Hydrogen is defined as an attractive energy carrier due to its potentially higher energy efficiency and low generation of pollutants, which can replace conventional fossil fuels in the future. The ...governments have invested huge funds and made great efforts on the research of hydrogen production. Among the various options, supercritical water gasification (SCWG) is a most promising method of hydrogen production from biomass. Supercritical water (SCW) has received a great deal of attention as a most suitable reaction medium for biomass gasification because it is safe, non-toxic, readily available, inexpensive and environmentally benign. However, high temperature and pressure are required to meet the minimum reaction condition. Therefore, the high operating cost has become the biggest obstacle to the development of this technology. To overcome this bottleneck, many researchers have carried out intensive research work on the catalytic supercritical water gasification (CSCWG). Based on the previous studies stated in the literature, the authors try to give an overview (but not an exhaustive review) on the recent investigations of CSCWG. Besides, the physicochemical properties of SCW and its contributions in subcritical and supercritical water reaction are also summarized.
We studied paediatric patients with human adenovirus (HAdV) infection during the 2011 outbreak in northern Taiwan to define the clinical features of different HAdV genotypes in children.
Between ...January and December 2011, 637 patients <19 years of age exhibited culture-confirmed adenoviral infection in Chang Gung Memorial Hospital, and provided specimens available for genotyping by multiplex real-time PCR. Clinical data were collected retrospectively.
Excluding five cases with multiple genotypes, 632 cases were included for analysis. Three genotypes were identified, including HAdV-3 (429/632; 67.6%), HAdV-7 (144/632; 22.6%) and HAdV-2 (59/632; 9.8%). Median age was 4.58 years (range 2 months to 18 years), with children infected with HAdV-3 significantly older (82.9% >3 years; p <0.001). Of the 621 inpatients, 98.2% had fevers and all exhibited respiratory symptoms, 75 patients (12.1%) had lower respiratory tract infections, 20 (3.2%) required intensive care (HAdV-2: 1; HAdV-3: 8; and HAdV-7: 11), and three died (all HAdV-7-infected). HAdV-3-infected patients were significantly more likely to have upper respiratory symptoms and a high serum C-reactive protein level >100 mg/L, whereas leucocytosis (white blood cell count >15 000/mm3) was more common in HAdV-2-infected patients (p 0.007). HAdV-7 infections were significantly associated with a longer duration of fever, leucopenia (white blood cell count <5000/mm3), thrombocytopenia (platelet count <150 000/mm3), lower respiratory tract infections, a longer length of hospital stay, and requiring intensive care (all p <0.001).
Childhood HAdV-2, HAdV-3 and HAdV-7 infections may exhibit different clinical manifestations. Although HAdV-3 was the most prevalent genotype observed during the 2011 Taiwan outbreak, HAdV-7 caused more severe disease characteristics and outcomes.
Fetal and early childhood environment, including the nutritional status of the pregnant mother and the infant, are considered critical for growth and risk of disease in later life. 1 Many people in ...developing countries are not only malnourished but also chronically exposed to high levels of toxic fungal metabolites (mycotoxins). In West Africa, people are chronically exposed to high levels of aflatoxins starting in utero and continuing throughout life. 4 In this study, children still partially breast fed had lower exposure, almost certainly reflecting lower toxin levels in milk than in weaning and family foods. ...growth faltering occurs at a time of change to solid foods, when there is co-exposure to aflatoxin and a plethora of infectious hazards (for example, malaria, diarrhoea, respiratory infections).
