The synthetic application of nickel catalysts in Heck‐coupling reactions is quite prominent and noticeable of late in organic synthesis. It shows great interest over the other transition metal ...catalysts due to its unique characteristic that prepares them more significantly applicable in different fields of synthetic application. The usefulness of nickel‐catalysts relies in the fact that they are abundant in nature, relatively less precious and environment friendly. Nickel plays pivotal role in different kind of Heck reactions known such as intramolecular‐, intermolecular‐, reductive‐Heck type reaction producing mainly carbocycles and hetero cycles of biological significance. Carbocyclization or hetero‐cyclization reaction occurred under optimized reaction conditions developed and come up with the formation of various structural building blocks of naturally occurring compounds. Via reductive Heck cyclization large membered ring of carbo‐ or hetero‐cyclic system was formed which performed key role as building blocks in pharmaceutical synthesis and bioactive molecule formation. Intermolecular Heck type reactions were comparatively more explored. Silyl‐Heck, carbonyl‐Heck, and other miscellaneous type reactions were covered up through nickel‐catalyzed intermolecular Heck reaction. Asymmetric versions of Heck‐ coupling reactions are also reported to proceed even with unactivated alkenes, offering molecules having quaternary stereogenic center in a regio‐ and enantioselective manner. This manuscript intends to cover these entire concepts.
Aims
To establish whether irrigant activation techniques (IATs) result in greater intracanal smear layer and debris removal than conventional needle irrigation (CNI).
Methodology
Six electronic ...databases were searched to identify scanning electron microscopy studies evaluating smear layer and/or debris removal following the use of manual dynamic activation (MDA), passive ultrasonic irrigation (PUI), sonic irrigation (SI) or apical negative pressure (ANP) IATs in mature permanent teeth. Meta‐analyses were performed for each canal segment (coronal, middle, apical and apical 1 mm) in addition to subgroup analyses for individual IATs with respect to CNI. Outcomes were presented as standardized mean differences (SMD) alongside 95% confidence intervals (95% CI) and chi‐squared analysis.
Results
From 252 citations, 16 studies were identified. The meta‐analyses demonstrated significant improvements in coronal (SMD: 1.15, 95% CI: 0.72–1.57 / SMD: 0.54, 95% CI: 0.29–0.80), middle (SMD: 1.30, 95% CI: 0.59–2.53 / SMD: 0.8, 95% CI: 0.58–1.13) and apical thirds (SMD: 1.22, 95% CI: 0.83–1.62 / SMD: 1.86, 95% CI: 0.76–2.96) for smear layer and debris removal, respectively. In the apical 1 mm IATs improved cleanliness; however, differences were insignificant (SMD: 1.15, 95% CI: ‐0.47–2.77). Chi‐squared analysis revealed heterogeneity scores of 79.3–92.8% and 0.0–93.5% for smear layer and debris removal, respectively.
Conclusions
IATs improve intracanal cleanliness across a substantial portion of the canal, and therefore, their use is recommended throughout root canal preparation. However, current data is too heterogeneous to compare and identify superiority of an individual technique highlighting the need to standardize experimental protocols and develop a more representative research model to investigate the in vivo impact of IATs on clinical outcomes and periapical healing following root canal treatment.
This review summarizes recent developments (from 2006 to 2022) in numerous important and efficient carbo‐ and heterocycle generations using gold‐catalyzed cascade protocols. Herein, methodologies ...involve selectivity, cost‐effectiveness, and ease of product formation being controlled by the ligand as well as the counter anion, catalyst, substrate, and reaction conditions. Gold‐catalyzed cascade reactions covered different strategies through the compilation of various approaches such as cyclization, hydroarylation, intermolecular and intramolecular cascade reactions, etc. This entitled reaction is also useful for the synthesis of spiro, fused, bridged carbo‐ and heterocycles.
Gold‐catalyzed cascade reaction approach provides one‐pot synthetic access to a large spectrum of organic molecules and natural products with biological and therapeutic properties. The ligand, catalyst, substrate, and reaction conditions were used to regulate the formation of numerous carbo‐ and heterocycles of various sizes with good yields and selectivity, demonstrating the elegance, impact, and practicality of this cascade protocol.
