Completely understanding the working mechanisms of sophisticated supramolecular self-assembly exhibiting competing paths is very important for chemists en route to acquiring the ability of ...constructing supramolecular systems with controlled structures and designed functions. Here, the self-aggregation behaviors of an N-heterocyclic aromatic dicarboximide molecule 1, boasting two competing paths that give rise to different supramolecular structures and exhibit distinct thermodynamic features, are carefully examined. First, a group of H-aggregates are observed when providing a medium driving force for aromatic stacking, and their formation is manifested as an anticooperative process. When exposed to enhanced strength of aromatic interactions, these H-aggregates are found to transform into J-aggregates via a cooperative assembly mechanism. With the assistance of a mathematic model accommodating two competing polymerization pathways, calculations are conducted to simulate and explain the thermodynamic equilibria of such a unique supramolecular system. The calculation results are highly consistent with the experimental observations, and some important properties are elucidated. Specifically, the anticooperative assembly mechanism generally promotes the formation of low to medium oligomers, whereas the cooperative path is more competent at producing high polymers. If the anticooperative and cooperative routes coexist and compete for the same molecule, the cooperative formations of high polymers are significantly suppressed unless a very high degree of polymerization can be achieved. Such a unique feature of concurring anticooperative and cooperative paths emerges to the H- and J-aggregates of molecule 1 and thus brings about the interesting sequential appearances of the two types of aggregates under conditions of continuously enlarged driving force for self-aggregation. Finally, based on the knowledge acquired from this study and by analyzing the steric features of 1 that influence its supramolecular packing motifs, a slightly modified molecular structure is designed, with which the intermediate H-aggregation state was successfully suppressed, and a single cooperative J-aggregation path is manifested.
Time-restricted feeding (TRF) is a form of intermittent fasting, which is beneficial for weight loss and cardiometabolic health. Polycystic ovary syndrome (PCOS) is one of the most common ...reproductive endocrine and metabolic diseases affecting women of childbearing age. It is associated with an increased prevalence of metabolic syndrome, cardiovascular diseases and type 2 diabetes. The effects of TRF on PCOS patients remains undefined, here we investigated the impact of TRF on women with anovulatory PCOS.
Eighteen PCOS women aged between 18 and 31 with anovulation participated in a 6-week trial which were divided into two consecutive periods: (1) 1-week baseline weight stabilization period and (2) 5-week TRF period. Fifteen participants completed the study. Changes in body weight, body mass index (BMI), Waist-to-Hip Ratio, skeletal muscle mass, body fat mass (BFM), body fat percentage (BF%), visceral fat area (VFA), luteinizing hormone (LH), follicle-stimulating hormone (FSH), LH/FSH, total testosterone (TT), sex hormone-binding globulin (SHBG), free androgen index (FAI), fasting glucose, fasting insulin (FINS), homeostasis model assessment-insulin resistance (HOMA-IR), area under the curve (AUC) for insulin (AUCIns), area under the curve (AUC) for glucose (AUCGlu), AUCIns/AUCGlu Ratio, lipids, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase, high-sensitivity C-reactive protein (hsCRP), insulin-like growth factor (IGF-1), menstrual cycle and eating behaviors were evaluated.
Significant changes in body weight, BMI, BFM, BF%, VFA, TT, SHBG, FAI, FINS, HOMA-IR, AUCIns, AUCIns/AUCGlu Ratio, ALT, hsCRP and IGF-1 were found after the TRF period. An improvement in menstrual cycle irregularity was detected in 73.3% (11/15) patients.
The diet of TRF may be beneficial to anovulatory PCOS on weight loss especially reducing body fat, improving menstruation, hyperandrogenemia, insulin resistance and chronic inflammation. Trial registration Clinicaltrial.gov, NCT04580433, registered October 8, 2020, https://clinicaltrials.gov/ct2/show/NCT04580433.
It was well documented that calcium (Ca), phosphorus (P), and magnesium (Mg) participate in many physiological processes. We aimed to study the changing trend of serum levels of Ca, P, and Mg in ...frequent respiratory tract infections (FRTI) in children.
A retrospective study was performed in our centre. A total of 213 FRTI cases and 33 controls were enrolled in our study. We analyzed the correlation between serum Ca/P/Mg levels and inflammatory indexes by using Spearman correlation analysis. Standard mean difference (SMD) was applied to test the differences of serum Ca/P/Mg levels between FRTI subgroups and controls. In terms of the findings of SMD between Ca/P/Mg status between FRTI subgroups and controls, receiver operating characteristics (ROC) curve analysis was further applied to test the association between serum Ca level and bronchitis, parainfluenza virus infection, influenza B virus infection and cytomegalovirus infection.
