Standardizing Substrate Selection: A Strategy toward Unbiased Evaluation of Reaction Generality

With over 10,000 new reaction protocols arising every year, only a handful of these procedures transition from academia to application. A major reason for this gap stems from the lack of comprehensive knowledge about a reaction's scope, i.e., to which substrates the protocol can or cannot be applied. Even though chemists invest substantial effort to assess the scope of new protocols, the resulting scope tables involve significant biases, reducing their expressiveness. Herein we report a standardized substrate selection strategy designed to mitigate these biases and evaluate the applicability, as well as the limits, of any chemical reaction. Unsupervised learning is utilized to map the chemical space of industrially relevant molecules. Subsequently, potential substrate candidates are projected onto this universal map, enabling the selection of a structurally diverse set of substrates with optimal relevance and coverage. By testing our methodology on different chemical reactions, we were able to demonstrate its effectiveness in finding general reactivity trends by using a few highly representative examples. The developed methodology empowers chemists to showcase the unbiased applicability of novel methodologies, facilitating their practical applications. We hope that this work will trigger interdisciplinary discussions about biases in synthetic chemistry, leading to improved data quality.

Discovery of Organic Optoelectronic Materials Powered by Oxidative Ar-H/Ar-H Coupling

Efficient and streamlined synthetic methods that facilitate the rapid build-up of structurally diverse π-conjugated systems are of paramount importance in the quest for organic optoelectronic materials. Among these methods, transition-metal-catalyzed oxidative Ar-H/Ar-H coupling reactions between two (hetero)arenes have emerged as a concise and effective approach for generating a wide array of bi(hetero)aryl and fused heteroaryl structures. This innovative approach bypasses challenges associated with substrate pre-activation processes, thereby allowing for the creation of frameworks that were previously beyond reach using conventional Ar-X/Ar-M coupling reactions. These inherent advantages have ushered in new design patterns for organic optoelectronic molecules that deviate from traditional methods. This ground-breaking approach enables the transcendence of the limitations of repetitive material structures, ultimately leading to the discovery of novel high-performance materials. In this Perspective, we provide an overview of recent advances in the development of organic optoelectronic materials through the utilization of transition-metal-catalyzed oxidative Ar-H/Ar-H coupling reactions. We introduce several notable synthetic strategies in this domain, covering both directed and non-directed oxidative Ar-H/Ar-H coupling strategies, dual chelation-assisted strategy and directed ortho-C-H arylation/cyclization strategy. Additionally, we shed light on the role of oxidative Ar-H/Ar-H coupling reactions in the advancement of high-performance organic optoelectronic materials. Finally, we discuss the current limitations of existing protocols and offer insights into the future prospects for this field.

Iron-Catalyzed para-Selective C-H Allylation of Aniline Derivatives

Transition-metal-catalyzed directed C-H allylation of arenes offers an efficient and straightforward approach to construct value-added allylic arenes. However, these reactions are often performed with precious transition-metal catalysts and mainly limited to ortho-C-H allylation of arenes. Herein, we disclose a novel iron-catalyzed para-C-H allylation of aniline derivatives with allyl alcohols via a chelation-induced strategy, providing various allylic arenes in good yields with excellent regio- and chemoselectivity. A simple FeCl3·6H2O is employed as a catalyst, serving a dual role in the reaction: (1) coordination with N-arylpicolinamide to alter the electronic property of the aromatic ring and (2) reaction with allyl alcohol to form allyl-Fe species.

Pathogenic SCN2A variants cause early-stage dysfunction in patient-derived neurons

