Silicomolybdic Acid Cluster as Biocompatible Catalyst for One-Pot Tandem Synthesis of Orthogonally Protected Glycosides.

The present paper describes a new and practical approach for the one-pot preparation of O-isopropylidene derivatives and also orthogonally protected S- and O-glycosides from the corresponding unprotected saccharides by employing 2 mol % of a silicomolybdic acid (SMA) cluster as a versatile and biocompatible catalyst. The present protocol is applicable to two-step one-pot tandem transformations, which include the O-isopropylidation, spiroketal functionalization, 4,6-O-arylidene acetalations, and arylidene acetylation processes under relatively mild reaction conditions. One-pot sequential transformations, low catalyst loading, rapid transformation, high to excellent reaction yields, mild reaction conditions, and a nontoxic biocompatible workup procedure are the notable advantages of devised protocol.

Corrigendum to: Recent Progress on Synthesis of Functionalized 1,5- disubstituted Triazoles.

Two errors appeared in the text of the manuscript titled "Recent Progress on Synthesis of Functionalized 1,5- disubstituted Triazoles", 2024; 21(4) : 513-558 [1]. We regret the errors and apologize to readers. The original article can be found online at: https://www.eurekaselect.com/article/131107.

Recent Progress on Synthesis of Functionalized 1,5-Disubstituted Triazoles.

Immediately after the invention of 'Click Chemistry' in 2002, the regioselective 1,2,3- triazole scaffolds resulted from respective organic azides and terminal alkynes under Cu(I) catalysis have been well recognized as the functional heterocyclic core at the centre of modern organic chemistry, medicinal chemistry, and material sciences. This CuAAC reaction has several notable features including excellent regioselectivity, high-to-excellent yields, easy to execute, short reaction time, modular in nature, mild condition, readily available starting materials, etc. Moreover, the resulting regioselective triazoles can serve as amide bond isosteres, a privileged functional group in drug discovery and development. More than hundreds of reviews had been devoted to the 'Click Chemistry' in special reference to 1,4-disubstituted triazoles, while only little efforts were made for an opposite regioisomer i.e., 1,5-disubstituted triazole. Herein, we have presented various classical approaches for an expeditious synthesis of a wide range of biologically relevant 1,5- disubstituted 1,2,3-triazole analogues. The syntheses of such a class of diversly functionalized triazoles have emerged as a crucial investigation in the domain of chemistry and biology. This tutorial review covers the literature assessment on the development of various synthetic protocols for the functionalized 1,5-disubstituted triazoles reported during the last 12 years.

Sustainable water management in rice cultivation reduces arsenic contamination, increases productivity, microbial molecular response, and profitability.

Arsenic (As) and silicon (Si) are two structurally competitive natural elements where Si minimises As accumulation in rice plants, and based on this two-year field trial, the study proposes adopting alternating wetting and drying (AWD) irrigation as a sustainable water management strategy allowing greater Si availability. This field-based project is the first report on AWD's impact on As-Si distribution in fluvio-alluvial soils of the entire Ganga valley (24 study sites, six divisions), seasonal variance (pre-monsoon and monsoon), rice plant anatomy and productivity, soil microbial diversity, microbial gene ontology profiling and associated metabolic pathways. Under AWD to flooded and pre-monsoon to monsoon cultivations, respectively, greater Si availability was achieved and As-bioavailability was reduced by 8.7 ± 0.01-9.2 ± 0.02% and 25.7 ± 0.09-26.1 ± 0.01%. In the pre-monsoon and monsoon seasons, the physiological betterment of rice plants led to the high rice grain yield under AWD improved by 8.4 ± 0.07% and 10.0 ± 0.07%, proving the economic profitability. Compared to waterlogging, AWD evidences as an optimal soil condition for supporting soil microbial communities in rice fields, allowing diverse metabolic activities, including As-resistance, and active expression of As-responsive genes and gene products. Greater expressions of gene ontological terms and complex biochemical networking related to As metabolism under AWD proved better cellular, genetic and environmental responsiveness in microbial communities. Finally, by implementing AWD, groundwater usage can be reduced, lowering the cost of pumping and field management and generating an economic profit for farmers. These combined assessments prove the acceptability of AWD for the establishment of multiple sustainable development goals (SDGs).

