Incorporation of rubidium cations into perovskite solar cells improves photovoltaic performance

All of the cations currently used in perovskite solar cells abide by the tolerance factor for incorporation into the lattice. We show that the small and oxidation-stable rubidium cation (Rb⁺) can be embedded into a "cation cascade" to create perovskite materials with excellent material properties. We achieved stabilized efficiencies of up to 21.6% (average value, 20.2%) on small areas (and a stabilized 19.0% on a cell 0.5 square centimeters in area) as well as an electroluminescence of 3.8%. The open-circuit voltage of 1.24 volts at a band gap of 1.63 electron volts leads to a loss in potential of 0.39 volts, versus 0.4 volts for commercial silicon cells. Polymer-coated cells maintained 95% of their initial performance at 85°C for 500 hours under full illumination and maximum power point tracking.

Additive-Free Transparent Triarylamine-Based Polymeric Hole-Transport Materials for Stable Perovskite Solar Cells

Triarylamine-based polymers with different functional groups were synthetized as hole-transport materials (HTMs) for perovskite solar cells (PSCs). The novel materials enabled efficient PSCs without the use of chemical doping (or additives) to enhance charge transport. Devices employing poly(triarylamine) with methylphenylethenyl functional groups (V873) showed a power conversion efficiency of 12.3 %, whereas widely used additive-free poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) demonstrated 10.8 %. Notably, devices with V873 enabled stable PSCs under 1 sun illumination at maximum power point tracking for approximately 40 h at room temperature, and in the dark under elevated temperature (85 °C) for more than 140 h. This is in stark contrast to additive-containing devices, which degrade significantly within the same time frame. The results present remarkable progress towards stable PSC under real working conditions and industrial stress tests.

Protective Role of PEDF-Derived Synthetic Peptide Against Experimental Diabetic Nephropathy

Pigment epithelium-derived factor (PEDF) is a glycoprotein with complex neuroprotective, anti-angiogenic, and anti-inflammatory properties, all of which could potentially be exploited as a therapeutic option for vascular complications in diabetes. We have previously shown that PEDF-derived synthetic peptide, P5-3 (FIFVLRD) has a comparable ability with full PEDF protein to inhibit rat corneal neovascularization induced by chemical cauterization. However, the effects of PEDF peptide on experimental diabetic nephropathy remain unknown. To address the issue, we modified P5-3 to stabilize and administered the modified peptide (d-Lys-d-Lys-d-Lys-Gln-d-Pro-P5-3-Cys-amide, 0.2 nmol/day) or vehicle to streptozotocin-induced diabetic rats (STZ-rats) intraperitoneally by an osmotic mini pump for 2 weeks. We further examined the effects of modified peptide on human proximal tubular cells. Renal PEDF expression was decreased in STZ-rats. Although the peptide administration did not affect blood glucose or blood pressure, it decreased urinary excretion levels of 8-hydroxy-2'-deoxyguanosine, an oxidative stress marker, and reduced plasminogen activator inhibitor-1 (PAI-1) gene expression, and suppressed glomerular expansion in the diabetic kidneys. High glucose or advanced glycation end products stimulated oxidative stress generation and PAI-1 gene expression in tubular cells, all of which were significantly suppressed by 10 nM modified P5-3 peptide. Our present study suggests that PEDF-derived synthetic modified peptide could protect against experimental diabetic nephropathy and inhibit tubular cell damage under diabetes-like conditions through its anti-oxidative properties. Supplementation of modified P5-3 peptide may be a novel therapeutic strategy for diabetic nephropathy.

Sulforaphane reduces advanced glycation end products (AGEs)-induced inflammation in endothelial cells and rat aorta

BACKGROUND AND AIMS

Advanced glycation end products (AGEs)-receptor RAGE interaction evokes oxidative stress and inflammatory reactions, thereby being involved in endothelial cell (EC) damage in diabetes. Sulforaphane is generated from glucoraphanin, a naturally occurring isothiocyanate found in widely consumed cruciferous vegetables, by myrosinase. Sulforaphane has been reported to protect against oxidative stress-mediated cell and tissue injury. However, effects of sulforaphane on AGEs-induced vascular damage remain unclear.

METHODS AND RESULTS

In this study, we investigated whether and how sulforaphane could inhibit inflammation in AGEs-exposed human umbilical vein ECs (HUVECs) and AGEs-injected rat aorta. Sulforaphane treatment for 4 or 24 h dose-dependently inhibited the AGEs-induced increase in RAGE, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecular-1 (VCAM-1) gene expression in HUVECs. AGEs significantly stimulated MCP-1 production by, and THP-1 cell adhesion to, HUVECs, both of which were prevented by 1.6 μM sulforaphane. Sulforaphane significantly suppressed oxidative stress generation and NADPH oxidase activation evoked by AGEs in HUVECs. Furthermore, aortic RAGE, ICAM-1 and VCAM-1 expression in AGEs-injected rats were increased, which were suppressed by simultaneous infusion of sulforaphane.