Pathogenic heterozygous variants in SCN2A, which encodes the neuronal sodium channel NaV1.2, cause different types of epilepsy or intellectual disability (ID)/autism without seizures. Previous studies using mouse models or heterologous systems suggest that NaV1.2 channel gain-of-function typically causes epilepsy, whereas loss-of-function leads to ID/autism. How altered channel biophysics translate into patient neurons remains unknown. Here, we investigated iPSC-derived early-stage cortical neurons from ID patients harboring diverse pathogenic SCN2A variants [p.(Leu611Valfs*35); p.(Arg937Cys); p.(Trp1716*)] and compared them with neurons from an epileptic encephalopathy (EE) patient [p.(Glu1803Gly)] and controls. ID neurons consistently expressed lower NaV1.2 protein levels. In neurons with the frameshift variant, NaV1.2 mRNA and protein levels were reduced by ~ 50%, suggesting nonsense-mediated decay and haploinsufficiency. In other ID neurons, only protein levels were reduced implying NaV1.2 instability. Electrophysiological analysis revealed decreased sodium current density and impaired action potential (AP) firing in ID neurons, consistent with reduced NaV1.2 levels. In contrast, epilepsy neurons displayed no change in NaV1.2 levels or sodium current density, but impaired sodium channel inactivation. Single-cell transcriptomics identified dysregulation of distinct molecular pathways including inhibition of oxidative phosphorylation in neurons with SCN2A haploinsufficiency and activation of calcium signaling and neurotransmission in epilepsy neurons. Together, our patient iPSC-derived neurons reveal characteristic sodium channel dysfunction consistent with biophysical changes previously observed in heterologous systems. Additionally, our model links the channel dysfunction in ID to reduced NaV1.2 levels and uncovers impaired AP firing in early-stage neurons. The altered molecular pathways may reflect a homeostatic response to NaV1.2 dysfunction and can guide further investigations.

Stereochemical Editing

Stereochemical editing has recently risen to prominence, allowing the direct editing of organic molecules with stereocenter(s) to adjust their relative stereochemistry at a late-stage. Several seminal light-driven stereochemical editing reactions such as deracemization and epimerization have been successively developed. Recently, Wendlandt and co-workers reported a versatile photochemical epimerization of unactivated tertiary stereogenic centers to rapidly prepare the stereoisomers that were previously challenging to access.

Metal-free photosensitized radical relay 1,4-carboimination across two distinct olefins

Intermolecular carboamination of olefins offers a powerful platform for the rapid construction of structurally complex amines from abundant feedstocks. However, these reactions often require transition-metal catalysis, and are mainly limited to 1,2-carboamination. Herein, we report a novel radical relay 1,4-carboimination across two distinct olefins with alkyl carboxylic acid-derived bifunctional oxime esters via energy transfer catalysis. The reaction is highly chemo- and regioselective, and multiple C-C and C-N bonds were formed in a single orchestrated operation. This mild and metal-free method features a remarkably broad substrate scope with excellent tolerance of sensitive functional groups, therefore providing easy access to structurally diverse 1,4-carboiminated products. Moreover, the obtained imines could be easily converted into valuable biologically relevant free γ-amino acids.

1182 THE PREVALENCE OF ORAL FRAILTY AND ITS ASSOCIATION WITH DYSPHAGIA, FRAILTY AND FORMAL CARE NEEDS

Introduction

Oral frailty (OF), gradual loss of oral function combined associated with presbyphagia often in conjunction with cognitive and physical decline, has been recommended to be considered as a geriatric giant. DENTAL has been suggested as a possible screening tool for OF. We have looked at the prevalence of OF and its association with dysphagia, frailty and formal care, amongst people admitted acutely to the acute medical/frailty wards in our hospital.

Methods

OF, dysphagia and frailty were screened for as part of the routine clinical assessment of patients during the usual clinical ward round. Screening tools used were DENTAL for OF, Rockwood Score for frailty and 4QT for dysphagia. Age, sex comorbidities and the need for formal care was documented.

Results

101 people were assessed over a 4-week period. Mean age was 84 years (65-99), 58 (57.4%) were female, 31(30.7%) were independent, 33 (32.6%) dementia, 57 (56.4%) frail, 54 (53.4%) had swallowing problems, and 34 (33.6%) OF. Of those with OF 97% had dysphagia, 88% were frail and 85% required formal care support (85%). OF was associated with dysphagia (p<0.0001), frailty (p< 0.0001), formal care support (p<0.05) and dementia (p<0.05). There was an association between needing care and frailty (p<0.01).

Conclusions

OF is associated with dysphagia, frailty and the need for formal care. OF may result in poor oral health and contribute to dysphagia and frailty, conversely frailty and dysphagia may result in poor oral health due to dependency and poor nutrition and dehydration. The associations are most likely be bidirectional. Further work is required to elucidate this. Clinical staff need to be aware of OF and oral health and include oral screening in their clinical assessment of an older adult.

