Steering the Surprisingly Modular π-Acceptor Properties of N-Heterocyclic Carbenes: Implications for Gold Catalysis

Thumbnail image of graphical abstract Accept it! Although the π-acceptor properties of N-heterocyclic carbenes (NHCs) are often considered negligible, they can be enhanced to the extent that they start to dominate the catalytic behavior of gold–NHC complexes (see scheme). As it seems to be easier to tune the π acidity of NHCs than to alter their σ-donor properties, the general perception of this important class of ancillary ligands needs to be revised

Acute Kidney Injury in Severe Trauma Patients; a Record-Based Retrospective Study

Introduction: Acute kidney injury (AKI) is a common and devastating clinical issue in the community associated with high rates of morbidity and mortality. Objective: We aimed at estimating the frequency and levels of severity of AKI in trauma patients requiring hospital admission using the RIFLE criteria and assess their outcome. Method: Our retrospective record based study enrolled data of 80 participants aged 18-59 years who presented to the emergency department of KIMS hospital following an acute traumatic event. Participants with pre-existing renal dysfunction, chronic heart failure and chronic liver disease were excluded. Tests of significance were Chi square and independent sample t test, a p<0.05 was considered statistically significant. Results: Participants with AKI had significantly lower age (p=0.02) and lower revised trauma score (RTS) (p=0.01). Significant association of AKI with hypotension (p=0.01) and Glasgow coma scale (GCS) (p=0.008) was observed. No association of AKI with gender was observed (p=0.6). None of the AKI patients required renal replacement therapy and all participants attained normal renal function at discharge. Significantly longer mean duration of hospital stay (14.4 days) was observed among AKI patients (p=0.02). Totally, 6.3 % mortality was observed among both participants with and without AKI. Conclusion: Forty percent of acute trauma patients had AKI (in risk and injury category); but none were in failure, loss or end stage renal disease. No association of AKI and mortality was observed. AKI was associated with age, RTS, hypotension and GCS

Mitral Leaflet Separation Index in Assessing the Severity of Mitral Stenosis

Determining the severity of mitral stenosis (MS) is important for both prognostic and therapeutic reasons. The mitral valve area (MVA) can be measured by planimetry, pressure half-time, continuity equation, and proximal isovelocity surface area methods. In this study, we propose a novel yet simple, independent measure of MS severity–the mitral leaflet separation (MLS) index. This new index could be a useful surrogate measure of the MVA. This index would also help when there is a discrepancy between severities of MS estimated by existing methods, in the presence of atrial fibrillation and in the presence of mitral regurgitation

Functional outcome following conservative management of acetabular fractures

Background: Acetabular fractures are complex injuries caused due to high velocity injury and constitutes about 18 % of Pelvic fractures. To obtain articular congruency and anatomical reduction is the gold standard in treating these fractures. In this study we have studied about the functional outcome in acetabular fractures managed conservatively with the long-term follow.Methods: A retrospective study with prospective analysis done between 2011-2020 involved 39 patients with acetabular fractures who were treated conservatively at St John’s Medical college Hospital. Patients were followed up at 6 months, 1 year, 2 years and at the end of 5 years for functional evaluation and assessment with the clinical outcome scores with Merle d’Aubigne and Postel score & Harris Hip Score.Results: Study included 39 patients with the average age of 41.3 years with 31 male and 8 female patients. Functional outcome score showed good to excellent results in 80%, fair to satisfactory results in 18%, 0.5 to 2% had poor result in the patient analyzed with both Merle d’Aubigne and Postel score and Harris Hip Score. 80 % of the patients were able to sit cross legged, 90% had returned to regular work and 10% of the patients changed their occupation to desk jobs.Conclusions: Conservative management of acetabular fractures gives a good long-term result following congruent reduction of the fracture, good early rehabilitation and gradual weight bearing. Return to activity of daily living was good even in congruently reduced acetabular dome fractures with good to excellent functional outcome scores

Potential of Egg shell powder as replacement of Lime in soil stabilization

This paper presents a study on the properties of soil stabilized by using lime and egg shell powder. Tests were conducted to assess the potential of egg shell powder in replacing lime, which can make the overall stabilization process economical and eco-friendly. Results obtained show that all the treated mixes gave much better strength than untreated soil. Egg shell powder was introduced in quantities of 0.5%, 1%, 1.5% and 2% of the weight of soil. Tests were conducted replacing up to 50% of the lime used for stabilization. It was observed that 25% replacement of lime by egg shell powder gave better strength properties and can be adopted for practical purposes