CONCLUSION

The present study demonstrated for the first time that sulforaphane could inhibit inflammation in AGEs-exposed HUVECs and AGEs-infused rat aorta partly by suppressing RAGE expression through its anti-oxidative properties. Inhibition of the AGEs-RAGE axis by sulforaphane might be a novel therapeutic target for vascular injury in diabetes.

Unbroken Perovskite: Interplay of Morphology, Electro-optical Properties, and Ionic Movement

Hybrid organic-inorganic perovskite materials have risen up as leading components for light-harvesting applications. However, to date many questions are still open concerning the operation of perovskite solar cells (PSCs). A systematic analysis of the interplay among structural features, optoelectronic performance, and ionic movement behavior for FA0.83 MA0.17 Pb(I0.83 Br0.17 )3 PSCs is presented, which yield high power conversion efficiencies up to 20.8%.

Acarbose, an α-Glucosidase Inhibitor, Decreases Aortic Gene Expression and Serum Levels of Monocyte Chemoattractant Protein-1 in Fructose-fed Rats

Insulin resistance is one of the determinants of post-prandial hyperglycaemia. Recently, acarbose, an α-glucosidase inhibitor that delays the absorption of carbohydrates from the small intestine, has been found to reduce the incidence of cardiovascular disease in patients with impaired glucose tolerance or diabetes. However, the molecular mechanism by which acarbose inhibits cardiovascular events remains unknown. In this study, we examined whether oral administration of acarbose could suppress expression of monocyte chemoattractant protein-1 (MCP-1) in fructose-fed rats, a widely used animal model of insulin resistance. Serum MCP-1 levels were elevated in fructose-fed rats after 4 weeks. Acarbose treatment for 4 weeks reduced the fructose-induced elevation of serum MCP-1 levels. Acarbose treatment for 8 weeks decreased MCP-1 mRNA levels in the aortae of fructose-fed rats. These results suggest that the cardioprotective effects of acarbose could be due, at least in part, to the suppression of MCP-1 expression.

Nifedipine, a Calcium-channel Blocker, Inhibits Advanced Glycation End-product-induced Expression of Monocyte Chemoattractant Protein-1 in Human Cultured Mesangial Cells

The interaction between advanced glycation end-products (AGEs) and their receptors mediates the progressive alteration in renal architecture and loss of renal function in diabetic nephropathy. This study investigated whether nifedipine, a widely used anti-hypertensive drug, suppresses expression of monocyte chemoattractant protein-1 (MCP-1), a chemokine that mediates the recruitment of monocytes to inflammatory sites, in AGE-exposed human cultured mesangial cells. Cells were treated with 100 μg/ml AGE-bovine serum albumin (BSA) or non-glycated BSA in the presence or absence of 1 μM nifedipine or 50 nM diphenylene iodonium, an inhibitor of reduced nicotinamide-adenine dinucleotide phosphate oxidase, for 4 or 24 h. Expression of MCP-1 mRNA was measured using a semi-quantitative reverse transcription-polymerase chain reaction; MCP-1 protein production was measured using an enzyme-linked immunosorbent assay. AGEs significantly increased both MCP-1 mRNA expression and protein production in mesangial cells; this increase was blocked by both nifedipine and diphenylene iodonium. These results suggest that nifedipine could play a protective role against early diabetic nephropathy by suppressing MCP-1 overexpression via blockade of AGE signalling in mesangial cells.

Influence of Angiotensin-converting Enzyme Genetic Polymorphism on Late Renal Dysfunction After Adult-to-adult Living-donor Liver Transplantation

BACKGROUND

Late renal dysfunction (LRD) is known to be one of the most important complications to affect long-term outcome after living-donor liver transplantation (LDLT). The relationship between angiotensin-converting enzyme insertion (I)/deletion (D) gene polymorphism and renal function after LDLT are still unknown. The aim of this study was to elucidate the risk factors for LRD after LDLT, focusing on ACE gene polymorphism.

MATERIALS AND METHODS

Among the 94 recipients who underwent adult-to-adult LDLT between March 2002 and September 2009, the total number of subjects who survived more than 1 year after LDLT and in whom angiotensin-converting enzyme genotype could be measured was 64. LRD was defined as estimated glomerular filtration rate level less than 60 mL/min/1.73 m(2) at any point after 1 year from undergoing LDLT.