Divergent single cell transcriptome and epigenome alterations in ALS and FTD patients with C9orf72 mutation.

A repeat expansion in the C9orf72 (C9) gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here we investigate single nucleus transcriptomics (snRNA-seq) and epigenomics (snATAC-seq) in postmortem motor and frontal cortices from C9-ALS, C9-FTD, and control donors. C9-ALS donors present pervasive alterations of gene expression with concordant changes in chromatin accessibility and histone modifications. The greatest alterations occur in upper and deep layer excitatory neurons, as well as in astrocytes. In neurons, the changes imply an increase in proteostasis, metabolism, and protein expression pathways, alongside a decrease in neuronal function. In astrocytes, the alterations suggest activation and structural remodeling. Conversely, C9-FTD donors have fewer high-quality neuronal nuclei in the frontal cortex and numerous gene expression changes in glial cells. These findings highlight a context-dependent molecular disruption in C9-ALS and C9-FTD, indicating unique effects across cell types, brain regions, and diseases.

Growing Impact of Intramolecular Click Chemistry in Organic Synthesis.

Click Chemistry, a modular, rapid, and one of the most reliable tool for the regioselective 1,2,3-triazole forming [3+2] reaction of organic azide and terimal alkyne is widely explored in various emerging domains of research ranging from chemical biology to catalysis and medicinal chemistry to material science. This regioselective reaction from a diverse range of azido-alkyne scaffolds has been well performed in both intermolecular as well as intramolecular fashions. In comparison to the intermolecular metal (Cu/Ru/Ni) variant of 'Click Chemistry', the intramolecular click tool is little addressed. The intramolecular click chemistry is exemplified as a mordern tool of cyclization which involves metal-catalyzed (CuAAC/RuAAC) cyclization, organo-catalyzed cyclization, and thermal-induced topochemical reaction. Thus, we report herein the recent approaches on intramolecular azide-alkyne cycloaddition 'Click Chemistry' with their wide-spread emerging applications in the developement of a diverse range of molecules including fused-heterocycles, well-defined peptidomemics, and macrocyclic architectures of various notable features.

Design, Synthesis, and Docking Study of Quinine-9-Triazolyl Conjugates.

To develop a better chemotherapeutically potential candidate for lung cancer treatment and cure with repurposed motifs, quinine has been linked with biocompatible CuAAC-inspired regioselective 1,2,3-triazole linker and a series of ten novel 1,2,3-triazolyl-9-quinine conjugates have been developed by utilizing click conjugation of glycosyl ether alkynes with 9-epi-9-azido-9-deoxy-quinine under standard click conditions. In parallel, the docking study indicated that the resulting conjugates have an overall appreciable interaction with ALK-5 macromolecules. Moreover, the mannose-triazolyl conjugate exhibited the highest binding interactions of -7.6 kcal/mol with H-bond interaction with the targeted macromolecular system and indicate the hope for future trials for anti-lung cancer candidates.

Organocatalyzed Regioselective Synthesis of 1,5-Disubstituted 1,2,3-Triazolyl Glycoconjugates.

A novel organocatalyzed [3+2] cycloaddition reaction of nitroolefins with glycosyl azides as well as organic azides has been developed for successful construction of 1,5-disubstituted triazolyl glycoconjugates. This metal-free and acid-free, regioselective synthetic protocol proceeds in the presence of only Schreiner thiourea organocatalysts, which enable the required activation of nitroolefins through double hydrogen bonding. The straightforward, operationally simple, and regioselectivity of this methodology, complementing to the classical RuAAC catalyzed synthesis of 1,5-disubstituted 1,2,3-triazoles. In the presence of catalytic amount of Schreiner thiourea organocatalyst, organic azides react with a broad array of nitroolefins producing a series of diverse 1,5-disubstituted 1,2,3- triazoles in good yields with excellent regioselectivity.

Pyrene appendant triazole-based chemosensors for sensing applications.

Over the last two decades, the design and development of fluorescent chemosensors for the targeted detection of heavy transition-metal (HTM) ions, anions, and biological analytes, have drawn much interest. Since the introduction of click chemistry in 2001, triazole moieties have become an increasingly prominent part of chemosensors. Triazoles generated via click reactions are crucial for sensing various ions and biological analytes. Recently, the number of studies in the field of pyrene appendant triazole moieties has risen dramatically, with more sophisticated and reliable triazole-containing chemosensors for various analytes of interest described. This review provides a general overview of pyrene appendant-triazole-based chemosensors that can detect a variety of metal cations, anions, and neutral analytes by using modular click-derived triazoles.

