Molybdenum disulfide as hydrogen evolution catalyst:From atomistic to materials structure and electrocatalytic performance

Hydrogen production via water electrolysis defines the novel energy vector for achieving a sustainable society.However,the true progress of the given technology is hindered by the sluggish and complex hydrogen evolution reaction(HER)occurring at the cathodic side of the system where overpriced and scarce Pt-based electrocatalysts are usually employed.Therefore,efficient platinum group metals(PGMs)-free electrocatalysts to carry out HER with accelerated kinetics are urgently demanded.In this scenario,molybdenum disulfide(MoS_(2))owing to efficacious structural attributes and optimum hydrogen-binding free energy(ΔG_(H*))is emerging as a reliable alternative to PGMs.However,the performance of MoS_(2)-based electrocatalysts is still far away from the benchmark performance.The HER activity of MoS_(2)can be improved by engineering the structural parameters i.e.,doping,defects inducement,modulating the electronic structure,stabilizing the 1 T phase,creating nanocomposites,and altering the morphologies using appropriate fabrication pathways.Here,we have comprehensively reviewed the majority of the scientific endeavors published in recent years to uplift the HER activity of MoS_(2)-based electrocatalysts using different methods.Advancements in the major fabrication strategies including hydrothermal synthesis methods,chemical vapor deposition,exfoliation techniques,plasma treatments,chemical methodologies,etc.to tune the structural parameters and hence their ultimate influence on the electrocatalytic activity in acidic and/or alkaline media have been thoroughly discussed.This study can provide encyclopedic insights about the fabrication routes that have been pursued to improve the HER performance of MoS_(2)-based electrocatalysts.

Topical delivery of nerve growth factor for treatment of ocular and brain disorders

Neurotrophins are a family of proteins that support neuronal proliferation, survival, and differentiation in the central and peripheral nervous systems, and are regulators of neuronal plasticity. Nerve growth factor is one of the best-described neurotrophins and has advanced to clinical trials for treatment of ocular and brain diseases due to its trophic and regenerative properties. Prior trials over the past few decades have produced conflicting results, which have principally been ascribed to adverse effects of systemic nerve growth factor administration, together with poor penetrance of the blood-brain barrier that impairs drug delivery. Contrastingly, recent studies have revealed that topical ocular and intranasal nerve growth factor administration are safe and effective, suggesting that topical nerve growth factor delivery is a potential alternative to both systemic and invasive intracerebral delivery. The therapeutic effects of local nerve growth factor delivery have been extensively investigated for different ophthalmic diseases, including neurotrophic keratitis, glaucoma, retinitis pigmentosa, and dry eye disease. Further, promising pharmacologic effects were reported in an optic glioma model, which indicated that topically administered nerve growth factor diffused far beyond where it was topically applied. These findings support the therapeutic potential of delivering topical nerve growth factor preparations intranasally for acquired and degenerative brain disorders. Preliminary clinical findings in both traumatic and non-traumatic acquired brain injuries are encouraging, especially in pediatric patients, and clinical trials are ongoing. The present review will focus on the therapeutic effects of both ocular and intranasal nerve growth factor delivery for diseases of the brain and eye.

Free triiodothyronine level correlates with statin responsiveness in acute myocardial infarction

Background Although thyroid hormone （TH） has important effects on lipid metabolism, the relationship between TH and statin responsiveness has never been investigated. We hypothesize that TH plays an important role in statin responsiveness in patients with acute myocardial infarction （AMI）. Methods Consecutive 1091 hospitalized AMI patients in Fuwai hospital （Beijing, China） were enrolled into this current study. The study population was divided into three groups based on the intensity of statin treatment： low-intensity （n = 221）, moderate-intensity （n = 712） and high-intensity （n = 158）. Lipid levels were measured after statin therapy lasting for 10-14 days. The association between TH, lipid profile levels and achievement of low-density lipoprotein cholesterol （LDL-C） lowering goals was explored in patients with AMI on statin therapy. Results By general linear analysis, a significant linear trend between free triiodothyronine （FT3） and LDL-C level （linear coefficient r = -0.082, P = 0.001） and FT3 and total cholesterol （TC） level （r = -0.105, P = 0.031） was observed in the moderate-intensity statin group. A more apparent linear trend was detected in the high-intensity statin group （for LDL-C： r = -0.113, P = 0.005; for TC： r = -0.172, P = 0.029, respectively）. However, no significant correlation was observed in the low-intensity statin group. Compared with the low-FT3 group （defined as FT3 〈 1.79 pg/mL）, the OR （95% CI） for attaining a LDL-C 〈 3.0mmol/L was found to be 2.217 （1.001–4.839） in the higher FT3 group （〉 2.95 pg/mL）. The OR （95% CI） for attaining the more intensive goal （LDL-C 〈 1.8mmol/L） was 2.836 （1.014–5.182）. Conclusions Our study reveals that variation in FT3 levels is related to the cholesterol-lowering responsiveness of statins in AMI patients. These findings suggest that low FT3 may be a factor responsible for lack of LDL-C goal attainment and patients’ poor responsiveness to statin treatment.

