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Dicarbofunctionalization is an important efficient synthetic technique for adding two chemical moieties across an alkene. Here, a novel method of reductive dicarbofunctionalization has been developed using a single alkenyl triflate as the electrophile, combined with an unactivated alkene. The reaction does not require an external auxiliary and proceeds with complete regioselectivity.

Nanoparticles have been used in various fields of science and technology ranging from material science to biotechnology. The formation of nanoparticles has been confirmed through UV-visible spectroscopy (at 420 nm) by the change of color representing surface plasmon resonance. The synthesis of silver nanoparticles by a biogenic method is a novel approach due to its cost-effective, eco-friendly, and large-scale production possibilities. In the present study, silver nanoparticles (TC-AgNPs) were successfully synthesized using Terminalia chebula Retz. (T. chebula) leaf extract. Characterization of green synthesized silver nanoparticles was performed using UV-visible spectroscopy, Fourier transforms infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The formation of nanoparticles has been confirmed through UV-visible spectroscopy (at 420 nm) by the change of color representing surface plasmon resonance. The crystalline face-centred cubic property of the biosynthesized silver nanoparticles was established using XRD analysis. The XRD data gave the average particle size of 6.1 nm. The functional groups such as -OH, C=O, =NH were found responsible for reducing silver ions and helping to stabilize nanoparticles which were analyzed using FTIR spectroscopy. As the silver nanoparticles possess diverse applications, TC-AgNPs were investigated for antioxidant, antibacterial, and cytotoxic activity. The results showed TC-AgNPs showed potential antioxidant (IC50=312.8 ± 2.28 µg/mL) and antibacterial activities against four pathogenic bacteria like Staphylococcus aureus, Acinetobacter baumannii, Salmonella typhi, and Escherichia coli. Also, the silver nanoparticles exhibited moderate cytotoxicity (LC50= 477.53 ± 0.684 µg/mL) against brine shrimps nauplii in a dose-dependent manner.

We disclose a Ni-catalyzed cyclization/alkylmetal interception reaction in which products are readily linearized to permit regiodefined alkene dicarbofunctionalization. This method offers a convenient route to access 1,2-oxasilolane heterocycles, 3-hydroxysilanes and 4-arylalkanols with the formation of C(sp3)-C(sp3) bonds at primary and secondary alkyl carbon centers. In this reaction, a silicon-oxygen (Si-O) bond functions as a detachable linker that can be delinked with several hydride, alkyl, aryl and vinyl nucleophiles to create profusely functionalized 3-hydroxysilanes. A silicon motif in the cyclic C(sp3)-Si-O construct in 1,2-oxasilolane heterocycles can also be selectively deleted by Pd-catalyzed hydrodesilylation affording Si-ablated linear alcohol products reminiscent of vicinal ethylene dicarbofunctionalization with C(sp3) and C(sp2) carbon sources.

We disclose a Ni-catalyzed regioselective dialkylation reaction of alkenylarenes with -halocarbonyls and alkylzinc reagents. The reaction produces -arylated alkanecarbonyl compounds with the generation of two new C(sp3)-C(sp3) bonds at the vicinal carbons of alkenes. This reaction is effective for the use of primary, secondary and tertiary -halocarboxylic esters, amides and ketones in conjunction with primary and secondary alkylzinc reagents as the sources of two C(sp3) carbons for the dialkylation of terminal and cyclic internal alkenes.

