Browse Articles

Reflexive Chirality Transfer (RCT): Asymmetric 1,3-Dipolar Cycloaddition of α-Amino Acid Schiff Base with Nonchiral Copper Catalyst

Extreme compound events in the equatorial and South Atlantic

Live streaming mode selection strategy under the background of virtual anchor supplementation

In the context of virtual anchors as a supplement to human anchors in live streaming e-commerce. In this paper, for the first time, virtual anchors are included in the live streaming mode selection strategy, combined with the characteristics of the live streaming anchor and the cost of live streaming, constructed a model of the four live streaming modes, and used the Stackelberg game method to study. The results show that: (1) live streaming prices are positively correlated with cross price elasticity coefficient, market share of live streaming channels and consumer sensitivity to live streaming e-commerce. (2) When the cross price elasticity coefficient or market share of live streaming channels is small, the influence of influencer anchors can attract more consumers to purchase products, and the influencer anchor live streaming mode is the optimal choice; When the cross price elasticity coefficient or market share of live streaming channels is large, the merchant combined with virtual anchors live streaming mode is the optimal choice due to the low cost of live streaming for merchant staff anchors, as well as the advantage of continuous live streaming for virtual anchors. (3) When the consumer sensitivity to live streaming e-commerce is small, due to the low cost of live streaming for merchant staff anchors, the merchant live streaming mode is the optimal choice; When the consumer sensitivity to live streaming e-commerce is large, based on the influence of influencer anchors and the advantage of continuous live streaming for virtual anchors, the influencer anchor combined with virtual anchors live streaming mode is the optimal choice.

Validation of the Swedish Eating Assessment Tool, S-EAT-10, for patients with head and neck cancer

Abstract The aim of this study was to validate the Swedish version of Eating Assessment Tool (S-EAT-10) for head and neck cancer patients. The participants (n = 60) had persistent swallowing difficulties 6–36 months after completion of curative radiotherapy. The videofluoroscopic swallowing study was assessed using the Penetration Aspiration Scale and the Yale Pharyngeal Residue Severity Rating Scale modified for videofluoroscopy. Participants completed questionnaires S-EAT-10, M.D. Anderson Dysphagia Inventory (MDADI) and study-specific questions. Internal consistency was excellent and the test–retest reliability was good. Regarding convergent validity, S-EAT-10 showed moderate to strong correlation with the MDADI and no to weak correlation with study-specific questions regarding meal duration and weight change. Regarding criterion validity, there was a weak correlation between S-EAT-10 and instrumental measures. S-EAT-10 showed 85% sensitivity in identifying patients with dysphagia. S-EAT-10 could not discriminate between different degrees of dysphagia. Thus, S-EAT-10 showed sufficient psychometric properties regarding head and neck cancer patients.

The effects of disorder in superconducting materials on qubit coherence

Target sample mining with modified activation residual network for speaker verification

In the domain of speaker verification, Softmax can be used as a backend for multi-classification, but traditional Softmax methods have some limitations that limit performance. During the training phase, Softmax is used for multi-class training, while the speaker verification stage is a binary classification validation, leading to a discrepancy between the multi-class training in the training phase and the binary classification validation in the verification stage. It is also important to notice the issue of the disparity in the number of positive and negative samples in the sampling process of a binary classification problem. The difference in positive and negative samples can lead to the dominance of negative sample gradients during machine learning training, which can affect the performance of the speaker verification system. During the process of calculating similarity between positive and negative samples, there may be encountered an issue of overlapping similarity scores. If the overlapping portion is too large, it can reduce the discriminability between positive and negative samples, affecting the speaker system’s ability to distinguish between positive and negative samples. Considering the relatively compact distribution of positive and negative sample spaces, it is beneficial for enhancing the performance of the speaker system, and focusing more on the learning of difficult samples is conducive to improving the network’s convergence and generalization. Thus, this paper introduces an adaptive target function capable of solving these issues (SphereSpeaker). SphereSpeaker introduces different types of hyperparameters on the basis of Softmax, making it more suitable for handling speaker verification problems. SphereSpeaker also introduces three different angular margins to update the network, further enhancing the stability and generalization ability of the network model. Meanwhile, considering the issues of gradient vanishing, gradient explosion, and model degradation that can occur in deep neural networks, this paper introduces a deep neural network, which is named as Residual Network PReLu(ResNet-P). The experimental results indicate that compared to other deep neural network methods, this method has the lowest equal error rate, significantly improving the performance of the speaker verification system.