Rock temperature variability in high-altitude rockfall-prone areas

In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this critical relationship,it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions,and also to increase local scale studies,increasing the quality and the comparability of the data.This paper shows an example of metrological characterization of sensors used for rock temperature measurement in mountain regions,by means of the measurement uncertainty.Under such approach,data and results from temperature measurements carried out in the Bessanese high-elevation experimental site(Western European Alps)are illustrated.The procedures for the calibration and field characterization of sensors allow to measure temperature in different locations,depths and lithotypes,within 0.10°C of overall uncertainty.This work has highlighted that metrological traceability is fundamental to asses data quality and establish comparability among different measurements;that there are strong differences between air temperature and near-surface rock temperature;and that there are significant differences of rock temperature acquired in different aspect conditions.Finally,solar radiation,slope/aspect conditions and lithotype,seem to be the main driving factors of rock temperature.

Nuclear imaging to characterize adrenal tumors: Comparison with MRI

AIM:To describe the role of nuclear imaging modalities using nor-cholesterol,metaiodobenzylguanidine(MIBG)and fluorine-deoxy-glucose(FDG)in adrenal tumors for lesion characterization in comparison with magnetic resonance(MR).METHODS:Population was classified in group 1 consisting of 30 patients with non-hypersecreting unilateral adrenal masses,in group 2 consisting of 34 patients with hypersecreting(n=19)or non-hypersecreting(n=15)adrenal adenomas and in group 3 consisting of 18 patients with chromaffin-tissue tumors(CTT),of which 14 were pheochromocytomas while 4 were paragangliomas(n=4).All patients underwent MR and nuclear studies(nor-cholesterol,MIBG and FDG).Pathology samples(n=63)or follow-up data in adenomas(n=19)were used as standard of reference forimaging studies interpretation.RESULTS:In group 1,MR findings were not highly accurate for lesion characterization,while the results of nuclear scans showed abnormal nor-cholesterol,MIBG and FDG concentration in all cases of adenomas,pheos and malignant tumors,respectively.In group 2,no differences in MR parameters were found between hyperfunctioning and non-hyperfunctioning adenomas,while nor-cholesterol uptake was significantly higher in hyperfunctioning compared to non-hyperfunctioning lesions.In group 3,no differences in MR parameters were found between benign and malignant CCT,while MIBG uptake was significantly higher in malignant compared to benign tumors.CONCLUSION:On the basis of our findings,nuclear imaging modalities using specific target agents are able to better characterize adrenal tumors,compared with MR.In particular,radionuclide techniques are able to identify the nature of adrenal incidentalomas and to differentiate between hypersecreting and non-hypersecreting adenomas as well as between benign and malignant CTT.

Effect of PLA/ZnO Packaging and Gamma Radiation on the Content of Listeria innocua, Escherichia coil and Salmonella enterica on Ham during Storage at 4℃

The effect of ZnO and low y-radiation on PLA based-films was investigated to be used for food packaging application. Ham slices were inoculated with E. coli, L. innocua and S. enterica and then covered with PLA and PLA/5% ZnO films. The samples were irradiated with a y-radiation dose of 0.3 kGy at dose rate of 13.5 kGy/h. Microbiological analysis was performed at 0, 1 and 5 days on samples stored at 4 ℃. Results showed that no consistent reduction of bacteria was obtained, even at the fifth day of storage, when the ham was covered with PLA/5% ZnO film and no γ-radiation was performed. The use of γ-radiation results necessary to reduce the bacteria growth. In fact E. coli and S. enterica were not detected after 5 days of storage; whereas in the case of test with L. innocua a reduction of 1.3 log CFU/g was observed after 5 days of storage. The antibacterial results indicate that the presence of ZnO in PLA film is effective only for E. coll. The differences of the results obtained here with those reported in literature （where ZnO particles are reported to be very effective as antimicrobial material） are accounted for the different methodologies used. In conclusion considering the positive results, even if small, obtained here at least only for the E. Coli and considering that PLA/5% ZnO film shows, compared to plain PLA film, good tensile properties （especially Young＇s modulus and stress at yielding） and good permeability （to O2 and CO2） induce to consider the PLA/5% ZnO composite film usable for food packaging when long shelf life and food safety are required, considering also that it is biodegradable and compostable.