Cyclopropane, a versatile synthetic intermediate, is forged as a key structural feature in many preclinical, clinical and commercial drugs, and occur as a skeletal motif in numerous natural products. The most prolific technique for its synthesis is the metal-catalyzed reaction of an alkene with a diazoalkane, a highly energetic, reactive and explosive reagent requiring stringent safety precautions. The expedient construction of cyclopropyl ring on alkenes with convenient and innocuous reagents under nonhazardous conditions remains an ongoing challenge. Herein, we report a simple photoredox-catalyzed intermolecular cyclopropanation of unactivated alkenes with a diverse set of active methylene compounds that demonstrates striking conceptual and practical synthetic advances over the known methods. The reaction proceeds with a photoredox catalyst (PC*) excited under a blue LED light in air/O2 and neutral reaction conditions in the presence of catalytic amounts of iodine, either in the form of added molecular I2 or generated in situ from alkyl iodides. . The reaction demonstrates a remarkably broad scope on the applicability of 19 different active methylene compounds in 5 different clusters from the standpoint of synthetic tolerability, and tolerates a wide range of functional groups. Moreover, the reaction is also amenable for the cyclopropanation of alkenes in complex molecular architectures, pharmaceuticals and natural products. Mechanistic investigation through the isolation of a series of intermediate products, probes, control experiments, UV-Vis and fluorescence studies indicate that photosensitized dioxygen plays a vital role in the generation of carbon-centered radicals for both the addition of active methylene compounds to alkenes and ring closure, and catalytically generated iodine recycles the PC.

We report a Cu(II)-catalyzed cyclization/coupling of alkenyl aldimines with arylzinc reagents to create indole-3-diarylmethane derivatives (Sapkota et al.

We disclose a nickel-catalyzed reaction, which enabled us to difunctionalize unactivated γ,δ-alkenes in ketones with alkenyl triflates and arylboronic esters. The reaction was made feasible by the use of 5-chloro-8-hydroxyquinoline as a ligand along with NiBr(2)•DME as a catalyst and LiOtBu as base. The reaction proceeded with a wide range of cyclic, acyclic, endocyclic and exocyclic alkenyl ketones, and electron-rich and electron-deficient arylboronate esters. The reaction also worked with both cyclic and acyclic alkenyl triflates. Control experiments indicate that carbonyl coordination is required for the reaction to proceed.

Electrochemical C-H functionalization is a rapidly growing area of interest in organic synthesis. To achieve maximum atom economy, the flow electrolysis process is more sustainable. This allows shorter reaction times, safer working environments, and better selectivities. Using this technology, the problem of overoxidation can be reduced and less emergence of side products or no side products are possible. Flow electro-reactors provide high surface-to-volume ratios and contain electrodes that are closely spaced where the diffusion layers overlap to give the desired product, electrochemical processes can now be managed without the need for a deliberately added supporting electrolyte. Considering the importance of flow electrochemical C-H functionalization, a comprehensive review is presented. Herein, we summarize flow electrolysis for the construction of C-C and C-X (X=O, N, S, and I) bonds formation. Also, benzylic oxidation and access to biologically active molecules are discussed.

OBJECTIVES Our goal was to investigate the efficacy of balanced forced diuresis in reducing the rate of acute kidney injury (AKI) in cardiac surgical patients requiring cardiopulmonary bypass (CPB), using the RenalGuard® (RG) system. METHODS Patients at risk of developing AKI (history of diabetes and/or anaemia; estimated glomerular filtration rate 20–60 ml/min/1.73 m2; anticipated CPB time >120 min; log EuroSCORE > 5) were randomized to the RG system group (n = 110) or managed according to current practice (control = 110). The primary end point was the development of AKI within the first 3 postoperative days as defined by the RIFLE (Risk, Injury, Failure, Loss of kidney function, End-stage renal disease) criteria. RESULTS There were no significant differences in preoperative and intraoperative characteristics between the 2 groups. Postoperative AKI rates were significantly lower in the RG system group compared to the control group [10% (11/110) vs 20.9% (23/110); P = 0.025]. This effect persisted even after controlling for a number of potential confounders (odds ratio 2.82, 95% confidence interval 1.20–6.60; P = 0.017) when assessed by binary logistic regression analysis. The mean volumes of urine produced during surgery and within the first 24 h postoperatively were significantly higher in the RG system group (P, Acute kidney injury (AKI) after cardiac surgery is well documented [1].

