187 research outputs found
cis-Diaquabis(2,2′,2′′-tripyridylamine)zinc(II) bis(perchlorate)
In the title compound, [Zn(2,2′,2′′-tpa)2(H2O)2](ClO4)2 (2,2′,2′′-tpa is 2,2′,2′′-tripyridylamine, C15H12N4), the Zn center lies on a twofold axis and is coordinated octahedrally by two water molecules and two bidentate 2,2′,2′′-tpa ligands. The perchlorate anions are linked to the coordinated water molecules in the complex cations via O—H⋯O hydrogen bonds
Comparison of three magnetization transfer ratio parameters for assessment of intestinal fibrosis in patients with Crohn’s disease
Psychological well-being and associated factors among parents of adolescents with non-suicidal self-injury: a cross-sectional study
BackgroundNon-suicidal self-injury (NSSI) impacts not only adolescents who engage in it but also their parents. However, there has been limited research into the psychological well-being of these parents. This cross-sectional study aims to investigate the symptoms of anxiety and depression among parents of adolescents who engaged in NSSI in China and the factors associated with them.MethodsA total of 400 parents of adolescents with NSSI were included. Socio-demographic information of these parents was collected. The Generalized Anxiety Disorder 7-item (GAD-7), the Patient Health Questionnaire 9-item (PHQ-9), and the Connor-Davidson Resilience Scale (CD-RISC) were used to assess symptoms of anxiety, depression, and psychological resilience, respectively.ResultsThe majority of the parents were female (83.5%), married (86.3%), and had a senior high school or equivalent and lower education level (67.1%). The study found that 35.3% of the parents experienced clinically significant symptoms of anxiety (GAD-7 ≥ 7) and 40.1% had clinically significant symptoms of depression (PHQ-9 ≥ 7). Parents with larger ages and lower levels of psychological resilience were more likely to experience symptoms of anxiety and depression (p < 0.05). Parents who reported bad parent–child relationships showed a higher level of anxiety.ConclusionThis study provides important insights into the symptoms of anxiety and depression among parents of adolescents with NSSI. Parental age, parent–child relationship, and psychological resilience were associated with symptoms of anxiety and depression in these parents. Implications for the development of interventions aimed at addressing symptoms of anxiety and depression in parents of adolescents with NSSI were discussed
The investigation into the adsorption removal of ammonium by natural and modified zeolites: Kinetics, isotherms, and thermodynamics
The objectives of this study were to modify Chinese natural zeolite by NaCl and to investigate its suitability as a low-cost clay adsorbent to remove ammonium from aqueous solution. The effect of pH on ammonium removal was investigated by batch experiments. The findings indicated that pH has a significant effect on the removal of ammonium by M-Zeo and maximum adsorption occured at pH 8. Ion exchange dominated the ammonium adsorption process at neutral pH, with the order of exchange selectivity being Na+ > Ca2+ > K+ > Mg2+. The Freundlich model provided a better description of the adsorption process than the Langmuir model. The maximum ammonium adsorption capacity was 17.83 mg/g for M-Zeo at 293K. Considering the adsorption isotherms and thermodynamic studies, the adsorption of ammonium by M-Zeo was endothermic and spontaneous chemisorption. Kinetic studies indicated that the adsorption of ammonium onto M-Zeo is well fitted by the pseudo-second-order kinetic model. Ea in the Arrhenius equation suggested the adsorption of ammonium on M-Zeo was a fast and diffusion-controlled process. The regeneration rate was 90.61% after 5 cycles. The removal of ammonium from real wastewater was carried out, and the removal efficiency was up to 99.13%. Thus, due to its cost-effectiveness and high adsorption capacity, M-Zeo has potential for use in ammonium removal from aqueous solutions.Keywords: zeolite, sodium chloride modified, adsorbent, regeneration, wastewate
Multiple abiotic and biotic drivers of long-term wood decomposition within and among species in the semi-arid inland dunes:A dual role for stem diameter