Site-directed RNA editing is an important technique for correcting gene sequences and ultimately tuning protein function. In this study, we engineered the deaminase domain of adenosine deaminase ...acting on RNA (ADAR1) and the MS2 system to target-specific adenosines, with the goal of correcting G-to-A mutations at the RNA level. For this purpose, the ADAR1 deaminase domain was fused downstream of the RNA-binding protein MS2, which has affinity for the MS2 RNA. To direct editing to specific targets, we designed guide RNAs complementary to target RNAs. The guide RNAs directed the ADAR1 deaminase to the desired editing site, where it converted adenosine to inosine. To provide proof of principle, we used an allele of enhanced green fluorescent protein (EGFP) bearing a mutation at the 58th amino acid (TGG), encoding Trp, into an amber (TAG) or ochre (TAA) stop codon. In HEK-293 cells, our system could convert stop codons to read-through codons, thereby turning on fluorescence. We confirmed the specificity of editing at the DNA level by restriction fragment length polymorphism analysis and sequencing, and at the protein level by western blotting. The editing efficiency of this enzyme system was ~5%. We believe that this system could be used to treat genetic diseases resulting from G-to-A point mutations.
The usage of PV technology based electricity generation is much more popular nowadays and is being adopted by many countries as an alternative option for fossil fuel power generations. The present ...paper focuses on normalized performance indices and techno-economic based feasibility analysis of PV plant in an Indian isolated island, Andaman and Nicobar island where grid supply is not feasible. The estimated normalized indices range obtained for the aforementioned island are 3.0–5.10h/d for array yield, 2.70–4.59h/d for final yield, 1.10–1.95h/d for array capture losses, 0.3–0.51 for system losses and 68.55–80.22% for performance ratio. The island annual global solar radiation is found to be 5.29kWh/m2/day with clearness index lies within 0.42–0.68. The techno-economic analysis is performed by using HOMER simulation software to obtained optimal size by assuming typical seasonal load profile for a single household. The obtained optimal PV configuration contains 2.5kW PV array, 12 numbers of battery and converter size of 2.0kW with cost of energy is found to be $0.398, net present cost of $9637, 224$/year operating cost, 9.3years as battery life, initial capital cost of $6773 and renewable fraction of 1.
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A nail patch is an attractive option for the topical treatment of onychomycosis, although no product is commercially available. We previously identified optimal nail patch ...formulations for two anti-onychomycotic drugs, based on their properties, as well as those of the other patch components. In this paper, our aim was to further investigate the potential of the patch formulations as topical nail medicines, in particular, whether the drug-in-adhesive patches release drug which then permeates into and through the nail plate and show anti-fungal efficacy, and whether and to what extent they remain adhered to the human nail plate in vivo when tested over 2 week durations. In addition, the influence of the drug (amorolfine HCl, ciclopirox olamine) and PSA (Duro-Tak 2852 or Duro-Tak 202A) on these parameters was determined. We found that both the nature of the drug and of the PSA influenced in vitro drug release. The nature of the drug, but not that of the PSA, influenced ungual drug permeation through human nail clippings, with considerably greater (almost double) permeation for ciclopirox olamine, the smaller and less lipophilic molecule. In vivo residence, tested with 3 out of the 4 patches, excluding the patch where ciclopirox olamine degraded with time, showed greater residence on toenails compared to fingernails reflecting their far lesser exposure to environmental stresses during daily activities. In vivo residence was enhanced when the patch was cut to the shape of the nail, was applied at bedtime, and when a clear colourless nail varnish was applied on top of the patch to ‘seal’ it into place on the nail. Comparison of the patches indicated greater residence of Duro-Tak 202A containing patches over those containing Duro-Tak 2852. Amorolfine HCl in Duro-Tak 202A based patch also showed antifungal efficacy in contrast to Duro-Tak 2852-based patch, and is particularly promising for further development as a potential toenail medicine, remaining almost fully adhered to toenails for at least two weeks.