Exploring the Associations between Alzheimer's Disease and GBM Mediated by Microglia Based on Network Analysis

Previous studies have revealed that there existed epidemic associations between Alzheimer's disease (AD) and many types of tumors, however, the inner biological mechanism connecting these diseases was not clear currently. In this study, we explored the transcriptome associations between AD and glioblastoma multiforme (GBM) that both originate in the brain, using microglia as a bridge, from gene and network levels. Firstly, we extracted human scRNA sequencing datasets from Gene Expression Omnibus (GEO) database, and identified differentially expressed genes within microglia after cell annotation. It was observed that there were 11 common genes shared by AD and GBM dys-regulated genes. Next, we utilized DIAMOnD and Flow Centrality algorithms to identify microglia modules and mediating pathways connecting these two diseases based on global network topology. Among these candidate pathways, the mediating genes FURIN and BACE1 (from SPIKN5 to CSNK1A1) were not only related to the formation of amyloid beta plaques that accumulate in the brain of AD patients, but also involved in cancer biology. Furthermore, the biological explorations of mediating pathways connecting AD and GBM modules reveal inflammatory response, lipid metabolism disorder, and cell proliferation terms. Finally, novel signatures for early AD detection as well as risk models for glioma prognosis were identified based on mediating genes involved in these pathways. In conclusion, this study provided a novel network-based strategy for exploring microglia mediation between AD and GBM and identified candidate signatures for disease detection and prognosis.

Highly Selective Radical Relay 1,4-Oxyimination of Two Electronically Differentiated Olefins

Radical addition reactions of olefins have emerged as an attractive tool for the rapid assembly of complex structures, and have plentiful applications in organic synthesis, however, such reactions are often limited to polymerization or 1,2-difunctionalization. Herein, we disclose an unprecedented radical relay 1,4-oxyimination of two electronically differentiated olefins with a class of bifunctional oxime carbonate reagents via an energy transfer strategy. The protocol is highly chemo- and regioselective, and three different chemical bonds (C-O, C-C, and C-N bonds) were formed in a single operation in an orchestrated manner. Notably, this reaction provides rapid access to a large variety of structurally diverse 1,4-oxyimination products, and the obtained products could be easily converted into valuable biologically relevant δ-hydroxyl-α-amino acids. With a combination of experimental and theoretical methods, the mechanism for this 1,4-oxyimination reaction has been investigated. Theoretical calculations reveal that a radical chain mechanism might operate in the reaction.

Identifying proteomic profiles as indicators of disease severity in arrhythmogenic cardiomyopathy

Introduction

Arrhythmogenic cardiomyopathy (ACM) is an inherited heart muscle disease characterized by progressive fibrofatty replacement of the myocardium and ventricular arrhythmias. Biventricular (BiV) involvement may lead to heart failure. This study aimed to investigate characteristic proteomic patterns in plasma of ACM patients, and correlated them with clinical outcome as well as physical exercise, to assess if key soluble molecules may serve as specific biomarkers for ACM, and whether mechanical stress induced by physical exercise may alter proteomic patterns in ACM patients.

Methods

In 38 ACM patients clinical parameters and major adverse cardiovascular events (MACE defined as presence of sustained ventricular tachycardia, ventricular fibrillation, appropriate therapy from implantable cardioverter defibrillator, sudden cardiac death, death related to end-stage heart failure or cardiac transplant) were obtained prospectively during a mean follow-up period of 36 months. All patients received genetic testing using next generation DNA sequencing. Plasma protein expression was analysed using the Proximity Extension Assay (PEA) technology, where a pair of oligonucleotide-labelled antibody probe binds to each targeted protein. In a subgroup of 11 patients blood was drawn immediately before and 3 hours after standardised bicycle exercise testing, and plasma protein expression was compared.

Results

12 patients had ACM with BiV involvement, and 26 patients had isolated right ventricular (RV) involvement. During the follow-up period, 34 patients had a MACE (30% with RV and 14% with BiV). Over 360 proteins were assessed in all ACM patients and compared to 24 healthy controls. The proteomic signature of ACM patients differed significantly compared to controls, and 32 proteins were upregulated in ACM (Figure 1). The proteomic profiles of patients with RV involvement also differed from those with BiV involvement. Most importantly, after exercise, over 40 proteins were upregulated specifically in ACM patients compared to controls, including key pro-inflammatory, adipogenic molecules and also markers of cardiac fibrosis.

