The impact of alternating drainage and inundation cycles on geochemistry and microbiology of intact peat cores.

The rewetting of degraded peatlands has been adopted as a method to address climate change. Concerns have been raised about the effects of peat inundation and drying cycles, in more extreme climate events, on the potential release of nitrogen (N) species, in particular ammonium (NH4-N), once rewetted, as well as the physico-chemical and biological properties of the peat. This study used intact peat cores to measure the impact of two different cycles of peat inundation and drying (1 month and 2 month) over a total study duration of 56 weeks on the (1) NH4-N, nitrate-N (NO3-N) and dissolved reactive phosphorus (DRP) in the soil pore water; (2) microbial community structure; (3) physico-chemical properties of the peat; and (4) the structure of the peat, and therefore its ability to mitigate flood risks and storm surges. The study found that rewetted cores released NO3-N in the pore water up to a concentration of 6.25 mg L-1, but had no appreciable impact on NH4-N, which remained below 1.7 mg L-1 over the study duration. DRP moved quickly though the upper layers of the cores, but physico-chemical analysis suggested it was adsorbed to more iron-rich soil, which was present at depths below 0.4 m in the cores. Time intervals between inundation produced no significant difference on the forms of inorganic N released, nor did it compact the soil or change the microbial community structure. The depth of the water table, however, had a significant impact on inorganic N release, particularly NO3-N, which indicates that this N species, and not NH4-N, may be problematic in rewetted peatlands.

Characteristics associated with significantly worse quality of life in mycosis fungoides/Sézary syndrome from the Prospective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study.

BACKGROUND: Mycosis fungoides (MF) and Sézary Syndrome (SS) are the most common cutaneous T-cell lymphomas. MF/SS is accompanied by considerable morbidity from pain, itching and disfigurement. AIM: To identify factors associated with poorer health-related quality of life (HRQoL) in patients newly diagnosed with MF/SS. METHODS: Patients enrolled into Prospective Cutaneous Lymphoma International Prognostic Index (PROCLIPI; an international observational study in MF/SS) had their HRQoL assessed using the Skindex-29 questionnaire. Skindex-29 scores were analysed in relation to patient- and disease-specific characteristics. RESULTS: The study population consisted of 237 patients [60·3% male; median age 60 years, (interquartile range 49-70)], of whom 179 had early MF and 58 had advanced MF/SS. In univariate analysis, HRQoL, as measured by Skindex-29, was worse in women, SS, late-stage MF, those with elevated lactate dehydrogenase, alopecia, high modified Severity Weighted Assessment Tool and confluent erythema. Linear regression models only identified female gender (ß = 8·61; P = 0·003) and alopecia (ß = 9·71, P = 0·02) as independent predictors of worse global HRQoL. Item-level analysis showed that the severe impairment in symptoms [odds ratio (OR) 2·14, 95% confidence interval (CI) 1·19-3·89] and emotions (OR 1·88, 95% CI 1·09-3·27) subscale scores seen in women was caused by more burning/stinging, pruritus, irritation and greater feelings of depression, shame, embarrassment and annoyance with their diagnosis of MF/SS. CONCLUSIONS: HRQoL is significantly more impaired in newly diagnosed women with MF/SS and in those with alopecia. As Skindex-29 does not include existential questions on cancer, which may cause additional worry and distress, a comprehensive validated cutaneous T-cell lymphoma-specific questionnaire is urgently needed to more accurately assess disease-specific HRQoL in these patients. What's already known about this topic? Cross-sectional studies of mixed populations of known and newly diagnosed patients with mycosis fungoides (MF)/Sézary syndrome (SS) have shown significant impairment in health-related quality of life (HRQoL). Previous studies on assessing gender-specific differences in HRQoL in MF/SS are conflicting. More advanced-stage disease and pruritus is associated with poorer HRQoL in patients with MF/SS. What does this study add? This is the first prospective study to investigate HRQoL in a homogenous group of newly diagnosed patients with MF/SS. In patients newly diagnosed with MF/SS, HRQoL is worse in women and in those with alopecia and confluent erythema. MF/SS diagnosis has a multidimensional impact on patient HRQoL, including a large burden of cutaneous symptoms, as well as a negative impact on emotional well-being.

Effects of livestock grazing and well construction on prairie vegetation structure surrounding shallow natural gas wells.

Short and sparse vegetation near shallow gas wells has generally been attributed to residual effects from well construction, but other mechanisms might also explain these trends. We evaluated effects of distance to shallow gas wells on vegetation and bare ground in mixed-grass prairies in southern Alberta, Canada, from 2010 to 2011. We then tested three hypotheses to explain why we found shorter vegetation and more bare ground near wells, using cattle fecal pat transects from 2012, and our vegetation quadrats. We evaluated whether empirical evidence suggested that observed patterns were driven by (1) higher abundance of crested wheatgrass (Agropyron cristatum) near wells, (2) residual effects of well construction, or (3) attraction of livestock to wells. Crested wheatgrass occurrence was higher near wells, but this did not explain effects of wells on vegetation structure. Correlations between distance to wells and litter depth were the highest near newer wells, providing support for the construction hypothesis. However, effects of distance to wells on other vegetation metrics did not decline as time since well construction increased, suggesting that other mechanisms explained observed edge effects. Cattle abundance was substantially higher near wells, and this effect corresponded with changes in habitat structure. Our results suggest that both residual effects of well construction and cattle behavior may explain effects of shallow gas wells on habitat structure in mixed-grass prairies, and thus, to be effective, mitigation strategies must address both mechanisms.

