Entropy in catalyst dynamics under confinement.

Entropy during the dynamic structural evolution of catalysts has a non-trivial influence on chemical reactions. Confinement significantly affects the catalyst dynamics and thus impacts the reactivity. However, a full understanding has not been clearly established.

Biphasic Dose-Response of Mn-Induced Mitochondrial Damage, PINK1/Parkin Expression, and Mitophagy in SK-N-SH Cells.

Excessive manganese (Mn) exposure produces neurotoxicity with mitochondrial damage. Mitophagy is a protective mechanism to eliminate damaged mitochondria to protect cells. The aim of this study was to determine the dose-response of Mn-induced mitochondria damage, the expression of mitophagy-mediated protein PINK1/Parkin and mitophagy in dopamine-producing SK-N-SH cells.

Structural dynamics of Ru clusters during nitrogen dissociation in ammonia synthesis.

The dynamic evolution of catalyst structures greatly influences the reactivity, especially sub-nanometer clusters, exhibiting complex configurational fluctuation. In the present work, we study the structural dynamics of a Ru cluster during the dissociation of N and calculate the reaction free energies using molecular dynamics (AIMD). Our AIMD calculation predicts a peak-shaped reaction entropy curve due to the adsorption-induced phase transition of the Ru cluster.

Manganese Intoxication Recovery and the Expression Changes of Park2/Parkin in Rats.

Occupational overexposure to manganese (Mn) produces Parkinson's disease-like manganism. Acute Mn intoxication in rats causes dopaminergic neuron loss, impairment of motor activity and reduction of the expression of Park2/Parkin. The expression of Park2/Parkin is also reduced.

Size-Sensitive Dynamic Catalysis of Subnanometer Cu Clusters in CO Dissociation.

Small cluster catalysts are highly size-dependent and exhibit complex structural dynamic effects during catalytic reactions. Understanding their structural dynamics is of great importance in tuning the catalytic performances of small clusters that widely exist in supported catalysts. However, very little is known about the size dependence of the dynamic effect of small clusters.

Molecular origin of negative component of Helmholtz capacitance at electrified Pt(111)/water interface.

Electrified solid/liquid interfaces are the key to many physicochemical processes in a myriad of areas including electrochemistry and colloid science. With tremendous efforts devoted to this topic, it is unexpected that molecular-level understanding of electric double layers is still lacking. Particularly, it is perplexing why compact Helmholtz layers often show bell-shaped differential capacitances on metal electrodes, as this would suggest a negative capacitance in some layer of interface water.

Adsorption-Induced Liquid-to-Solid Phase Transition of Cu Clusters in Catalytic Dissociation of CO.

Sub-nanometer metal clusters widely existing in catalysts have a large ensemble of metastable isomers that can interconvert during catalytic reactions, exhibiting complex dynamical catalytic effects. In this work, we systematically investigate the temperature dependent structural dynamics of the Cu cluster in CO dissociation using molecular dynamics and the free energy calculation method. We find an abnormal entropic effect due to adsorption-induced liquid-to-solid phase transition of the cluster during the course of the elementary dissociation step at transition temperatures.

Chronic Manganese Administration with Longer Intervals Between Injections Produced Neurotoxicity and Hepatotoxicity in Rats.

Subacute exposure to manganese (Mn) produced Parkinson's disease-like syndrome called Manganism. Chronic onset and progression are characteristics of Manganism, therefore, this study aimed to examine Mn toxicity following chronic exposures. Male Sprague-Dawley rats were injected Mn 1 and 5 mg/kg, every 10 days for 150 days (15 injections).

Joint neurodevelopmental and behavioral effects of nonylphenol and estradiol on F1 male rats.

The purpose of present study is to examine whether gestational exposure of two major environmental endocrine-disrupting chemicals, nonylphenol (NP) and estradiol (E2), would affect nervous system development of offspring rats and explore the joint effects of NP and E2. After impregnation, dams were assigned to seven groups. The first and second groups received gavage with NP at dose levels of 50 mg/kg/day (NP-L) and 100 mg/kg/day (NP-H); the third and fourth groups were gavaged with E2 at dose levels of 10 μg/kg/day (E2-L) and 20 μg/kg/day (E2-H); the fifth and sixth groups were gavaged with joint NP and E2 [NP 50 mg/kg/day + E2 10 μg/kg/day (NP-E2-L) and NP 100 mg/kg/day+E2 20 μg/kg/day (NP-E2-H)] dissolved in groundnut oil; and the seventh group was orally administered with groundnut oil alone (vehicle control; 2 ml/kg/day), respectively, daily from gestational days 9 to 15 (transplacental exposures).

Protective effects of dietary fibre against manganese-induced neurobehavioral aberrations in rats.

We tested the hypothesis that dietary fibre (DF) has protective effects against manganese (Mn)-induced neurotoxicity. Forty-eight one-month old Sprague-Dawley rats were randomly divided into six groups: control, 16 % DF, Mn (50 mg kg-1 body weight), Mn+ 4 % DF, Mn+ 8 % DF, and Mn+ 16 % DF. After oral administration of Mn (as MnCl2) by intragastric tube during one month, we determined Mn concentrations in the blood, liver, cerebral cortex, and stool and tested neurobehavioral functions.

[Early biological markers of manganese exposure].

Objective: To explore the biomarker of manganese exposure by analyzing the relationship between manganese exposure and concentration in some biomaterials.

Methods: The air samples were collected through the individual air sample. According to the manganese levels in the air, workers were assigned to control group, low concentration group and high concentration group, and manganese in the hair, urine, serum, blood cell and saliva from different group were measured respectively.

Toxic effect of gestational exposure to nonylphenol on F1 male rats.

Objective: The purpose of this study was to examine whether gestational exposure to major environmental endocrine-disrupting chemicals, nonylphenol (NP), would lead to nerve behavioral and learning and memory capacity alterations in the male offspring of rats, and reproductive development alterations in the male offspring of rats.

Methods: Dams were gavaged with NP at a dose level of 50 mg/kg/day, 100 mg/kg/day or 200 mg/kg/day daily from gestational day 9 to 15, and at a dose level of 40 mg/kg/day, 80 mg/kg/day or 200 mg/kg/day daily from gestational day 14 to 19 (transplacental exposures).

Results: Exposure to 200 mg/kg/day NP produced a significant decrease in learning and memory functions in offspring rats (P<0.

[Preliminary study of biomarker in blood or cerebrospinal fluid of rat following manganese exposure].

Objective: To explore the biomarkers of manganese exposure by measuring the manganese (Mn) and iron (Fe) level as well as the mRNA change of Hepcidin, divalent metal-ion transporter-1 (DMT1) and Parkin-2, one of genes related to Parkinson disease in body fluid and brain tissues of rat.

Methods: Male Sprague-Dawley rats were administered (i.p) either MnCl2 solution (6 mg Mn/kg) or the same volume saline, 5 times per week and for 4 weeks.

[Effects of nonylphenol exposure via placenta on early nervous reflex and locomotives of offspring in rat].

Objective: To explore the influence of nonylphenol (NP) on the neural behavioral development of filial generation rats exposed via placenta.

Methods: On the first day of the pregnancy, the SD rats were divided into four groups, and orally administered with NP at doses of 0, 50, 100 and 200 mg/kg on gestational day 9 approximately 15 respectively. The offspring rats of each groups were examined to observe the impact of NP on the early physiological, neurobehavioral development.