We report a Cu(II)-catalyzed cyclization/coupling of alkenyl aldimines with arylzinc reagents to create complex indole-3-diarylmethane derivatives. The aldimines are readily available by simple dehydration, making the process a formal three-component reaction that strategically combines alkenyl aldehydes, anilines and arylzinc reagents to generate substituted indole-3-diarylmethane cores. Since the cyclization/coupling of alkenyl aldimines is unknown to date, the current method discloses an uncharted chemical space with regard to both the substrate and product diversity for this class of reaction.

We describe a novel method to synthesize 2,5-dialkyl-4,6,7-tricyanoindole derivatives from a base-catalyzed reaction of 1,3-diketones with fumaronitrile. The reaction proceeds by the condensation o...

We report a Ni-catalyzed regioselective α-carbonylalkylarylation of vinylarenes with α-halocarbonyl compounds and arylzinc reagents. The reaction works with primary, secondary, and tertiary α-halocarbonyl molecules, and electronically varied arylzinc reagents. The reaction generates γ,γ-diarylcarbonyl derivatives with α-secondary, tertiary, and quaternary carbon centers. The products can be readily converted to aryltetralones, including a precursor to Zoloft, an antidepressant drug.

The objective of this study was to assess the diagnostic value of plasma neutrophil gelatinase‑associated lipocalin (pNGAL) for the early diagnosis of acute kidney injury (AKI) in adult patients following cardiac surgery requiring cardiopulmonary bypass (CPB). Electronic databases and other resources were systematically searched for relevant studies. Risk of bias was assessed using the Quality Assessment for Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Studies were assigned to a sub-group based on the timing of the pNGAL sample in relation to the cessation of CPB. These were

Recently, alkene dicarbofunctionalization, i.e., the powerful organic synthesis method of alkene difunctionalization with two carbon sources, emerged as a formidable reaction with immense promise to synthesize complex molecules expeditiously from simple chemicals. This reaction is generally achieved with transition metals (TMs) through interception by carbon sources of an alkylmetal [β-H–C(sp(3))–[M]] species, a key intermediate prone to undergo rapid β-H elimination. Related prior reports, since Paolo Chiusoli and Catellani’s work in 1982 [Tetrahedron Lett. 1982, 23, 4517], have used bicyclic and disubstituted terminal alkenes, wherein β-H elimination is avoided by geometric restriction or complete lack of β-H’s. With reasoning that β-H–C(sp(3))–[M] intermediates could be rendered amenable to interception with the use of first row late TMs and formation of coordination-assisted transient metallacycles, these two strategies were implemented to address the β-H elimination problem in alkene dicarbofunctionalization reactions. Because first row late TMs catalyze C(sp(3))–C(sp(3)) coupling, Cu and Ni were anticipated to impart sufficient stability to β-H–C(sp(3))–[M] intermediates, generated catalytically upon alkene carbometalation, for their subsequent interception by carbon electrophiles/nucleophiles in three-component reactions. Additionally, such an innate property could enable alkene difunctionalization with carbon coupling partners through entropically driven cyclization/coupling reactions. The cyclometalation concept to stabilize intractable β-H–C(sp(3))–[M] intermediates was hypothesized when three-component reactions were performed. The idea of cyclometalation to curtail β-H elimination is founded upon Whitesides’s [J. Am. Chem. Soc. 1976, 98, 6521] observation that metallacycles undergo β-H elimination much slower than acyclic alkylmetals. In this Account, examples of alkene dicarbofunctionalization reactions demonstrate that Cu and Ni catalysts could enable cyclization/coupling of alkenylzinc reagents, alkyl halides, and aryl halides to afford complex carbo- and heterocycles. In addition, forming coordination-assisted transient nickellacycles enabled regioselective performance of three-component dicarbofunctionalization of various alkenyl compounds. In situ reaction of [M]-H with alkenes generated after β-H elimination induced an unprecedented metallacycle contraction process, in which six-membered metal-containing rings shrank to five-membered cycles, allowing creation of new carbon–carbon bonds at allylic (1,3) positions. Applications of these regioselective alkene dicarbofunctionalization reactions are discussed.