Detection and correction of interference in SRM analysis.

Selected Reaction Monitoring (SRM) is a method of choice for accurate quantitation of low-abundance proteins in complex backgrounds. This strategy is, however, sensitive to interference from other components in the sample that have the same precursor and fragment masses as the monitored transitions. We present here an approach to detect interference by using the expected relative intensity of SRM transitions. We also designed an algorithm to automatically detect the linear range of calibration curves. These approaches were applied to the experimental data of Clinical Proteomic Tumor Analysis Consortium (CPTAC) Verification Work Group Study 7 and show that the corrected measurements provide more accurate quantitation than the uncorrected data.

Inorganic and organozinc fluorocarboxylates: synthesis, structure and materials chemistry.

The organozinc fluorocarboxylates RZnO2CRf and RZnO2CRf·TMEDA, along with Zn(O2CRf)2·TMEDA (R = Me, Et; Rf = C2F5, C3F7) have been synthesized. The structures of EtZnO2C2F5 (5), EtZnO2C3F7 (7), EtZnO2C2F5·TMEDA (11), Zn(O2C2F5)2·TMEDA (13), along with products from the adventitious reaction with either O2 or H2O, Zn10Me4(OMe)4(O2CC2F5)12 (2), Zn9Et2(O2CC2F5)12(O)2 (6), Zn8Et4(OEt)4(O2CC3F7)6(O) (8), [Zn(O2CC3F7)2·TMEDA]2·H2O (15) have been determined. Thin films of oriented ZnO have been deposited on glass substrates by low-pressure chemical vapor deposition (LPCVD) using 3 and 10 as precursors, though no fluorine incorporation in the films was noted. LPCVD using 13 as precursor also yielded fluorine-free ZnO, but lacking the oriented growth observed using 3, 10. However, 5, which exhibits short intermolecular Zn···F contacts in the solid state, thermally decomposes to bulk ZnF2.

Synthesis, characterization, and materials chemistry of Group 4 silylimides.

This paper focuses on the development of potential single source precursors for M-N-Si (M = Ti, Zr or Hf) thin films. The titanium, zirconium, and hafnium silylimides (Me(2)N)(2)MNSiR(1)R(2)R(3) [R(1) = R(2) = R(3) = Ph, M = Ti(1), Zr (2), Hf (3); R(1) = R(2) = R(3) = Et, M = Ti (4), Zr (5), Hf (6); R(1) = R(2) = Me, R(3) = (t)Bu, M = Ti (7), Zr (8), Hf (9); R(1) = R(2) = R(3) = NMe(2), M = Ti (10), Zr (11), Hf (12)] have been synthesized by the reaction of M(NMe(2))(4) and R(3)R(2)R(1)SiNH(2). All compounds are notably sensitive to air and moisture. Compounds 1, 2, 4, and 7-10 have been structurally characterized, and all are dimeric, with the general formula [M(NMe(2))(2)(µ-NSiR(3))](2), in which the µ(2)-NSiR(3) groups bridges two four-coordinate metal centers. The hafnium compound 3 possesses the same basic dimeric structure but shows additional incorporation of liberated HNMe(2) bonded to one metal. Compounds 11 and 12 are also both dimeric but also incorporate additional µ(2)-NMe(2) groups, which bridge Si and either Zr or Hf metal centers in the solid state. The Zr and Hf metal centers are both five-coordinated in these species. Aerosol-assisted CVD (AA-CVD) using 4-7 and 9-12 as precursors generates amorphous films containing M, N, Si, C, and O; the films are dominated by MO(2) with smaller contributions from MN, MC and MSiON based on XPS binding energies.

Formation of PbS materials from lead xanthate precursors.

Six lead xanthate adducts Pb(S(2)COR)(2).L [R = Et, (n)Bu, L = bipy, TMEDA (tetramethylethylenediamine), PMDETA (pentamethyldiethylenetriamine)] have been synthesised and the structures of all, save Pb(S(2)COBu(n))(2).TMEDA (4) which is an oil, determined. Pb(S(2)COEt)(2).TMEDA (3) is seven-coordinate at lead through three chelating ligands and one weak intermolecular Pb‥S interaction. Both Pb(S(2)COR)(2).bipy [R = Et (1), (n)Bu (2)] are dimers in which one xanthate is terminal and the other µ(2) bridging at each sulphur, generating an eight-coordinate lead when the bipy donor is included. Both Pb(S(2)COR)(2).PMDETA [R = Et (5), (n)Bu (6)] are seven-coordinate at lead by virtue of two bidentate chelating xanthate ligands and a tridentate PMDETA; there are no intermolecular interactions. Trends in the (207)Pb NMR chemical shifts mirror the changes in the intramolecular coordination number across the series. Pb(S(2)COEt)(2).TMEDA (3) has been used to deposit PbS films on glass, Mo-coated glass and Si by AACVD. Pb(S(2)COEt)(2) also generated PbS nanocubes when decomposed under an autogenerated pressure.

