Reusable Au/Pd-coated chestnut-like copper oxide SERS substrates with ultra-fast self-recovery

Reliable and reusable plasmonic substrates are crucial for the development of biosensing applications using surface-enhanced Raman scattering (SERS), as they can provide unique advantages for ultrafast and accurate single-molecule recognition of different species. These properties are unrevealed in this paper, where thermally annealed cupric CuO and cuprous oxide Cu2O heterostructures were used as templates for highly stable nanotextured surfaces and design of robust 3D plasmonic biochips. Differently tailored nano/micro-roughness provided outstanding light trapping abilities that lead to significant SERS performance improvement. It was found that Cu2O chestnut-like substrate activated with 80 nm Au/Pd alloy film reveals impressive 3.7-fold Raman signal increment in respect to grainy-like structure and about twice larger amplification than that of nanowires enriched platform decorated in the same manner. Large enhancement factor AEF ~5 × 105 of a chestnut-like Au/Pd@/Cu2O chip allows adding it up to the list of the most effective oxide-based plasmonic substrates. Moreover, the substrate shows unprecedented durability during repetitive plasma-cleaning, demonstrating a remarkable 100 self-recovery in less than 1 min, accompanied by virtually no thickness degradation of the plasmonic layer. © 2020 Elsevier B.V

Effects of chronic acetazolamide administration on gas exchange and acid-base control in pulmonary circulation in exercising horses

P>Reasons for performing study:Carbonic anhydrase (CA) catalyses the hydration/dehydration reaction of CO(2) and increases the rate of Cl- and HCO(3)- exchange between the erythrocytes and plasma. Therefore, chronic inhibition of CA has a potential to attenuate CO(2) output and induce greater metabolic and respiratory acidosis in exercising horses.Objectives:To determine the effects of Carbonic anhydrase inhibition on CO(2) output and ionic exchange between erythrocytes and plasma and their influence on acid-base balance in the pulmonary circulation (across the lung) in exercising horses with and without CA inhibition.Methods:Six horses were exercised to exhaustion on a treadmill without (Con) and with CA inhibition (AczTr). CA inhibition was achieved with administration of acetazolamide (10 mg/kg bwt t.i.d. for 3 days and 30 mg/kg bwt before exercise). Arterial, mixed venous blood and CO(2) output were sampled at rest and during exercise. An integrated physicochemical systems approach was used to describe acid base changes.Results:AczTr decreased the duration of exercise by 45% (P < 0.0001). During the transition from rest to exercise CO(2) output was lower in AczTr (P < 0.0001). Arterial PCO(2) (P < 0.0001; mean +/- s.e. 71 +/- 2 mmHg AczTr, 46 +/- 2 mmHg Con) was higher, whereas hydrogen ion (P = 0.01; 12.8 +/- 0.6 nEq/l AczTr, 15.5 +/- 0.6 nEq/l Con) and bicarbonate (P = 0.007; 5.5 +/- 0.7 mEq/l AczTr, 10.1 +/- 1.3 mEq/l Con) differences across the lung were lower in AczTr compared to Con. No difference was observed in weak electrolytes across the lung. Strong ion difference across the lung was lower in AczTr (P = 0.0003; 4.9 +/- 0.8 mEq AczTr, 7.5 +/- 1.2 mEq Con), which was affected by strong ion changes across the lung with exception of lactate.Conclusions:CO(2) and chloride changes in erythrocytes across the lung seem to be the major contributors to acid-base and ions balance in pulmonary circulation in exercising horses

The role of obesity, biomechanical constitution of the pelvis and contact joint stress in progression of hip osteoarthritis

SummaryObjectiveThe aim of our study was to explore whether earlier hip arthroplasty for idiopathic osteoarthritis (OA) might be explained by enlarged contact stress in the hip joint, and to what amount can that be attributed to obesity and biomechanical constitution of the pelvis.MethodFifty subjects were selected from a list of consecutive recipients of hip endoprosthesis due to idiopathic OA; standard pelvic radiographs made years prior to surgery were the main selection criteria. For 65 hips resultant hip force and peak contact hip stress normalized to the body weight (R/Wb and pmax/Wb) were determined from the radiographs with the HIPSTRESS method. Body weight and body mass index (BMI) were obtained with an interview. Regression analysis was used to correlate parameters of obesity (body weight, BMI), biomechanical constitution of the pelvis (R/Wb, pmax/Wb) and mechanical loading within the hip joint (R, pmax) with age at hip arthroplasty.ResultsYounger age at hip arthroplasty was associated with higher body weight (P=0.009), higher peak contact hip stress normalized to the body weight – pmax/Wb (P=0.019), higher resultant hip force – R (P=0.027) and larger peak contact hip stress – pmax (P<0.001), but not with BMI (P=0.121) or R/Wb (P=0.614).ConclusionOur results suggest that enlarged contact stress (pmax) plays an important role in rapid progression of hip OA with both obesity (increased body weight) and unfavorable biomechanical constitution of the pelvis (greater pmax/Wb) contributing

Pathway to tailor the phase composition, microstructure and mechanical properties of pulsed laser deposited cobalt-substituted calcium phosphate coatings on titanium

Dense calcium phosphate-based ceramics were fabricated to be used as targets for pulsed laser deposition (PLD). Nanostructured cobalt-substituted hydroxyapatite (Co:HAP) was used as a starting powder. To vary phase composition and microstructure of targets, two sintering approaches were applied, conventional (CS) and two-step sintering (TSS). The obtained results show that in both cases biphasic calcium phosphate (BCP) ceramics (targets) were prepared, with slightly different HAP-to-β–TCP amount ratio and a significantly different microstructure. While the CS method yielded fully dense ceramics with an average grain size of 1.3 μm, the ceramics prepared by TSS had a density of 98.5%, with a predominant grain size below 100 nm. (Ca + Co)P coatings were prepared by PLD of (Ca + Co)P targets. The temperature of the Ti substrate was adjusted to be 25 and 500 °C. The results show that the phase composition of (Ca + Co)P coatings depended on the phase composition of targets as well as on the temperature of the Ti substrate. The coating prepared at 25 °C using CS target consisted of three calcium phosphate phases, HAP, β–TCP and α–TCP; when the TSS target was used, the coating was biphasic, containing HAP and β–TCP. When the substrate was heated to 500 °C, regardless of whether the CS or the TSS target was used, the deposited coatings were composed of HAP and α–TCP. Due to different phase compositions, the (Ca + Co)P coatings deposited at 25 °C showed an improved hardness compared to those deposited at 500 °C. The obtained results confirmed that the phase composition, morphology and mechanical properties of 0.3 μm thick (Ca + Co)P coatings on a Ti substrate can be tailored by employing (Ca + Co)P targets with different microstructures, and also by varying the temperature of the Ti substrate during deposition experiments