Multi-omics analysis reveals key immunogenic signatures induced by oncolytic Zika virus infection of paediatric brain tumour cells

Abstract Brain tumours disproportionately affect children and are the largest cause of paediatric cancer-related death. Novel therapies that engage the immune system, such as oncolytic viruses (OVs), hold great promise and are desperately needed. Zika virus (ZIKV) infects and destroys aggressive cells from multiple paediatric central nervous system (CNS) tumours. Despite this, the molecular mechanisms underpinning this response are largely unknown. We comprehensively investigate the transcriptomic response of paediatric medulloblastoma and atypical teratoid rhabdoid tumour (ATRT) cells to ZIKV infection. We observe conserved TNF signalling and cytokine signalling-related signatures and show that the TNF-alpha signalling pathway is implicated in oncolysis by reducing the viability of ZIKV-infected brain tumour cells. Our findings highlight TNF-alpha as a potential prognostic marker for oncolytic ZIKV (oZIKV) therapy. Complementing our analysis with a 49-plex ELISA, we demonstrate that ZIKV infection induces a clinically relevant and diverse pro-inflammatory brain tumour cell secretome, including TNF-alpha. We assess publicly available scRNA-Seq data to model how ZIKV-induced secretome paracrine and endocrine signalling may orchestrate the anti-tumoural immune response during oZIKV infection of brain tumours. Our findings significantly contribute to understanding the molecular mechanisms governing oZIKV infection and will help pave the way towards oZIKV therapy.

Nanoscale Grain Boundary-Weakened Ce–O Covalency and Surface Confinement Intrinsically Boosting Ceria Surface Oxygen Reactivity

Optochemical control over mRNA translation by photocaged phosphorodiamidate morpholino oligonucleotides in vivo

Abstract We developed an efficient, robust, and broadly applicable system for light-induced protein translation to control the production of proteins of interest and study their function. The method is based on the displacement of a single type of antisense morpholino from RNA by the uncaged guanidinium-linked morpholino (GMO)-phosphorodiamidate morpholino oligonucleotide (PMO) chimera upon UV irradiation. The GMO-PMO chimera designed here is cell-permeable and the GMO part can be produced employing a mercury-free approach compatible with the synthesis on solid support. We demonstrate the function of this optochemical approach in live embryos by inducing, at desired times and locations, the expression of proteins that label specific cells, ablate tissue regions, and affect embryonic development. Together, our results demonstrate that the cell-permeable GMO-PMO chimera offers a strategy for controlling the function of mRNAs of interest. This method allows for the production of proteins at specific times and positions within live organisms, facilitating numerous applications in biomedical research and therapy.

The Association between PTPN22 SNPs and susceptibility to type 1 diabetes: An updated meta-analysis

Type 1 diabetes (T1D) is a significant global health concern, characterized by the autoimmune destruction of insulin-producing pancreatic β-cells, resulting in lifelong dependence on insulin therapy. Although genetic predisposition plays a crucial role in the pathogenesis of T1D, environmental factors also contribute to its onset and progression. Recent research has identified a number of genetic polymorphisms, particularly in the protein tyrosine phosphatase non-receptor 22 gene (PTPN22), that are strongly associated with an increased risk of T1D and may serve as potential biomarkers for early diagnosis and prevention. Despite this, studies investigating the relationship between PTPN22 rs2476601 and T1D risk have consistently demonstrated an association in certain populations, whereas research on rs1310182 has yielded conflicting and less conclusive results. This study presents an updated meta-analysis of two key PTPN22 polymorphic loci — rs2476601 (C1858T) and rs1310182 (A852G) — with the aim of clarifying their associations with T1D. The analysis revealed a significant association between PTPN22 rs2476601 and an increased risk of T1D. In contrast, no significant correlation was found for rs1310182. These findings suggest that PTPN22 rs2476601 as a marker for T1D susceptibility, offering insights into the development of early intervention strategies. However, further research is required to validate these associations and deepen our understanding of the genetic factors involved in T1D pathogenesis.

A SMOTE PCA HDBSCAN approach for enhancing water quality classification in imbalanced datasets

Structure of human MUTYH and functional profiling of cancer-associated variants reveal an allosteric network between its [4Fe-4S] cluster cofactor and active site required for DNA repair

Abstract MUTYH is a clinically important DNA glycosylase that thwarts mutations by initiating base-excision repair at 8-oxoguanine (OG):A lesions. The roles for its [4Fe-4S] cofactor in DNA repair remain enigmatic. Functional profiling of cancer-associated variants near the [4Fe-4S] cofactor reveals that most variations abrogate both retention of the cofactor and enzyme activity. Surprisingly, R241Q and N238S retained the metal cluster and bound substrate DNA tightly, but were completely inactive. We determine the crystal structure of human MUTYH bound to a transition state mimic and this shows that Arg241 and Asn238 build an H-bond network connecting the [4Fe-4S] cluster to the catalytic Asp236 that mediates base excision. The structure of the bacterial MutY variant R149Q, along with molecular dynamics simulations of the human enzyme, support a model in which the cofactor functions to position and activate the catalytic Asp. These results suggest that allosteric cross-talk between the DNA binding [4Fe-4S] cofactor and the base excision site of MUTYH regulate its DNA repair function.