Conclusion

Our study shows that ACM patients with RV and BiV involvement have different plasma proteomic profiles compared to healthy controls. Furthermore we were able to demonstrate that, specifically in ACM patients, several pro-inflammatory pathways are upregulated after exercise compared to healthy controls, further elucidating the molecular pathways associated with arrhythmogenicity and disease progression and highlighting the key role of physical stress. Our results may enable the identification of potential future biomarkers for diagnosis and risk stratification and may pave the way for personalized patient specific treatments.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Baugarten Foundation ZurichSwiss National Foundation

Photochemical single-step synthesis of β-amino acid derivatives from alkenes and (hetero)arenes

β-Amino acids are frequently found as important components in numerous biologically active molecules, drugs and natural products. In particular, they are broadly utilized in the construction of bioactive peptides and peptidomimetics, thanks to their increased metabolic stability. Despite the number of methodologies established for the preparation of β-amino acid derivatives, the majority of these methods require metal-mediated multistep manipulations of prefunctionalized substrates. Here we disclose a metal-free, energy-transfer enabled highly regioselective intermolecular aminocarboxylation reaction for the single-step installation of both amine and ester functionalities into alkenes or (hetero)arenes. A bifunctional oxime oxalate ester was developed to simultaneously generate C-centred ester and N-centred iminyl radicals. This mild method features a remarkably broad substrate scope (up to 140 examples) and excellent tolerance of sensitive functional groups, and substrates that range from the simplest ethylene to complex (hetero)arenes can participate in the reaction, thus offering a general and practical access to β-amino acid derivatives.

10 Tip-Apex Distance in DHS & IM Nail Fixations for Hip Fractures

Aim

Dynamic hip screws (DHS) and intramedullary nail (IMN) fixations have been successful in treating extracapsular hip fractures. Tip to apex distance (TAD) is defined as the total sum of distance from tip of the lag screw to the femoral head tip on both AP and lateral radiographs. Baumgartner et al. defined TAD<25 mm to be predictive of a successful result, with reduced rates of metalwork failure. Therefore, this study aims to assess if TAD principles are practiced during DHS and IMN fixations.

Method

102 patients were identified between December 2019 and February 2020. The distance was measured on AP and lateral radiographs to calculate the TAD. Patients were followed up for 1 year where the fractures either united or failed.

Results

Patients recruited had age ranges between 19–103 years old, of which 36% are male and 64% are female. 68% had underwent DHS while 32% underwent IM nail. In the DHS group, 13 patients had TAD of >25 mm, 28 with TAD of 20–25 mm, 18 with TAD of 15–20mm and 6 with TAD of <15 mm. For the IM nail group, there are 7 with TAD of 20–25 mm, 13 with TAD of 15–20mm and 10 with TAD of <15 mm.

Conclusions

There were no IM nails that exceeded TAD of 25mm, but 13 DHS fixations were >25mm. 12/13 DHS fixations >25mm TAD were performed by trainees. We advocate emphasis on the TAD principle and re-enforcing to orthopaedic trainees to improve the outcome of DHS in patients with neck of femur fractures.

11 Robotic Left Lower Sleeve Lobectomy with Bronchoplasty for the Removal of a Carcinoid Tumour

Lung carcinoid tumours constitute approximately 1–2% of all pulmonary tumours. They are derived from enterochromaffin cells, which are also known as ‘Kulchitsky cells' and generally have indolent growth and development patterns. Carcinoid tumours are categorized as typical or atypical, depending on the number of mitoses per high power field and the presence of necrosis. In terms of management, surgical resection has been recognized to be the standard treatment for pulmonary carcinoid tumours. To our knowledge, the da Vinci system and robotic surgery have not been applied in sleeve lobectomies and bronchoplasty for the removal of carcinoid tumours in the United Kingdom. Therefore, we present a case of a sleeve lobectomy with bronchoplasty procedure for the removal of a carcinoid tumour located in the left lower lobe of the patient. The bronchus was repaired using a V-lock suture & Prolene sutures with the surgery performed using the da Vinci robotic surgical system.

