One-pot pyro synthesis of a nanosized-LiMn2O4/C cathode with enhanced lithium storage properties

A simple one-pot polyol-assisted pyro-technique has been adopted to synthesize highly crystalline, carbon-coated LiMn₂O₄ (LMO/C) nanoparticles for use as a cathode material in rechargeable Li-ion battery (LIB) applications. The phase purity, structure and stoichiometry of the prepared cathode was confirmed using X-ray techniques that included high-resolution powder X-ray diffraction and X-ray absorption fine structure spectroscopy. Electron microscopy studies established that the synthetic technique facilitated the production of nano-sized LMO particles with uniform carbon coating. The prepared LMO/C cathode demonstrates excellent electrochemical properties (cycling stabilities of 86% and 77.5% and high rate capabilities of 79% and 36% within the potential windows of 3.3–4.3 V and 2.5–4.3 V, respectively). The high electrochemical performance of the LMO/C cathode is attributed to the nano-size of the LiMn₂O₄ particles enabling high surface area and hence greater lithium insertion and also the uniform amorphous carbon coating facilitating effective reduction in manganese dissolution and volume expansion during the lithium de-intercalation/intercalation reactions. In addition, cyclic voltametry and impedance characterization confirm the reversible Li-intercalation and the role of the solid electrolyte interface layer (SEI) in the stable electrochemical reaction of the LMO/C electrode. Furthermore, this study shows the efficacy of a simple and low-cost pyro-synthetic method to realize high performance nano-sized particle electrodes with uniform carbon coating for useful energy storage applications.

A simple one-pot polyol-assisted pyro-synthesized LiMn₂O₄/C cathode demonstrated remarkable lithium cycling stabilities of 86% and 19% and high rate capabilities of 77.5% and 36% at 3.3–4.3 V and 2.5–4.3V, respectively.     

Risk factors,including different biologics,associated with depression and anxiety in patients with rheumatoid arthritis: a cross-sectional observational study

Clinical Rheumatology - To evaluate the associated factors of depression and anxiety in patients with rheumatoid arthritis (RA) and examine the effect of different biologics. This cross-sectional...     

A Comparative Study of Three-Year Weight Loss and Outcomes After Laparoscopic Gastric Bypass in Patients with “Yellow Light” Psychological Clearance

The relationship between psychological factors and bariatric surgical outcomes is unclear. While some psychological contraindications to bariatric surgery are described, there is no consensus on preoperative psychological evaluation or on factors that can predict bariatric outcomes. Our aim was to determine whether full or reserved psychological clearance predicts early weight loss or compliance with follow-up. We found no clinically significant differences in short-term weight loss outcomes or in attendance at scheduled follow-up visits between patients receiving full or “green light” clearance versus “yellow light” clearance, meaning clearance with recommendations for ongoing therapy. Further research may identify psychological predictors of success following bariatric surgery and help optimize preoperative evaluation practices.     

Benzo[d]thiazole-2-thiol bearing 2-oxo-2-substituted-phenylethan-1-yl as potent selective lasB quorum sensing inhibitors of Gram-negative bacteria

Quorum sensing is a well-known term for describing bacterial cell–cell communication. Bacteria use quorum sensing pathways to respond to external factors such as nutrient availability, defense mechanisms, and coordinate host toxic behaviors such as biofilm formation, virulence production, and other pathogenesis. Discovery of novel compounds which inhibit quorum sensing without being antibiotic are currently emerging fields. Herein, the library of fifteen benzo[d]thiazole/quinoline-2-thiol bearing 2-oxo-2-substituted-phenylethan-1-yl compounds was designed, synthesized and evaluated to find novel quorum sensing inhibitors. Firstly, compounds were evaluated for their growth inhibitory activities at high concentrations up to 1000 μg mL⁻¹ toward Pseudomonas aeruginosa. Under our conditions, twelve compounds showed moderate growth inhibitory activities in the concentration tested. To our delight, three compounds 3, 6 and 7 do not affect the growth of the bacteria which were chosen for the evaluation of quorum sensing inhibitor activities. In the LasB system, our compounds 3, 6, 7 showed promising quorum-sensing inhibitors with IC₅₀ of 115.2 μg mL⁻¹, 182.2 μg mL⁻¹ and 45.5 μg mL⁻¹, respectively. In the PqsR system, no activity observed suggesting that the selectivity of the compound toward the LasB system. In addition, 7 showed the moderate anti-biofilm formation of Pseudomonas aeruginosa. Docking studies revealed that 3, 6 and 7 binding to the active site of Pseudomonas aeruginosa quorum sensing LasR system with better affinity compared to reference compounds 4-NPO. Finally, computation calculations suggest that compounds are a good template for further drug development.