Litter decomposition in sunny, semi-arid and arid ecosystems is controlled by both biotic factors including litter traits and abiotic factors including UV light, but for wood decomposition it still remains uncertain which of these environmental factors are the predominant controls among different woody species. In these dry ecosystems, it is likely that the stem diameter and spatial position of the dead wood are of particular importance especially where wood can be buried versus exposed due to substrate displacement by wind. Here we focus on the fact that stem diameter can affect decomposition rates both via the relative surface exposure to sunlight or soil and via higher resource quality of narrower stems to decomposers. In a field manipulation experiment, we investigated the relative importance of litter position (sand burial vs. surface vs. suspended above the surface), UV radiation (block versus pass) and stem diameter class (<2, 2–4, 4–8, 8–13 and 13–20 mm) on the mass loss of woody litters of four shrub species in an inland dune ecosystem in northern China. We found that after 34 months of in situ incubation, the mass loss of buried woody litters was three times faster than those of suspended and surface woody litters (53.5 ± 2.7%, 17.0 ± 1.0% and 14.4 ± 1.2%, respectively). In surface and suspended positions, litter decomposition rates were almost equally low and most mass loss was during the first 2 years, when bark was still attached and UV radiation had no significant effect on woody litter mass loss. These findings suggest that sand burial is the main environmental driver of wood decomposition via its control on microbial activity. Moreover, wood N and diameter class were the predominant factors driving woody litter decomposition. A key finding was that wider stems had slower litter decomposition rates not only directly (presumably via greater relative surface exposure) but also indirectly via their higher wood dry matter content or lower wood N; these effects were modulated by litter position. Our findings highlight a dual role of stem diameter on wood decomposition, that is, via relative surface exposure and via wood traits. The accuracy and confidence of global carbon cycling models would be improved by incorporating the different effects of stem diameter on woody litter decomposition and below-ground wood decomposition processes in drylands
Seed Germination Responses to Seasonal Temperature and Drought Stress Are Species‐Specific but Not Related to Seed Size in a Desert Steppe: Implications for Effect of Climate Change on Community Structure
Investigating how seed germination of multiple species in an ecosystem responds to environmental conditions is crucial for understanding the mechanisms for community structure and biodiversity maintenance. However, knowledge of seed germination response of species to environmental conditions is still scarce at the community level. We hypothesized that responses of seed germination to environmental conditions differ among species at the community level, and that germination response is not correlated with seed size. To test this hypothesis, we determined the response of seed germination of 20 common species in the Siziwang Desert Steppe, China, to seasonal temperature regimes (representing April, May, June, and July) and drought stress (0, −0.003, −0.027, −0.155, and −0.87 MPa). Seed germination percentage increased with increasing temperature regime, but Allium ramosum, Allium tenuissimum, Artemisia annua, Artemisia mongolica, Artemisia scoparia, Artemisia sieversiana, Bassia dasyphylla, Kochia prastrata, and Neopallasia pectinata germinated to \u3e60% in the lowest temperature regime (April). Germination decreased with increasing water stress, but Allium ramosum, Artemisia annua, Artemisia scoparia, Bassia dasyphylla, Heteropappus altaicus, Kochia prastrata, Neopallasia pectinata, and Potentilla tanacetifolia germinated to near 60% at −0.87 MPa. Among these eight species, germination of six was tolerant to both temperature and water stress. Mean germination percentage in the four temperature regimes and the five water potentials was not significantly correlated with seed mass or seed area, which were highly correlated. Our results suggest that the species‐specific germination responses to environmental conditions are important in structuring the desert steppe community and have implications for predicting community structure under climate change. Thus, the predicted warmer and dryer climate will favor germination of drought‐tolerant species, resulting in altered proportions of germinants of different species and subsequently change in community composition of the desert steppe
3-Aminobenzonitrile–3,5-dinitrobenzoic acid (1/1)
The asymmetric unit of the title co-crystal, C7H6N2·C7H4N2O6, contains two formula units of both components. The crystal structure is stabilized by intermolecular O—H⋯O, N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds, generating a two-dimensional wave-like network. π–π stacking interactions [centroid–centroid distances = 3.702 (2), 3.660 (2)and 3.671 (2) Å] stabilize the crystal packing
An Enhanced Grey Wolf Optimization Based Feature Selection Wrapped Kernel Extreme Learning Machine for Medical Diagnosis
