The presence of calcium-containing molten salts in the electrolysis of oxides for metal production can lead to the formation of CaO and, subsequently, the generation of intermediate products, ...affecting the reduction of metals. To investigate the impact of CaO on the reduction process, experiments were conducted using a Fe2O3-CaO cathode and a graphite anode in a NaCl-CaCl2 molten salt electrolyte at 800 °C. The electrochemical reduction kinetics of the intermediate product Ca2Fe2O5 were studied using cyclic voltammetry and I-t curve analysis. The phase composition and morphology of the electrolysis products were analyzed using XRD, SEM-EDS, and XPS. The experimental results demonstrate that upon addition of CaO to the Fe2O3 cathode, Ca2Fe2O5 is formed instantly in the molten salt upon the application of an electrical current. Research conducted at different voltages, combined with electrochemical analysis, indicates that the reduction steps of Ca2Fe2O5 in the NaCl-CaCl2 molten salt are as follows: Ca2Fe2O5 ⟶ Fe3O4 ⟶ FeO ⟶ Fe. The presence of CaO accelerates the electrochemical reduction rate, promoting the formation of Fe. At 0.6 V and after 600 min of electrolysis, all of the Ca2Fe2O5 is converted into Fe, coexisting with CaCO3. With an increase in the electrolysis voltage, the electrolysis product Fe particles visibly grow larger, exhibiting pronounced agglomeration effects. Under the conditions of a 1 V voltage, a study was conducted to investigate the influence of time on the reduction process of Ca2Fe2O5. Gradually, it resulted in the formation of CaFe3O5, CaFe5O7, FeO, and metallic Fe. With an increased driving force, one gram of Fe2O3-CaO mixed oxide can completely turn into metal Fe by electrolysis for 300 min.
Solutes segregating at the grain boundary (GB) have a significant influence on the mechanical and chemical properties of steel. In this study, the segregation effects of Si, P, and S on γ-Fe ∑5 ...(210)001 GB were systematically analyzed with solution energy, segregation energy, and tensile tests by using a first principles calculation. Si, P, and S are preferred to segregate at substitutional sites in the first layer near the GB. The variation in atomic configuration and electron distribution were investigated by the analysis of bond lengths, charge density, charge density difference, and density of states (DOS), which is caused by the atomic size and electronegativity of solute atoms. Through tensile tests, it was found that Si has a strengthening effect on GB, while P and S exhibit embrittlement effects at low concentration. As the concentration of solutes increase, the segregation sites of P are different from the others owing to the tendency to form Fe3P. The exhibited embrittlement effect is mitigated at first and then aggravated. However, in both cases Si and S show aggravating embrittlement effects on GB cohesion, while the effect of Si changes from strengthening to embrittlement. This work provides comprehensive insights into the effects of Si, P, and S, which will be a useful guidance in steel design.
Considering the issues that can accompany prosthetic breast implants, augmentation mammoplasty (AM) with autologous fat grafting (AFG) has attracted growing interest globally, especially in the last ...two decades, as breast implant-associated anaplastic large cell lymphoma has been increasing in incidence over time. Here, we review the detailed processes of AFG to the breast and the pertinent complications associated with this procedure. This study aims to elucidate the critical points and technique improvements in AM with AFG in recent years, as well as discuss how to decrease complications related to this procedure. Attention was focused on the specific AFG steps, clinical outcomes, and complications to highlight the advantages and disadvantages of the available protocols.
Secondary lymphedema is a refractory disease, for which adipose-derived stem cells have shown some therapeutic potential. However, the mechanism of this action remains poorly understood.
The authors ...identified podoplanin-expressing adipose-derived stem cells, which allowed them to divide adipose-derived stem cells into podoplanin-positive and podoplanin-negative groups that they characterized in vitro. The authors then used a mouse hindlimb model for lymphedema to trace the fate of podoplanin-positive, podoplanin-negative, and unsorted adipose-derived stem cells in vivo.
When induced in culture, podoplanin-positive cells were noted to up-regulate the expression of lymphatic endothelial cell markers, including LYVE-1, and assumed a cobblestone morphology. In addition, a substantial increase in lymphangiogenic cytokines was detected in the podoplanin-positive supernatant. The above findings were largely absent from the podoplanin-negative and unsorted groups. In the mouse model, the implanted cells relieved the limb lymphedema by promoting lymphangiogenesis, with the podoplanin-positive group showing the most significant effect. Immunocolocalization further revealed that the podoplanin-positive cells incorporated into lymphatic vessels were positive for LYVE-1.
These data demonstrated that actions by means of both paracrine and differentiation pathways were involved in the adipose-derived stem cell-mediated therapeutic effects. The podoplanin-positive cells possessed lymphatic paracrine and differentiation abilities and may represent lymphatic endothelial cell precursor cells. The podoplanin-negative cells, which constitute a considerable proportion of the adipose-derived stem cells, may play an important paracrine role by secreting mesenchymal stem cell-related factors.
Abstract
Objective
This study aimed to investigate the relationship between traumatic stress and tumor growth, proliferation, and metastasis.
Methods
A scalding method was used as an injurious factor ...to induce traumatic stress in Wistar rats. The rats were randomly divided into three groups—the control group, mild-scald group, and severe-scald group, with 14 rats in each group. Wistar rats were used to subculture the Walker-256 cell line for the generation of tumor ascites. Tumor cells from the ascites were cultured and used to establish a rat subcutaneous xenograft model. After 7 days, the mild-burn group and the severe-burn group were subjected burns to 10% and 15% of their backs, respectively. Blood was taken from the tail vein of rats at different times to detect changes in blood cortisol, IL-1β, and TNF-α levels. Pathological specimens were collected 14 days later, and immunohistochemistry was performed to examine vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), E-cadherin, and vimentin.
