluated by daily urine protein and urinalysis at two years after commencing induction treatment and the development of end-stage renal disease (ESRD). In total, 50.7% patients achieved complete remission (CR) or partial remission (PR), while 49.3% patients were categorized as nonresponders. Therapeutic responses in terms of CR/PR rates were associated with Systemic Lupus Erythematosus Disease Activity Index scores (odds ratio (OR): 1.34, 95% confidence interval (CI): 1.12-1.60, p = 0.001). Moreover, higher baseline creatinine levels (hazard ratio (HR): 2.10, 95% CI: 1.29-3.40, p = 0.003), higher renal activity index (HR: 1.30, 95% CI: 1.07-1.58, p = 0.008) and chronicity index (HR: 1.40, 95% CI: 1.06-1.85, p = 0.017) predicted ESRD. Among pathological scores, cellular crescents (HR: 4.42, 95% CI: 1.01-19.38, p = 0.049) and fibrous crescents (HR: 5.93, 95% CI: 1.41-24.92, p = 0.015) were independent risk factors for ESRD. In conclusion, higher lupus activity was a good prognostic marker for renal remission. Renal histology was predictive of ESRD. Large-scale prospective studies are required to verify the efficacy of mycophenolate in combination with azathioprine or cyclosporine in LN patients.

An accurate potential model for the a3Σu+ state of the alkali dimers Na2, K2, Rb2, and Cs2.

A modified semi-empirical Tang-Toennies potential model is used to describe the a3Σu+ potentials of the alkali dimers. These potentials are currently of interest in connection with the laser manipulation of the ultracold alkali gases. The fully analytical model is based on three experimental parameters, the well depth De, well location Re, and the harmonic vibrational frequency ωe of which the latter is only slightly optimized within the range of the literature values. Comparison with the latest spectroscopic data shows good agreement for Na2, K2, Rb2, and Cs2, comparable to that found with published potential models with up to 55 parameters. The differences between the reduced potential of Li2 and the conformal reduced potentials of the heavier dimers are analyzed together with why the model describes Li2 less accurately. The new model potential provides a test of the principle of corresponding states and an excellent first order approximation for further optimization to improve the fits to the spectroscopic data and describe the scattering lengths and Feshbach resonances at ultra-low temperatures.

Suicidal drug overdose in patients with systemic lupus erythematosus, a nationwide population-based case-control study.

OBJECTIVE: A four-fold increase of suicide mortality has been demonstrated in systemic lupus erythematosus (SLE) patients. Prior studies showed that the most common method of suicide attempts in SLE patients involves drug overdose. Therefore, we conducted a nationwide population-based case-control study to elucidate factors associated with drug overdose as suicide attempt in SLE patients. METHODS: This study was based on the National Health Insurance Research Database in Taiwan. We identified all SLE patients from January 1, 2000 to December 31, 2010. Patients who had suicidal drug overdose (SDO) were selected as cases while age- and gender-matched patients who did not have SDO were selected as controls. RESULTS: The incidence rate of SDO in SLE patients was 291 cases per 100,000 person-years, higher than that in the general population (160 cases per 100,000 person-years). In a multivariate logistic regression analysis, we observed that SDO was associated with psychiatric disorders such as depressive disorders (odds ratio: 8.36, 95% confidence interval (CI): 5.60-12.48) and insomnia (odds ratio: 2.71, 95% CI: 1.73-4.25), and lower monthly income (odds ratios: 2.74 to 3.50) in SLE patients. CONCLUSION: SDO is associated with psychiatric disorders such as depressive disorders and insomnia, and lower monthly income in SLE patients.

Apelin polymorphism predicts blood pressure response to losartan in older Chinese women with essential hypertension.

We determined whether the blood pressure response to losartan in an older Chinese population with essential hypertension was associated with apelin gene polymorphisms. We genotyped the -1860T>C polymorphism of the apelin gene in a case-control study of 222 patients with hypertension and 250 controls. Following 24 weeks of treatment with losartan (50 mg/day), reductions in systolic blood pressure were significantly different among the additive (CT vs CC vs TT), dominant (TT vs CC/CT), and recessive models (CC vs CT/TT; all P < 0.05) in women but not in men. In the additive model, the TT group showed the greatest reductions in systolic BP (23 ± 10 mmHg) after treatment. The CT group showed greater reductions in systolic BP (21 ± 11 mmHg) compared to the CC group (8 ± 3 mmHg) (P < 0.05). The reductions in systolic BP of the TT and CT/CC groups were 23 ± 10 and 19 ± 10 mmHg, respectively. The reductions in systolic BP of the CC and TT/CT groups were 8 ± 3 and 21 ± 10 mmHg, respectively. After adjustment for confounding factors, quantitative trait analysis with a general linear model showed that the female patients with TT genotype showed greater reductions in systolic blood pressure after 24 weeks of treatment compared to the patients with the C allele (P < 0.05). The apelin -1860T>C genotype may play an important predictive role in the response to losartan in hypertensive women.