Bis(trimethyl-ammonium) tetra-chlorido-diphenyl-stannate(IV).

The title compound, [(CH(3))(3)NH](2)[Sn(C(6)H(5))(2)Cl(4)], consists of [(CH(3))(3)NH](+) cations and [SnPh(2)Cl(4)](2-) anions in which the Sn atom, located on a centre of inversion, is bonded to four Cl atoms and two phenyl rings, giving an octa-hedral geometry with the phenyl rings in trans positions. In the crystal, the cations and the anions are connected by N-H⋯Cl hydrogen bonds and C-H⋯Cl inter-actions.

Bis(dicyclo-hexyl-ammonium) µ-oxalato-κO,O:O,O-bis-[aqua-(oxalato-κO,O)diphenyl-stannate(IV)].

The structure of the title compound, (C(12)H(24)N)(2)[Sn(2)(C(6)H(5))(4)(C(2)O(4))(3)(H(2)O)(2)], consists of a bischelating oxalate ion, located on an inversion center, which is linked to two SnPh(2) groups. The coordination sphere of the Sn(IV) ion is completed by a monochelating oxalate anion and a water mol-ecule. The Sn(IV) atoms are thus seven-coordinated. The discrete binuclear units are further connected by hydrogen bonds, leading to a supra-molecular crystal structure. The asymmetric unit contains one half dianion and one (Cy(2)NH(2))(+) cation.

Unstable carotid plaques exhibit raised matrix metalloproteinase-8 activity.

BACKGROUND: The fibrous cap of atherosclerotic plaques is composed predominantly of type I and III collagen. Unstable carotid plaques are characterized by rupture of their cap, leading to thromboembolism and stroke. The proteolytic mechanisms causing plaque disruption are undefined, but the collagenolytic matrix metalloproteinase (MMP) -1, -8, and -13 may be implicated. The aim of this study was to quantify the concentrations of these collagenases in carotid plaques and to determine their relationship to markers of plaque instability. METHODS AND RESULTS: Atherosclerotic plaques were collected from 159 patients undergoing carotid endarterectomy. The presence and timing of carotid territory symptoms were ascertained. Preoperative embolization was recorded by transcranial Doppler. Each plaque was assessed for histological features of instability. Plaque MMP concentrations were quantified with ELISA. Significantly higher concentrations of active MMP-8 were observed in the plaques of symptomatic patients (20.5 versus 11.4 ng/g; P=0.0002), in plaques of emboli-positive patients (22.7 versus 13.5 ng/g; P=0.0037), and in those plaques showing histological evidence of rupture (20.8 versus 14.7 ng/g; P=0.0036). No differences were seen in the levels of MMP-1 and MMP-13. Immunohistochemistry, in situ hybridization, and colocalization studies confirmed the presence of MMP-8 protein and mRNA within the plaque, which colocalized with macrophages. CONCLUSIONS: These data suggest that the active form of MMP-8 may be partly responsible for degradation of the collagen cap of atherosclerotic plaques. This enzyme represents an attractive target for drug therapy aimed at stabilizing vulnerable plaques.

Elevation in plasma MMP-9 following carotid endarterectomy is associated with particulate cerebral embolisation.

OBJECTIVES: To study plasma MMP-9 levels before and after carotid endarterectomy (CEA). DESIGN: Observational study. METHODS: Pre-operative (morning of surgery) and post-operative (48 h) plasma samples were obtained from 75 consecutive patients undergoing CEA. MMP-9 concentrations were quantified using ELISA. Transcranial Doppler monitoring was performed on each patient to detect particulate embolisation during the dissection phase of the CEA, until the application of carotid clamps. RESULTS: The median post-operative plasma MMP-9 level of emboli-positive patients was significantly higher than their median pre-operative value (14.9 ng/ml vs. 8.8 ng/ml; p=0.038). However, no significant difference was seen in the plasma MMP-9 level of emboli-negative patients (7.7 ng/ml vs. 7.1 ng/ml; p=0.364). A greater rise was seen in the median plasma MMP-9 levels of those patients suffering >2 emboli (from 3.4 to 19.3 ng/ml; p=0.041) than those patients suffering 1 or 2 emboli (from 10.1 to 12.8 ng/ml; p=0.340). CONCLUSIONS: Plasma MMP-9 only rises after CEA in patients with evidence of embolisation. This increase is more pronounced in those with high numbers of emboli. These data suggest that the increase in MMP-9 is due to cerebral damage caused by embolisation.