Development of hydrogel-based MEMS piezoresistive sensors for detection of solution pH and glucose concentration

Hydrogels are water-swollen polymeric materials that maintain a distinct three-dimensional structure. Manipulation of hydrogel structure has produced stimuli sensitive hydrogels, which change their swelling degree or undergo phase transition in response to minimal changes in environmental conditions. This paper presents the development of hydrogel-based sensors for measurement of solution pH and glucose concentration using commercial MEMS piezoresistive pressure transducers. pH-sensitive PVA/PAA and glucose-sensitive AAm/3-APB/BIS hydrogels are used in the experiments. Two types of sensor packaging, one is used as solution container and the other used to dip into solution have been performed. The measurements for different solutions having pH values between 1 to 11 and glucose concentrations between 2.5 mM and 15 mM have been carried out. The output characteristics of sensors have been demonstrated showing the long-term reproduction and relatively good sensitivity, namely approximately 20 mV/pH for pH sensor and 7 mV/1 mM of glucose concentration for glucose sensor

The clinical and subclinical features of spinal cord injury on magnetic resonance imaging of patients with N2O intoxication

Nitrous oxide (N2O) is a weak anesthetic gas that was first used in 1844 in the field of dental anesthesia. However, currently, N2O is being abused for entertainment purposes in the form of N2O-filled balloons, called funky balls, which can cause many adverse effects, especially nervous system injury. This study aimed to investigate the detailed clinical and subclinical features associated with N2O intoxication. We retrospectively reviewed 47 patients diagnosed with N2O intoxication, from May 2018 to July 2019, and collected demographic data, clinical and laboratory tests, and spinal cord magnetic resonance imaging (MRI) findings. The mean time of funky ball use was 8.8 months, with a mean use of 36.3 balls per day. All patients presented with superficial sensory disorders. Reductions in muscle strength, decreased vibration sensation, and decreased or lost tendon reflexes were the most common clinical signs of N2O intoxication. Romberg sign and Lhermitte sign were observed in 39 patients (83%) and 21 patients (44.7%), respectively. Spinal cord lesions on MRI were observed in 32 patients (68.1%), which mostly presented with an inverted V sign. The total duration of N2O use, the number of days of using N2O per week, and the presence of Lhermitte sign (P<0.05) were significantly different between patients with and without spinal cord lesions on MRI. Serum levels of homocysteine and vitamin B12 were significantly different between the time of admission and discharge (P<0.05). Our study indicated that the days of using N2O per week was significantly associated with Spinal Cord Injuries (SCI) on MRI. According to the Receiver Operating Characteristic (ROC) curve analysis, a cutoff days of using per week value of 2.5 days could predict SCI with a sensitivity of 81.3%, a specificity of 73.3%, and an area under the ROC curve (AUC) of 0.813. Changes in the serum levels of homocysteine and vitamin B12 were effective markers for the evaluation of treatment response

Granulocyte colony-stimulating factor reduces biliary fibrosis and ductular reaction in a mouse model of chronic cholestasis

Background: Biliary atresia is a rare congenital bile duct disease that is the leading cause of liver fibrosis in neonates. Granulocyte colony-stimulating factor (GCSF) is a potential therapy for hepatocellular diseases, but data on GCSF for cholestatic conditions remain limited. Materials and methods: The current study examines the role of GCSF in improving bile duct obstruction in mice. Two doses were administered: 10.0 μg/kg/day and 61.5 μg/kg/day, which is the animal equivalent dose of 5.0 μg/kg in humans. Seven days (D7) after bile duct ligation (BDL), Swiss mice were treated with phosphate buffered saline or GCSF for 5 days. The intrahepatic adaptive response of BDL mice was evaluated on postsurgical days D12, D19, and D26. Results: Treatment with 61.5 μg/kg of GCSF resulted in a significant increase in circulating leukocytes and neutrophils on D12. Amelioration of liver injury, as shown by reduced aspartate aminotransferase levels, increased albumin levels and survival rate, as well as reduced intrahepatic inflammation and hepatic myeloperoxidase expression, downregulated ductular proliferation, periportal fibroblast activation, and fibrosis, enhanced expressions of hepatocyte growth factor, peroxisome proliferator-activated receptor-alpha, and ki67, and suppressed expression of cleaved caspase-3 protein, was noted after treatment with 61.5 μg/kg of GCSF. Additionally, GCSF treatment was associated with an increased number of intrahepatic cd3-Sca1+c-Kit+ bone marrow cells. Conclusions: Treatment with 61.5 μg/kg of GCSF resulted in liver regeneration and survival in BDL mice was seen, suggesting its potential use for human liver diseases

Improvements in hydrogen production from methane dry reforming on filament-shaped mesoporous alumina-supported cobalt nanocatalyst

The mesoporous gamma-alumina (g-Al2O3) synthesized via evaporation-induced self-assembly method (EISA) using inorganic salt, Al(NO3)3$9H2O precursor and water-ethanol solvent mixture was implemented as a support for Co catalyst in methane dry reforming at 973e1073 K under 1 atm. The g-Al2O3 support possessed filament-shaped morphology with surface area of 173.4 m2 g1 and cobalt nanoparticles were successfully dispersed on support with small crystallite size of 7.8 nm. The stability of 10%Co/Al2O3 was evident for CH4 and CO2 conversions at 1023 and 1073 K. CH4 conversion could reach to 76.2% while 81.6% was observed for CO2 conversion at 1073 K. Although graphitic and amorphous carbons were unavoidably formed on used catalyst, 10%Co/Al2O3 exhibited an outstanding performance comparable to noble metals with the desired ratio of H2/CO for downstream Fischer-Tropsch process