Communication: A simple full range analytical potential for H2b(3)∑u (+), H-He (2)∑(+), and He2 (1)∑g (.).

The Tang-Toennies potential for the weakly interacting systems H2b(3)Σu (+), H-He (2)Σ(+), and He2 (1)Σg (+) is extended down to the united atom limit of vanishing internuclear distance. A simple analytic expression connects the united atom limiting potential with the Tang-Toennies potential in the well region. The new potential model is compared with the most recent ab initio calculations for all three systems. The agreement is better than 20% (H2 and He2) or comparable with the differences in the available ab initio calculations (H-He) over six orders of magnitude corresponding to the entire range of internuclear distances.

Corresponding states principle and van der Waals potentials of Zn2, Cd2, and Hg2.

Based on the assumptions that the corresponding states principle is valid for the group 12 dimers and that the interaction potentials of these dimers can be described by the Tang-Toennies potential model, a set of correlation relations between the spectroscopic constants of these dimers are derived. Some recently measured spectroscopic constants satisfy these relations quite well, but older experimental data do not. These recent spectroscopic constants and the newly available dispersion coefficients are used to construct the entire van der Waals potentials of Zn2, Cd2, and Hg2. There are indications that the ground state Hg2 potential predicted by the present study is possibly the most accurate to date. No unequivocal conclusion can be made for Zn2 and Cd2 potentials. Compared with the recent experiments, the present Zn2 bond length is eight percent too small, and the present Cd2 bond length is eight percent too large. However, both Zn2 and Cd2 bond lengths predicted by the present study are in good agreement with the quantum Monte Carlo results.

Dynamic polarizabilities of Zn and Cd and dispersion coefficients involving group 12 atoms.

The refractive index data for Zn and Cd measured by Goebel and Hohm are analyzed with a three-term Maxwell-Sellmeier expression which incorporates the experimental oscillator strengths of the first two dipole transitions. These expressions are extended to imaginary frequencies for the determination of the upper and lower bounds of the dynamic polarizabilities α(iω), from which the van der Waals coefficients of two-body interactions and the non-additive three-body interactions are generated. The determined C(6) values for Zn(2) (359±8 a.u.) and Cd(2) (686±10 a.u.) are much larger than those originally estimated by Goebel and Hohm. This is because their one-term approximation of α(ω), which fits the measurements very well in the normal frequency range, greatly underestimates α(iω) when the frequency is extended into the imaginary domain. On the other hand, the present results of heteronuclear interactions verify once again that Tang's one-term approximation of α(iω) leads to accurate combining rules. The two- and three-body interaction coefficients between group 12 atoms (Zn, Cd, Hg) and the alkali, alkaline-earth, rare-gas atoms, and some molecules are estimated with these combining rules.

A bio-inspired two-layer multiple-walled carbon nanotube-polymer composite sensor array and a bio-inspired fast-adaptive readout circuit for a portable electronic nose.

We report a fully integrated, portable, battery-operated electronic nose system comprising a bio-inspired two-layer multiple-walled carbon nanotube (MWNT)-polymer composite sensor array, a bio-inspired fast-adaptive readout circuit, and a microprocessor embedded with a pattern recognition algorithm. The two-layer MWNT-polymer composite sensor is simple to operate, and the membrane quality can be easily controlled. These two-layer membranes have improved sensitivity and stability. The fast-adaptive readout circuit responds to the sensor response, while tuning out the long-term constant background humidity, temperature, and odors. This portable electronic nose system successfully classified four complex alcohol samples 40 times for each sample; these samples were sake, sorghum liquor, medical liquor, and whisky.

Asymptotic exchange energy of heteronuclear dimers.

A simple expression for the asymptotic exchange energy of heteronuclear dimers is derived from the surface integral method. A five-dimensional hypersurface, consisting of all spherical surfaces centered at the nucleus of the atom with higher ionization energy, more appropriate for the case where the two atoms have different ionization energies, is used in the surface integral. All integrals are carried out analytically. Compared with the exchange energy of Smirnov and Chibisov, which is also obtained from the surface integral method with a hypersurface consisting of all infinite planes perpendicular to the internuclear axis, the present result is much simpler. The exchange energies of alkali hydrides are computed as an illustration. It is shown that the present method and the method of Smirnov and Chibisov are complementary to each other.