Benzo[d]thiazole-2-thiol bearing 2-oxo-2-substituted-phenylethan-1-yl as potent selective lasB quorum sensing inhibitors and anti-biofilm formation of Pseudomonas aeruginosa.     

Enhancing the chloramphenicol sensing performance of Cu–MoS2 nanocomposite-based electrochemical nanosensors: roles of phase composition and copper loading amount

The rational design of nanomaterials for electrochemical nanosensors from the perspective of structure–property–performance relationships is a key factor in improving the analytical performance toward residual antibiotics in food. We have investigated the effects of the crystalline phase and copper loading amount on the detection performance of Cu–MoS₂ nanocomposite-based electrochemical sensors for the antibiotic chloramphenicol (CAP). The phase composition and copper loading amount on the MoS₂ nanosheets can be controlled using a facile electrochemical method. Cu and Cu₂O nanoparticle-based electrochemical sensors showed a higher CAP electrochemical sensing performance as compared to CuO nanoparticles due to their higher electrocatalytic activity and conductivity. Moreover, the design of Cu–MoS₂ nanocomposites with appropriate copper loading amounts could significantly improve their electrochemical responses for CAP. Under optimized conditions, Cu–MoS₂ nanocomposite-based electrochemical nanosensor showed a remarkable sensing performance for CAP with an electrochemical sensitivity of 1.74 μA μM⁻¹ cm⁻² and a detection limit of 0.19 μM in the detection range from 0.5–50 μM. These findings provide deeper insight into the effects of nanoelectrode designs on the analytical performance of electrochemical nanosensors.

In this work, we clarify the roles of phase composition and copper loading amount on the CAP sensing performance of Cu–MoS₂ nanocomposite-based electrochemical nanosensors.     

The binary aluminum scandium clusters AlxScy with x + y = 13: when is the icosahedron retained?

Geometrical and electronic structures of the 13-atom clusters Al_xSc_y with x + y = 13, as well as their thermodynamic stabilities were investigated using DFT calculations. Both anionic and neutral isomers of Al_xSc_y were found to retain an icosahedral shape of both Al₁₃ and Sc₁₃ systems in which an Al atom occupies the endohedral central position of the icosahedral cage, irrespective of the number of Al atoms present. Such a phenomenon occurs to maximize the number of stronger Al–Al and Sc–Al bonds instead of the weaker Sc–Sc bonds. NBO analyses were applied to examine their electron configurations and rationalize the large number of open shells and thereby high multiplicities of the mixed clusters having more than three Sc atoms. The SOMOs are the molecular orbitals belonged to the irreducible representations of the symmetry point group of the clusters studied, rather than to the cluster electron shells. Evaluation of the average binding energies showed that the thermodynamic stability of Al_xSc_y clusters is insignificantly altered as the number y goes from 0 to 7 and then steadily decreases when y attains the 7–13 range. Increase of the Sc atom number also reduces the electron affinities of the binary Al_xSc_y clusters, and thus they gradually lose the superhalogen characteristics with respect to the pure Al₁₃.

The icosahedral structure of the Al_xSc_y clusters with x + y = 13.