Growing impact of sialic acid-containing glycans in future drug discovery.

In nature, almost all cells are covered with a complex array of glycan chain namely sialic acids or nuraminic acids, a negatively charged nine carbon sugars which is considered for their great therapeutic importance since long back. Owing to its presence at the terminal end of lipid bilayer (commonly known as terminal sugars), the well-defined sialosides or sialoconjugates have served pivotal role on the cell surfaces and thus, the sialic acid-containing glycans can modulate and mediate a number of imperative cellular interactions. Understanding of the sialo-protein interaction and their roles in vertebrates in regard of normal physiology, pathological variance, and evolution has indeed a noteworthy journey in medicine. In this tutorial review, we present a concise overview about the structure, linkages in chemical diversity, biological significance followed by chemical and enzymatic modification/synthesis of sialic acid containing glycans. A more focus is attempted about the recent advances, opportunity, and more over growing impact of sialosides and sialoconjugates in future drug discovery and development.

Erratum: Addendum: Improved postoperative recovery profile in pediatric oral rehabilitation with low-dose dexmedetomidine as an opioid substitute for general anesthesia: a randomized double-blind clinical trial.

[This corrects the article on p. 357 in vol. 22, PMID: 36246035.].

Elevated insulin growth factor-1 in dentate gyrus induces cognitive deficits in pre-term newborns.

Prematurely born infants are deprived of maternal hormones and cared for in the stressful environment of Neonatal Intensive Care Units (NICUs). They suffer from long-lasting deficits in learning and memory. Here, we show that prematurity and associated neonatal stress disrupt dentate gyrus (DG) development and induce long-term cognitive deficits and that these effects are mediated by insulin growth factor-1 (IGF1). Nonmaternal care of premature rabbits increased the number of granule cells and interneurons and reduced neurogenesis, suggesting accelerated premature maturation of DG. However, the density of glutamatergic synapses, mature dendritic spines, and synaptic transmission were reduced in preterm kits compared with full-term controls, indicating that premature synaptic maturation was abnormal. These findings were consistent with cognitive deficits observed in premature rabbits and appeared to be driven by transcriptomic changes in the granule cells. Preterm kits displayed reduced weight, elevated serum cortisol and growth hormone, and higher IGF1 expression in the liver and DG relative to full-term controls. Importantly, blocking IGF-1 receptor in premature kits restored cognitive deficits, increased the density of glutamatergic puncta, and rescued NR2B and PSD95 levels in the DG. Hence, IGF1 inhibition alleviates prematurity-induced cognitive dysfunction and synaptic changes in the DG through modulation of NR2B and PSD95. The study identifies a novel strategy to potentially rescue DG maldevelopment and cognitive dysfunction in premature infants under stress in NICUs.

Iron oxide doped rice biochar reduces soil-plant arsenic stress, improves nutrient values: An amendment towards sustainable development goals.

Arsenic (As) contamination in paddy soils and its further translocation to the rice is a serious global issue. Arsenic loading to the rice depends on soil physico-chemical parameters and agronomic practices. To minimize this natural threat, as a natural substance, rice straw was used to produce rice biochar (RBC) and doped with iron oxide (IO) nanoparticles, another eco-friendly composite. In this study, RBC was used at three different concentrations- 0.5%, 1%, and 1.5% alone as well as conjugated with fixed 20 ppm IO nanoparticles. These treatments were compared with the control soil and control plants that had only As in the setup, without any amendments. The application of these treatments was efficient in reducing soil As bioavailability by 43.9%, 60.5%, and 57.3% respectively. Experimental data proved a significant percentage of As was adsorbed onto the RBC + IO conjugate. Further, the 1% RBC + IO conjugate was found to be the best treatment in terms of making soil macro-nutrients bioavailable. Rice seedlings grown under this treatment was more stress tolerant and produced less antioxidant enzymes and stress markers compared to the control plants grown under As-stress only. Rice plants from these different growth setups were observed for internal anatomical integrity and found that the RBC alone and RBC + IO conjugate, both improved the internal vascular structure compared to the control plants. To minimize soil As stress in crops, IO-doped RBC was proven to be the best sustainable amendment for improving soil-crop quality and achieving the proposed motto of Sustainable Development Goals by the United Nations.