In this study, a new predictive framework is proposed by integrating an improved grey wolf optimization (IGWO) and kernel extreme learning machine (KELM), termed as IGWO-KELM, for medical diagnosis. The proposed IGWO feature selection approach is used for the purpose of finding the optimal feature subset for medical data. In the proposed approach, genetic algorithm (GA) was firstly adopted to generate the diversified initial positions, and then grey wolf optimization (GWO) was used to update the current positions of population in the discrete searching space, thus getting the optimal feature subset for the better classification purpose based on KELM. The proposed approach is compared against the original GA and GWO on the two common disease diagnosis problems in terms of a set of performance metrics, including classification accuracy, sensitivity, specificity, precision, G-mean, F-measure, and the size of selected features. The simulation results have proven the superiority of the proposed method over the other two competitive counterparts
High-fat diets enhance and delay ursodeoxycholic acid absorption but elevate circulating hydrophobic bile salts
Background: Ursodeoxycholic acid (UDCA) is a natural drug essential for the treatment of cholestatic liver diseases. The food effects on the absorption of UDCA and the disposition of circulating bile salts remain unclear despite its widespread global uses. This study aims to investigate the effects of high-fat (HF) diets on the pharmacokinetics of UDCA and disclose how the circulated bile salts were simultaneously perturbed.Methods: After an overnight fast, a cohort of 36 healthy subjects received a single oral dose (500 mg) of UDCA capsules, and another cohort of 31 healthy subjects received the same dose after consuming a 900 kcal HF meal. Blood samples were collected from 48 h pre-dose up to 72 h post-dose for pharmacokinetic assessment and bile acid profiling analysis.Results: The HF diets significantly delayed the absorption of UDCA, with the Tmax of UDCA and its major metabolite, glycoursodeoxycholic acid (GUDCA), changing from 3.3 h and 8.0 h in the fasting study to 4.5 h and 10.0 h in the fed study, respectively. The HF diets did not alter the Cmax of UDCA and GUDCA but immediately led to a sharp increase in the plasma levels of endogenous bile salts including those hydrophobic ones. The AUC0–72h of UDCA significantly increased from 25.4 μg h/mL in the fasting study to 30.8 μg h/mL in the fed study, while the AUC0–72h of GUDCA showed no difference in both studies. As a result, the Cmax of total UDCA (the sum of UDCA, GUDCA, and TUDCA) showed a significant elevation, while the AUC0–72h of total UDCA showed a slight increase without significance in the fed study compared to the fasting study.Conclusion: The HF diets delay UDCA absorption due to the extension of gastric empty time. Although UDCA absorption was slightly enhanced by the HF diets, the beneficial effect may be limited in consideration of the simultaneous elevation of circulating hydrophobic bile salts
Patterns of Cough Medication Prescribing among Patients with Chronic Cough in Florida: 2012–2021
Among patients with chronic cough (CC) in the 2012–2021 statewide OneFlorida Clinical Research Consortium database, we examined trends in cough medication (CM) prescribing prevalence over time in repeated cross-sectional analyses and identified distinct CM utilization trajectories using group-based trajectory modeling (GBTM) in a retrospective cohort study. Among eligible adults (≥18 years) without cancer/benign respiratory tumor diagnoses, we identified CC patients and non-CC patients with any cough-related diagnosis. In the GBTM analysis, we calculated the number of monthly prescriptions for any CMs (excluding gabapentinoids) during the 12 months from the first qualifying cough event to identify distinct utilization trajectories. From 2012 to 2021, benzonatate (9.6% to 26.1%), dextromethorphan (5.2% to 8.6%), and gabapentinoid (5.3% to 14.4%) use increased among CC patients, while opioid antitussive use increased from 2012 to 2015 and decreased thereafter (8.4% in 2012, 14.7% in 2015, 6.7% in 2021; all p < 0.001). Of 15,566 CC patients and 655,250 non-CC patients identified in the GBTM analysis, CC patients had substantial burdens of respiratory/non-respiratory comorbidities and healthcare service and concomitant medication use compared to non-CC patients. Among CC patients, GBTM identified three distinct CM utilization trajectories: (1) no CM use (n = 11,222; 72.1%); (2) declining CM use (n = 4105; 26.4%); and (3) chronic CM use (n = 239; 1.5%). CC patients in Florida had limited CM use with increasing trends in use of benzonatate, dextromethorphan, and gabapentinoids and a decreasing trend in opioid antitussive use. CC patients, particularly with chronic prescription CM use, experienced substantial disease burden
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