Transcription activator-like effectors (TALEs) have revolutionized the field of genome engineering. We present here a systematic assessment of TALE DNA recognition, using quantitative electrophoretic ...mobility shift assays and reporter gene activation assays. Within TALE proteins, tandem 34-amino acid repeats recognize one base pair each and direct sequence-specific DNA binding through repeat variable di-residues (RVDs). We found that RVD choice can affect affinity by four orders of magnitude, with the relative RVD contribution in the order NG > HD ≈ NN >> NI > NK. The NN repeat preferred the base G over A, whereas the NK repeat bound G with 10(3)-fold lower affinity. We compared AvrBs3, a naturally occurring TALE that recognizes its target using some atypical RVD-base combinations, with a designed TALE that precisely matches 'standard' RVDs with the target bases. This comparison revealed unexpected differences in sensitivity to substitutions of the invariant 5'-T. Another surprising observation was that base mismatches at the 5' end of the target site had more disruptive effects on affinity than those at the 3' end, particularly in designed TALEs. These results provide evidence that TALE-DNA recognition exhibits a hitherto un-described polarity effect, in which the N-terminal repeats contribute more to affinity than C-terminal ones.
High density genetic maps are a reliable tool for genetic dissection of complex plant traits. Mapping resolution is often hampered by the variable crossover and non-crossover events occurring across ...the genome, with pericentromeric regions (pCENR) showing highly suppressed recombination rates. The efficiency of linkage mapping can further be improved by characterizing and understanding the distribution of recombinational activity along individual chromosomes. In order to evaluate the genome wide recombination rate in common beans (Phaseolus vulgaris L.) we developed a SNP-based linkage map using the genotype-by-sequencing approach with a 188 recombinant inbred line family generated from an inter gene pool cross (Andean x Mesoamerican). We identified 1,112 SNPs that were subsequently used to construct a robust linkage map with 11 groups, comprising 513 recombinationally unique marker loci spanning 943 cM (LOD 3.0). Comparative analysis showed that the linkage map spanned >95% of the physical map, indicating that the map is almost saturated. Evaluation of genome-wide recombination rate indicated that at least 45% of the genome is highly recombinationally suppressed, and allowed us to estimate locations of pCENRs. We observed an average recombination rate of 0.25 cM/Mb in pCENRs as compared to the rest of genome that showed 3.72 cM/Mb. However, several hot spots of recombination were also detected with recombination rates reaching as high as 34 cM/Mb. Hotspots were mostly found towards the end of chromosomes, which also happened to be gene-rich regions. Analyzing relationships between linkage and physical map indicated a punctuated distribution of recombinational hot spots across the genome.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper uses adaptive backstepping sliding mode control to synchronize two satellite attitude dynamics with perturbing torques. The external perturbing torques induce chaotic motion with no ...control inputs. The proposed control system uses Lyapunov theory and Barbalat's Lemma to guarantee the asymptotic stability of the controlled system. Simulation results confirm the effectiveness of the proposed design.
Barbalat's lemma; Backstepping sliding mode control; Chaotic system; Lyapunov stability; Satellite attitude control; Synchronization.
Background
The purpose of this study was to review our experience with laparoscopic colectomy and fistula resection, evaluate the frequency of conversion to open, and to compare the perioperative ...courses of the complete laparoscopic and conversion groups.
Methods
This study is a retrospective analysis of 111 consecutive adult patients with diverticular fistulae diagnosed clinically or radiographically over 11 years at a single institution. Five patients were excluded for preoperative comorbidities. The remaining 106 consecutive patients underwent minimally invasive sigmoid colectomy with primary anastomosis. Preoperative, intraoperative, and postoperative variables were collected from the colorectal surgery service database. A retrospective cohort analysis was performed between laparoscopic and converted groups.
Results
Within the group, 47% had colovesical fistulas, followed by colovaginal, coloenteric, colocutaneous, and colocolonic fistulas. The overall conversion rate to laparotomy was 34.7% (
n
= 37). The most common reason for conversion was dense fibrosis. Mean operative time was similar between groups. Combined postoperative complications occurred in 26.4% of patients (21.4% laparoscopic and 37.8% converted,
p
= 0.075). Length of stay was significantly shorter in the laparoscopic group (5.8 vs 8.1 days,
p
= 0.014). There were two anastomotic leaks, both in the open group. There were no 30-day mortalities.
Conclusions
Laparoscopic sigmoid colectomy for diverticular fistula is safe, with complication rates comparable to open sigmoid resection. We identify a conversion rate which allows the majority of patients to benefit from minimally invasive procedures.
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