RESULTS

LRD was found in 24 patients (37.5%). The incidence of LRD was significantly higher in D/D type than in I/I or I/D type: 85.7% (6/7) vs. 42.1% (8/19), 35.7% (10/38) (P = .010). Preoperative estimated glomerular filtration rate was significantly lower in D/D type than in I/I, I/D types, and postoperatively they were significantly lower in D/D type at 2, 3, and 4 years after LDLT. By multivariate analysis, age and hypertension were the independent risk factors for LRD. The 10-year survival rate was much lower in the recipients with LRD than in those without LRD at 66.7% versus 87.5%, respectively (P = .053).

CONCLUSION

In conclusion, age and hypertension were determined as significant independent risk factors for LRD after adult-to-adult LDLT, and the recipients with D/D genotype should be strictly cared for the development of LRD.

Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency

Today's best perovskite solar cells use a mixture of formamidinium and methylammonium as the monovalent cations. With the addition of inorganic cesium, the resulting triple cation perovskite compositions are thermally more stable, contain less phase impurities and are less sensitive to processing conditions. This enables more reproducible device performances to reach a stabilized power output of 21.1% and ∼18% after 250 hours under operational conditions. These properties are key for the industrialization of perovskite photovoltaics.

Tofogliflozin, A Highly Selective Inhibitor of SGLT2 Blocks Proinflammatory and Proapoptotic Effects of Glucose Overload on Proximal Tubular Cells Partly by Suppressing Oxidative Stress Generation

Ninety percent of glucose filtered by the glomerulus is reabsorbed by a sodium-glucose cotransporter 2 (SGLT2), which is mainly expressed on S1 and S2 segment of renal proximal tubules. Since SGLT-2-mediated glucose reabsorption is increased under diabetic conditions, selective inhibition of SGLT2 is a potential therapeutic target for the treatment of diabetes. We have recently shown that an inhibitor of SGLT2 has anti-inflammatory and antifibrotic effects on experimental diabetic nephropathy partly by suppressing advanced glycation end products formation and oxidative stress generation in the kidney. However, the direct effects of SGLT2 inhibitor on tubular cell damage remain unclear. In this study, we investigated the effects of tofogliflozin, a highly selective inhibitor of SGLT2 on oxidative stress generation, inflammatory and proapoptotic reactions in cultured human proximal tubular cells exposed to high glucose. Tofogliflozin dose-dependently suppressed glucose entry into tubular cells. High glucose exposure (30 mM) for 4 and 24 h significantly increased oxidative stress generation in tubular cells, which were suppressed by the treatment of tofogliflozin or an antioxidant N-acetylcysteine (NAC). Monocyte chemoattractant protein-1 (MCP-1) gene expression and apoptotic cell death were induced by 4 h- and 8 day-exposure to high glucose, respectively, both of which were also blocked by tofogliflozin or NAC. The present study suggests that SGLT2-mediated glucose entry into tubular cells could stimulate oxidative stress and evoke inflammatory and proapoptotic reactions in this cell type. Blockade of glucose reabsorption in tubular cells by SGLT2 inhibitor might exert beneficial effects on tubulointerstitial damage in diabetic nephropathy.

Large-scale prospective pharmacogenomics study of oxaliplatin-induced neuropathy in colon cancer patients enrolled in the JFMC41-1001-C2 (JOIN Trial)

BACKGROUND

Peripheral sensory neuropathy (PSN) is a dose-limiting toxicity of oxaliplatin-based chemotherapy. Several genetic markers have been shown to predict oxaliplatin-induced PSN; however, results remain to be validated in a large-scale and prospective pharmacogenomics study.

PATIENTS AND METHODS

Among 882 patients enrolled in the JFMC41-1001-C2 (JOIN trial), which was designed to investigate the tolerability of adjuvant-modified FOLFOX6 (mFOLFOX6) in Japanese Patients with stage II or III colon cancers undergoing curative resection, 465 patients were eligible for this pharmacogenomics analysis. Twelve single-nucleotide polymorphisms (SNPs) were selected based on published data. The effect of each genotype on time to PSN onset was evaluated in all patients (n = 465) using the Cox proportional hazard model. For the association analysis between severity of PSN and 12 SNP markers, 84 patients who failed to complete 12 cycles of mFOLFOX6 from grade 0/1 PSN group were excluded because the termination of the protocol treatment had been caused by reasons other than PSN.

RESULTS

Comparison of grade 0/1 PSN with grade 2/3 PSN or grade 3 PSN showed no significant associations with any of the 12 SNP markers after adjustment for total dose of oxaliplatin. Time-to-onset analysis also failed to reveal any significant differences.

