Photoredox catalysis, especially in combination with transition metal catalysis, can produce redox states of transition metal catalysts to facilitate challenging bond formations that are not readily ...accessible in conventional redox catalysis. For arene functionalization, metallophotoredox catalysis has successfully made use of the same leaving groups as those valuable in conventional cross-coupling catalysis, such as bromide. Yet the redox potentials of common photoredox catalysts are not sufficient to reduce most aryl bromides, so synthetically useful aryl radicals are often not directly available. Therefore, the development of a distinct leaving group more appropriately matched in redox potential could enable new reactivity manifolds for metallophotoredox catalysis, especially if arylcopper(III) complexes are accessible, from which the most challenging bond-forming reactions can occur. Here we show the conceptual advantages of aryl thianthrenium salts for metallophotoredox catalysis, and their utility in site-selective late-stage aromatic fluorination.
► So-called “essential patents” included in standards have compared to control patents higher number of claims. ► They are also amended more often than the patents of the control group. ► The results ...have implications for the policies of patent offices.
This article addresses companies’ filing behaviour in respect of patents relevant for standard-setting (“essential patents”). We discuss applicants’ incentives to achieve conformity of patent applications with technology standards under development. Based on these incentive structures, we hypothesise that the claims of essential patents are amended more often than those of comparable patents. Additionally, we argue that applicants have incentives to delay the grant decision. As a result, essential patents are hypothesised to have longer pendency times than comparable patents. This implies more possibilities for applicants to exploit the flexibility within the patent application process to amend the claims of pending patent applications. For empiric validation, we use procedural patent data from the European patent application process. We adopt a one-to-one matching approach, pairing essential patents in telecommunications with control patents on the matching criteria of technology class, filing date and applicant name. Additionally, we compare these essentials with patents from companies that do not hold standards-relevant patents. We detect higher numbers of claims and amendments to claims as well as other relevant characteristics for the essential patents. Using survival analysis, we show that the higher numbers of amendments and claims and the higher share of X references are responsible for higher pendency times, since they significantly decrease hazard rates in the survival analysis. We discuss the general implications for the functioning of the patent system and address the detrimental effects caused by the high degree of uncertainty generated by these filing strategies. Possible solutions such as better co-ordination are devised.
Broad use of tenofovir and an ageing HIV- infected population have created an interest in renal function in HIV patients. Serum cystatin C is a newer marker of renal function and might be more ...sensitive than creatinine.
Patients were enrolled consecutively in an observational study. HIV-seropositive patients naive to antiretroviral therapy (n = 261) were compared with healthy volunteers undergoing check-up procedures (n = 193). Estimated glomerular filtration rate (eGFR) was derived using creatinine-based Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault formulas or cystatin C-based calculations. HIV-seropositive patients starting antiretroviral therapy (n = 92) were followed prospectively after enrolment.
MDRD showed a higher median eGFR in antiretroviral-naive HIV-seropositive patients compared with controls (104 versus 93 ml/min; P < 0.001). Cockcroft-Gault gave similar results (118 versus 106 ml/min; P < 0.001). By contrast, cystatin C levels in HIV-seropositive individuals were higher, resulting in a lower median eGFR compared with controls (99 versus 120 ml/min; P < 0.001). Cystatin C was positively correlated with HIV RNA (r = 0.33, P < 0.01) and inversely correlated with CD4+ T-cell count (r = -0.29, P < 0.01). Initiating antiretroviral therapy (n = 92) decreased cystatin C levels and led to an increased cystatin C-based eGFR from median 84 to 103 ml/min at week 24 (P < 0.001). Serum creatinine was not substantially altered.
Correlation of cystatin C with HIV RNA and CD4+ T-cell count, plus decrease of cystatin C after suppression of HIV replication, suggest an increase of cystatin C levels by active HIV infection. This might result in overestimation of renal impairment, particularly in treatment-naive patients. Therefore, use of cystatin C to calculate GFR in HIV-seropositive individuals should not be recommended without further validation.
We consider a pursuit-evasion problem where some lions have the task to clear a grid graph whose nodes are initially contaminated. The contamination spreads one step per time unit in each direction ...not blocked by a lion. A vertex is cleared from its contamination whenever a lion moves to it. Brass et al. 5 showed that n/2 lions are not enough to clear the n x n-grid. In this paper, we consider the same problem in dimension d > 2 and prove that Θ(nd-1/√d) lions are necessary and sufficient to clear the nd-grid. Furthermore, we analyze a problem variant where the lions are also allowed to jump from grid vertices to non-adjacent grid vertices.