Introduction Le risque d’hypoglycémie est particulièrement préoccupant chez les DT2 âgés particulièrement sous insuline ou sécrétagogues. Patients et méthodes Résultats réunis d’études cliniques ...international évaluant la tolérance, surtout survenue d’hypoglycémie chez des DT2 adultes ≥ 65 ans, sous linagliptine (LINA) participant à 11 études randomisées contrôlées par placebo (PBO). Ont été évaluées: – efficacité par mesure d’HbA1c à la semaine 24 vs inclusion (FAS*) – incidence des hypoglycémies (glycémie ≤ 70 mg/dl et nécessitant assistance) considérant le traitement de fond: insuline sans sécrétagogue, sécrétagogue sans insuline ou aucun des deux (ensemble patients traités: EPT). *FAS: full analysis set. Résultats 1 489 patients (EPT): 948 (LINA), 541 (placebo), 70,9 ± 4,6 ans (65-91). HbA1c moyenne 8,1 ± 0,8 % dans chaque groupe (FAS: LINA, n = 936 ; PBO, n = 530) A Semaine 24: HbA1c moyenne ajustée sous lina vs placebo: 0,60 % (IC 95 % 0,69/ 0,51 ; p < 0,0001) Incidence des hypoglycémies respectivement sous linagliptine et placebo: 26,3 % et 34,0 % (RR: 0,77 IC 95 % : 0,66/0,91 ; p < 0,05) – chez patients avec insuline sans sécrétagogue: 53,4 % (n = 247) et 55,9 % (n = 256) (RR: 0,96 IC: 0,82/1,12 ; p ≥ 0,05) – chez patients avec sécrétagogue sans insuline: 32,0 % (n = 309) et de 25,4 % (n = 126) (RR: 1,26 IC: 0,90/1,77 ; p ≥ 0,05). – chez patients sans sécrétagogue sans insuline: 1,3 % (n = 371) et 3,3 % (n = 152) (RR: 0,41 IC: 0,12/1,39 ; p ≥ 0,05). Incidence des hypoglycémies sévères: faible dans chaque groupe, respectivement 0,8 % et 1,3 %. Conclusion Dans une population de DT2 âgés, l’addition de linagliptine pour améliorer le contrôle glycémique n’a pas augmenté le risque global d’hypoglycémie. Son incidence, comparativement à un placebo, a été plus faible chez les patients sous insuline mais plus élevée chez ceux sous sécrétagogue. Déclaration d’intérêt Les auteurs déclarent avoir un intérêt avec un organisme privé, industriel ou commercial en relation avec le sujet présenté. Certains sont salariés de Boehringer-Ingelheim.
Sea urchin teeth are remarkable and complex calcite structures, continuously growing at the forming end and self-sharpening at the mature grinding tip. The calcite (CaCO3) crystals of tooth ...components, plates, fibers, and a high-Mg polycrystalline matrix, have highly co-oriented crystallographic axes. This ability to co-orient calcite in a mineralized structure is shared by all echinoderms. However, the physico-chemical mechanism by which calcite crystals become co-oriented in echinoderms remains enigmatic. Here, we show differences in calcite c-axis orientations in the tooth of the purple sea urchin (Strongylocentrotus purpuratus), using high-resolution X-ray photoelectron emission spectromicroscopy (X-PEEM) and microbeam X-ray diffraction (μXRD). All plates share one crystal orientation, propagated through pillar bridges, while fibers and polycrystalline matrix share another orientation. Furthermore, in the forming end of the tooth, we observe that CaCO3 is present as amorphous calcium carbonate (ACC). We demonstrate that co-orientation of the nanoparticles in the polycrystalline matrix occurs via solid-state secondary nucleation, propagating out from the previously formed fibers and plates, into the amorphous precursor nanoparticles. Because amorphous precursors were observed in diverse biominerals, solid-state secondary nucleation is likely to be a general mechanism for the co-orientation of biomineral components in organisms from different phyla.
Aflatoxins are fungal metabolites that frequently contaminate staple foods in much of sub-Saharan Africa, and are associated with increased risk of liver cancer and impaired growth in young children. ...We aimed to assess whether postharvest measures to restrict aflatoxin contamination of groundnut crops could reduce exposure in west African villages.
