A review of the methanol economy:The fuel cell route

This review presents methanol as a potential renewable alternative to fossil fuels in the fight against climate change. It explores the renewable ways of obtaining methanol and its use in efficient energy systems for a net zero-emission carbon cycle, with a special focus on fuel cells. It investigates the different parts of the carbon cycle from a methanol and fuel cell perspective. In recent years, the potential for a methanol economy has been shown and there has been significant technological advancement of its renewable production and utilization. Even though its full adoption will require further development, it can be produced from renewable electricity and biomass or CO2 capture and can be used in several industrial sectors, which make it an excellent liquid electrofuel for the transition to a sustainable economy. By converting CO2 into liquid fuels, the harmful effects of CO2 emissions from existing industries that still rely on fossil fuels are reduced. The methanol can then be used both in the energy sector and the chemical industry, and become an all-around substitute for petroleum. The scope of this review is to put together the different aspects of methanol as an energy carrier of the future, with particular focus on its renewable production and its use in high-temperature polymer electrolyte fuel cells (HT-PEMFCs) via methanol steam reforming

Efficacy of corneal collagen cross-linking for treatment of keratoconus: a meta-analysis of randomized controlled trials.

To evaluate the efficacy of corneal collagen cross-linking (CXL) for the treatment of keratoconus.We performed a literature search for randomized controlled trials that assessed the effect of CXL in slowing progression of keratoconus. The primary outcome measures included changes of topographic parameters, visual acuity, and refraction. Efficacy estimates were evaluated by weighted mean difference (WMD) and 95% confidence interval (CI) for absolute changes of the interested outcomes.Significant decrease in mean keratometry value, maximum keratometry value and minimum keratometry value were demonstrated in the CXL group compared with the control group (WMD = -1.65; 95% CI: -2.51 to -0.80; P < 0.00001; WMD = -2.05; 95% CI: -3.10 to -1.00; P < 0.00001; WMD = -1.94; 95% CI: -2.63 to -1.26; P < 0.00001; respectively). Best spectacle-corrected visual acuity improved significantly in CXL group (WMD = -0.10; 95% CI: -0.15 to -0.05; P < 0.00001), whereas uncorrected visual acuity did not differ statistically. Manifest cylinder error decreased significantly in patients undergoing CXL procedure compared with control patients in sensitivity analysis (WMD = -0.388; 95% CI: -0.757 to -0. 019; P = 0.04). The changes in central corneal thickness and intraocular pressure were not statistically significant.CXL may be an effective option in stabilizing keratoconus. Further long-term follow-up studies will be necessary to assess the persistence of CXL

Characteristics of 6 randomized controlled trials included in analysis.

<p>K_max = maximum keratometry value; D = diopters; NR: Not reported.</p><p>*Corneal collagen cross-linking group/Control group;</p><p>^†Corneal collagen cross-linking group/Sham control group/Fellow-Eye control group;</p><p>^‡Without baseline control group records.</p><p>Characteristics of 6 randomized controlled trials included in analysis.</p

Change in mean keratometry value (diopters) between corneal collagen cross-linking (CXL) and control patients: overall change (A) and subgroup analysis according to Jadad score (B).

<p>WMD, weighted mean difference.</p

Change in spherical equivalent (diopters) (A) and manifest cylindrical error (diopters) (B) between corneal collagen cross-linking (CXL) and control patients.

<p>WMD, weighted mean difference.</p

Change in maximum keratometry value (diopters) between corneal collagen cross-linking (CXL) and control patients (A); Change in minimum keratometry value (diopters) between CXL and control patients (B).

<p>WMD, weighted mean difference.</p

Flow chart of studies included in the meta-analysis.

<p>Flow chart of studies included in the meta-analysis.</p