Increased retention of tau PET ligand [18F]-AV1451 in Alzheimer's Disease Psychosis

Psychosis in Alzheimer's disease (AD) represents a distinct disease subtype with a more rapid progression of illness evidenced by an increased velocity of cognitive decline and a hastened mortality. Previous biomarker and post-mortem studies have implicated tau neuropathology as a possible mediator of the accelerated decline in AD psychosis. Tau positron emission tomography (PET) neuroimaging provides the opportunity to evaluate tau pathology in-vivo, so that clinical symptomatology can be correlated with disease pathology. [¹⁸F]-AV1451 (Flortaucipir) is a PET ligand with high affinity for insoluble paired-helical filaments (PHFs) of hyperphosphorylated tau. In order to determine whether the development of psychosis and worsened prognosis in AD is associated with an increased burden of tau pathology that can be identified with tau imaging, we identified subjects within the Alzheimer's disease neuroimaging initiative (ADNI) who had [¹⁸F]-AV1451 imaging at baseline and became psychotic over the course of the study (N = 17) and matched them 1:3 for gender, age, and education to subjects who had [¹⁸F]-AV1451 imaging at baseline and did not become psychotic (N = 50). We compared baseline [¹⁸F]-AV1451 retention, in addition to cognitive and functional baseline and longitudinal change, in those who became psychotic over the course of participation in ADNI with those who did not. Results suggest that increases in tau pathology in frontal, medial temporal, and occipital cortices, visualized with [¹⁸F]-AV1451 binding, are associated with psychosis and a more rapid cognitive and functional decline.

AIE-Active Difluoroboron Complexes with N,O-Bidentate Ligands: Rapid Construction by Copper-Catalyzed C-H Activation

The development of organic materials with high solid-state luminescence efficiency is highly desirable because of their fundamental importance and applicability in optoelectronics. Herein, a rapid construction of novel BF2 complexes with N,O-bidentate ligands by using Cu(BF4 )2 •6H2 O as a catalyst and BF2 source is disclosed, which avoids the need for pre-composing the N,O-bidentate ligands and features a broad substrate scope and a high tolerance level for sensitive functional groups. Moreover, molecular oxygen is employed as the terminal oxidant in this transformation. A library of 36 compounds as a new class of BF2 complexes with remarkable photophysical properties is delivered in good to excellent yields, showing a substituent-dependency on the photophysical properties, derived from the π-π* character of the photoexcited state. In addition, aggregation-induced emission (AIE) is observed and quantified for the brightest exemplars. The excited state properties are fully investigated in solids and in THF/H2 O mixtures. Hence, a new series of photofunctional materials with variable photophysical properties is reported, with potential applications for sensing, bioimaging, and optoelectronics.

Rhodium-Catalyzed Dealkenylative Arylation of Alkenes with Arylboronic Compounds

The C-C bond formation reaction represents a fundamental and important transformation in synthetic chemistry, and exploring new types of C-C bond formation reactions is recognized as appealing, yet challenging. Herein, we disclose the first example of rhodium-catalyzed dealkenylative arylation of alkenes with arylboronic compounds, thereby providing an unconventional access to bi(hetero)aryls with excellent chemoselectivity. In this method, C(aryl)-C(alkenyl) and C(alkenyl)-C(alkenyl) bonds in various alkenes and 1,3-dienes can be cleaved via a hydrometalation and followed by β-carbon elimination pathway for Suzuki-Miyaura reactions. Furthermore, a series of novel organic fluorescent molecules with excellent photophysical properties has been efficiently constructed with this protocol.

CHANGES OF WNT/B-CATENIN SIGNALING AND DIFFERENTIATION POTENTIAL OF BONE MARROW MESENCHYMAL STEM CELLS IN PROCESS OF BONE LOSS IN OVARIECTOMIZED RATS

Background

In vitro studies of the changes about osteoblastogenesis and adipogenesis potential of BMSCs were not clear. As it is the critical pathway for osteogenic differentiation and bone formation, whether or not Wnt/β-catenin signalling is involved in the changes of osteogenic and adipogenic potential of BMSCs and participates in bone content decrease of ovariectomized (OVX)osteoporosis rats has been rarely reported.

Material/Methods

BMSCs from femurs of ovariectomzed rats were isolated and cultured in vitro. The proliferation potential of BMSCs was analysed by CCK-8 assays . Osteoblastic and adipogenic differentiation potential of the BMSCs was assessed by ALP activity assay, Alizarin red S staining, Oil red O staining and RT-PCR analysis.

