Mutual neutralization in low-energy collisions of Na^(+)+H^(-)ions

The low-energy mutual neutralization(MN)reactions Na^(+)+H^(-)→Na(nl)+H have been studied by employing the full quantum-mechanical molecular-orbital close-coupling(QMOCC)method over a wide energy range of 10^(-3)-10^(3) e V/u.Total and state-selective cross sections have been investigated and compared with the available theoretical and experimental data,and the state-selective rate coefficients for the temperature range of 100-10000 K have been obtained.In the present work,all the necessary highly excited states are included,and the influences of rotational couplings and 10 active electrons are considered.It is found that in the energy below 10 e V/u,the Na(4s)state is the most dominant exit state with a contribution of approximately 78%to the branch fraction,which is in best agreement with the experimental data.For energies above 10 e V/u,the MN total cross section is larger than those obtained in other theoretical calculations and shows a slow decreasing trend because the main exit states change,when the energy is above 100 e V/u,the dominant exit state becomes the Na(3p)state,while the Na(4s)state becomes the third most important exit state.The datasets presented in this paper,including the potential energy curve,the radial and rotational couplings,the total and state-selective cross sections,are openly available at https://doi.org/10.57760/sciencedb.j00113.00112.

Study on mode-filtered light sensor for methane detection

A novel mode-filtered light gas sensor has been reported. It was constructed by inserting an optical fiber deposited by a thin silicone cladding of cryptophane A into a fused-silica capillary. When different concentration of methane gas was introduced to the sensor, the phenomenon that mode-filtered light intensity decreased with the increasing concentration of methane was observed. And a linear relationship was obtained within the methane concentration range of 0.0-16.0% （v/v）. The detection limit was 0.06% （v/v）. The mode-filtered light sensor has been exploited to respond to various concentrations of methane gas at room temperature.

Interference study on the free calcium in the human peripheral lymphocyte by acrylamide

The role of acrylamide on the human peripheral lymphocytes was studied by laser scanning confocal microscopy technique and fluo-3. The calibration value of the apparent dissociation constant （Kd） of the fluo-3-Ca^2＋ complex was obtained as 4.83 × 10^-7 moi/L. Acrylamide （〈54 μg/mL） evoked a rise in free intracellular calcium concentration [Ca^2＋]i, in a dosedependent manner. Acrylamide induced the increase of [Ca^2＋]i was discussed in detail.

Study on the effects of cefotaxime on intracellular Ca^(2+) in human peripheral lymphocytes by fluoremetry

Characteristic of Fura-2-Ca^2＋ interaction was studied based on the fluorescence technique. The apparent dissociation constants （Kd） of the Fura-2-Ca^2＋ complex were determined at different temperature. The effect of cefotaxime （CEFA） on intracellular Ca^2＋ concentration （[Ca^2＋]i） was discussed by using a ratiometric fluorescence dye Fura-2 as a probe. The basal [Ca^2＋]i in resting human peripheral lymphocytes was 100 4- 7 nmol/L but after treatment with cefotaxime, the changes of [Ca^2＋]i were observed in different conditions. In the concentration range of 1-30 μmol/L of cefotaxime [Ca^2＋]i increased, as a result of releasing intracellular Ca^2＋ stores. Higher concentration of cefotaxime （50-500 μmol/L） stimulated to decrease of [Ca^2＋]i.

Study on the Interaction of Mitomycin C with ct-DNA by Pd-Porphin Room Temperature Phosphorescence Probe

Anticancer drug Mitomycin C (MMC) quenches remarkably phosphorescence and reduces lifetime of phosphorescence probe, Pd-meso-tetrakis-(4-trimethylaminophenyl)porphin (Pd-TAPP), in the presence of calf thymus DNA. These results may be attributed to the site competition of MMC with the probe and electron transfer between MMC and probe. MMC also increases polarization degree of the probe by covalent drug-DNA or DNA-drug-DNA crosslinking.

Protein surface recognition of the novel tetra-carboxylphenyl calix[4]arene to cytochrome c

The interaction of the novel tetra-carboxylphenyl calix[4]arene （TCPC） with the bovine heart cytochrome c （Cc） was first investigated by fluorescence spectroscopy and molecular modeling methods. The formation of a stable 1：1 complex was monitored by fluorescence titration, and its binding constant is 1.916 ×10^7 L mol^-1. Molecular modeling reveals the recognition mechanism of TCPC to the Cc surface, that is, the electrostatic interaction drives TCPC to the Cc surface, and the van der Waals interaction orientates TCPC parallel to the cleft of Cc.