Biomass is a heterogeneous material with respect to its chemical composition due to different plant species and components as well as the potential content of impurities. Especially in the production ...of large fuel batches heterogeneous chemical compositions are a challenge with respect to the required compliance with fuel standards and emission thresholds during utilization. This can be avoided by fuel pre-treatment and systematic homogenization during fuel production. For this reason, the study analyses the effects of biomass leaching in combination with homogenization of biomass batches on industrial-scale. Within two case studies, low-quality herbaceous biomasses, i.e. foliage and wheat straw were pretreated and homogenized in quantities ranging from 8 to 51 tons. In the first case study, foliage was first leached, then mixed with sawdust and homogenized by separating batch parts with high ash content, followed by systematic recombination of the batches. In the second case study, homogenization of straw pellets (untreated and leached) was attempted by a layering approach during bagging. Both case studies (i) confirm earlier findings that critical fuel components can be substantially reduced by leaching (i.e. reduction of ash content MV by 45 w-%) but indicate that material agitation during leaching is necessary; (ii) underscore that systematic homogenization is necessary for fuel batches consisting of materials from different origins and reduce i.e.-the ash content RSD by 48%, and (iii) demonstrate that even low-quality fuels from herbaceous biomass assortments can comply with the requirements of fuel standards if dedicated fuel pretreatment is employed.
•Homogenization is recommended for fuel batches with biomass of different origin.•If sub-batches can be identified, homogenization can be achieved by cross blending.•If differentiation of sub-batches is not possible, the layering approach can be used.
Presynaptic metabotropic glutamate receptors (mGluRs) are essential for the control of synaptic transmission. However, how the subsynaptic dynamics of these receptors is controlled and contributes to ...synaptic signaling remain poorly understood quantitatively. Particularly, since the affinity of individual mGluR subtypes for glutamate differs considerably, the activation of mGluR subtypes critically depends on their precise subsynaptic distribution. Here, using superresolution microscopy and single-molecule tracking, we unravel novel molecular mechanisms that control the nanoscale distribution and mobility of presynaptic mGluRs in hippocampal neurons. We demonstrate that the high-affinity group II receptor mGluR2 localizes diffusely along the axon, and is highly mobile, while the low-affinity group III receptor mGluR7 is stably anchored at the active zone. We demonstrate that intracellular interactions modulate surface diffusion of mGluR2, while immobilization of mGluR7 at the active zone relies on its extracellular domain. Receptor activation or increases in synaptic activity do not alter the surface mobility of presynaptic mGluRs. Finally, computational modeling of presynaptic mGluR activity revealed that this particular nanoscale arrangement directly impacts their ability to modulate neurotransmitter release. Altogether, this study demonstrates that distinct mechanisms control surface mobility of presynaptic mGluRs to contribute differentially to glutamatergic synaptic transmission.
Here we report the synthesis and application of trifluoromethyl thianthrenium triflate (TT-CF
OTf
) as a novel trifluoromethylating reagent, which is conveniently accessible in a single step from ...thianthrene and triflic anhydride. We demonstrate the use of TT-CF
OTf
in electrophilic, radical, and nucleophilic trifluoromethylation reactions.
We report a nucleophilic substitution reaction of five-membered hetarylsulfonium salts that results in a change of the substitution pattern on the arene. The products of these cine-substitutions are ...hard to access synthetically otherwise. The sulfonium salts that serve as starting materials are generated by a highly site-selective C–H functionalization reaction.
Background
A major issue of cardiac implantable electronic device therapy in pediatric patients is the high incidence of lead dysfunctions and associated reinterventions. This study aims to analyze ...the timing and mode of generator and lead dysfunction.
Methods
Retrospective single‐center analysis of 283 children and young adults with an epicardial pacemaker or implantable cardioverter defibrillator therapy from 1998 to 2018.
Results
Mean age at implant was 6.1 years (SD ± 5.8 years) and median follow‐up 6.4 years (IQR, 3.4–10.4 years) with a total of 1998.1 patient‐years of cardiac device therapy. A total of 120 lead‐related complications were observed in 82 patients (29.0%). They were detected by device interrogation (n = 86), symptoms (n = 13), intraoperative findings (n = 7), routine chest radiography (n = 5), routine ECG (n = 4), patient alert sound by device (n = 3), and physical examination (n = 2). It was possible to find the date of the event on the device memory in 21 out of 120 lead dysfunctions (18%) with a median time interval between occurrence and detection of 1.3 months (IQR, 0.2–5.0 months). Moreover, 20 generator‐related complications were found in 13 patients.
Conclusions
Early recognition of lead and generator dysfunction remains challenging in pediatric patients. As symptoms are relatively rare conditions in the context of PM and ICD dysfunction, close patient monitoring is mandatory, even in asymptomatic patients with a good clinical course. To further improve the safety of pediatric pacing systems, more durable epicardial electrodes are desirable.
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