Results

The results demonstrated that BMSCs from bilateral ovariectomization rats were endowed with lower proliferation and osteoblastic differentiation potential but higher adipogenic potential than the control group in vitro. In addition, β-catenin was found to have been decreased in OVX BMSCs, indicating that Wnt/β-catenin signalling pathways were suppressed in OVX BMSCs .

Conclusions

Results suggested that changes in the Wnt canonical signalling pathway may be related to imbalances of osteogenic and adipogenic potential of BMSCs, and this may be an important factor related to bone content decrease in ovariectomized osteoporosis rats.

[Cancer metabolism: a novel perspective on precision diagnosis and treatment for liver cancer]

Metabolic reprogramming has been identified as a hallmark of cancer. Liver is an essential hub in the body for the metabolism of three major nutrients including glucose, lipids and amino acids. Hepatocellular carcinoma(HCC) usually presents a variety of changes in characteristic metabolism, such as increased aerobic glycolysis, enhanced de novo lipid synthesis, glutamine depletion, and oxidative metabolism imbalance, which can provide energy and bio-macromolecular raw materials for rapidly growing and proliferating tumor cells. The process of tumor metabolic reprogramming is regulated by multiple factors, such as alterations in metabolic enzyme activity, abnormal gene expression, and signaling pathway disturbance. Advances in high-throughout metabolomics technology have provided a powerful platform for discovering the novel biomarkers and metabolic targets of HCC. Therefore, in-depth study of the metabolic characteristics and regulatory mechanisms of HCC is critical for the development of novel antimetabolites.

Syngas-Free Highly Regioselective Rhodium-Catalyzed Transfer Hydroformylation of Alkynes to α,β-Unsaturated Aldehydes

The hydroformylation of alkynes is a fundamental and important reaction in both academic research and industry. Conventional methods focus on the conversion of alkynes, CO, and H₂ into α,β-unsaturated aldehydes, but they often suffer from problems associated with operation, regioselectivity, and chemoselectivity. Herein, we disclose an operationally simple, mild, and syngas-free rhodium-catalyzed reaction for the hydroformylation of alkynes via formyl and hydride transfer from an alkyl aldehyde. This synthetic method uses inexpensive and easy-to-handle n-butyraldehyde to overcome the challenge posed by the use of syngas in traditional approaches and employs a commercially available catalyst and ligand to transform a broad range of internal alkynes, especially alkynyl-containing complex molecules, into versatile stereodefined α,β-unsaturated aldehydes with excellent chemo-, regio-, and stereoselectivity.

Evaluation of self-collected vaginal specimens for the detection of high-risk human papillomavirus infection and the prediction of high-grade cervical intraepithelial lesions in a high-burden, low-resource setting

OBJECTIVES

To compare the performance of self-collected vaginal (V) specimens with clinician-collected cervical (C) specimens for detection of high-risk human papillomavirus (hrHPV) and cervical disease using the Cepheid Xpert HPV, Roche Cobas 4800 HPV and Hologic Aptima HPV assays.

METHODS

Women aged 30-59 years (n = 1005) were recruited at two clinics in Papua New Guinea, and they provided specimens for testing at point-of-care using the Xpert HPV Test, and for subsequent testing using the Cobas HPV (n = 981) and Aptima HPV (n = 983) assays. Liquid-based cytology was performed on C specimens to predict underlying high-grade squamous intraepithelial lesions (HSIL). V specimen results of each assay were evaluated against a constructed reference standard and for detection of HSIL or worse.

RESULTS

There was substantial (κ >0.6) agreement in hrHPV detection between V and C specimens across all three assays. The sensitivity, specificity, and positive and negative predictive values of Xpert HPV using self-collected V specimens for the detection of HPV type 16 according to the constructed reference standard were 92.1%, 93.1%, 63.6% and 98.9%, respectively; compared with 90.4%, 94.3%, 67.8% and 98.7% for Cobas 4800 HPV; and 63.2%, 97.2%, 75.0% and 95.3% for Aptima HPV. Similar results were observed for all hrHPV types (combined) and for HPV types 18/45, on all three assays. The detection of any hrHPV using self-collected specimens had high sensitivity (86%-92%), specificity (87%-94%) and negative predictive value (>98%) on all assays for HSIL positivity.