Results
Cortisol, IL-1β and TNF-α levels were significantly higher in the scalding groups than in the control group. Tumor examination was performed after 14 days. The changes in tumor size showed that the tumor volume in the control group (0.593 ± 0.195 cm
3
) and the mild-scald group (0.782 ± 0.344 cm
3
) were not significantly different. However, the tumor volume was significantly larger in the severe-burn group (1.806 ± 0.838 cm
3
) than in the control and the mild-burn groups(
P
< 0.05). Tumor tissue immunohistochemistry showed that the percentage of cells expressing PCNA in the control group, mild-scald group, and severe-scald group was 57.1%, 71.4% and 85.7%, respectively, and the differences among the groups were statistically significant. The number of VEGF-positive cells in the mild- and severe-scald groups was significantly higher than those of the control group (
P
< 0.05). The number of E-cadherin-positive cells in the tumor tissues was significantly lower in the severe-scald group than that in the control and mild-scald groups. Vimentin showed the opposite trend in the tumor tissue, and the differences were statistically significant (
P
< 0.05).
Conclusion
Different degrees of a traumatic response in tissues caused by scalding can cause a corresponding stress response in the body. The release of inflammatory mediators; increase in VEGF, PCNA and vimentin in the tumor tissue; and decrease in E-cadherin lead to a change in tumor tissue growth and metastasis. Traumatic stress is associated with tumor growth, proliferation, and metastasis.
A new method is proposed for the recovery of Mn via the direct electrochemical reduction of LiMn
2
O
4
from the waste of lithium-ion batteries in NaCl−CaCl
2
melts at 750°C. The results show that the ...LiMn
2
O
4
reduction process by the electrochemical method on the coated electrode surface occurs in three steps: Mn(IV) → Mn(III) → Mn(II) → Mn. The products of this electro-deoxidation are CaMn
2
O
4
, MnO, (MnO)
x
(CaO)
1−
x
, and Mn. Metal Mn appears when the electrolytic voltage increases to 2.6 V, which indicates that increasing the voltage may promote the deoxidation reaction process. With the advancement of the three-phase interline (3PI), electric deoxygenation gradually proceeds from the outer area of the crucible to the core. At high voltage, the kinetic process of the reduction reaction is accelerated, which generates double 3PIs at different stages.
The electrochemical reduction mechanism of Mn in LiMn2O4 in molten salt was studied. The results show that in the NaCl-CaCl2 molten salt, the process of reducing from Mn (IV) to manganese is: Mn ...(IV)→Mn (III)→Mn (II)→Mn. LiMn2O4 reacts with molten salt to form CaMn2O4 after being placed in molten salt for 1 h. The reaction of reducing CaMn2O4 to Mn is divided into two steps: Mn (III)→Mn (II)→Mn. The results of constant voltage deoxidation experiments under different conditions show that the intermediate products of LiMn2O4 reduction to Mn are CaMn2O4, MnO, and (MnO)x(CaO)(1−x). As the reaction progresses, x gradually decreases, and finally the Mn element is completely reduced under the conditions of 3 V for 9 h. The CaO in the product can be removed by washing the sample with deionized water at 0 °C.
Steel slag, as industrial solid waste, is difficult to recycle owing to its complex components and poor mechanical properties. However, steel slag can be modified by adding Al2O3–SiO2 through high ...temperature sintering, which would improve the mechanical properties and expand the scope of its application. The phase changing, morphology evolution and the mechanical properties of the modified steel slag were investigated. The results indicate that the main phase changes to gehlenite occur with increasing temperature. The compressive strength increases to 115 MPa at 1350 °C. The relationship of the quantity of gehlenite and the compressive strength were explored.
The electrochemical reduction process of ZnFe2O4 in NaCl-CaCl2 melts was studied. Thermodynamic analysis shows that the reduction process of ZnFe2O4 is carried out in multiple steps, and it is ...difficult to reduce Fe3+ to Fe in one step. Electrochemical tests revealed that the reduction process of ZnFe2O4 includes three steps: First, Fe3+ is reduced to Fe in two steps, then Zn2+ is reduced to Zn in one step. The reduction of Fe3+ on the Mo electrode is a reversible process controlled by diffusion, while the reduction of Zn2+ is an irreversible process controlled by diffusion. The influence of electrolysis voltage and temperature on the process of electric deoxidation has also been studied. It is indicated that properly increasing the temperature is conducive to the diffusion of oxygen ions, thereby increasing the deoxidation rate. With the gradual increase of voltage, the reduction process of ZnFe2O4 is ZnFe2O4 → FeO + ZnO → Fe + ZnO → Fe + Zn.
The popularity of large-volume liposuction and the toxicity of lidocaine have led to a reduction of lidocaine dosage in tumescent liposuction. We have gradually reduced the concentration of lidocaine ...from 500 to 252 mg/l over the past decade.
To evaluate the partitioning and the recovery of lidocaine at a lower concentration in tumescent liposuction.
10 consecutive patients' aspirate samples were analysed for the lidocaine concentration in the fat and the fluid component, the percentage of injected lidocaine removed by aspiration and its partition coefficient in fat versus fluid.
7.5% of the injected lidocaine was removed; its partition coefficient was 0.21.
7.5% of the total lidocaine was aspirated in tumescent liposuction. The fat uptake of lidocaine was lower than in previous reports, which was of particular interest for future studies on lidocaine toxicity for the safety of the patients undergoing tumescent liposuction.
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