Deep Learning Models for Classification of Deciduous and Permanent Teeth From Digital Panoramic Images.

INTRODUCTION: Dental radiographs are essential in the diagnostic process in dentistry. They serve various purposes, including determining age, analyzing patterns of tooth eruption/shedding, and treatment planning and prognosis. The emergence of digital radiography technology has piqued interest in using artificial intelligence systems to assist and guide dental professionals. These cutting-edge technologies assist in streamlining decision-making processes by enabling entity classification and localization tasks. With the integration of artificial Intelligence algorithms tailored for pediatric dentistry applications and utilizing automated tools, there is an optimistic outlook on improving diagnostic capabilities while reducing stress and fatigue among clinicians. METHODOLOGY: The dataset comprised 620 images (mixed dentition: 314, permanent dentition: 306). Panoramic radiographs taken were within the age range of 4-16 years. The classification of deciduous and permanent teeth involved training CNN-based models using different architectures such as Resnet, AlexNet, and EfficientNet, among others. A ratio of 70:15:15 was utilized for training, validation, and testing, respectively. RESULT AND CONCLUSION: The findings indicated that among the models proposed, EfficientNetB0 and EfficientNetB3 exhibited superior performance. Both EfficientNetB0 and EfficientNetB3 achieved an accuracy rate, precision, recall, and F1 scores of 98% in classifying teeth as either deciduous or permanent. This implies that these models were highly accurate in identifying patterns/features within the dataset used for evaluation.

Central Odontogenic Fibroma of the Mandible in a 9-year-old Child: A Case Report with 24-month Follow-up.

Background: Central odontogenic fibroma (COF) is a rarely benign tumor with an incidence of only 0.1% among all odontogenic tumors, which commonly involve the mandible. Case description: A 9-year-old child reported with asymptomatic bony expansion of the mandible, showing an unilocular radiolucency on an orthopantomogram. The tumor was managed surgically by enucleation, and the surgical stent was placed, which was later modified as a removable functional space maintainer. The patient was followed up for 24 months with the complete healing of periapical radiolucency and the eruption of displaced permanent tooth to the proper position. Conclusion: This case report discusses the importance of the dentist in assessing and diagnosing COF, especially in the pediatric age group.

Improved postoperative recovery profile in pediatric oral rehabilitation with low-dose dexmedetomidine as an opioid substitute for general anesthesia: a randomized double-blind clinical trial.

Background: Low-dose dexmedetomidine may be a suitable alternative to opioids for pediatric ambulatory procedures under general anesthesia (GA). However, the recovery profile remains unclear. Herein, we aimed to evaluate the effects of low-dose dexmedetomidine on the recovery profile of children. Methods: Seventy-two children undergoing ambulatory oral rehabilitation under GA were randomly and equally distributed into two groups (D and F). Group D received an infusion of dexmedetomidine 0.25 µg/kg for 4 min for induction, followed by maintenance of 0.4 µg/kg/h. Group F received an infusion of fentanyl 1 µg/kg over 4 min for induction, followed by maintenance at 1 µg/kg/h. The primary outcome was the extubation time. The secondary outcomes were awakening time, end-tidal sevoflurane (ET-Sevo) requirement, change in hemodynamic parameters, Richmond Agitation-Sedation Scale (RASS), Children's Hospital of Eastern Ontario pain scale (CHEOPS) score, length of PACU stay, and incidence of adverse events. Results: Statistically significant differences were observed in the recovery profile between the groups: the median time for extubation was 3.65 (3.44-6.2) vs. 6.25 (4.21-7) minutes in groups D vs. F (P = 0.001), respectively, while the corresponding awakening times were 19 (18.75-21) and 22.5 (22-24) minutes, respectively (P < 0.001). The mean ET-Sevo was low in group D (1.1 vs. 1.2; P < 0.001). The heart rate was significantly low across all time points in group D, without resulting in bradycardia. The median RASS and CHEOPS scores were also significantly lower in group D. No significant differences were observed in the mean arterial pressure, incidence of adverse events, or length of PACU stay. Conclusion: Low-dose dexmedetomidine was more effective than fentanyl as an opioid substitute at providing a better recovery profile in pediatric ambulatory oral rehabilitation under GA. Dexmedetomidine also significantly reduced sevoflurane consumption without causing adverse events or prolonging hospital stay.

