200 research outputs found
The Hidden Strengths in Family Business: Functional Conflict
Conflict is likely in family businesses. Although some types of conflict are negative and should be minimized, other types are helpful and should be understood and encouraged to improve decisions. Using Jehn's (1997) framework, three types of conflict are identified and related to family business issues. A framework for conflict resolution is presented. Finally, recommendations for introducing and managing positive conflict in family businesses are offered.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
2-Amino-N-[3-(2-chloroÂbenzoÂyl)-5-ethylÂthioÂphen-2-yl]acetamide
In the title compound, C15H15ClN2O2S, the 2-aminoÂacetamide NâC(=O)âCâN unit is approximately planar, with an r.m.s. deviation of 0.020â
(4)â
Ă
. The central thioÂphene ring makes dihedral angles of 7.84â
(11) and 88.11â
(11)°, respectively, with the 2-aminoÂacetamide unit and the 2-chloroÂphenyl ring. An intraÂmolecular NâHâŻO hydrogen bond generates an S(6) ring motif. In the crystal, molÂecules are linked by an NâHâŻO hydrogen bond and weak CâHâŻO interÂactions into a chain along the c axis. A CâHâŻĎ interÂaction is also present
Rh-POP Pincer Xantphos Complexes for C-S and C-H Activation. Implications for Carbothiolation Catalysis
The neutral RhÂ(I)âXantphos
complex [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)ÂCl]<sub><i>n</i></sub>, <b>4</b>, and cationic RhÂ(III) [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(H)<sub>2</sub>]Â[BAr<sup>F</sup><sub>4</sub>], <b>2a</b>, and [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos-3,5-C<sub>6</sub>H<sub>3</sub>(CF<sub>3</sub>)<sub>2</sub>)Â(H)<sub>2</sub>]Â[BAr<sup>F</sup><sub>4</sub>], <b>2b</b>, are described [Ar<sup>F</sup> = 3,5-(CF<sub>3</sub>)<sub>2</sub>C<sub>6</sub>H<sub>3</sub>; Xantphos
= 4,5-bisÂ(diphenylphosphino)-9,9-dimethylxanthene; Xantphos-3,5-C<sub>6</sub>H<sub>3</sub>(CF<sub>3</sub>)<sub>2</sub> = 9,9-dimethylxanthene-4,5-bisÂ(bisÂ(3,5-bisÂ(trifluoromethyl)Âphenyl)Âphosphine].
A solid-state structure of <b>2b</b> isolated from C<sub>6</sub>H<sub>5</sub>Cl solution shows a Îş<sup>1</sup>-chlorobenzene
adduct, [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos-3,5-C<sub>6</sub>H<sub>3</sub>(CF<sub>3</sub>)<sub>2</sub>)Â(H)<sub>2</sub>(Îş<sup>1</sup>-ClC<sub>6</sub>H<sub>5</sub>)]Â[BAr<sup>F</sup><sub>4</sub>], <b>3</b>. Addition of H<sub>2</sub> to <b>4</b> affords,
crystallographically characterized, [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(H)<sub>2</sub>Cl], <b>5</b>. Addition of diphenyl
acetylene to <b>2a</b> results in the formation of the CâH
activated metallacyclopentadiene [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(ClCH<sub>2</sub>Cl)Â(Ď,Ď-(C<sub>6</sub>H<sub>4</sub>)ÂCÂ(H)îťCPh)]Â[BAr<sup>F</sup><sub>4</sub>], <b>7</b>, a rare example of a crystallographically characterized Rhâdichloromethane
complex, alongside the RhÂ(I) complex <i>mer</i>-[RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(Ρ<sup>2</sup>-PhCCPh)]Â[BAr<sup>F</sup><sub>4</sub>], <b>6</b>. Halide abstraction from [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)ÂCl]<sub><i>n</i></sub> in the presence of diphenylacetylene affords <b>6</b> as the
only product, which in the solid state shows that the alkyne binds
perpendicular to the Îş<sup>3</sup>-POP Xantphos ligand plane.
