Liquid Phase Isolation of SnS Monolayers with Enhanced Optoelectronic Properties.

Recent advances in atomically thin two dimensional (2D) anisotropic group IVA -VI metal monochalcogenides (MMCs) and their fascinating intrinsic properties and potential applications are hampered due to an ongoing challenge of monolayer isolation. Among the most promising MMCs, tin (II) sulfide (SnS) is an earth-abundant layered material with tunable bandgap and anisotropic physical properties, which render it extraordinary for electronics and optoelectronics. To date, however, the successful isolation of atomically thin SnS single layers at large quantities has been challenging due to the presence of strong interlayer interactions, attributed to the lone-pair electrons of sulfur. Here, a novel liquid phase exfoliation approach is reported, which enables the overcome of such strong interlayer binding energy. Specifically, it demonstrates that the synergistic action of external thermal energy with the ultrasound energy-induced hydrodynamic force in solution gives rise to the systematic isolation of highly crystalline SnS monolayers (1L-SnS). It is shown that the exfoliated 1L-SnS crystals exhibit high carrier mobility and deep-UV spectral photodetection, featuring a fast carrier response time of 400 ms. At the same time, monolayer-based SnS transistor devices fabricated from solution present a high on/off ratio, complemented with a responsivity of 6.7 × 10-3 A W-1 and remarkable stability upon prolonged operation in ambient conditions. This study opens a new avenue for large-scale isolation of highly crystalline SnS and other MMC manolayers for a wide range of applications, including extended area nanoelectronic devices, printed from solution.

Effects of dietary fibre on metabolism and performance in sows.

The etiology of Postpartum dysgalactia syndrome (PDS) includes stress οn preparturition and constipation associated with low water intake or low fiber intake. The aim of this study was to investigate the effects of a raw crude fibre concentrate (Arbocel®) on sow's metabolism and performance. 100 sows from a farm suffering from PDS, were divided into two groups, with equal distribu- tion of their parity (1 to 5 parity): a) T1 group (control group): 50 sows were fed with regular gestation feed (GF), pre-farrowing feed (PFF), and lactation feed (LF), b) T2 group: 50 sows were fed with regular GF, PFF and LF supplemented with topdress Arbocel® from 104th day of gestation until 7th day of lactation). Health parameters [faeces score (FS), PDS score (PDSS), body condition score (BCS)], performance parameters and liter characteristics were recorded. Blood samples were collected from 25 sows / group (5 sows per parity) 24 h after birth of last piglet and on 14th day of lactation for the evaluation of insulin, leptin and ghrelin levels in the serum, using commercial ELISA kits. In T2 group, BCS at farrowing (p⟨0.001), FS (p=0.001) and PDSS (p=0.003) were improved significantly. The number of piglets stillborn and dead due to crushing decreased (p=0.001), while the number of liveborn (p=0.016) and weaned piglets (p=0.001) increased in T2 group. Moreover, in T2 group, the BW of piglets at weaning was higher (p⟨0.001). A significant increase of insulin (p=0.032) and leptin (p=0.032) levels in serum was noticed in T2 group 24 h after farrowing. In conclusion, the supplementation of extra crude fibre in breeding stock with PDS problems due to nutritional imbalance has beneficial effects on their health and performance.

First case of Serratia liquefaciens isolated from urinary tract infection in sows and associated clinicopathological and pathological findings.

An incident of sudden deaths in the breeding stock was reported from a farrow-to-finish commercial pig farm in Greece. The 8·4% of sows during lactation and gestation period presented anorexia, fever, haematuria, return-to-oestrus and sudden deaths (mortality rate: 2·3%). Blood and urine samples were collected from four diseased sows. Furthermore, swabs from urine bladders were collected from two dead sows and four culled sows at the slaughterhouse. Blood testing demonstrated mild leucocytosis and absence of azotaemia. Urinalysis revealed haematuria, proteinuria, bilirubinuria and active urine sediment with bacilli, epithelial cells and leucocytes, crystals and granular casts. Histopathological evaluation of the bladder demonstrated chronic active polypoid cystitis. The bacterial culture revealed the presence of Serratia liquefaciens. The antibiotic susceptibility testing showed high resistance to the most common antibiotics, with the highest sensitivity of the isolate towards quinolones. After the administration of a single dose of 7·5 mg kg-1 body weight enrofloxacin intramuscularly, the mortality rate decreased to less than 0·5% along with a remarkable reduction in the severity of clinical signs. Based on our findings, S. liquefaciens induced severe clinical signs and deaths in sows, mainly due to urinary infection. Inadequate water sanitation might have been responsible for increased exposure to S. liquefaciens. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, the isolation of Serratia liquefaciens from the urinary tract of pigs associated with clinical signs and increased mortality was described for the first time. Serratia liquefaciens is an important cause of hospital-acquired human infections. The isolate in this study was resistant to the most common antibiotics. Therefore, the use of quinolones which are drugs of last resort for treatment of infections was the only therapeutic option. The presence of the resistant bacterium in the urinary tract raises concerns for its zoonotic potential.