Cross-Linked Gel Electrolytes with Self-Healing Functionalities for Smart Lithium Batteries.

Next-generation Li-ion batteries must guarantee improved durability, quality, reliability, and safety to satisfy the stringent technical requirements of crucial sectors such as e-mobility. One breakthrough strategy to overcome the degradation phenomena affecting the battery performance is the development of advanced materials integrating smart functionalities, such as self-healing units. Herein, we propose a gel electrolyte based on a uniform and highly cross-linked network, hosting a high amount of liquid electrolyte, with multiple advantages: (i) autonomous, fast self-healing, and a promising PF5-scavenging role; (ii) solid-like mechanical stability despite the large fraction of entrapped liquid; and (iii) good Li+ transport. It is shown that such a gel electrolyte has very good conductivity (>1.0 mS cm-1 at 40 °C) with low activation energy (0.25 eV) for the ion transport. The transport properties are easily restored in the case of physical damages, thanks to the outstanding capability of the polymer to intrinsically repair severe cracks or fractures. The good elastic modulus of the cross-linked network, combined with the high fraction of anions immobilized within the polymer backbone, guarantees stable Li electrodeposition, disfavoring the formation of mossy dendrites with the Li metal anode. We demonstrate the electrolyte performance in a full-cell configuration with a LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode, obtaining good cycling performance and stability.

Autonomous Self-Healing Strategy for Stable Sodium-Ion Battery: A Case Study of Black Phosphorus Anodes.

Autonomic self-healing (SH), namely, the ability to repair damages from mechanical stress spontaneously, is polarizing attention in the field of new-generation electrochemical devices. This property is highly attractive to enhance the durability of rechargeable Li-ion batteries (LIBs) or Na-ion batteries (SIBs), where high-performing anode active materials (silicon, phosphorus, etc.) are strongly affected by volume expansion and phase changes upon ion insertion. Here, we applied a SH strategy, based on the dynamic quadruple hydrogen bonding, to nanosized black phosphorus (BP) anodes for Na-ion cells. The goal is to overcome drastic capacity decay and short lifetime, resulting from mechanical damages induced by the volumetric expansion/contraction upon sodiation/desodiation. Specifically, we developed novel ureidopyrimidinone (UPy)-telechelic systems and related blends with poly(ethylene oxide) as novel and green binders alternative to the more conventional ones, such as polyacrylic acid and carboxymethylcellulose, which are typically used in SIBs. BP anodes show impressively improved (more than 6 times) capacity retention when employing the new SH polymeric blend. In particular, the SH electrode still works at a current density higher than 3.5 A g-1, whereas the standard BP electrode exhibits very poor performances already at current densities lower than 0.5 A g-1. This is the result of better adhesion, buffering properties, and spontaneous damage reparation.

Lithiation Mechanism in High-Entropy Oxides as Anode Materials for Li-Ion Batteries: An Operando XAS Study.

High-entropy oxides based on transition metals, such as Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O (TM-HEO), have recently drawn special attention as potential anodes in lithium-ion batteries due to high specific capacity and cycling reversibility. However, the lithiation/delithiation mechanism of such systems is still controversial and not clearly addressed. Here, we report on an operando XAS investigation into TM-HEO-based anodes for lithium-ion cells during the first lithiation/delithiation cycle. This material showed a high specific capacity exceeding 600 mAh g-1 at 0.1 C and Coulombic efficiency very close to unity. The combination of functional and advanced spectroscopic studies revealed complex charging mechanisms, developing through the reduction of transition-metal (TM) cations, which triggers the conversion reaction below 1.0 V. The conversion is irreversible and incomplete, leading to the final collapse of the HEO rock-salt structure. Other redox processes are therefore discussed and called to account for the observed cycling behavior of the TM-HEO-based anode. Despite the irreversible phenomena, the HEO cubic structure remains intact for ∼60% of lithiation capacity, so proving the beneficial role of the configuration entropy in enhancing the stability of the HEO rock-salt structure during the redox phenomena.

Photosynthetic microbial fuel cell with polybenzimidazole membrane: synergy between bacteria and algae for wastewater removal and biorefinery.