Corresponding states principle for the alkaline earth dimers and the van der Waals potential of Ba2.

A simple method based on the corresponding states principle and the Tang-Toennies potential model is used for the determination of the ground state van der Waals potential of barium dimer. The potential energy curve calculated from the theoretical dispersion coefficients and the experimental vibrational frequency is comparable to other quantum chemical calculations. To assess its validity, the same method is used to calculate the potential of the strontium dimer, for which there are many theoretical and experimental determinations. A comparison with experimental measurements suggests that the present method is highly accurate. The potentials of five alkaline earth dimers are compared. The potentials of Mg(2), Ca(2), Sr(2), and Ba(2) are shown to be nearly conformal with each other. The potential of Be(2) has a different shape.

The van der Waals potential of the magnesium dimer.

The ground state van der Waals potential of the magnesium dimer is described by the Tang-Toennies potential model, which requires five essential parameters. Among them, the three dispersion coefficients C(6), C(8), and C(10) are available from accurate ab initio calculations. The other two are the Born-Mayer parameters in A exp(-bR). In this paper, we show that A and b can be determined from the self-consistent Hartree-Fock calculations and the experimental dissociation energy D(0). The predicted well depth D(e) and equilibrium distance R(e) are in nearly perfect agreement with the experiment. In fact, the entire potential energy curve, which is given by a single analytic function, is in excellent agreement with the pointwise potential energies constructed from the spectroscopic measurements in the interval of 6a(0)-14a(0) and in good agreement with the experimental repulsive potential determined from Franck-Condon factors of the bound-free transitions for R less than 6a(0). The reduced potential of Mg(2) is analyzed in terms of its components, and the number of terms in the dispersion series necessary for convergence is investigated.

The ground state van der Waals potentials of the strontium dimer and strontium rare-gas complexes.

The entire ground state potential energy curve of the strontium dimer is accurately described by the Tang-Toennies potential model defined by the three dispersion coefficients and two well parameters. The predicted vibrational frequency, anharmonicity, and vibration-rotation coupling constant are in excellent agreement with experiment. The Sr(2) reduced potential is almost identical to that of Ca(2) and Hg(2), providing further evidence to the conjecture that the van der Waals dimer potentials of group IIA and group IIB elements have the same shape, which is different from that of rare-gas dimers. The potentials of Sr-RG complexes (RG=He,Ne,Ar,Kr,Xe) are generated by the same potential model with its parameters calculated with combining rules. These potentials are shown to have the same shape which is between that of the strontium and rare-gas dimers.

A combining rule calculation of the ground state van der Waals potentials of the mercury rare-gas complexes.

The ground state van der Waals potentials of the Hg-RG (RG = He,Ne,Ar,Kr,Xe) systems are generated by the Tang-Toennies potential model. The parameters of the model are calculated from the potentials of the homonuclear mercury and rare-gas dimers with combining rules. The predicted spectroscopic parameters for these mercury rare-gas complexes are in good agreement with available experimental values, except for Hg-He. In the repulsive and potential well regions, the predicted potential energy curves agree with the available experimental hybrid potentials, but they differ in the long range part of the potential. On the other hand, the present potentials are in agreement with the ab initio CCSD(T) calculations in the long range part of the potential, but there are some differences in the short repulsive regions. According to the present theory, the reduced potential curves of these five systems, including Hg-He, are almost identical to each other. This reduced potential curve can also describe, within a few percent, the five reduced potentials obtained from the ab initio CCSD(T) calculations. These reduced potentials have a potential bowl that is wider than that of the rare-gas dimers, but narrower than the mercury dimer.

The ground state van der Waals potentials of the calcium dimer and calcium rare-gas complexes.

The entire potential energy curve of the Ca(2) ground state generated by the Tang-Toennies potential model with its parameters specified by the three theoretical dispersion coefficients and the experimentally determined equilibrium distance and well depth is in excellent agreement with the accurate experimental potential of Allard et al. [Phys. Rev. A 66, 042503 (2002)]. The reduced potential of Ca(2) is almost identical with that of Hg(2). This leads to the conjecture that the ground state van der Waals dimer potentials of group IIA, except Be, and group IIB elements have the same shape, which is different from that of the rare-gas dimers. The potentials of Ca-RG complexes (RG=He,Ne,Ar,Kr,Xe) are generated by the same potential model with its parameters calculated from the homonuclear potentials of calcium and rare-gas dimers with combining rules. The predicted spectroscopic constants are comparable to other theoretical computations.