We report a Ni-catalyzed regioselective arylbenzylation of alkenylarenes with benzyl halides and arylzinc reagents. The reaction furnishes differently substituted 1,1,3-triarylpropyl structures that are reminiscent of the cores of oligoresveratrol natural products. The reaction is also compatible for the coupling of internal alkenes, secondary benzyl halides and variously substituted arylzinc reagents. Kinetic studies reveal that the reaction proceeds with a rate-limiting single electron transfer process and is autocatalyzed by in situ-generated ZnX2. The reaction rate is amplified by three-fold through autocatalysis upon addition of ZnX2.

Background Acute kidney injury (AKI), a frequent and serious complication of hospitalized patients, is associated with increased mortality and morbidity. Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker for the early identification of AKI. We report a comparative laboratory verification of the Abbott Diagnostics (ARCHITECT® urine NGAL) and BioPorto Diagnostics (NGAL TestTM) assays including an assessment of the Abbott assay’s performance in EDTA plasma. Methods Intra-/interbatch imprecision, linearity, recovery, and limit of quantitation (LoQ) were assessed and an interassay comparison performed (n = 51). Between-laboratory agreement was assessed against other laboratories using the Abbott (n = 48) and BioPorto (n = 94) assays. Plasma NGAL (pNGAL) levels were measured in non-AKI patients with a range of estimated glomerular filtration rates (n = 80). Results Coefficients of variation (CVs) for intra- and interbatch imprecision were 0.7%–12.4% and 1.9%–27.5% for the BioPorto assay, respectively, and 1.4%–6.3%/3.4%–6.8%, respectively, for the Abbott assay. The BioPorto assay exhibited a higher LoQ (27.5 ng/mL vs 1.2 ng/mL). Both assays were linear over the range 5–6000 ng/mL. Recovery of recombinant NGAL was 113.1 ± 7.1% and 96.5 ± 7.8% for the Abbott and BioPorto assays, respectively. On average, the Abbott assay gave results 9.2% lower than the BioPorto assay. Mean differences of 0.2% (Abbott) and 20.2% (BioPorto) were observed in the between-laboratory comparison. In patients without AKI, pNGAL levels were inversely proportional to eGFR. Conclusions Performance of the Abbott and BioPorto assays was similar although the latter performed less well at lower NGAL concentrations. The Abbott assay tended to yield lower results, exhibited a lower LoQ and over-recovered NGAL. Although only Conformité Européenne-marked and marketed for use in urine, the Abbott assay demonstrated equivalent performance to the BioPorto assay with EDTA plasma.

We disclose a transmetalation-initiated Ni(I)-catalyzed regioselective β,δ-vinylarylation of γ,δ-alkenyl α-cyanocarboxylic esters with vinyl triflates and arylzinc reagents. This reaction proceeds via contraction of six-membered nickellacycles to five-membered nickellacycles to form carbon–carbon bonds at the nonclassical homovicinal sites, and it provides expeditious access to a wide range of complex aliphatic α-cyanoesters, α-cyanocarboxylic acids, dicarboxylic acids, dicarboxylic acid monoamides, monocarboxylic acids, nitriles, and spirolactones. Control, deuterium labeling, and crossover experiments indicate that (i) the nickellacycle contraction occurs by β-H elimination, followed by hydronickellation on transiently formed alkenes, and (ii) the Ni species are stabilized as Ni-enolates.

