Kinetic Study of Factor X During Oral Anticoagulation with Acenocoumarol: Potential Value for the Initiation of Treatment

We measured prothrombin time and coagulation factors (F) VII and X in 19 patients under heparin treatment receiving acenocoumarol (3 mg per day) without a loading dose. Blood samples were obtained on the 1st (D0), 2nd (D1), 3d (D2), 5th (D4), 7th (D6) and 9th (D8) days of treatment. In 7 patients (group A) acenocoumarol dosage had to be reduced at D2, D4, or D6, based on a prothrombin time smaller than 25% of normal. In the remaining 12 patients (group B), FVII and prothrombin time followed a double exponential decline. Conversely, the FX decrease could be fitted to a single exponential pattern. The slope of the linear relation, loge (FX) = b - a (D), calculated from measurements made at D0, D1, and D2, allowed us to predict the FX level at D8 by simple extrapolation, and, consequently, to estimate as early as D2 whether a change of acenocoumarol dosage would have been required. In group A this extrapolation always announced a dangerously low FX concentration at Dg that justified the preventive reduction of acenocoumarol dosage. We conclude that FX can be a valuable guide in the initiation of an oral anticoagulant treatment.

F-Specific RNA Bacteriophages, Especially Members of Subgroup II, Should Be Reconsidered as Good Indicators of Viral Pollution of Oysters

Norovirus (NoV) is the leading cause of gastroenteritis outbreaks linked to oyster consumption. In this study, we investigated the potential of F-specific RNA bacteriophages (FRNAPH) as indicators of viral contamination in oysters by focusing especially on FRNAPH subgroup II (FRNAPH-II). These viral indicators have been neglected because their behavior is sometimes different from that of NoV in shellfish, especially during the depuration processes usually performed before marketing. However, a significant bias needs to be taken into account. This bias is that, in the absence of routine culture methods, NoV is targeted by genome detection, while the presence of FRNAPH is usually investigated by isolation of infectious particles. In this study, by targeting both viruses using genome detection, a significant correlation between the presence of FRNAPH-II and that of NoV in shellfish collected from various European harvesting areas impacted by fecal pollution was observed. Moreover, during their depuration, while the long period of persistence of NoV was confirmed, a similar or even longer period of persistence of the FRNAPH-II genome, which was over 30 days, was observed. Such a striking genome persistence calls into question the relevance of molecular methods for assessing viral hazards. Targeting the same virus (i.e., FRNAPH-II) by culture and genome detection in specimens from harvesting areas as well as during depuration, we concluded that the presence of genomes in shellfish does not provide any information on the presence of the corresponding infectious particles. In view of these results, infectious FRNAPH detection should be reconsidered as a valuable indicator in oysters, and its potential for use in assessing viral hazard needs to be investigated.IMPORTANCE This work brings new data about the behavior of viruses in shellfish, as well as about the relevance of molecular methods for their detection and evaluation of the viral hazard. First, a strong correlation between the presence of F-specific RNA bacteriophages of subgroup II (FRNAPH-II) and that of norovirus (NoV) in shellfish impacted by fecal contamination has been observed when both viruses are detected using molecular approaches. Second, when reverse transcription-PCR and culture are used to detect FRNAPH-II in shellfish, it appears that the genomes of the viruses present a longer period of persistence than infectious virus, and thus, virus genome detection fails to give information about the concomitant presence of infectious viruses. Finally, this study shows that FRNAPH persist at least as long as NoV does. These data are major arguments to reconsider the potential of FRNAPH as indicators of shellfish viral quality.

Human shields mediate sexual conflict in a top predator

Selecting the right habitat in a risky landscape is crucial for an individual's survival and reproduction. In predator-prey systems, prey often can anticipate the habitat use of their main predator and may use protective associates (i.e. typically an apex predator) as shields against predation. Although never tested, such mechanisms should also evolve in systems in which sexual conflict affects offspring survival. Here, we assessed the relationship between offspring survival and habitat selection, as well as the use of protective associates, in a system in which sexually selected infanticide (SSI), rather than interspecific predation, affects offspring survival. We used the Scandinavian brown bear (Ursus arctos) population with SSI in a human-dominated landscape as our model system. Bears, especially adult males, generally avoid humans in our study system. We used resource selection functions to contrast habitat selection of GPS-collared mothers that were successful (i.e. surviving litters, n = 19) and unsuccessful (i.e. complete litter loss, n = 11) in keeping their young during the mating season (2005-2012). Habitat selection was indeed a predictor of litter survival. Successful mothers were more likely to use humans as protective associates, whereas unsuccessful mothers avoided humans. Our results suggest that principles of predator-prey and fear ecology theory (e.g. non-consumptive and cascading effects) can also be applied to the context of sexual conflict.