Here, we demonstrate a very efficient simultaneous approach of bioenergy generation from wastewater and added-value compounds production by using a photosynthetic microalgae microbial fuel cells (PMFC), based on polybenzimidazole (PBI) composite membrane as separator. The use of PBI was proved to be very promising, even more convenient than Nafion™ in terms of energy performances as well as cost and sustainability. This polymer is also easily autoclavable, so allowing a re-use of the separator with a consequent beneficial cost effect. Two PMFCs were investigated: 1) Pt electrocatalysed and 2) Pt-free. They were operated as microbial carbon capture (MCC) device under continuous illumination, by using a domestic wastewater as anolyte and Scenedesmus acutus strain in the catholyte. The Pt-based cell allowed to generate higher volumetric power density (∼400 mW m-3) after more than 100 operating days. This resulted in an improved wastewater treatment efficiency, determined in terms of normalised energy recovery (NER > 0.19 kWh kgCOD-1 in case of Pt). The CO2 fixation of the PMFC-grown microalgae leaded to a high accumulation of added-value products, namely pigments and fatty acids. A significant quantity of lutein was observed as well as a relevant amount of other valuable carotenoids, as violaxanthin, astaxanthin and cantaxanthin. The lipids were even excellently accumulated (49%dw). Their profile was mainly composed by fatty acids in the range C16-18, which are particularly indicated for the biofuel production. These results demonstrate the feasibility and the implemented sustainability of such PMFCs as a great potential technology for the wastewater treatment and the simultaneous production of valuable products.

Effects of water-soluble functionalized multi-walled carbon nanotubes examined by different cytotoxicity methods in human astrocyte D384 and lung A549 cells.

The widespread projected use of functionalized carbon nanotubes (CNTs) makes it important to understand their potential harmful effects. Two cell culture systems, human A549 pneumocytes and D384 astrocytoma cells, were used to assess cytotoxicity of multi-walled CNTs (MWCNTs) with varying degrees of functionalization. Laboratory-made highly functionalized hf-MW-NH(2) and less functionalized CNTs (MW-COOH and MW-NH(2)) were tested in comparison with pristine MWCNTs, carbon black (CB) and silica (SiO(2)) by MTT assay and calcein/propidium iodide (PI) staining. Purity and physicochemical properties of the test nanomaterials were also determined. In both MTT and calcein/PI assays, highly functionalized CNTs (hf-MW-NH(2)) caused moderate loss of cell viability at doses >or=100 microg/ml being apparently less cytotoxic than SiO(2). In preparations treated with CB or the other nanotube types (pristine MWCNTs, MW-COOH and the less functionalized amino-substituted MW-NH(2)) the calcein/PI test indicated no loss of cell viability, whereas MTT assay apparently showed apparent cytotoxic response, occurring not dose-dependently at exceedingly low CNT concentrations (1 microg/ml). The latter nanomaterials were difficult to disperse showing higher aggregate ranges and tendency to agglomerate in bundle-like form in cell cultures. In contrast, hf-MW-NH(2) were water soluble and easily dispersible in medium; they presented lower aggregate size range as well as considerably lower length to diameter ratios and low tendency to form aggregates compared to the other CNTs tested. The MTT data may reflect a false positive cytotoxicity signal possibly due to non-specific CNT interaction with cell culture components. Thus, these properties obtained by chemical functionalization, such as water solubility, high dispersibility and low agglomeration tendency were relevant factors in modulating cytotoxicity. This study indicates that properties obtained by chemical functionalization, such as water solubility, high dispersibility and low agglomeration tendency are relevant factors in modulating cytotoxicity of CNTs.

Evaluation of circulating endothelial cells, VEGF and VEGFR2 serum levels in patients with chronic myeloproliferative diseases.

Authors evaluated some markers of angiogenetic activity in patients with chronic myeloproliferative diseases (CMDs). In this study by using a cytofluorimetric analysis we evaluated circulating endothelial progenitor cells (EPCs) in patients with chronic myeloproliferative disease. Moreover, in the same group of subjects, we evaluated serum levels of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR2). In our patients, we have found an increase in the number of endothelial progenitor cells in primary myelofibrosis (PMF) and polycythaemia vera (PV) patients, while an increase of circulating endothelial cells (CECs) was found in all patients with CMD. Moreover, we found higher serum levels of VEGF with respect to control subjects in every group of patients with CMD, and a not significant reduction of VEGFR2 levels in essential thrombocythaemia (ET) patients. A correlation was also found in PV patients between VEGF levels and erythrocyte number and in PMF subjects with the count of white cells. Our data suggest that some markers of angiogenesis are activated in CMD patients and angiogenesis may have a role in the pathophysiology of chronic myeloproliferative disorders.

Patients with bisphosphonates-associated osteonecrosis of the jaw have reduced circulating endothelial cells.

Osteonecrosis of the jaws (ONJ) associated with the use of bisphosphonates is a newly described entity. To elucidate the mechanism leading to ONJ and to test the hypothesis that in patients with ONJ the bisphosphonates may interfere with endothelial cell proliferation, using flow cytometric analysis we evaluated the number of circulating endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) in eight patients with bisphosphonate treatment and osteonecrosis, eight multiple myeloma (MM) patients with bisphosphonates treatment without ONJ and five normal subjects. MM patients showed an increase of CD34+ cells with respect the control subjects and ONJ subjects. EPCs and CECs were higher in MM patients compared to controls and ONJ patients. ONJ patients showed a decrease of EPCs compared to control subjects while CECs were similar to the controls group. Our results seem to show the possibility that bisphosphonates could have a antiangiogenic effect and a suppressive effect on CECs of patients with ONJ.