Experimental characterization and CFD simulation of gas maldistribution in turbulent fluidization of Group A particles

The study presented hereby investigates experimentally and with CFD simulations the gas distribution effect on the hydrodynamic of a Geldart Group A turbulent fluidized bed. Experiments were carried out on a cold flow fluidized bed column with an even and uneven gas distribution. Local solid volume fraction profiles were measured using optical probes at different bed heights and along two radial directions. Optical probe measurements allow catching a clear hydrodynamic difference between both even and uneven gas distributions. These results were then used to assess CFD simulations with the code Barracuda^(TM) (MP-PIC approach). It is noteworthy that the choice of drag correlation and boundary conditions strongly influences the agreement between the experimental and CFD results. Once the correct parameters are chosen, CFD simulations captured the effect of gas distribution changes.

Litchi-derived platinum groupmetal-free electrocatalysts for oxygen reduction reaction and hydrogen evolution reaction in alkalinemedia

Within the framework of the circular economy,the waste litchi’s skins were upgraded and transformed into electrocatalysts for oxygen reduction reaction(ORR)and hydrogen evolution reaction(HER).The waste litchi’s skins were pyrolyzed,activated,and then used as carbon support for fabricating metal–nitrogen–carbons(M–N–Cs)which belong to a promising class of platinum group metal-free electrocatalysts.The activated char was functionalized with transition metal(Fe,Ni,and Co)-phthalocyanine(Pc)in monometallic and bimetallic fashion by subjecting it to a thermal treatment at 600 and 900◦C.The samples functionalized at 900℃ showed higher performance for HER due to the formation of metal nanoparticles,whereas the samples functionalized at 600℃ showed higher performance for ORR.Particularly,sample Ni–Co 900 had an overpotential of−0.38 V for HER,while the sample Fe 600 was the most active electrocatalyst for ORR by demonstrating the onset potential of∼0.9 V(a half-wave potential of∼0.81 V)with the least production of unwanted peroxide anion.

Deformation history and processes during accretion of seamounts in subduction zones:The example of the Durkan Complex(Makran,SE Iran)

The Durkan Complex is a tectonic element of the Makran Accretionary Prism(SE Iran)that includes fragments of Late Cretaceous seamounts.In this paper,the results of map-to micro-scale structural studies of the western Durkan Complex are presented with the aim to describe its structural and tectonometamorphic evolution.The Durkan Complex consists of several tectonic units bordered by mainly NNW-striking thrusts.Three main deformation phases(D_(1),D_(2),and D_(3))are distinguished and likely occurred from the Late Cretaceous to the Miocene–Pliocene.D_(1) is characterized by sub-isoclinal to close and W-verging folds associated with an axial plane foliation and shear zone along the fold limbs.This phase records the accretion of fragments of the seamount within the Makran at blueschist facies metamorphic conditions(160–300℃ and 0.6–1.2 GPa).D_(2) is characterized by open to close folds with subhorizontal axial plane that likely developed during the exhumation of previously accreted seamount fragments.An upper Paleocene–Eocene siliciclastic succession unconformably sealed the D_(1) and D_(2) structures and is,in turn,deformed by W-verging thrust faults typical of D_(3).The latter likely testifies for a Miocene–Pliocene tectonic reworking of the accreted seamount fragments with the activation of out of sequence thrusts.Our results shed light on the mechanism of accretion of seamount materials in the accretionary prisms,suggesting that seamount slope successions favour the localization and propagation of the basal décollement.This study further confirms that the physiography of the subducting plates plays a significant role in the tectonic evolution of the subduction complexes.

CYP72A67 Catalyzes a Key Oxidative Step in Medicago truncatula Hemolytic Saponin Biosynthesis

In the Medicago genus, triterpenic saponins are bioactive secondary metabolites constitutively synthesized in the aerial and subterranean parts of plants via the isoprenoid pathway. Exploitation of saponins as pharmaceutics, agrochemicals and in the food and cosmetic industries has raised interest in identifying the enzymes involved in their synthesis. We have identified a cytochrome P450 （CYP72A67） involved in hemolytic sapogenin biosynthesis by a reverse genetic TILLING approach in a Medicago truncatula ethyl- methanesulfonate （EMS） mutagenized collection. Genetic and biochemical analyses, mutant complementation, and expression of the gene in a microsome yeast system showed that CYP72A67 is responsible for hydroxylation at the C-2 position downstream of oleanolic acid synthesis. The affinity of CYP72A67 for substrates with different substitutions at multiple carbon positions was investigated in the same in vitro yeast system, and in relation to two other CYP450s （CYP72A68） responsible for the production of medicagenic acid, the main sapogenin in M. truncatula leaves and roots. Full sib mutant and wild-type plants were compared for their sapogenin profile, expression patterns of the genes involved in sapogenin synthesis, and response to inoculation with Sinorhizobium meliloti. The results obtained allowed us to revise the hemolytic sapogenin pathway in M. truncatula and contribute to highlighting the tissue specificities （leaves/roots） of sapogenin synthesis.