Spatial and Functional Relationships Among Pol V-Associated Loci, Pol IV-Dependent siRNAs, and Cytosine Methylation in the \u3cem\u3eArabidopsis\u3c/em\u3e Epigenome

Multisubunit RNA polymerases IV and V (Pols IV and V) mediate RNA-directed DNA methylation and transcriptional silencing of retrotransposons and heterochromatic repeats in plants. We identified genomic sites of Pol V occupancy in parallel with siRNA deep sequencing and methylcytosine mapping, comparing wild-type plants with mutants defective for Pol IV, Pol V, or both Pols IV and V. Approximately 60% of Pol V-associated regions encompass regions of 24-nucleotide (nt) siRNA complementarity and cytosine methylation, consistent with cytosine methylation being guided by base-pairing of Pol IV-dependent siRNAs with Pol V transcripts. However, 27% of Pol V peaks do not overlap sites of 24-nt siRNA biogenesis or cytosine methylation, indicating that Pol V alone does not specify sites of cytosine methylation. Surprisingly, the number of methylated CHH motifs, a hallmark of RNA-directed de novo methylation, is similar in wild-type plants and Pol IV or Pol V mutants. In the mutants, methylation is lost at 50%–60% of the CHH sites that are methylated in the wild type but is gained at new CHH positions, primarily in pericentromeric regions. These results indicate that Pol IV and Pol V are not required for cytosine methyltransferase activity but shape the epigenome by guiding CHH methylation to specific genomic sites

COMBINATORIAL EFFECT OF D-AMINOACIDS AND TETRACYCLINE AGAINST PSEUDOMONAS AERUGINOSA BIOFILM

Objective: The present study attempted to evaluate the anti-biofilm activity of D-amino acids (D-AAs) on Pseudomonas aeruginosa and determine if the combination of D-AAs with tetracycline enhances the anti-biofilm activity in vitro and ex vivo.Methods: Different D-AAs were tested for antibiofilm activity against wild type P. aeruginosa PAO1 and two multidrug resistant P. aeruginosa clinical strains in the presence of sub inhibitory concentrations of tetracycline using crystal violet microtitre plate assay. Results were further validated using in vitro wound dressing and ex vivo porcine skin models followed by cytotoxicity and hemocompatibility studies.Results: D-tryptophan (5 mmol) showed 61 % reduction in biofilm formation of P. aeruginosa. Interestingly combinatorial effect of 5 mmol D-tryptophan and 0.5 minimum inhibitory concentration (MIC) (7.5µg/ml) tetracycline showed 90% reduction in biofilm formation. 5 mmol D-methionine shows 28 % reduction and combination with tetracycline shows 41% reduction in biofilm formation of P. aeruginosa. D-leucine and D-tyrosine alone or in combination with tetracycline did not show significant anti-biofilm activity. D tryptophan-tetracycline combination could reduce 80 % and 77 % reduction in biofilm formation in two multi drug resistant P. aeruginosa clinical strains. D-tryptophan-tetracycline-combination could also reduce 76% and 66% reduction in biofilm formation in wound dressing model and porcine skin explant respectively. The cytotoxicity and hemocompatibility studies did not show significant toxicity when this combination was used.Conclusion: The results established the potential therapeutic application of D-tryptophan alone or in combination with tetracycline for treating biofilm associated clinical problems caused by P. aeruginosa

The Seroepidemiology of Haemophilus influenzae Type B Prior to Introduction of an Immunization Programme in Kathmandu, Nepal.

Haemophilus influenzae type b (Hib) is now recognized as an important pathogen in Asia. To evaluate disease susceptibility, and as a marker of Hib transmission before routine immunization was introduced in Kathmandu, 71 participants aged 7 months-77 years were recruited and 15 cord blood samples were collected for analysis of anti-polyribosylribitol phosphate antibody levels by enzyme-linked immunosorbent assay. Only 20% of children under 5 years old had levels considered protective (>0.15 µg/ml), rising to 83% of 15-54 year-olds. Prior to introduction of Hib vaccine in Kathmandu, the majority of young children were susceptible to disease