Direct heteroarylation polymerization: guidelines for defect-free conjugated polymers

Direct (hetero)arylation polymerization (DHAP) has emerged as a valuable and atom-economical alternative to traditional cross-coupling methods for the synthesis of low-cost and efficient conjugated polymers for organic electronics. However, when applied to the synthesis of certain (hetero)arene-based materials, a lack of C-H bond selectivity has been observed. To prevent such undesirable side-reactions, we report the design and synthesis of new, bulky, phosphine-based ligands that significantly enhance selectivity of the DHAP process for both halogenated and non-halogenated electron-rich and electron-deficient thiophene-based comonomers. To better understand the selectivity issues, density functional theory (DFT) calculations have been performed on various halogenated and non-halogenated electron-rich and electron-deficient thiophene-based comonomers. Calculations showed that the presence of bromine atoms decreases the energy of activation (Ea) of the adjacent C-H bonds, allowing undesirable β-defects for some brominated aromatic units. Both calculations and the new ligands should lead to the rational design of monomers and methods for the preparation of defect-free conjugated polymers from DHAP.

Salt-induced thermochromism of a conjugated polyelectrolyte

We report here the photophysical properties of a water-soluble polythiophene with cationic side-chains in PBS buffer solution.

Increasing Polymer Solar Cell Fill Factor by Trap-Filling with F4-TCNQ at Parts Per Thousand Concentration

Intrinsic traps in organic semiconductors can be eliminated by trap-filling with F4-TCNQ. Photovoltaic tests show that devices with F4-TCNQ at parts per thousand concentration outperform control devices due to an improved fill factor. Further studies confirm the trap-filling pathway and demonstrate the general nature of this finding.

Structural robustness of the gut mucosal microbiota is associated with Crohn's disease remission after surgery

OBJECTIVES

Preventing postoperative recurrence after ileocolonic resection (ICR) for Crohn's disease (CD) is challenging. Defining the disturbances of the microbial composition and community structure after ICR and their link with early disease recurrence is crucial.

DESIGN

Microbiota composition (fingerprinting and 16S rDNA sequencing) and community structure (correlation networks of bacterial species) were assessed from ileal mucosa sampled in 20 patients undergoing ICR and 6 months later during endoscopy from above (neoterminal ileum) and below (subanastomotic colon) the surgical anastomosis.

RESULTS

ICR had a dramatic effect on gut microbial ecosystem. At surgery, CD mucosa harboured a dysbiotic microbiota with high proportions of α/β Proteobacteria and Bacilli. Six months later, half of the patients had recurrent lesions at ileocolonoscopy and presented higher numbers of Lachnospiraceae. Recurrence of endoscopic lesions was associated with enrichment in Enterococcus durans while patients in remission had increased proportions of Dorea longicatena and Bacteroides plebeius. Structural differences were striking between recurrence and remission microbiota; while the microbiota of patients with CD recurrence exhibited a loose community structure, the microbiota of patients in remission displayed communities that were robustly correlated to each other. Microbiota colonising the neoterminal ileum and subanastomotic colon 6 months after ICR only differed in patients with recurrence.

CONCLUSIONS

ICR modifies the gut microbiome. Remission after 6 months was associated with homogenous bacterial distribution around the anastomosis. Community structure and bacterial networks highlight target species, including Faecalibacterium prausnitzii and Ruminococcus gnavus, which may allow precise modulations of the overall microbial ecosystem towards remission pattern.

Combination of C-reactive protein, infliximab trough levels, and stable but not transient antibodies to infliximab are associated with loss of response to infliximab in inflammatory bowel disease

BACKGROUND

Antibodies to infliximab [ATI] and trough levels to infliximab [TRI] are associated with loss of response in inflammatory bowel diseases [IBD]. The best way to predict loss of response [LOR] to infliximab [IFX] is unknown.

METHODS

We conducted a prospective observational cohort study enrolling all IBD patients who were in clinical remission at Week 14 after IFX treatment initiation. TRI, ATI and C-reactive protein [CRP] level were measured at Week 22 [T1] and thereafter at every other IFX infusion. Loss of clinical response was defined by a flare requiring therapeutic change [IFX dose intensification, initiation of another drug class, and/or surgery].