Study on the Interferation of the Concentration of Free Calcium in Peripheral Human Lymphocyte by Low Dose Penicillin, Using Fura-2 as Fluorescent Probe

The effect of penicillin on the human peripheral lymphocytes was studied by steady fluorescent technique and ratiometric fluorescence dye, Fura-2, The change of the free calcium concentration in cytosol was examined under different conditions. A characterization of Fura-2-Ca interaction in an isotonic saline solution showed that Ca^2＋ formed a 1：1 Fura-2-Ca complex with the apparent dissociation constant 1.81×10^-7 mol/L. The mechanism, by which penicillin induced the decrease of [Ca^2＋]i , was discussed in detail. The low dose of penicillin might modify the lymphocytes＇ immunology response by interfering the increase in the intracellular free calcium concentration.

Methane sensor based on palladium/MWNT nanocomposites

Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide （ITO） glass substrates. A linear response for methane was obtained in the range of 0-16% （v/v） with a detection limit of 0.167% （v/ v） and R.S.D. of 4.1%. After 100 times sensing or stable stored more than 12 months in atmosphere, unconspicuous measurable decrease was observed. The response time was less than 60 s at room temperature and ambient pressure. Some common potential interferents in samples such as N2, CO, CO2, ethane, propane, pentane, methanol, ethanol, H2 and NH3 were investigated and all the effects were less than 5% on the response for 3.0% （v/v） methane. The sensor was applied to methane determinations in man-made gas samples, the results are satisfied.

Study on the supramolecular systems of two basic violets with cyclodextrins by MWNTs/Nafion modified glassy carbon electrode

Abstract The electrochemical properties of two basic violets （methyl violet and ethyl violet） at the MWNTs/Nafion modified glassy carbon electrode were investigated. The redox of the basic violets is two-electron and two-proton process, and methyl violet presents stronger electron transfer capacity than ethyl violet. Meanwhile, the inclusion constants of the two basic violets with five CDs were determined by differential pulse voltammetry （DPV）. The two basic violets and CDs can form 1：1 complexes, The inclusion capacities of the two basic violets follow the same order： CM-β-CD 〉 HP-β-CD 〉 TM-β-CD 〉 DM-β- CD 〉 β-CD. ？2009 Yu Jing Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Electron excitation processes in low energy collisions of hydrogen-helium atoms

The electron excitation processes of H(1s)+He(1s^(2))→H(2s/2p)+He(1s^(2))are studied in impact energy range of 20-2000 e V/u by using the quantum-mechanical molecular orbital close-coupling(QMOCC)method.Total and state-selective cross sections have been obtained and compared with the available theoretical and experimental results.The results agree well with available measurements in the overlapping energy regions overall.The comparison of our results with other theoretical calculations further demonstrates the importance of considering a sufficient number of channels.The datasets presented in this paper,including the excitation cross sections,are openly available at https://www.doi.org/10.57760/sciencedb.j00113.00083.

A novel sensor of potassium ions based on mode-filtered light detection

A novel potassium ions sensor based on mode-filtered light detection was reported. The analyzer was consisting of an optical fiber immobilized with a dye of bromocresol green and a fused-silica capillary. It was found that mode-filtered light intensity decreased with the concentration of potassium ions and a linear detection range of 0.25-20 mmol/L （R^2 = 0.9977） was obtained with a detection limit of 9 ×10^-5 mol/L as well as fast response, good reproducibility and reversibility in the working concentration range.

Study on the Absorption Properties of C_(60) in Micellar Aqueous Solutions and Mechanisms for Solubilisation

C60 is successfully solubilized in micelle of six kinds of surfactants and UV/Vis spectra ofC60 in micellar system are studied. It is found that Brij-35 is the most efficient surfactant forsolubilization of C60 and the possible states of C60 existed in surfactants are also studied.Experiments of surface tension show that the sites for solubilization of C60 not only depend on thesorts of surfactants but also on their structures.