CONCLUSIONS

Our large-scale and prospective pharmacogenomics study of Japanese patients receiving protocol treatment of adjuvant mFOLFOX6 could not verify a role for any of the 12 SNP markers reported as being significantly associated with PSN. Considering the OR observed in this study (range: 0.76-1.89), further evaluation of these 12 SNP markers in the context of L-OHP-induced PSN is unlikely to be clinically informative.

Successful control of an outbreak of GES-5 extended-spectrum β-lactamase-producing Pseudomonas aeruginosa in a long-term care facility in Japan

BACKGROUND

Little is known about multidrug-resistant Pseudomonas aeruginosa (MDRP) outbreaks in long-term care facilities (LTCFs).

AIM

To describe an MDRP outbreak in an LTCF and to clarify risk factors for MDRP acquisition.

METHODS

Patients who were positive for MDRP at an LTCF from January 2013 to January 2014 were analysed. A descriptive analysis, a case-control study, and a microbiological analysis were performed.

FINDINGS

A total of 23 MDRP cases were identified, 16 of which were confirmed in sputum samples. Healthcare workers were observed violating hand hygiene procedures when performing oral, wound, and genital care. Nasogastric tube and oxygen mask use was associated with MDRP acquisition in the respiratory tract, which might have been confounded by poor hand hygiene. Sharing unhygienic devices, such as portable oral suction devices for oral care, and washing bottles and ointments for wound and genital care with inadequate disinfection could explain the transmission of MDRP in some cases. Isolates from 11 patients were found to be indistinguishable or closely related by pulsed-field gel electrophoresis and harbouring the blaGES-5 gene. Subsequent enhanced infection control measures were supported by nearby hospitals and a local public health centre. No additional cases were identified for a year after the last case occurred in January 2014.

CONCLUSION

An outbreak of MDRP with an antimicrobial resistance gene, blaGES-5, occurred in a Japanese LTCF. It was successfully controlled by enhanced infection control measures, which neighbouring hospitals and a local public health centre supported.

Empagliflozin, an Inhibitor of Sodium-Glucose Cotransporter 2 Exerts Anti-Inflammatory and Antifibrotic Effects on Experimental Diabetic Nephropathy Partly by Suppressing AGEs-Receptor Axis

Advanced glycation end products (AGEs) and receptor RAGE play a role in diabetic nephropathy. We have previously shown that increased glucose uptake into proximal tubular cells via sodium-glucose cotransporter 2 (SGLT2) stimulates oxidative stress generation and RAGE expression, thereby exacerbating the AGE-induced apoptosis in this cell type. However, the protective role of SGLT2 inhibition against the AGE-RAGE-induced renal damage in diabetic animals remains unclear. In this study, we investigated the effects of empagliflozin, SGLT2 inhibitor on AGE-RAGE axis, inflammatory and fibrotic reactions, and tubular injury in the kidney of streptozotocin-induced diabetic rats.Administration of empagliflozin for 4 weeks significantly improved hyperglycemia and HbA1c, and decreased expression levels of AGEs, RAGE, 8-hydroxydeoxyguanosine (8-OHdG), and F4/80, markers of oxidative stress and macrophages, respectively, in the diabetic kidney. Although empagliflozin did not reduce albuminuria, it significantly decreased urinary excretion levels of 8-OHdG and L-fatty acid binding protein, a marker of tubular injury. Moreover, inflammatory and fibrotic gene expression such as monocyte chemoattractant protein-1, intercellular adhesion molecule-1, plasminogen activator inhibitor-1, transforming growth factor-β, and connective tissue growth factor was enhanced in the diabetic kidney, all of which were prevented by empagliflozin. The present study suggests that empagliflozin could inhibit oxidative, inflammatory and fibrotic reactions in the kidney of diabetic rats partly via suppression of the AGE-RAGE axis. Blockade of the increased glucose uptake into renal proximal tubular cells by empagliflozin might be a novel therapeutic target for tubulointerstitial damage in diabetic nephropathy.

Spinal cord ischemia/injury

A spinal cord injury leads to disturbances of sensory and motor signals due to the damage to white matter and myelinated fiber tracts. Moreover, the damage to gray matter causes segmental loss of interneurons of dorsal horn and motoneurons and restricts the therapeutic options. Neuroprotective strategies have the potential to improve the neurological outcome of patients. To achieve this, concerns to anesthetics or analgesics as neuroprotective interventions have been accumulating to explore neuroprotection during perioperative period. This review includes consideration of: 1) basic concepts of the pathophysiological mechanisms following spinal cord injury and 2) anesthetics and analgesics displaying neuroprotective potential. In particular, we review the application of isoflurane as an inhalational neuroprotectant and discuss evidence for the neuroprotection provided by barbiturates. In addition, 3) recent advances in stem cell biology, neural injury and repair, and progress toward the development of neuroprotective and regenerative interventions are the basis for increased optimism.