One-pot expeditious synthesis of glycosylated esters through activation of carboxylic acids using trichloroacetonitrile.

Acetimidates, a valuable intermediate has been well explored as versatile synthon in a number of organic transformations particularly as suitable donors in glycosylation reactions. Herein, we explored acetimidates to furnish high-to-excellent yield of diverse glycosylated esters under one-pot mild reaction condition. The commercially available trichloroacetonitrile is implemented for the activation of carboxylic acid via in situ generation of trichloroacetimidate, which was subsequently attacked by sugar alcohols to deliver high-to-excellent yields of desired glycosylated esters. The devised method has some notable features such as metal-free condition, one-pot mild reaction condition, easy-handling, high-to-excellent yields, and broad substrate scope.

The Effect of Video-Based Preanaesthetic Preparation Versus Conventional Approach on Parental Anxiety in Paediatric Dental Procedures: A Prospective Cohort Study.

Background Parental anxiety has been identified as a risk factor affecting the behaviour of children before operative intervention. A preanaesthetic visit is a standard component of preoperative preparation, which may reduce parental anxiety. The use of audiovisual aids to demonstrate the conduct of anaesthesia may help improve parental education and reduce anxiety. Patient and methods We analysed data from a prospective randomised trial conducted at a tertiary care hospital. Parents of children posted for day care dental procedures were enrolled in the study. Children could be of either gender, aged 2-6 years, and categorised as American Society of Anesthesiologists Physical Status (ASA-PS) 1 or 2. Parents' anxiety regarding the surgical and anaesthesia procedure was assessed using the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The first APAIS scoring was recorded on arrival in the preoperative holding area. Thereafter, the participants were randomly allocated into two groups; one group was shown a short video on a smartphone of a dental operating theatre (OT), dental chair and anaesthesia equipment (SPG group), while the other group was verbally explained the dental procedure (conventional management or CM group). The second APAIS scoring was done in the postoperative recovery area one hour after the procedure. Demographic characteristics, socio-economic conditions and history were recorded. Anxiety scores were compared between the two groups, and any change was analysed. Results Seventy parents were included in the study, with 36 randomised to the SPG group and 34 to the CM group. Both groups were comparable in terms of demographic characteristics. There was a statistically significant decrease in anxiety scores in the SPG group, from a mean of 25.47 at the preoperative assessment to 14.92 at the postoperative timepoint (p<0.001). In the CM group, the mean APAIS score decreased from 25.26 to 24.56 (p=0.059). Conclusion There was a significant reduction in anxiety scores in the postoperative period among parents who were shown an operating room video in the preoperative period.

Top 100 cited articles on Silver diamine fluoride-A bibliometric analysis.

Background: Identification of top cited articles aids in providing comprehensive and cumulative standardized quality work to research community. The present bibliometric study was aimed at identifying 100 top cited articles on Silver diamine fluoride, highlighting its landmark publications available in the current literature and aids in providing comprehensive and cumulative standardised quality work to research community. Methodology: Four major databases (Web of science, Pubmed, Scopus and Embase) were searched using search terms like 'silver fluoride' OR 'silver diamine fluoride' OR 'silverdiammine fluoride' OR 'diamine silver fluoride' OR 'diammine silver fluoride' OR silver ammonia fluoride AND dentistry. Selected publications were studied to tabulate information like journal, authors, year etc and contents of the publications were summarised. Variables such as journal name, first author, journal rank, citation count and average citations per year, authorship patterns, author's country of origin, most productive authors, journals and countries were identified. Additional outcome variables were SDF concentrations used, study designs adopted and SDF use like caries arrest/prevention/anti-hypersensitive agent and as an irrigant. Results: Among them maximum articles were clinical trials(n = 24) however systematic(n = 12), literature(n = 14) and narrative reviews(n = 12) had an equal share. The countries with the highest number of most-cited papers were China and USA. The most studied aspect was caries arrest. Journal of Dentistry and Journal of Dental Research had major publications among top cited papers. Conclusion: This particular review will prove to be a great source of information for research community worldwide and will aid in directing them towards relevant articles.