This complex acts as a latent source of the [RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)]<sup>+</sup> fragment and facilitates
<i>ortho</i>-directed CâS activation in a number
of 2-arylsulfides to give <i>mer</i>-[RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(Ď,Îş<sup>1</sup>-Ar)Â(SMe)]Â[BAr<sup>F</sup><sub>4</sub>] (Ar = C<sub>6</sub>H<sub>4</sub>COMe, <b>8</b>; C<sub>6</sub>H<sub>4</sub>(CO)ÂOMe, <b>9</b>; C<sub>6</sub>H<sub>4</sub>NO<sub>2</sub>, <b>10</b>; C<sub>6</sub>H<sub>4</sub>CNCH<sub>2</sub>CH<sub>2</sub>O, <b>11</b>; C<sub>6</sub>H<sub>4</sub>C<sub>5</sub>H<sub>4</sub>N, <b>12</b>).
Similar CâS bond cleavage is observed with allyl sulfide,
to give <i>fac</i>-[RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(Ρ<sup>3</sup>-C<sub>3</sub>H<sub>5</sub>)Â(SPh)]Â[BAr<sup>F</sup><sub>4</sub>], <b>13</b>. These products of CâS
activation have been crystallographically characterized. For <b>8</b> in situ monitoring of the reaction by NMR spectroscopy reveals
the initial formation of <i>fac</i>-Îş<sup>3</sup>-<b>8</b>, which then proceeds to isomerize to the <i>mer</i>-isomer. With the <i>para</i>-ketone aryl sulfide, 4-SMeC <sub>6</sub>H<sub>4</sub>COMe, CâH activation <i>ortho</i> to the ketone occurs to give <i>mer</i>-[RhÂ(Îş<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Â(Ď,Îş<sup>1</sup>-4-(COMe)ÂC<sub>6</sub>H<sub>3</sub>SMe)Â(H)]Â[BAr<sup>F</sup><sub>4</sub>], <b>14</b>. The temporal evolution of carbothiolation catalysis using <i>mer</i>-Îş<sup>3</sup>-<b>8</b>, and phenyl acetylene
and 2-(methylthio)Âacetophenone substrates shows initial fast catalysis
and then a considerably slower evolution of the product. We suggest
that the initially formed <i>fac</i>-isomer of the CâS
activation product is considerably more active than the <i>mer</i>-isomer (i.e., <i>mer</i>-<b>8</b>), the latter of
which is formed rapidly by isomerization, and this accounts for the
observed difference in rates. A likely mechanism is proposed based
upon these data
Hypoxia Sensitive Metal β-Ketoiminate Complexes Showing Induced Single Strand DNA Breaks and Cancer Cell Death by Apoptosis
A series of ruthenium and iridium complexes have been synthesised and characterised with 20 novel crystal structures discussed. The library of β-ketoiminate complexes has been shown to be active against MCF-7 (human breast carcino-ma), HT-29 (human colon carcinoma), A2780 (human ovarian carcinoma) and A2780cis (cisplatin resistant human ovarian carcinoma) cell lines, with selected complexes being more than three times as active as cisplatin against the A2780cis cell line. Complexes have also been shown to be highly active under hypoxic conditions, with the activities of some complexes increasing with a decrease in O2 concentration. The enzyme thioredoxin reductase is over-expressed in cancer cells and complexes reported herein have the advantage of inhibiting this enzyme, with IC50 values measured in the nanomolar range. The anti-cancer activity of these complexes was further investigated to determine whether activity is due to effects on cellular growth or cell survival. The complexes were found to induce significant cancer cell death by apoptosis with levels induced correlating closely with activity in chemosensitivity studies. As a possible cause of cell death, the ability of the complexes to induce damage to cellular DNA was also assessed. The complexes failed to induce double strand DNA break or DNA crosslinking but induced significant levels of single DNA strand breaks indi-cating a different mechanism of action to cisplatin
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2â4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genesâincluding reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)âin critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Fatigue in primary SjĂśgren's syndrome (pSS) is associated with lower levels of proinflammatory cytokines: a validation study