Environmentally persistent free radicals in PM_(2.5)from a typical Chinese industrial city during COVID-19 lockdown:The unexpected contamination level variation

The outbreak of COVID-19 has caused concerns globally.To reduce the rapid transmission of the virus,strict city lockdown measures were conducted in different regions.China is the country that takes the earliest home-based quarantine for people.Although normal industrial and social activities were suspended,the spread of virus was efficiently controlled.Simultaneously,another merit of the city lockdown measure was noticed,which is the improvement of the air quality.Contamination levels of multiple atmospheric pollutants were decreased.However,in this work,24 and 14 air fine particulate matter(PM_(2.5))samples were continuously collected before and during COVID-19 city lockdown in Linfen(a typical heavy industrial city in China),and intriguingly,the unreduced concentration was found for environmentally persistent free radicals(EPFRs)in PM_(2.5)after normal life suspension.The primary non-stopped coal combustion source and secondary Cu-related atmospheric reaction may have impacts on this phenomenon.The cigarette-based assessment model also indicated possible exposure risks of PM_(2.5)-bound EPFRs during lockdown of Linfen.This study revealed not all the contaminants in the atmosphere had an apparent concentration decrease during city lockdown,suggesting the pollutants with complicated sources and formation mechanisms,like EPFRs in PM_(2.5),still should not be ignored.

Chronic Real-Ambient PM_(2.5)Exposure Exacerbates Cardiovascular Risk via Amplifying Liver Injury in Mice Fed with a High-Fat and High-Cholesterol Diet

Epidemiology has associated fine particulate matter(PM_(2.5))exposure with an increased cardiovascular risk.However,the underlying mechanism,particularly from the liver perspective,remains unclear.Here,the influence of chronic PM_(2.5)exposure on cardiovascular risk in mice fed a high-fat and high-cholesterol diet(HFCD)was studied by using a real-world PM_(2.5)exposure system.Results showed that PM_(2.5)exposure elevated the serum levels of nonhigh-density lipoprotein cholesterol(non-HDL-C)and oxidized low-density lipoprotein(oxLDL)in HFCD-fed mice,demonstrating increased cardiovascular risk.To investigate the molecular mechanism,lipidomics and metabolomics analyses were conducted and revealed that PM_(2.5)exposure enhanced lipid accumulation and disturbed purine metabolism and glutathione metabolism in the liver of HFCD-fed mice,contributing to the elevated non-HDL-C levels and intensified oxidative stress.Moreover,PM_(2.5)exposure increased total cholesterol levels by upregulating Hmgcr expression and downregulating Cyp7a1 expression in the livers of HFCD-fed mice.The HDL-C level was reduced by inhibiting the hepatic Abca1 and Abcg1 expression and decreasing the levels of ApoA-I and LCAT.Additionally,the PM_(2.5)-induced pro-oxidative environment impeded the oxLDL clearance and further triggered inflammation,in turn exacerbating oxidative stress and oxLDL production.This study demonstrated a synergy of PM_(2.5)and HFCD on cardiovascular risk and illuminated the molecular mechanism in PM_(2.5)-susceptible populations.

Airborne fine particulate matter induces cognitive and emotional disorders in offspring mice exposed during pregnancy

Gestational exposure to PM_(2.5) is associated with adverse postnatal outcomes.PM_(2.5) can enter alveoli by using intratracheal instillation,even penetrate through lung cells into the blood circulation.Subsequently,they are transferred across the placenta and fetal blood brain barrier,causing the adverse birth outcomes of offspring.This study demonstrated that the gestational exposure resulted in cognitive and emotional disorders in female offspring although the offspring were not exposed to PM_(2.5).Placental metabolic pathways modulated fetal brain development and played a pivotal role for maternal-placentalfetal interactions in the fetal programming of adult behavioral and mental disorders.Samples of fetus,offspring hippocampus and placenta from the mice exposed to PM_(2.5) were investigated using a comprehensive approach including mass spectrometry-based lipidomics and three-dimensional imaging.The exposure induced the neuro-degeneration in hippocampus,impairment of placental cytoarchitecture,and reprogramming of lipidome,which might affect the modulation of maternal-fetal cross-talk and result in the behavior disorders of offspring.The variation of spatial distribution of lipids was profoundly affected in dorsal pallium and hippocampal formation regions of fetal brain,offspring hippocampus,as well as labyrinth and junctional zones of placenta.The abundance alteration of lipid markers associated with neurodegenerative diseases was validated in transgenic mouse model with Alzheimer’s disease and human cerebrospinal fluid from patients with Parkinson’s disease.The finding could help with the selection of more suitable heterogeneous-related substructures targeting PM_(2.5) exposure and the exploration of PM_(2.5)-induced toxicological effects on neurodegenerative diseases.