CONCLUSIONS

Xpert HPV, using self-collected vaginal specimens, has sufficient accuracy for use in point-of-care 'test-and-treat' cervical screening strategies in high-burden, low-resource settings.

Iridium-Catalyzed Annulation Reactions of Thiophenes with Carboxylic Acids: Direct Evidence for a Heck-type Pathway

The functionalization of thiophenes is a fundamental and important reaction. Herein, we disclose iridium-catalyzed one-pot annulation reactions of (benzo)thiophenes with (hetero)aromatic or α,β-unsaturated carboxylic acids, which afford thiophene-fused coumarin-type frameworks. Dearomatization reactions of 2-substituted thiophenes with α,β-unsaturated carboxylic acids deliver various thiophene-containing spirocyclic products. The occurrence of two interconnected reactions provides direct evidence for a Heck-type pathway. The mechanistic scenario described herein is distinctly different from the S_E Ar and concerted metalation-protodemetalation (CMD) pathways encountered in the well-described oxidative C-H/C-H cross-coupling reactions of thiophenes with other heteroarenes.

Antitumor activity of chitosan from mayfly with comparison to commercially available low, medium and high molecular weight chitosans

Insects' cuticles have a potential to be evaluated as a chitin source. Especially adults of aquatic insects like mayflies (order Ephemeroptera) swarm in enormous numbers in artificially lit areas while mating in spring and then die by leaving huge amounts of dead insects' bodies. Here in this study, mayfly corpses were harvested and used for production of low MW chitosan. Dried mayfly bodies had 10.21% chitin content; mayfly chitin was converted into chitosan with efficiency rate of 78.43% (deacetylation degree, 84.3%; MW, 3.69 kDa). Cytotoxicity and anti-proliferative activity of mayfly and commercially available shrimp chitosans (low, medium, and high MW) were determined on L929 fibroblast and three different cancer types including HeLa, A549, and WiDr. Apoptosis and necrosis stimulating potential of mayfly and commercial chitosans were also evaluated on A549 and WiDr cells using acridine orange and propidium iodide dual staining to observe morphological changes in nuclei and thus to reveal the predominant cell death mechanism. The effects of chitosans have varied depending on cell types, concentration, and chitosan derivatives. Mayfly and low MW chitosans had a cytotoxic effect at a concentration of 500 μg mL^-1 on non-cancer cells. At concentrations below this value (250 μg mL^-1), mayfly and commercial chitosans except high MW one exhibited strong inhibitory activity on cancer cells especially A549 and WiDr cells. Mayfly chitosan induced early and late apoptosis in A549 cells, but late apoptosis and necrosis in WiDr cells. This study suggests that dead bodies of mayflies can be used for production of low MW chitosan with anti-proliferative activity.

Rhodium-catalyzed oxidative C–H/C–H cross-coupling of aniline with heteroarene: N-nitroso group enabled mild conditions

A rhodium(iii)-catalyzed oxidative ortho-heteroarylation of N-nitrosoaniline with heteroarene has been developed for the synthesis of (2-aminophenyl)heteroaryls under mild conditions.

Iridium-catalyzed oxidative Ar–H/Ar–H cross-coupling of primary benzamides with thiophenes

Described herein is an iridium(iii)-catalyzed oxidative Ar–H/Ar–H cross-coupling of primary benzamides with thiophenes for the synthesis of (2-thienyl)benzamides.

Rhodium(III)-Catalyzed Oxidative Cross-Coupling of Unreactive C(sp3)-H Bonds with C(sp2)-H Bonds

The development of the oxidative cross-coupling of unreactive C(sp³)-H bonds with (hetero)arene C(sp²)-H bonds is considerably appealing, yet conceptually and practically challenging. Here, we disclose the rhodium-catalyzed oxidative heteroarylation of unactivated C(sp³)-H bonds with heteroarene C(sp²)-H bonds. This method provides a step-economic route to β-heteroarylated 2-ethylpyridine derivatives, which exhibits relatively broad substrate scope, high tolerance level of sensitive functional groups, and high selectivity. The protocol can also be extended to the coupling reaction between 8-methylquinoline derivatives and heteroarenes.