Forced-diuresis during cardiopulmonary bypass (CPB) can be associated with significant electrolyte shifts. This study reports on the serum electrolyte changes during balanced forced-diuresis with the RenalGuard® system (RG) during CPB.Patients at risk of acute kidney injury (AKI)-(history of diabetes/or anaemia, e-GFR 20-60 ml/min/1.73 mThe use of RG reduced AKI rate (10% for RG and 20.9% in control, p = .03). Mean urine output was significantly higher in the RG group during surgery (2366 ± 877 ml vs. 765 ± 549 ml, p .001). The serum potassium levels were maintained between 3.96 and 4.97 mmol/L for the RG group and 4.02 and 5.23 mmol/L for the controls. Median potassium supplemental dose was 60 (0-220) mmol (RG group) as compared to 30 (0-190) mmol for control group over first 24 h (p .001). On Day 1 post-op, there were no significant differences in the serum sodium, potassium, calcium, magnesium, phosphate, and chloride levels between the two groups. Otherwise, postoperative clinical recovery was also similar.Balanced forced-diuresis with the RG reduced AKI rates after on-pump cardiac surgery compared to controls. Although the RG group required higher doses of IV potassium replacement in the postoperative period, normal serum levels of potassium were maintained by appropriate intravenous potassium supplementation and the clinical outcomes between groups were similar.

We report a nickel-catalyzed one pot synthesis of 9-arylmethylanthracene motifs, which find applications in medicinal and material chemistry. In this synthesis, we apply three component alkene dicarbofunctionalization of 2-vinylaldimines with aryl iodides and arylzinc reagent to generate a 1,1,2-diarylethyl scaffold, which then undergoes an acidpromoted cyclization followed by aromatization to furnish 9-arylmethylanthracene cores. With the new method, a number of differently-substituted 9-arylmethylanthracene derivatives can be synthesized in good yields.

We disclose a transmetalation-initiated Ni(I)-catalyzed regioselective β,δ-vinylarylation of γ,δ-alkenyl α-cyanocarboxylic esters with vinyl triflates and arylzinc reagents. This reaction proceeds ...

We report the synthesis and characterization of novel anionic arylfluoroborate, three-coordinate ligated arylcopper(I) and cationic ligated copper(I) complexes. We show through in situ 19F NMR monitoring that neutral arylboronate ester is more kinetically competent than anionic arylfluoroborate for transmetalation with (PN)CuF (PN = o-(di-tert-butylphosphino)-N,N-dimethylaniline). The transmetalation of the neutral arylboronate ester proceeds via a two-step process involving a cationic copper(I) species wherein an anionic arylfluoroborate is generated in situ as a competent aryl group transferring reagent.

We report a five-step synthesis of the biologically important 1,1-diarylalkane 1, a potential 5-lipoxygenase activating protein (FLAP) inhibitor that was synthesized previously in 12 steps. In this...

We disclose unprecedented synergistic bimetallic Ni/Ag and Ni/Cu catalysts for regioselective γ,δ-diarylation of unactivated alkenes in simple ketimines with aryl halides and arylzinc reagents. The bimetallic synergy, which generates cationic Ni(II) species during reaction, promotes migratory insertion and transmetalation steps and suppresses β-H elimination and cross-coupling, the major side reactions that cause serious problems during alkene difunctionalization. This diarylation reaction proceeds at remote locations to imines to afford, after simple H+ workup, diversely substituted γ,δ-diaryl ketones that are otherwise difficult to access readily with existing methods.