Primary SjĂśgrenâs syndrome (pSS) is a chronic autoimmune rheumatic disease with symptoms including dryness, fatigue, and pain. The previous work by our group has suggested that certain proinflammatory cytokines are inversely related to patient-reported levels of fatigue. To date, these findings have not been validated. This study aims to validate this observation. Blood levels of seven cytokines were measured in 120 patients with pSS from the United Kingdom Primary SjĂśgrenâs Syndrome Registry and 30 age-matched healthy non-fatigued controls. Patient-reported scores for fatigue were classified according to severity and compared to cytokine levels using analysis of variance. The differences between cytokines in cases and controls were evaluated using Wilcoxon test. A logistic regression model was used to determine the most important identifiers of fatigue. Five cytokines, interferon-Îł-induced protein-10 (IP-10), tumour necrosis factor-Îą (TNFÎą), interferon-Îą (IFNÎą), interferon-Îł (IFN-Îł), and lymphotoxin-Îą (LT-Îą) were significantly higher in patients with pSS (nâ=â120) compared to non-fatigued controls (nâ=â30). Levels of two proinflammatory cytokines, TNF-Îą (pâ=â0.021) and LT-Îą (pâ=â0.043), were inversely related to patient-reported levels of fatigue. Cytokine levels, disease-specific and clinical parameters as well as pain, anxiety, and depression were used as predictors in our validation model. The model correctly identifies fatigue levels with 85% accuracy. Consistent with the original study, pain, depression, and proinflammatory cytokines appear to be the most powerful predictors of fatigue in pSS. TNF-Îą and LT-Îą have an inverse relationship with fatigue severity in pSS challenging the notion that proinflammatory cytokines directly mediate fatigue in chronic immunological conditions
Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy
Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2¡5% in each group for fatal or disabling stroke, and 5¡3% with CAS versus 4¡5% with CEA for any stroke (rate ratio [RR] 1¡16, 95% CI 0¡86â1¡57; p=0¡33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1¡11, 95% CI 0¡91â1¡32; p=0¡21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable. Funding: UK Medical Research Council and Health Technology Assessment Programme
Genetic mechanisms of critical illness in COVID-19.
Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, PÂ =Â 1.65Â ĂÂ 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, PÂ =Â 2.3Â ĂÂ 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, PÂ =Â 3.98Â ĂÂ Â 10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, PÂ =Â 4.99Â ĂÂ 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice
Common, low-frequency, rare, and ultra-rare coding variants contribute to COVID-19 severity
The combined impact of common and rare exonic variants in COVID-19 host genetics is currently insufficiently understood. Here, common and rare variants from whole-exome sequencing data of about 4000 SARS-CoV-2-positive individuals were used to define an interpretable machine-learning model for predicting COVID-19 severity. First, variants were converted into separate sets of Boolean features, depending on the absence or the presence of variants in each gene. An ensemble of LASSO logistic regression models was used to identify the most informative Boolean features with respect to the genetic bases of severity. The Boolean features selected by these logistic models were combined into an Integrated PolyGenic Score that offers a synthetic and interpretable index for describing the contribution of host genetics in COVID-19 severity, as demonstrated through testing in several independent cohorts. Selected features belong to ultra-rare, rare, low-frequency, and common variants, including those in linkage disequilibrium with known GWAS loci. Noteworthily, around one quarter of the selected genes are sex-specific. Pathway analysis of the selected genes associated with COVID-19 severity reflected the multi-organ nature of the disease. The proposed model might provide useful information for developing diagnostics and therapeutics, while also being able to guide bedside disease management. Š 2021, The Author(s)
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