Bisphosphonate-associated osteonecrosis of the jaw in patients with multiple myeloma and breast cancer.

Osteonecrosis of the jaw is an unremitting adverse outcome associated with bisphosphonate therapy in patients with multiple myeloma or bone metastases from solid tumors. Twelve patients who presented with exposed bone associated with bisphosphonates were reviewed to determine the type, dosage and duration of their bisphosphonate therapy, presenting findings, comorbidities and the event that incited the bone exposure. The discontinuation of bisphosphonate therapy has not helped reverse the presence of osteonecrosis, and the surgical manipulation of the involved site appears to worsen the underlying bone pathology. Hyperbaric oxygen, which has proven efficacious in other forms of osteonecrosis by establishing an oxygen gradient, is of no definitive benefit to patients with bisphosphonate-induced exposed bone. Antibiotic therapy is useful in controlling pain and swelling but ineffective in preventing the progression of the exposed bone. To date, prevention is the only currently possible therapeutic approach to the management of this complication.

Differential levels of soluble angiopoietin-2 and Tie-2 in patients with haematological malignancies.

The system involving angiopoietin-2 (Ang-2) and its receptor, Tie-2, appears to play an important role not only in tumor angiogenesis, but also in the biology of haematological and non-haematological malignancies. In the present study we evaluated the serum levels of soluble Ang-2 (sAng-2) and soluble Tie-2 (sTie-2) in patients with haematological malignancies. Measurements were carried out in 15 patients with chronic myeloid leukaemia (CML), 25 with essential thrombocythemia (ET), 24 with multiple myeloma (MM) and six with monoclonal gammopathy of undetermined significance (MGUS). In addition, we correlated the levels of angiopoietins with known prognostic factors. sAng-2 and sTie-2 were quantified with enzyme-linked immunosorbent assay (ELISA). In patients with CML and MM the levels of sAng-2 were significantly higher (1686.53 +/- 936.41 pg/mL and 1917.82 +/- 1427 pg/mL, respectively) than in controls (n = 15; 996.096 +/- 414.65 pg/mL) (P < 0.01). In patients with MM sAng-2 levels were significantly increased with increasing stage of disease, from stage I to stage III (P < 0.03) and presented a trend of correlation with Beta2-microglobulin levels (r = 0.317) and grade of bone involvement. Furthermore, the levels of sAng-2 determined after 6 months of chemotherapy in CML patients were significantly lower than at diagnosis in the patients who achieved haematological remission. Circulating sTie-2 levels were increased in patients with ET (17.5 +/- 9.2 vs 9 +/- 3.5 ng/mL; P < 0.01) and in those with CML (16.29 +/- 8.7 ng/mL; P < 0.04). In conclusion, abnormal levels of sAng-2 and sTie-2 are present in some haematological malignancies. These markers may play a role in the pathophysiology of these conditions and their progression.

Systemic aspergillosis in a patient with non-Hodgkin's lymphoma developing acute graft-versus-host disease after autologous peripheral blood stem cell transplantation.

Graft-versus-host disease (GVHD) is rare in the autologous setting. We describe a non-Hodgkin's lymphoma case developing acute GVHD after autologous peripheral blood stem cell transplantation following several lines of chemotherapy inclusive of fludarabine. At day +33, he complained of fever, diffused erythematous papulosis with ulceration of skin lesions. A punch biopsy indicated a grade III GVHD. A dose escalation of corticosteroids, cyclosporin-A and photoapheresis induced a transient response. He developed positivity to CMV and systemic aspergillosis. He died at day +185 in haematological complete remission, despite infection-oriented treatment. In spite of the use of prophylactic immunosuppressive drugs, between 50% and 70% of patients given HLA-identical marrow graft develop acute graft-versus-host disease (GVHD) that, in turn, significantly increases the risk of transplant-related mortality. Autologous BMT has been shown to be an effective procedure in several malignancies, persistently becoming a first-line choice in treating patients affected with lymphoproliferative disorders, specially non-Hodgkin's lymphoma (NHL). Although GVHD is a very rare event in the autologous setting (AuGVHD), a consistent number of reports dealing with GVHD-like phenomena has emerged, especially in breast cancer patients. More often, AuGVHD has been induced by the use of immunosuppressive agents, such as cyclosporin-A (CSA), in attempt to evoke a graft-versus-tumor (GVT) effect. However, AuGVHD is mild and self-limited phenomenon. We report the case of a NHL patient who developed unresponsive GVHD after autologous peripheral blood stem cell transplantation (PBSCT). Because of the immunosuppressive therapies, he developed systemic aspergillosis. He died in haematological complete remission despite infection-oriented treatment.