β-Cyclodextrin and Its Derivatives Functionalized Magnetic Nanoparticles for Targeting Delivery of Curcumin and Cell Imaging

β-Cyclodextrin （β-CD） and its derivatives functionalized magnetic nanoparticles （MNPs） with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydroxy- propyl/sulfobutyl ether-β-CD-MNPs （CM/HP/SBE-β-CD-MNPs） nanocomposites were characterized by the TEM, FTIR, DLS, Zeta potential, XRD and VSM. In addition, the loading and release performance of the as-prepared nanocarriers for the hydrophobic anti-cancer drug curcumin was also investigated. The results revealed that the SBE-fl-CD-MNPs possessed the highest loading and release capacity in comparison with other two nanosystems. Cellular uptake and imaging suggested that the SBE-β-CD-MNPs entered into the cell, and curcumin could be suc-cessfully delivered into the cell by SBE-β-CD-MNPs nanocarrier. Moreover, cell toxicity experiments demonstrated the SBE-β-CD-MNPs were non-toxic, while curcumin loaded SBE-β-CD-MNPs showed high potential to kill the HepG2 cells. The as-prepared magnetic composites were expected to expand their potential applications in bio- medical field.

Pollution characteristics of ambient PM_(2.5)-bound PAHs and NPAHs in a typical winter time period in Taiyuan

The pollution characteristics of ambient fine particulate matter（PM2.5） containing polycyclic aromatic hydrocarbons（PAHs） and nitrated PAHs（NPAHs） in samples collected during a typical winter time period in Taiyuan of China were investigated.The obtained results revealed that the mean mass concentrations of PM2.5,SPAHs（sum of 16 PAHs） and SNPAHs（sum of 3 NPAHs） on PM2.5were161.4 mg/m3,119.8 ng/m3and 0.446 ng/m3,respectively.Diagnostic ratios of PAHs and NPAHs implied that coal consumption might be the main source of the PM2.5pollution.The measured PM2.5mass concentrations,BaP equivalent toxicity（28.632 ng/m3） and individual carcinogenicity index（3.14 10 5） were much higher than those of the recommended safety standards.

Recent Advances in Carbon Nanodots:Properties and Applications in Cancer Diagnosis and Treatment

Cancer is a serious threat to human health.Survival rates of cancer patients are highly dependent on the early diagnosis and treatment.Carbon nanodots(CDs),a rising star of carbon nanomaterial family,can be developed as a promising terrace for cell labeling,bioimaging,drug delivery,diagnosis,and therapy by virtue of many superior properties including unique photo-luminescence properties,low toxicity,excellent biocompatibility,and easy functionalization.In this mini review,we present the recent progress in fundamental properties of CDs,and highlight their bioapplications in cancer diagnosis and treatment.

A Mitochondria-Specific Orange/Near-Infrared-Emissive Fluorescent Probe for Dual-Imaging of Viscosity and H_(2)0_(2) in Inflammation and Tumor Models

Elucidating the intrinsic relationship between viscosity/H_(2)0_(2) and mitochondria-associated diseases remains a great challenge owing to the lack of research on multiple diseases models,such as inflammation and malignant tumor models.In this work,we have developed a mitochondria-specific orange/near-infrared-emissive fluorescent probe TTPB,for dual-imaging of viscosity and H_(2)0_(2) levels in two different channels.The probe exhibited a remarkable response to viscosity with NIR emission round 666 nm,and was highly sensitive to H_(2)0_(2) in orange channel with emission peak at 586 nm.Moreover,TTPB has good mitochondria-specific ability and permits individual detecting of viscosity in NIR channels and H_(2)0_(2) levels in orange channel in living cells.More notably,TTPB was successfully applied to simultaneously image the viscosity and H_(2)0_(2) levels in inflammation and cancer models.

Chemical compositions and effects on chemiluminescence of AMs in vitro of chalk dusts

The aim of this study was to investigate the chemical compositions of chalk dust and examine the adverse effects of fine chalk particle matters（PM（2.5）） on rat alveolar macrophages（AMs） in vitro.Morphologies and element concentrations of chalk particles were analyzed using quantitative energydispersive electron probe X-ray microanalysis（ED-EPMA）.The oxidative response of AMs exposed to chalk PM（2.5） was measured by luminol-dependent chemiluminescence（CL）.The results showed that（1）Chalk dust was mainly composed of gypsum（CaSO4）,calcite（CaCO3）/dolomite（CaMg（CO3）2）,and organic adhesives;（2） Fine chalk particles induced the AM production of CL,which was inhibited by about 90%by diphenyleneiodonium chloride（DPI）.Based on these results,we showed that cytotoxicity of chalk PM（2.5） may be related to the reactive oxygen species（ROS） generation.