Surficial grafting of organoimido moieties enhances the capacity performance of oxometallic clusters.

Molybdenum trioxide (MoO3) with a theoretical specific capacity of 1117 mA h g-1 is widely considered a promising anode material for lithium-ion batteries. However, the irreversible conversion reactions, low electrical conductivity, and detrimental volume expansion upon Li intercalation between the one-dimensional layered structures of MoO3 hinder its practical implementation. Herein, we report a facile synthetic protocol that allows surficial modification by replacing the terminal and bridging oxo groups of molybdenum oxide clusters. Successful organoimido functionalization resulted in a large cathodic shift in Mo(VI/V) reduction by 0.6 V, pronounced electronic communication between the organic moiety and the metal-oxide unit, and significant increase in electrical conductivity (80-100 Ω interfacial charge-transfer resistance). Combined with the enlarged active surface area due to the structural hindrance induced by the organic functionality, the steady specific capacity of the organoimido-modified molybdenum oxide clusters was greater than 1200 mA h g-1 at 900 mA g-1 at the end of 360 cycles, where the best value of 1653 mA h g-1 was achieved for the nitroaniline-substituted species. The steady capacity of 480 mA h g-1 was achieved in the fast charge-discharge process (3000 mA g-1) over 1400 cycles. The results indicate that the surficial modification of metal oxides with organo moieties using our facile synthetic method has broad application potential for metal oxides to be used as high-capacity electrode materials in the future.

Non-Antibacterial and Antibacterial ZnO Nanoparticles Composed of Different Surfactants.

Zinc oxide nanoparticles were synthesized using different surfactants such as SDS, CTAB, Triton X-100, PVP K-30 and ethylene glycol. ZnO NPs were tested for antibacterial activity before and after calcination against different micro-organisms like E. coli and P. aeruginosa (Gram negative) as well as S. aureus and B. subtilis (Gram positive). Antibacterial activity was observed in SDScapped ZnO NPs only against B. subtilis. Antibacterial activity of ZnO-capped SDS was tested in a concentration range 0.625-10 mg/mL. Increased antibacterial activity was observed before calcination as compared to after calcination. Minimum concentration at which uncalcinated as well as calcinated SDS-capped ZnO NPs show antibacterial activity is 2.5 mg/mL and 5 mg/mL respectively. Non-antibacterial nature of ZnO NPs highlights its further use in drug delivery due to its inert nature, enhanced efficacy in association with therapeutic drugs as well as easy disposal.

Asymmetric Benzotrithiophene-Based Hole Transporting Materials Provide High-Efficiency Perovskite Solar Cells.

In this study, we synthesized a series of small-molecule benzotrithiophenes (BTTs) and used them as hole transporting materials (HTMs) in perovskite solar cells (PSCs). The asymmetric benzo[2,1-b:-3,4-b':5,6-b″]trithiophene unit was used as the central core to which were appended various donor groups, namely, carbazole (BTT-CB), thieno thiophene (BTT-FT), triphenylamine (BTT-TPA), and bithiophene (BTT-TT). The extended aromatic core in the asymmetric BTT provided full planarity, thereby favoring intermolecular π-stacking and charge transport. The physical, optical, and electrical properties of these small-molecule HTMs are reported herein. BTT-TT displayed good crystallinity and superior hole mobility, when compared with those of the other three HTMs, and formed smooth and uniform surfaces when covering the perovskite active layer. Accordingly, among the devices prepared in this study, a PSC incorporating BTT-TT as the HTM achieved the highest power conversion efficiency (18.58%). Moreover, this BTT-TT-containing device exhibited good stability after storage for more than 700 h. Thus, asymmetric BTTs are promising candidate materials for use as small-molecule HTMs in PSCs.

Mechanism of thyroid gland invasion in laryngeal cancer and indications for thyroidectomy.

Invasion of thyroid gland (TG) by laryngeal cancer is rare. However, ipsilateral hemithyroidectomy is routinely performed during total laryngectomy (TL) for laryngeal cancers. Even hemithyroidectomies are associated with hypothyroidism in 23-63% and hypoparathyroidism in 25-52%. Most of the studies on laryngectomy have advised thyroidectomy for T3 and T4 lesion, transglottic growth, subglottic disease or extension and involvement of anterior commissure. The role of tumour differentiation in TG invasion is unknown. The cases with TG invasion have been reported to have poorer prognosis. This is a retrospective study of 45 patients undergoing thyroidectomy along with TL. Of these, five had TG invasion. Extra-laryngeal soft tissue involvement [RR 1.89 (1.02, 4.24)] and transglottic growths [RR 1.18 (1.02, 1.36)] had a significant association with TG invasion. The mode of spread, contiguous or non-contiguous, depended on tumour differentiation. Well differentiated cancers had propensity for contiguous spread and moderately differentiated cancers for non-contiguous spread (p = 0.05). The 5 years survival of T4a cases was 30%. The difference in survival between TG invasion (p = 0.618), cartilage invasion (p = 0.111) and soft tissue infiltration (p = 0.474) was statistically insignificant. Anatomically direct TG invasion can only occur through extralaryngeal soft tissue which is includes cricopharyngeus and cricothyroid muscles. We recommend thyroidectomy only when these muscles are involved by the tumour in case of well differentiated cancers. The probability of TG invasion increases with transglottic growths with subglottic extension more than 10 mm. We recommend ipsilateral hemithyroidectomy in less differentiated cancers as they have propensity for non-contiguous spread.

Dopamine, by acting through its D2 receptor, inhibits insulin-like growth factor-I (IGF-I)-induced gastric cancer cell proliferation via up-regulation of Krüppel-like factor 4 through down-regulation of IGF-IR and AKT phosphorylation.

The overexpression of insulin-like growth factor receptor-I (IGF-IR) and the activation of its signaling pathways both play critical roles in the development and progression of gastric cancer. Dopamine (DA), a major enteric neurotransmitter, has been reported to have a wide variety of physiological functions in the gastrointestinal tract, including the stomach. We have previously reported that both DA and tyrosine hydroxylase, the rate-limiting enzyme required for the synthesis of DA, are lost in malignant gastric tissues. The effect of this loss of DA on IGF-IR-induced growth of gastric cancer has not yet been elucidated; we therefore investigated the role of DA, if any, on IGF-IR-induced proliferation of malignant gastric cells. There was a significant increase in the expression of phosphorylated IGF-IR and its downstream signaling molecule AKT in human malignant gastric tissues compared with normal nonmalignant tissues. Furthermore, to determine whether this loss of DA has any effect on the activation of IGF-IR signaling pathways in malignant gastric tumors, in vitro experiments were undertaken, using AGS gastric cancer cells. Our results demonstrated that DA acting through its D(2) receptor, inhibits IGF-I-induced proliferation of AGS cells by up-regulating KLF4, a negative regulator of the cell cycle through down regulation of IGF-IR and AKT phosphorylation. Our results suggest that DA is an important regulator of IGF-IR function in malignant gastric cancer cells.