Anion Photoelectron Spectroscopy and Quantum Chemistry Calculations of Gas-Phase TaSi17Ì and TaSi18Ì Clusters: Structural Determination, Bonding Characteristics, and Multiplicity of Structural Forms.

This study explores the structures and chemical bonding properties of TaSi17̅ and TaSi18̅ clusters by employing anion photoelectron spectroscopy and theoretical computations. Utilizing CALYPSO and ABCluster programs for initial structure prediction, B3LYP hybrid functional for optimization, and CCSD(T)/def2-TZVPPD level for energy calculations, the research identifies the most stable isomers of these clusters. Key findings include the identification of two coexisting low-energy isomers for TaSi17̅, exhibiting Ta-endohedral fullerene-like cage structures, and the lowest-energy structures of TaSi17̅ and TaSi18̅ anions can be considered as derived from the TaSi16̅ superatom cluster. The study enhances the understanding of group 14 element chemistry and guides the design of novel inorganic metallic compounds, potentially impacting materials science.

Structural evolution and bonding properties of Nb1-2Gen-/0 (n = 3-7) clusters: Anion photoelectron spectroscopy and theoretical calculations.

This study presents a collaborative experimental and theoretical investigation into the structures and electronic properties of niobium-doped germanium clusters. Anion photoelectron spectra for Nb1-2Gen- (n = 3-7) clusters were acquired using 266 nm photon energies, enabling the determination of adiabatic detachment energies and vertical detachment energies. In conjunction with these experimental measurements, density functional theory (DFT) calculations were conducted to validate the experimentally obtained electron detachment energies and elucidate the geometric and electronic structures of each anionic cluster. The agreement between DFT calculations and experimental data establishes a solid foundation for assessing the structural evolution and electronic properties of niobium-doped germanium clusters. It is noted that both neutral and anionic clusters exhibit predominantly similar overall structural characteristics, with the exception of Nb2Ge6- and Nb2Ge6. Furthermore, this investigation emphasizes the exceptional chemical stability of the D3d symmetric chair-shaped structure in Nb2Ge6-, providing insights into its bonding characteristics.

Structural Determination and Bonding Characteristics of the Gas-Phase Ta2Si2Ì Anion and Its Neutral: Anion Photoelectron Spectroscopy and Theoretical Studies.

The structures and bonding characteristics of Ta2Si2̅/0 clusters are investigated using anion photoelectron spectroscopy and quantum chemical calculations. The vertical detachment energy of the Ta2Si2̅ anion is measured to be 2.00 ± 0.08 eV using the 266 nm photon. It is found that the Ta2Si2̅ anion has three low-energy isomers with a C2v symmetric Ta-Ta dibridged structural framework, all of which contribute to the experimental photoelectron spectrum, while the Ta2Si2 neutral also has a C2v symmetric Ta-Ta dibridged structural framework. The charge-transfer from Ta atoms to Si atoms is discovered using atomic dipole moment corrected Hirshfeld analysis for the Ta2Si2̅ anion and Ta2Si2 neutral. Chemical bonding investigations show that both the Ta2Si2̅ anion and Ta2Si2 neutral have a strong covalent Ta-Ta bond, as well as σ and π double bonding patterns. Furthermore, the Ta atoms are linked together by a single 2c-2e Ta2 σ bond, whereas the Si atoms are linked together with the Ta atoms via four 2c-2e TaSi σ bonds, two 3c-2e TaSi2 σ bonds, one 4c-2e Ta2Si2 σ bond, and one 4c-2e Ta2Si2 π bond.

Adjusting for covariates in analysis based on restricted mean survival times.

We summarize extensions to the analysis of restricted mean survival time (RMST) in the context of time-to-event outcomes. The RMST estimate and its inference are based on the classical Kaplan-Meier curves. When covariate effects are considered, an adjusted RMST (ARMST) estimate can be derived analogously based on adjusted Kaplan-Meier curves. The adjusted Kaplan-Meier Estimator (AKME) was developed to reduce confounding by the method of inverse probability of treatment weighting. We will show how the ARMST method combines the concepts of the RMST and AKME to make inferences. Two regression based methods to adjust for potential covariate effect on the RMST estimates will be compared with the ARMST approach. Simulation studies are performed to compare the different methods with and without covariate adjustments. In addition, we will summarize the extension of RMST and ARMST to the setting with competing risks. The restricted mean time lost (RMTL) and adjusted RMTL (ARMTL) are estimates of interest from cumulative incidence curves. A phase 3 oncology clinical trial example is provided to demonstrate the applications of these methods.

