Accurate in vivo real-time determination of the hydrogen concentration in different tissues of mice after hydrogen inhalation

Zn-Fe primary battery-enabled controlled hydrogen release in stomach for improving insulin resistance in obesity-associated type 2 diabetes

Chronic systemic inflammation in obesity-associated type 2 diabetes (T2D) is a key inducing factor of insulin resistance (IR). Hydrogen molecule (H2) has been proved to be a safe and effective anti-inflammatory agent, but conventional H2 administration methods cannot provide a high dosage and a long duration of H2 treatment in IR-related tissues and thus lead to limited therapeutic efficacies. We here propose a new strategy of controlled H2 release to match the time window of gastric emptying for maximizing the bioavailability and therapeutic outcome of H2. This work enhances the hydrolysis rate of Zn by constructing a Zn-Fe primary-battery micro-/nano-structure, and the H2-releasing rate is adjusted by tuning the ratio of Zn to Fe. The Zn-Fe micro-/nano-structure is orally administrated once daily to alleviate obesity-associated T2D in a leptin-deficient (ob/ob) mouse model. The H2 generation time of the Zn-Fe primary-battery micro-/nano-structure with the Fe/Zn ratio of 1:100 in gastric acid is about 3 h, just matching with the time window of gastric emptying in mice. In vivo monitoring results show that H2 generated by Zn-Fe micro-/nano-structure in stomach can effectively accumulate in major IR-sited tissues including liver, adipose tissue, and skeletal muscle at a high dose for a relatively long time compared to H2-rich water drinking. Oral administration of Zn-Fe micro-/nano-structure at 200 mg/kg body weight has realized an efficient IR improvement and remarkably ameliorated systemic inflammation in ob/ob mice. In addition, a high-dose administration of Zn-Fe shows no visible toxicity in mice. This work provides a new strategy to maximize the outcome of hydrogen therapy.

Aspects of an experimental study of hydrogen use at automotive diesel engine

Hydrogen may represents a good alternative fuel that can be used to fuel internal combustion engines in order to ameliorate energetic and emissions performance. The paper presents some experimental aspects registered at hydrogen use to fuel a diesel engine, different substitute ratios being use in the area of 18-34%, at 40% engine load and speed of 2000 rev/min. The engine is equipped with an open ECU and the control of the cyclic dosses of diesel fuel and hydrogen are adjusted in order to maintain the engine power performance. The in-cylinder pressure diagrams show the increase of the maximum pressure with 17%, from 78.5 bar to 91.8 bar for the maximum substitute ratio. Also, values of maximum pressure rise rate start to increase for hydrogen addition, in correlation with the increase of fuel amount burned into the premixed stage, without exceed the normal values with assure the normal and reliable engine operation. Higher Lower Heating Value and combustion speed of hydrogen assure the increase in thermal efficiency, the brake specific energy consumption decreases with 5.4%-7.8% at substitute ratios of 20-27%. The CO₂ emission level decreases with 20% for maximum hydrogen cyclic dose. In terms of pollutant emission level, at hydrogen use the emission level of the NO_x decreases with 50% and the smoke number decreases with 73.8% comparative to classic fuelling at the maximum hydrogen cyclic dose.