Background Neutrophil gelatinase-associated lipocalin (NGAL) is a recognised biomarker for acute kidney injury (AKI).This study investigated the impact of balanced forced-diuresis using RenalGuard® system (RG), in reducing acute kidney injury (AKI) rates and the associated NGAL levels (6-h post-CPB plasma level) post adult cardiac surgery with cardiopulmonary bypass (CPB). Methods Patients included in the study were at high-risk for AKI post cardiac surgery, namely history of diabetes and/or anaemia, e-GFR 20–60 ml/min/1.73 m2, Logistic EuroScore > 5, anticipated CPB time > 120 min. Patients were randomized to either RG (n = 110) or managed as per current practice (control = 110). RIFLE-defined AKI rate (based on serum creatinine level increase) within first 3 days of surgery and 6-h post CPB NGAL levels were the primary and secondary end-points. Results Pre and intra-operative characteristics between the two groups were similar (p > 0.05) including the pre-op NGAL levels, the oxygen delivery (ecDO2i) and the carbon dioxide production (ecVCO2i) during CPB. Patients in the RG group had a significantly lower post-operative RIFLE-defined AKI rate compared to control (10% (11/110) v/s 20.9% (23/110), p = 0.03). Overall, median 6-h post CPB NGAL levels in patients with AKI were significantly higher than those who did not develop AKI (211 vs 150 ng/ml, p Conclusions Overall, the 6-h post-CPB plasma NGAL levels were significantly higher in patients who developed AKI. Patients managed with the novel approach of balanced forced-diuresis, provided by the RenalGuard® system, had a lower AKI rate and lower NGAL levels indicating a lesser degree of renal tissue injury. Trial registration ClinicalTrials.gov website, NCT02974946, https://clinicaltrials.gov/ct2/show/NCT02974946.

We disclose a Ni-catalyzed vicinal difunctionalization of alkenes with benzyl halides and alkylzinc reagents, which produces products with two new alkyl–alkyl bonds. This alkene dialkylation is effective in combining secondary benzyl halides and secondary alkylzinc reagents with internal alkenes, which furnishes products with three contiguous all-carbon secondary stereocenters. The products can be readily elaborated to access complex tetralene, benzosuberene, and bicyclodecene cores. The reaction also features as the most efficient alkene difunctionalization process to date with catalyst loadings down to 500 ppm and the catalytic turnover number (TON) and turnover frequency (TOF) registering up to 2 × 10(3) and 165 h(−1) at rt, respectively.

We describe a novel method to synthesize 2,5-dialkyl-4,6,7-tricyanoindole derivatives from a base-catalyzed reaction of 1,3-diketones with fumaronitrile. The reaction proceeds by the condensation of two molecules of fumaronitrile and one molecule of 1,3-diketone in a remarkable process that involves the cleavage of one C(sp

We report a Ni-catalyzed regioselective alkylarylation of vinylarenes with alkyl halides and arylzinc reagents to generate 1,1-diarylalkanes. The reaction proceeds well with primary, secondary and tertiary alkyl halides, and electronically diverse arylzinc reagents. Mechanistic investigations by radical probes, competition studies and quantitative kinetics reveal that the current reaction proceeds via a Ni(0)/Ni(I)/Ni(II) catalytic cycle by a rate-limiting direct halogen atom abstraction via single electron transfer to alkyl halides by a Ni(0)-catalyst.

We report a nonpyrolytic chemical synthesis of model iron–nitrogen–carbon electrocatalysts for oxygen reduction reaction (ORR) to elucidate the role of Fe–N centers in the catalysis mechanism. The graphene-supported and unsupported catalysts were analyzed in detail by X-ray spectroscopy techniques. The electrochemical analysis was performed by linear sweep voltammetry and square wave voltammetry in 0.5 M H2SO4 and 0.1 M KOH electrolytes. In this article, with the use of model catalysts, we manifest and confirm the difference in the specific role of Fe–N active sites toward ORR in acidic and alkaline environments.

We disclose a [(PhO)3P]/NiBr2-catalyzed regioselective β,δ-diarylation of unactivated olefins in ketimines with aryl halides and arylzinc reagents. This diarylation proceeds at remote locations to the carbonyl group to afford, after simple H+ workup, diversely substituted β,δ-diarylketones that are otherwise difficult to access readily with existing methods. Deuterium-labeling and crossover experiments indicate that diarylation proceeds by ligand-enabled contraction of transient nickellacycles.

The use of combined Heck carbometalation and cross-coupling remains one of the most powerful ways for the difunctionalization of unactivated olefins with organometallic reagents and organohalides. This synopsis will provide an overview of this reaction developed in the last three and a half decades. Herein, both the three-component and the two-component cyclization/cross-coupling processes will be reviewed with a focus on strategies utilized to overcome the complications of β-hydride elimination from Heck C(sp3)-[M] intermediates, which usually functions as a major side reaction.