Serum Ca level was significantly associated with white blood cell (WBC), platelet (PLT) and procalcitonin (PCT) (
= 0.006;
< 10
;
= 0.004). Serum P level was markedly associated with eryhtrocyte sedimentation rate (ESR) and PCT (
= 0.018;
< 10
). Controls showed significantly lower serum Ca level than that among bronchitis (
= 0.001), parainfluenza virus infection (
= 0.027), influenza B virus infection (
= 0.017), cytomegalovirus infection (
= 0.029), and two pathogens infected (
= 0.020). ROC curve analysis showed that serum Ca level was significantly associated with bronchitis (
= 0.047) and influenza B virus infection (
= 0.049).
Serum levels of Ca and P may reflect the inflammatory status in children with FRTI. Alteration of serum Ca level may predict the risk of bronchitis and influenza B virus infection. Keeping the homeostasis of Ca, P, and Mg may be important for the prevention and treatment of FRTI.
Molecules constituted by different isotopes are different in vibrational modes, making it possible to elucidate the mechanism of a chemical reaction via the kinetic isotope effect. However, the ...real-time observation of the vibrational motion of isotopic nuclei in molecules is still challenging due to its ultrashort time scale. Here we demonstrate a method to monitor the nuclear vibration of isotopic molecules with the frequency modulation of high-order harmonic generation (HHG) during the laser-molecule interaction. In the proof-of-principle experiment, we report a red shift in HHG from H
and D
. The red shift is ascribed to dominant HHG from the stretched isotopic molecules at the trailing edge of the laser pulse. By utilizing the observed frequency shift, the laser-driven nuclear vibrations of H
and D
are retrieved. These findings pave an accessible route toward monitoring the ultrafast nuclear dynamics and even tracing a chemical reaction in real time.
It is well-documented that the dysregulation of trace elements may be involved in the pathogenesis of asthma. However, the precise changes of trace elements levels in asthma cases remain elusive. We ...established whether trace elements levels were associated with asthma susceptibility by pooling case-control studies.
34 studies were included. We extracted the standard mean differences (SMDs) and corresponding 95% confidence intervals (CIs). A pooled-analysis was performed.
No marked difference (95% CI: -1.437–0.218, p = 0.149) of Se level between asthma and controls. Significant difference (95% CI: 0.112–1.032, p = 0.015; 95% CI: 0.376–1.331, p < 10−4) of Cu level between asthma and controls was noted among overall populations and Asians. No marked difference of Zn level between asthma and controls was observed among overall populations, Asians, Caucasians and Africans. Significant difference (95% CI: -0.567 to −0.238, p < 10−4) of Mg level between asthma and controls was noted among Asians. Marked difference (95% CI: 0.258–2.864, p = 0.019; 95% CI: 0.270–3.282, p = 0.021) of Fe level between asthma and controls was noted among overall populations and Asians. Age had no impact on the pooled SMDs of Se, Cu, Zn, Mg and Fe between asthma and controls. Sensitivity analyses did not change the overall results. No publication bias was noted for overall populations.
Alterations of Cu, Mg and Fe levels may be a biomarker of asthma risk among specific populations. Further studies should be performed to clarify the strength of these elements in asthma.
•The association between trace elements levels and asthma risk was assessed.•The quality of this study was based on MOOSE.•Se, Cu, Mg and Fe status may reflect asthma risk irrespective of age.
Can Paris pledges avert severe climate change? Fawcett, Allen A.; Iyer, Gokul C.; Clarke, Leon E. ...
Science (American Association for the Advancement of Science),
12/2015, Letnik:
350, Številka:
6265
Journal Article
Recenzirano
Reducing risks of severe outcomes and improving chances of limiting warming to 2°C
Current international climate negotiations seek to catalyze global emissions reductions through a system of ...nationally determined country-level emissions reduction targets that would be regularly updated. These “Intended Nationally Determined Contributions” (INDCs) would constitute the core of mitigation commitments under any agreement struck at the upcoming Paris Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) (
1
). With INDCs now reported from more than 150 countries and covering around 90% of global emissions, we can begin to assess the role of this round of INDCs in facilitating or frustrating achievement of longer-term climate goals. In this context, it is important to understand what these INDCs collectively deliver in terms of two objectives. First, how much do they reduce the probability of the highest levels of global mean surface temperature change? Second, how much do they improve the odds of achieving the international goal of limiting temperature change to under 2°C relative to preindustrial levels (
2
)? Although much discussion has focused on the latter objective (
3
–
5
), the former is equally important when viewing climate mitigation from a risk-management perspective.