RESULTS

A total of 93 patients [59 Crohn's disease, mean duration of follow-up 17.2 months] were included; 32 patients [34.4%] lost clinical response during follow-up. Cumulative probability of LOR was 50% at 20 months. Mean TRI at T1 was significantly lower in IBD patients with stable ATI as compared with those with transient ATI or without ATI [0.052, 3.34 ,and 4.29 µg/ml, respectively; p = 0.001 between no ATI vs stable ATI, and p = 0.005 between stable and transient ATI] [p = 0.0001]. Three independent factors were predictive of LOR after Cox proportional hazards modelling: TRI > 5.5 µg/ml (hazard ratio [HR]: 0.21; 95% confidence interval [CI]: 0.05-0.89;p = 0.034) at T1, CRP > 5mg/l [HR: 2.5; 95% CI: 1.16-5.26; p = 0.019] at T1, and stable ATI defined by two consecutive ATI > 20ng/ml [HR: 3.77; 95% CI: 1.45-10.0; p = 0.007]. Transient ATI did not influence LOR.

CONCLUSIONS

LOR can be predicted based on a combination of CRP, TRI and stable ATI with a high degree of accuracy.

Small-bandgap polymer solar cells with unprecedented short-circuit current density and high fill factor

Small-bandgap polymer solar cells (PSCs) with a thick bulk heterojunction film of 340 nm exhibit high power conversion efficiencies of 9.40% resulting from high short-circuit current density (JSC ) of 20.07 mA cm(-2) and fill factor of 0.70. This remarkable efficiency is attributed to maximized light absorption by the thick active layer and minimized recombination by the optimized lateral and vertical morphology through the processing additive.

Elucidating the impact of molecular packing and device architecture on the performance of nanostructured perylene diimide solar cells

The performance of organic photovoltaic devices (OPV) with nanostructured polymer:perylene diimide (PDI) photoactive layers approaches the levels of the corresponding polymer:fullerene systems. Nevertheless, a coherent understanding of the difficulty for PDI-based OPV devices to deliver high power conversion efficiencies remains elusive. Here we perform a comparative study of a set of four different polymer:PDI OPV model systems. The different device performances observed are attributed to differences in the nanostructural motif of these composites, as determined by wide-angle X-ray scattering (WAXS) measurements. Long-range structural order in the PDI domain dictates (i) the stabilization energy and (ii) the concentration of the PDI excimers in the composites. The quenching of the PDI excimer photoluminescence (PL) is found to be insensitive to the former, but it depends on the latter. High PL quenching occurs for the low concentration of PDI excimers that are formed in PDI columns with a length comparable to the PDI excimer diffusion length. The stabilization of the PDI excimer state increases as the long-range order in the PDI domains improves. The structural order of the PDI domains primarily affects charge transport. Electron mobility reduces as the size of the PDI domain increases, suggesting that well-ordered PDI domains suffer from poor electronic connectivity. WAXS further reveals the presence of additional intermolecular PDI interactions, other than the direct face-to-face intermolecular coupling, that introduce a substantial energetic disorder in the polymer:PDI composites. Conventional device architectures with hole-collecting ITO/PEDOT:PSS bottom electrodes are compared with inverted device architectures bearing bottom electron-collecting electrodes of ITO/ZnO. In all cases the ZnO-functionalized devices surpass the performance of the conventional device analogues. X-ray photoelectron spectroscopy explains that in

PEDOT

PSS-functionalized devices, the PDI component preferentially segregates closer to the hydrophilic

PEDOT

PSS electrode, thus impeding the efficient charge extraction and limiting device photocurrent.

Mental health of transgender youth in care at an adolescent urban community health center: a matched retrospective cohort study

PURPOSE

Transgender youth represent a vulnerable population at risk for negative mental health outcomes including depression, anxiety, self-harm, and suicidality. Limited data exist to compare the mental health of transgender adolescents and emerging adults to cisgender youth accessing community-based clinical services; the present study aimed to fill this gap.

METHODS

A retrospective cohort study of electronic health record data from 180 transgender patients aged 12-29 years seen between 2002 and 2011 at a Boston-based community health center was performed. The 106 female-to-male (FTM) and 74 male-to-female (MTF) patients were matched on gender identity, age, visit date, and race/ethnicity to cisgender controls. Mental health outcomes were extracted and analyzed using conditional logistic regression models. Logistic regression models compared FTM with MTF youth on mental health outcomes.

RESULTS

The sample (N = 360) had a mean age of 19.6 years (standard deviation, 3.0); 43% white, 33% racial/ethnic minority, and 24% race/ethnicity unknown. Compared with cisgender matched controls, transgender youth had a twofold to threefold increased risk of depression, anxiety disorder, suicidal ideation, suicide attempt, self-harm without lethal intent, and both inpatient and outpatient mental health treatment (all p < .05). No statistically significant differences in mental health outcomes were observed comparing FTM and MTF patients, adjusting for age, race/ethnicity, and hormone use.

CONCLUSIONS

Transgender youth were found to have a disparity in negative mental health outcomes compared with cisgender youth, with equally high burden in FTM and MTF patients. Identifying gender identity differences in clinical settings and providing appropriate services and supports are important steps in addressing this disparity.