We undertook an intervention study at subsistence farms in the lower Kindia region of Guinea. Farms from 20 villages were included, ten of which implemented a package of postharvest measures to restrict aflatoxin contamination of the groundnut crop; ten controls followed usual postharvest practices. We measured the concentrations of blood aflatoxin–albumin adducts from 600 people immediately after harvest and at 3 months and 5 months postharvest to monitor the effectiveness of the intervention.
In control villages mean aflatoxin–albumin concentration increased postharvest (from 5·5 pg/mg 95% CI 4·7–6·1 immediately after harvest to 18·7 pg/mg 17·0–20·6 5 months later). By contrast, mean aflatoxin–albumin concentration in intervention villages after 5 months of groundnut storage was much the same as that immediately postharvest (7·2 pg/mg 6·2–8·4
vs 8·0 pg/mg 7·0–9·2). At 5 months, mean adduct concentration in intervention villages was less than 50% of that in control villages (8·0 pg/mg 7·2–9·2
vs 18·7 pg/mg 17·0–20·6, p<0·0001). About a third of the number of people had non-detectable aflatoxin–albumin concentrations at harvest. At 5 months, five (2%) people in the control villages had non-detectable adduct concentrations compared with 47 (20%) of those in the intervention group (p<0·0001). Mean concentrations of aflatoxin B1 in groundnuts in household stores in intervention and control villages were consistent with measurements of aflatoxin–albumin adducts.
Use of low-technology approaches at the subsistence-farm level in sub-Saharan Africa could substantially reduce the disease burden caused by aflatoxin exposure.
Carboxylesterases (CarEs) play an important role in detoxifying insecticides in insects. Over‐expression and structural modification of CarEs have been implicated in the development of ...organophosphate (OP) insecticide resistance in insects. A previous study identified four nonsynonymous mutations (resulting in four amino acid residue substitutions) in the open reading frame of the carboxylesterase gene of resistant cotton aphids compared to the omethoate susceptible strain, which has possibly influenced the development of resistance to omethoate (a systemic OP insecticide). The current study further characterized the function of these mutations, both alone and in combination, in the hydrolysis of OP insecticides. The metabolism results suggest that the combination of four mutations, mainly existing in the laboratory‐selected OP‐resistant cotton aphid population, increased the OP hydrolase activity (approximately twofold) at the cost of detectable carboxylesterase activity. The functional studies of single or multiple mutations suggest the positive effect of H104R, A128V and T333P on the acquisition of OP hydrolase activity, especially the combination of H104R with A128V or T333P. K484R substitution decreased both the OP hydrolase activity and the CarE activity, indicating that this mutation primarily drives the negative effect on the acquisition of OP hydrolase activity amongst these four mutations in the resistant strain. The modelling and docking results are basically consistent with the metabolic results, which strongly suggest that the structural gene modification is the molecular basis for the OP resistance in this laboratory‐selected cotton aphid strain.
In this study, surface formation mechanism in micro-grinding of single crystal silicon is investigated based on analysis of undeformed chip thickness hm. A predicting model of grinding force ...considering crystallographic effects in micro-grinding of single crystal silicon is built. In this model, micro-grinding process of single crystal silicon is divided into two steps by one line on which hm of single grit equals to lattice constant. Two micro-grinding experiments with different ranges of cutting depths and feed rates have been designed and conducted on single crystal silicon to verify the model this paper proposes. The relationship between micro-grinding parameters and crack length lc is investigated and the empirical formula of lc is derived based on analysis of experiment results. Ductile-regime transitions in micro-grinding process of single crystal silicon have been revealed, 20nm and 100nm are turned out to be two critical conditions based on analysis of experiment results. It is found that the grinding force has a sudden change when micro-grinding process comes within material's crystal boundary in experiment. The force predicting model this paper proposes has well explained this phenomenon in micro-grinding of single cyrstal silicon. When micro-grinding undeformed chip thickness hm belows 0.5nm, micro grinding force doesn't decrease with the decrease of cutting parameters but has a rising tendency, and these experimental measurements also provide a support to the result of model this paper proposes.