In this study, nine fulvic acid fractions (FAs) were obtained by a progressively extracting method from lake sediment and used as adsorbent for binding metal ions. The characterization indicated that ...former FA fractions had stronger polarity, more O-bearing functional groups, and less aliphaticity. And the results of EEM-PARAFAC indicated that there were four components in FAs, i.e., two humic-like components and two fulvic-like ones. The sorption experiments showed sorption capacity of selected metal ions onto FAs decreased with increasing extractions, and the analysis of binding stability for selected metal ions onto FAs were ranked as FAs-Cu>FAs-Pb>FAs-Cd. For all extracted FAs, the principal component analysis for sorption capacity showed that O-bearing functional groups and molecular weight were dominant factors for FAs binding metal ions. Furthermore, the characterization results of nine FAs pre- and post-adsorption indicated that the phenolic groups of FAs had a greater contribution to bind Pb
2+
over than Cd
2+
and Cu
2+
, while carboxyl and N-bearing groups had a stronger affinity for Cu
2+
than others. The study has the potential significance to insight the FA and metal ions cycling processes in lakes.
Graphical Abstract
The hybrid satellite-UAV-terrestrial maritime networks have shown great promise for broadband coverage at sea. The existing works focused on vessels collaboratively served by UAV-enabled aerial base ...station (ABSs) and terrestrial base stations (TBSs) deployed along the coast, and proved that data rate could be improved by optimizing transmit power and ABS's position. In practice, users on a vessel can be collaboratively served by an ABS and a vessel-enabled base station (VBS) in different networks. In this case, how to select the network for users on a vessel is still an open issue. In this paper, a TBS and a satellite respectively provide wireless backhaul for the ABS and the VBS. The network selection is jointly optimized with transmit power of ABS and VBS, and ABS's position for improving data rate of all users. We solve it by finding candidates for network selection and iteratively solving transmit power and ABS's position for each candidate. Simulation results demonstrate that data rate can be improved by collaborative coverage for users on a vessel.
, a medicinal food fungus, is a fruit from
. In this study, we purified ergosterol peroxide (EP) from the fermentation broth of
and investigated its effects on renal cell carcinoma (RCC) cells, in ...vitro. EP was purified from
fermentation broth. The human RCC cell line 786-0 was used to analyze the anticancer mechanism of EP and inhibit its effect on cancer cell proliferation, in vitro. EP with a validated structure showed a yield rate of 20.1 mg/L and a purity of 96%. EP significantly inhibited RCC cell growth and clone formation in vitro. In addition, EP suppressed the migration and invasion, triggered the apoptosis, and modulated the cell cycle of RCC cells, in a dose-dependent manner. It also downregulated β-catenin expression. EP could be routinely produced through
. It fights RCC cells in vitro through multiple mechanisms, including suppressing cell growth, colonization, migration, and invasion, arresting the cell cycle, attenuating β-catenin pathways, and triggering apoptosis.
Sodium-ion batteries (SIBs) have drawn more attention to serve as one of the promising energy storage devices owing to the abundance of sodium resources and similar characters with lithium element. ...Hard carbon materials derived from biomass or biomass waste have been considered to act as candidate anode materials for SIBs. In this paper, we have successfully prepared curly hard carbon materials using pistachio shells as biomass template via a two-step approach including hydrothermal treatment and following a pyrolysis process at various temperatures. Physical properties of pistachio shell-derived hard carbons (PSHCs) including microstructure, morphology and pore size distribution are evaluated by X-ray diffraction, Raman spectrum and N
2
sorption analysis. The PSHCs carbonized at 1000 °C (PSHC-1000) with average micropores of 0.7398 nm and larger interlayer space of the (002) crystal plane deliver the highest reversible capacity of 317 mAh g
−1
at 0.1C, also show the excellent long-term cycling and rate performances. Electrochemical impedance spectroscopy technology is introduced to study the kinetics parameters during the first sodiation process of PSHC-1000 electrode, and also to compare the resistance of the charge transfer process for all the PSHCs. Results exhibit PSHC-1000 electrode with the symmetry factor of 0.1352 has the smallest charge transfer resistance, leading to more easily transportation of electrons and ions. This work can provide a simple and green route for preparation of hard carbon materials derived from biomass waste with unique morphology and microstructure which can exhibit an excellent electrochemical performance.
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