Chemical-Structural Changes of Organic Matter in a Semi-Arid Soil After Organic Amendment

A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid soil.The changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical analyses.By the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage sludge.The non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly higher.After 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage sludge.However,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ones.Thus,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil OM.The pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 months.In conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.

Resin foraging dynamics in Varroa destructor-infested hives: a case of medication of kin?

t Social insects have evolved colony behavioral, physiological, and organiza. tional adaptations (social immunity) to reduce the risks of parasitization and/or disease transmission. The collection of resin from various plants and its use in the hive as propolis is a clear example of behavioral defense. For Apis mellifera, an increased propolis content in the hive may correspond to variations in the microbial load of the colony and to a downregulation of an individual bee's immune response. However, many aspects of such antimicrobial mechanism still need to be clarified. Assuming that bacterial and fungal infection mechanisms differ from the action of a parasite, we studied the resin collection dynamics in Varroa destructor-infested honeybee colonies. Comparative experiments involving hives with different mite infestation levels were conducted in order to assess the amount of resin collected and propolis quality within the hive, over a 2-year period (2014 and 2015). Our study demonstrates that when A. mellifera colonies are under stress because of Varroa infestation, an increase in the number of resin foragers is recorded, even if a general intensification of the foraging activity is not observed. A reduction in the total polyphenolic content in propolis produced in infested versus uninfested hives was also noticed. Considering that different propolis types show varying levels of inhibition against a variety of honey bee pathogens in vitro, it would be very important to study the effects against Varroa of two diverse types of propolis: from Varroa-free and from Varroa-infested hives.

Fertigation with Wastewater and Vermicompost: Soil Biochemical and Agronomic Implications

To study how wastewater(WW) and different organic sources(humic substances or vermicompost) affected soil chemical and biochemical fertility and agronomic productivity in field-grown melon, an experiment arranged in a randomized complete block design with three replications was conducted with the following treatments: three different mixtures of irrigation water(100% WW, 50% WW with 50% groundwater, and 100% groundwater) and, for each WW treatment, four different organic fertilization treatments of control without organic matter application(CK), vermicompost used as surface mulch(SM), vermicompost incorporated into the soil(VC),and humic substances extracted by vermicompost(HS). Chemical and biochemical results indicated an improvement in soil fertility,suggested by the increase in soil organic carbon and nutrient(nitrate and macro- and microelements) contents and in soil microbial activities(hydrolytic and oxidative enzymes), in particular in the VC treatments. In addition, even soil potential metabolism was stimulated by WW combined with organic treatments, as highlighted by the increase in the metabolic(dehydrogenase activity/watersoluble carbon) and nitrification indices(NO-3and NH+4). Melon productivity confirmed these results, with the highest yield and melon quality in the VC treatments irrigated with 100% WW. In conclusion, the combined use of WW and organic amendment,recovering both mineral and organic nutrients from these kinds of recycled materials, was effective in the improvement of soil quality and crop productivity.

Closing the THz gap with Dirac semimetals

High-performance THz photodetection is unprecedentedly accessed by integrating a topological Dirac(Weyl)semimetal in a carefully designed antenna at deep-subwavelength scales.

Carboxylated-xyloglucan and peptide amphiphile co-assembly in wound healing

Hydrogel wound dressings can play critical roles in wound healing protecting the wound from trauma or contamination and providing an ideal environment to support the growth of endogenous cells and promote wound closure.This work presents a self-assembling hydrogel dressing that can assist the wound repair process mimicking the hierarchical structure of skin extracellular matrix.To this aim,the co-assembly behaviour of a carboxylated variant of xyloglucan(CXG)with a peptide amphiphile(PA-H3)has been investigated to generate hierarchical constructs with tuneable molecular composition,structure,and properties.Transmission electron microscopy and circular dichroism at a low concentration shows that CXG and PA-H3 co-assemble into nanofibres by hydrophobic and electrostatic interactions and further aggregate into nanofibre bundles and networks.At a higher concentration,CXG and PA-H3 yield hydrogels that have been characterized for their morphology by scanning electron microscopy and for the mechanical properties by smallamplitude oscillatory shear rheological measurements and compression tests at different CXG/PAH3 ratios.A preliminary biological evaluation has been carried out both in vitro with HaCat cells and in vivo in a mouse model.