We disclose a (terpy)NiBr2-catalyzed reaction protocol that regioselectively difunctionalizes unactivated olefins with tethered alkyl halides and arylzinc reagents. The reaction shows an excellent functional group tolerance (such as ketones, esters, nitriles, and halides) and a moderate to good level of diastereoselectivity. The current cyclization/cross-coupling also tolerates molecules containing base-sensitive racemizable stereocenters, which are preserved without racemization during the reaction. This cyclization/cross-coupling provides a rapid access to (arylmethyl)carbo- and heterocyclic scaffolds, which occur widely as structural cores in various natural products and bioactive molecules. In order to show synthetic utility and generality, we have applied this new method in gram-scale quantities to the concise synthesis of six lignan natural products containing three different structural frameworks. We further conducted mechanistic investigations with radical probes and selectivity studies, which ind...

We report a Ni-catalysed diarylation of unactivated olefins in dimethylpyridylvinylsilane by intercepting Heck C(sp3)–NiX intermediates, derived from aryl halides, with arylzinc reagents. This approach utilizes a modifiable pyridylsilyl moiety as a coordinating group that plays a dual role of intercepting oxidative addition species to promote Heck carbometallation, and stabilizing the Heck C(sp3)–NiX intermediates as transient metallacycles to suppress β-hydride elimination, and facilitate transmetalation/reductive elimination. This method affords 1,2-diarylethylsilanes, which can be readily oxidized to 1,2-diarylethanols that occur as structural motifs in 3-aryl-3,4-dihydroisocoumarin and dihydrostilbenoid natural products.

This work applies digital holography to image stationary micro-particles in color. The approach involves a Michelson interferometer to mix reference light with the weak intensity light backscattered from a distribution of particles. To enable color images, three wavelengths are used, 430, 532, and 633 nm, as primary light sources. Three separate backscattered holograms are recorded simultaneously, one for each wavelength, which are resolved without spectral cross talk using a three-CMOS prism sensor. Fresnel diffraction theory is used to render monochrome images from each hologram. The images are then combined via additive color mixing with red, green, and blue as the primary colors. The result is a color image similar in appearance to that obtained with a conventional microscope in white-light epi-illumination mode. A variety of colored polyethylene micro-spheres and nonspherical dust particles demonstrate the feasibility of the approach and illustrate the effect of simple speckle-noise suppression and white balance methods. Finally, a chromaticity analysis is applied that is capable of differentiating particles of different colors in a quantitative and objective manner.

We present a strategy that difunctionalizes unactivated olefins in 1,2-positions with two carbon-based entities. This method utilizes alkyl/arylzinc reagents derived from olefin-tethered alkyl/aryl halides that undergo radical cyclization to generate C(sp3)-Cu complexes in situ, which are intercepted with aryl and heteroaryl iodides. A variety of (arylmethyl)carbo- and heterocycles (N, O) can be synthesized with this new method.

Ventilator-associated pneumonia (VAP) develops in up to 25% of patients following cardiac surgery. Colonization of the endotracheal tube (ETT) contributes to VAP. The PneuX ETT has been shown to halve VAP in high-risk patients undergoing cardiac surgery. This article reports on the secondary analysis of bacterial colonization in relation to VAP between the PneuX and standard ETTs.In this randomized controlled trial, patients were randomized on a 1:1 basis to Group A (PneuX ET, N=120) or Group B (standard ETT, N=120). Patients aged70 years with or without impaired left ventricular function (50%) undergoing elective and urgent cardiac surgery were included in this study. Incidence of postoperative VAP and analysis of bacterial colonization within the ETT (N=234) were measured for patients requiring24 h, 24-48 h and48 h of intubation.Baseline patient demographics were comparable. VAP was lower in Group A compared with Group B (10.8% vs 21%; P=0.03). The incidence of VAP was lower at each time point for Group A. There was a lower incidence of ETT colonization in Group A for patients needing48 h of intubation. There was no difference in the type of bacterial colonization (P=0.5) or the mean number of colony-forming units [4.35x10Colonization of the ETT does not seem to play an important role in early-onset VAP. There is a tendency for reduced colonization in the PneuX ETT with longer intubation times. This may have an impact on reducing the incidence of late-onset VAP.