•We build a predicting model of micro-grinding force considering crystallographic effects.•We divide micro-grinding process of single crystal silicon into two steps by lattice constant.•Two micro-grinding experiments with different cutting depths and feed rates are conducted.•Empirical formula of lc in single silicon crystal micro-grinding is derived.•Ductile-regime transitions in micro-grinding process of single crystal silicon are revealed.
Context.
The Serpens filament, a prominent elongated structure in a relatively nearby molecular cloud, is believed to be at an early evolutionary stage, so studying its physical and chemical ...properties can shed light on filament formation and early evolution.
Aims.
The main goal is to address the physical and chemical properties as well as the dynamical state of the Serpens filament at a spatial resolution of ~0.07 pc and a spectral resolution of ≲0.1 km s
−1
.
Methods.
We performed
13
CO (1–0), C
18
O (1–0), C
17
O (1–0),
13
CO (2–1), C
18
O (2–1), and C
17
O (2–1) imaging observations toward the Serpens filament with the Institut de Radioastronomie Millimétrique 30-m and Atacama Pathfinder EXperiment telescopes.
Results.
Widespread narrow
13
CO (2–1) self-absorption is observed in this filament, causing the
13
CO morphology to be different from the filamentary structure traced by C
18
O and C
17
O. Our excitation analysis suggests that the opacities of C
18
O transitions become higher than unity in most regions, and this analysis confirms the presence of widespread CO depletion. Further we show that the local velocity gradients have a tendency to be perpendicular to the filament’s long axis in the outskirts and parallel to the large-scale magnetic field direction. The magnitudes of the local velocity gradients decrease toward the filament’s crest. The observed velocity structure can be a result of gravity-driven accretion flows. The isochronic evolutionary track of the C
18
O freeze-out process indicates the filament is young with an age of ≲2 Myr.
Conclusions.
We propose that the Serpens filament is a newly-formed slightly-supercritical structure which appears to be actively accreting material from its ambient gas.
•The electronic structures have been altered by the newly formed CNM bonds and the relaxed chemical bonds around them.•The optical absorption edge (and intensity) in visible-light range red-shifts ...10–75nm (and increases about 14%–71%) except O– and S– doped specimens.•The separation of the HOMO and LUMO of H–, B–, O–, S–, F– and As– doped specimens can effectively enhance the photocatalytic efficiency.The electronic structures have been altered by the newly formed CNM bonds and the relaxed chemical bonds around them.•The optical absorption edge (and intensity) in visible-light range red-shifts 10–75nm (and increases about 14%–71%) except O– and S– doped specimens.•The separation of the HOMO and LUMO of H–, B–, O–, S–, F– and As– doped specimens can effectively enhance the photocatalytic efficiency.
Doping is an effective means to alter the electronic behavior of materials by forming new chemical bond and relaxing the surrounding chemical bonds. With the aid of first-principle studies, the effects of a series of nonmetal (NM) dopants on the geometric, thermodynamic, electronic and optical performances of monolayer g–C3N4 have been investigated. Results shown that, all considered NM atoms except Br and I atoms can be introduced into the monolayer g–C3N4 on account of the thermal stability, the supercell parameter and film thickness have been altered by the newly formed CNM bonds and the relaxed chemical bonds around them, which have affected their electronic structure. The band gap values were altered less than ±0.14eV. The optical absorption edge (and intensity) in visible light of all doped specimens red-shift 10–75nm (and increase about 14%–71%) except for O– and S–doped specimens, and thus the NM dopants can enhance the visible-light response capability. Moreover, the highest occupied molecular orbital and lowest unoccupied molecular orbital of H–, B–, O–, S–, F– and As–doped specimens have been separated adequately, it can effectively separate the photogenerated e−/h+ pairs and enhance the photocatalytic efficiency. Finally, we have confirmed six high efficiency monolayer g–C3N4 based photocatalysts by doping H, B, O, S, F and As atoms.
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