Factors Controlling the Distribution of Transitional Metal Elements in Marine Hydrogenic Ferromanganese Crusts

A series of selective dissolution experunents were conducted on the hydrogeinc ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and 6-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion bemg in agreement with the results of selective dissolution experiments. Transitional metal elements such as Cu, Co, Ni and Ti are enriched in different phases, i.e. Ni and Co are incorporated into 6-MnO2 while Cu and Ti are incorporated into ferric oxyhy- droxides. The distributions of the elements in amorphous ferric oxyhydroxides and δ-MnO2 are controlled by the existing states of the elements in the seawater and the crystal chemistry and geochemistry of these elements/inns in oxides.

Experience after 100 patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

AIM:To investigate perioperative patient morbidity/mortality and outcome after cytoreductive surgery(CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC).METHODS:Of 150 patients 100 were treated with cytoreductive surgery and HIPEC and retrospectively analyzed.Clinical and postoperative follow-up data were evaluated.Body mass index(BMI),age and peritoneal carcinomatosis index(PCI) were chosen as selection criteria with regard to tumor-free survival and perioperative morbidity for this multimodal therapy.RESULTS:CRS with HIPEC was successfully performed in 100 out of 150 patients.Fifty patients were excluded because of intraoperative contraindication.Median PCI was 17(1-39).In 89% a radical resection(CC0/CC1) was achieved.One patient died postoperatively due to multiorgan failure.Neither PCI,age nor BMI was a risk factor for postoperative complications/outcome according to the DINDO classification.In 9% Re-CRS with HIPEC was performed during the follow-up period.CONCLUSION:Patient selection remains the most important issue.Neither PCI,age nor BMI alone should be an exclusion criterion for this multimodal therapy.

Improved Double Deep Q Network Algorithm Based on Average Q-Value Estimation and Reward Redistribution for Robot Path Planning

By integrating deep neural networks with reinforcement learning,the Double Deep Q Network(DDQN)algorithm overcomes the limitations of Q-learning in handling continuous spaces and is widely applied in the path planning of mobile robots.However,the traditional DDQN algorithm suffers from sparse rewards and inefficient utilization of high-quality data.Targeting those problems,an improved DDQN algorithm based on average Q-value estimation and reward redistribution was proposed.First,to enhance the precision of the target Q-value,the average of multiple previously learned Q-values from the target Q network is used to replace the single Q-value from the current target Q network.Next,a reward redistribution mechanism is designed to overcome the sparse reward problem by adjusting the final reward of each action using the round reward from trajectory information.Additionally,a reward-prioritized experience selection method is introduced,which ranks experience samples according to reward values to ensure frequent utilization of high-quality data.Finally,simulation experiments are conducted to verify the effectiveness of the proposed algorithm in fixed-position scenario and random environments.The experimental results show that compared to the traditional DDQN algorithm,the proposed algorithm achieves shorter average running time,higher average return and fewer average steps.The performance of the proposed algorithm is improved by 11.43%in the fixed scenario and 8.33%in random environments.It not only plans economic and safe paths but also significantly improves efficiency and generalization in path planning,making it suitable for widespread application in autonomous navigation and industrial automation.

Enrichment mechanisms of rare earth elements in marine hydrogenic ferromanganese crusts

A series of selective extraction experiments were conducted on marine hydrogenic ferromanganese crusts from the seamount near the Line Island to investigate the distribution of rare earth elements （REEs） and the mechanisms of combination between REEs and the hydrogenic ferromanganese crusts. The enrichment of REEs in hydrogenic ferromanganese crusts is attributed mainly to the mineral or oxide/hydroxide of the crust rather than the growth environment. The REEs are present mainly in amorphous ferric oxide/hydroxide rather than in 6-MnO2. Amorphous ferric oxide/hydroxide preferentially combines free REE3＋, while 6-MnO2 combines the REE-carbonate complexes in modern seawater. The REEs in seawater are combined more strongly with amorphous ferric oxide/hydroxides than with 6-MnO2. The positive Ce anomaly in hydrogenic ferromanganese crusts results from the oxidation of soluble Ce3＋ to insoluble Ce4＋ by the actively soluble oxygen of the bottom current rather than by the oxidation of δ-MnO2.

A dopamine and noradrenaline reuptake inhibitor （bupropion） does not alter exercise performance of bank voles

Physical performance is determined both by biophysical and physiological limitations and behav- ioral characteristic, specifically motivation. We applied an experimental evolution approach com- bined with pharmacological manipulation to test the hypothesis that evolution of increased aerobic exercise performance can be triggered by evolution of motivation to undertake physical activity. We used a unique model system： bank voles from A lines, selected for high swim-induced aerobic metabolism （VO2swim）, which achieved a 61% higher mass-adjusted VO2swim than those from un- selected C lines. Because the voles could float on the water surface with only a minimum activity, the maximum rate of metabolism achieved in that test depended not only on their aerobic capacity, but also on motivation to undertake intensive activity. Therefore, we hypothesized that signaling of neurotransmitters putatively involved in regulating physical activity （dopamine and noradrenaline） had changed in response to selection. We measured VO2swim after intraperitoneal injections of sa- line or the norepinephrine and dopamine reuptake inhibitor bupropion （20 mg/kg or 30 mg/kg）. Additionally, we measured forced-exercise VO2 （VO2max）. In C lines, VO2swim （mass-adjusted mean ± standard error （SE）： 4.0 ± 0.1 mLO2/min） was lower than VO2max （5.0 ± 0.1 mLO2/min）, but in A lines VO2swim （6.0 ± 0.1 mLO2/min） was as high as VO2max （6.0 ± 0.1 mLO2/min）. Thus, the selection effectively changed both the physiological-physical performance limit and mechanisms responsible for the willingness to undertake vigorous locomotor activity. Surprisingly, the drug had no effect on the achieved level of VO2swim. Thus, the results did not allow firm conclusions concerning involvement of these neurotransmitters in evolution of increased aerobic exercise performance in the experimental evolution model system.