The similarity between the light-scattering pattern of a particle in the near-forward direction and diffraction from the particle’s silhouette is investigated. Images of irregularly shaped free-flowing aerosol particles are obtained from digital hologram measurements, which are then binarized to yield a silhouette. Application of Huygens’s principle to the silhouette generates an approximate scattering pattern, which when compared to the true measured pattern shows good agreement for particles much larger than the wavelength of light.

Black objects are sometimes associated with black carbon, while shiny, highly reflecting surfaces are typically associated with metals. Here, we discuss several objects in everyday life that upon use take on a black color that is unlikely to be due to black carbon. We propose that this black color is caused by the formation of metallic nanoparticles from abrasion processes. We support this hypothesis using Mie theory and the fact that spherical metal particles are only shiny or bright if the imaginary part of their refractive index and its product with the particle size-parameter are both larger than three. While this is commonly true for bulk metals, the second condition is generally not fulfilled for metallic nanoparticles, and hence, such particles become highly absorbing, i.e., black. For the black grime accumulated on bicycle drivetrains and climbing ropes, we detected metal nanoparticles with electron microscopy, which likely originated from mechanical abrasion processes during use.

We report an efficient copper(I) iodide catalyzed cross-coupling­ of diarylzinc reagents with aryl iodides. The reaction proceeds under ligand-free conditions at low catalyst loading (5 mol%) and tolerates a variety of functional groups.

We report a Ni-catalyzed regioselective alkylarylation of vinylarenes with alkyl halides and arylzinc reagents to generate 1,1-diarylalkanes. The reaction proceeds well with primary, secondary and tertiary alkyl halides, and electronically diverse arylzinc reagents. Mechanistic investigations by radical probes, competition studies and quantitative kinetics reveal that the current reaction proceeds via a Ni(0)/Ni(I)/Ni(II) catalytic cycle by a rate-limiting direct halogen atom abstraction via single electron transfer to alkyl halides by a Ni(0)-catalyst.

Background Ventilator-associated pneumonia (VAP) is common and costly. In a recent randomized controlled trial, the Venner-PneuX (VPX) endotracheal tube system (Qualitech Healthcare Limited, Maidenhead, United Kingdom) was found to be superior to standard endotracheal tubes (SET) in preventing VAP. However, VPX is considerably more expensive. We evaluated the costs and benefits of VPX to determine whether replacing SET with VPX is a cost-effective option for intensive care units. Methods We developed a decision analytic model to compare intubation with VPX or SET for patients requiring mechanical ventilation after cardiac operations. The model was populated with existing evidence on costs, effectiveness, and quality of life. Cost-effectiveness and cost-utility analyses were conducted from a National Health Service hospital perspective. Uncertainty was assessed through deterministic and probabilistic sensitivity analyses. Results Compared with SET, VPX is associated with an expected cost saving of £738 per patient. VPX led to a small increase in quality-adjusted life years, indicating that the device is overall less costly and more effective than SET. The probability of VPX being cost-effective at £30,000 per quality-adjusted life year is 97%. VPX would cease to be cost-effective if (1) it led to a risk reduction smaller than 0.02 compared with SET, (2) the acquisition cost of VPX was as high as £890, or (3) the cost of treating a case of VAP was lower than £1,450. Conclusions VPX resulted in improved outcomes and savings that far offset the cost of the device, suggesting that replacing SET with VPX is overall beneficial. Findings were robust to extreme values of key variables.