Association of frailty with quality of life in older hypertensive adults: a cross-sectional study.

BACKGROUND: Hypertension is one of the most common chronic cardiovascular diseases in older adults. Frailty and hypertension often coexist in older people, but few studies have explored frailty in older hypertensive adults. We aimed to explore the association of frailty with quality of life in older hypertensive adults. METHOD: We collected the data of 291 patients with hypertension aged ≥ 60 years. Blood pressure was measured with a standard aneroid sphygmomanometer and an ambulatory blood pressure monitor. The characteristics of the Fried phenotype were used to assess physical frailty. The Medical Outcomes Study's 36-Item Short Form Health Survey (SF-36) was used to assess the quality of life. RESULTS: Forty-eight (16.5%) patients were frail. Compared with pre-frail or robust older hypertensive patients, those who were frail were older, had higher incidences of living alone, a longer duration of hypertension, lower grip strength, and slower walking speed. Moreover, frail patients had a lower diastolic blood pressure (DBP) and mean arterial pressure (MAP), more chronic diseases, a lower proportion of beta-blocker usage, and worse quality of life. Frailty was positively correlated with pulse pressure and negatively correlated with DBP and MAP, but these associations disappeared after adjustment by age. The SF-36 score was negatively correlated with frailty and positively correlated with grip strength and walking speed. After adjusting for age, the SF-36 total score remained negatively correlated with frailty and positively correlated with walking speed. Frailty states remained significantly associated with the SF-36 score. CONCLUSION: Frailty was associated with a worse quality of life in older adults with hypertension. Frailty prevention and intervention may help improve the quality of life of older adults with hypertension.

The combined effect of retinoic acid and LSD1 siRNA inhibition on cell death in the human neuroblastoma cell line SH-SY5Y.

AIMS: Retinoic acid (RA) is used pharmacologically to treat neuroblastoma (NB), but its mechanism of action is unclear and it has limited use against refractory disease. This study investigated the expression of LSD1 (also known as KDM1A) in tumors, and assessed the efficacy of combining RA treatment with the inhibition of LSD1 expression. METHODS: LSD1 protein expression levels were assessed semi-quantitatively in specimens of NB and ganglioneuroblastoma (GNB), along with the apoptosis markers, Bcl-2 and Bax. The combined effect of RA and LSD1 siRNA inhibition on cell death was then assessed in the human neuroblastoma cell line, SH-SY5Y. RESULTS: LSD1 expression was higher in NB compared to GNB, and LSD1 overexpression directly correlated with Bcl-2 expression and inversely correlated with Bax expression. RA treatment or LSD1 siRNA inhibition alone inhibited the growth of SH-SY5Y cells, but did not cause significant apoptosis or cell death. Combined treatment led to higher rates of SH-SY5Y cell death, as reflected by an increased Bax/Bcl-2 ratio. CONCLUSIONS: The combined effect of RA and LSD1 siRNA inhibition had a synergistic effect on promoting the apoptosis of NB cells. This novel approach may improve the clinical treatment of NB.

Effect of Aeolian Sand Powder Addition on Frost Resistance of Concrete Pavement.

In order to solve the problem of exploring the freeze-thaw characteristics of modified aeolian sand mixed with cement and silt, the authors propose a freeze-thaw cycle test of modified aeolian sand under the condition of mixing 5% cement and silt with different contents. In this experiment, under freeze-thaw conditions, its intensity decay and mass volume change law and the changes of freeze-thaw characteristics were comprehensively characterized by multiple indicators. The result shows that, after two freeze-thaw cycles, the compressive strength and peak strain of the improved aeolian sand were positively correlated with the silt content. With the increase of the number of freeze-thaw cycles, the compressive and antidestruction capacity of the improved aeolian sand with high silt content and low silt content decreased significantly. 15% silt content improves the structural stability of aeolian sand. It is proved that the authors' experiment can intuitively and effectively reflect the change law of soil strength after freezing and thawing of such improved aeolian sandy soil, which has displayed significance.

Signature of Au as a Halogen.

Gold, although chemically inert in its bulk state, is reactive at the nanoscale and, in small clusters, even behaves like a hydrogen atom. Using a photoelectron spectroscopy experiment and first-principles theory, we show that Au also behaves like a halogen in small clusters. This is evident not only in strong resemblance between the photoelectron spectra of Au2F- and AuF2- but also in Au exhibiting one of the signature properties of halogens, its ability to form superhalogens with electron affinities higher than that of any halogen atom. For example, the electron affinity (EA) of Au2F- is 4.17 eV, while AuF2-, a known superhalogen, has an EA of 4.47 eV. Of particular interest is Au2F2, which, in spite of being a closed-shell system, is a pseudohalogen with an EA of 3.3 ± 0.1 eV. Here, one of the Au atoms behaves like a halogen, making Au2F2 mimic the property of AuF3.

A new semiparametric estimation method for accelerated hazard model.

The accelerated hazard model has been proposed for more than a decade. However, its application is still very limited, partly due to the complexity of the existing semiparametric estimation method. We propose a new semiparametric estimation method based on a kernel-smoothed approximation to the limit of a profile likelihood function of the model. The method leads to smooth estimating equations and is easy to use. The estimates from the method are proved to be consistent and asymptotically normal. Our numerical study shows that the new method is more efficient than the existing method. The proposed method is employed to reanalyze the data from a brain tumor treatment study.

[Analysis of volatile oil from different parts of Litsea cubeba].

OBJECTIVE: To analyze and compare the compounds of the essential oil from the fruits and leaves and roots of Litsea cubeba. METHODS: With steam distillation extraction method, Litsea cubeba essential oil was extracted from the fruits and leaves and roots. The qualitative and quantitative analysis of Litsea cubeba essential oil were carried out with GC-MS. RESULTS: 18 compounds were identified from the fruits (93.57% of the total essential oil) and 17 compounds were identified from the roots (98.01% of the total essential oil) and 28 compounds were identified from the leaves (95.33% of the total essential oil). The main constituents of the fruits essential oil were Citral, Limonene, and so on; The main constituents of the roots essential oil were Citral, 6-Octenal, 3,7-dimethyl-, 2-Octen-1-ol, 3,7-dimethyl-, and so on; The main constituents of the leaves essential oil were Citral, Eucalyptol, Citronellol, 6-Octenal, 3,7-dimethyl-, and so on. CONCLUSION: The constituents of volatile oil extracted from the different parts of Litsea cubeba were different, so they should be utilized differently in clinical application and study in great depth.

Starch-enhanced degradation of HMW PAHs by Fusarium sp. in an aged polluted soil from a coal mining area.

The present study used strain ZH-H2 (Fusarium sp.) isolated by our group as the PAH-degrading strain and 5-6-rings PAHs as degradation objects. The soil incubation experiment was carried out to investigate the starch-enhanced degradation effects of HMW PAHs by Fusarium sp. in an Aged Polluted Soil from a Coal Mining Area. The results showed that the removal rates of BaP, InP and BghiP increased with increasing inoculation rate of ZH-H2 in the unsterile aged polluted soil of coal mining area, with the exception of BbF degradation which increased in the H2 treatment and then decreased. Different addition dosage of starch apparently resulted in degradation of 4 PAHs in soil, with removal rates of 14.47% for BaP, 23.83% for DbA, 30.77% for BghiP and 31.00% for InP obtained with treatment D2, respectively higher than in treatment D1. So starch addition apparently enhanced the degradation of the 4 PAHs, especially InP and BghiP, by native microbes in the aged HMW PAH-polluted soil. By adding starch to these aged polluted soils with inoculated strain ZH-H2, HMW-PAHs degradation was further improved and addition of 0.5 g kg-1 starch to soils with 1.0 g kg-1 Fusarium ZH-H2 (D2 + H2) performed best to the 4 HMW-PAHs in all of these combination treatments by a factor of up to 3.09, depending on the PAH. We found that the highest polyphenol oxidase activities under D2 + H2 treatments are consistent with the results of removal rates of 4 PAHs. Our findings suggest that the combination of Fusarium sp. ZH-H2 and starch offers a suitable alternative for bioremediation of aged PAH-contaminated soil in coal mining areas, with a recommended inoculation size of 0.5 g Fusarium sp. ZH-H2 and addition of 0.5 g kg-1 starch per kg soil.