Population structure of yellowtail snapper using age-based life history and otolith shape in southern Gulf of México

Yellowtail snapper Ocyurus chrysurus is commercially important throughout its distribution range. In southern Gulf of México, it is caught as part of a largely undocumented multispecific snapper fishery. Samplings were done at three fishing sites with the highest landings volume of Yucatán, México: Celestún, Dzilam de Bravo, and Río Lagartos. Age and growth parameters were generated with the von Bertalanffy growth model via annuli counts in otolith thin sections of 1,124 individuals. Marginal increment analysis confirmed that opaque zone formation is annual and occurs from July to September. Overall age range was 0 + to 12 years (17.7 to 38.9 cm fork length) but differed between Celestún (0 + to 9 years), Dzilam de Bravo (1 to 12 years), and Río Lagartos (2 to 12 years). Growth parameters and lifespan for combined sexes also varied between sites: Celestún (L ∞ =  41.59 cm, K =  0.11 year-1, tmax =  22.41 years); Dzilam de Bravo (L ∞ =  38.36 cm, K =  0.16 year-1, tmax = 15.5 years); and Río Lagartos (L ∞ =  40.28 cm, K =  0.12 year-1, tmax =  20.01 years). Age at maturity was 1.3 years for females and < 1 year for males. Natural mortality based on tmax was 0.28 year-1 overall. A principal coordinates analysis identified morphometric variables as explaining 92.2% of otolith differentiation by fishing site, with average centroid distances: Celestún, 1.98; Dzilam de Bravo, 2.22; and Río Lagartos, 2.75. Differences in growth rate, lifespan, natural mortality and otolith shape indicate that O. chrysurus in southern GoM exhibits structural complexities that suggest the occurrence of repercussions from fishing-induced demographic changes.

Molecular epidemiological surveillance of respiratory syncytial virus infection in Myanmar from 2019 to 2023

Enhanced Pyridine-Oxazoline Ligand-Enabled Pd(II)-Catalyzed Aminoacetoxylation of Alkenes for the Asymmetric Synthesis of Biaryl-Bridged 7-Membered <i>N</i>-Heterocycles and Atropisomers

An automated framework for assessing how well LLMs cite relevant medical references

Evaluation of Onco E6 point of care rapid diagnostic test for human papilloma virus in Bahir Dar, Amhara Regional State, Ethiopia

Introduction Cervical cancer is a malignant tumor arising from the cells of the uterine cervix. The oncogenic human papillomavirus (HPV) infection is the main causative agent of cervical cancer. Effective HPV screening program can lead to a significant reduction in the morbidity and mortality associated with this cancer. Objective The aim of the study was to evaluate the diagnostic performance of OncoE6™ cervical test kit for cervical precancer and cancer in Amhara Regional State, northwest Ethiopia. Methods An institute-based cross-sectional study was conducted at Felege Hiwot Compressive Specialized Hospital which is found in Bahir Dar, Amhara Regional state. A total of 297 samples were collected. A sterile, disposable speculum was inserted, without lubricant, and two swabs were taken using the “Tipped Polyester” (Dacron) swab provided with the Onco E6™ kit. Swabs taken were tested for onco E6 proteins testing as per the manufacturer’s protocol and pap smear for cytology test. A punch of biopsy was also taken for histopathological diagnosis. Data for all samples were collected using pre-prepared excel database for onco E6 test, pap cytology and punch histopathology. All the data were coded and entered into Epi-info and transported to SPSS version 26.0 software package for analysis. Results Out of 56 (18.86%) participants who tested positive on the histo-pathological diagnosis, Onco E6 was positive in 32 (57.14%), negative in 24 (42.85%). Of 241 participants who tested negative on the histo-pathological diagnosis, Onco E6 was positive in 5 (2.07%) and negative in 236 (97.9%). OncoE6™ cervical test kit had a sensitivity of 57.14% (95% CI: 43.22%–70.29%) and specificity of 98% (95% CI: 95.23%–99.32%) with positive predictive value of 86.6% (95% CI: 71.36%–95.53%), negative predictive value of 90.76% (95% CI: 86.49%–93.93%), and accuracy of 90.18% (95% CI: 86.21%–93.31%). Conclusion The HPV 16/18 OncoE6™ Cervical test kit test had sub-optimum sensitivity and high specificity for detection of cervical precancer and cancer cases. The sensitivity of the kit could be increased by incorporating other more prevalent genotypes like genotype 52, 58, 31 and 35. The HPV16/18-E6 test could be used either as primary screening tool or in conjunction with other diagnostic methods.

Celastrol loaded nanocomplex for painless tumor therapy via YAP inhibition

Divergent evolution of slip banding in CrCoNi alloys

Abstract Metallic materials under high stress often exhibit deformation localization, manifesting as slip banding. Over seven decades ago, Frank and Read introduced the well-known model of dislocation multiplication at a source, explaining slip band formation. Here, we reveal two distinct types of slip bands (confined and extended) in compressed CrCoNi alloys through multi-scale testing and modeling from microscopic to atomic scales. The confined slip band, characterized by a thin glide zone, arises from the conventional process of repetitive full dislocation emissions at Frank–Read source. Contrary to the classical model, the extended band stems from slip-induced deactivation of dislocation sources, followed by consequent generation of new sources on adjacent planes, leading to rapid band thickening. Our findings provide insights into atomic-scale collective dislocation motion and microscopic deformation instability in advanced structural materials.

A phylogenomic perspective reveals mitochondrial-nuclear discordance and previously undescribed species nested within a widespread East African Reed frog species (Hyperolius substriatus Ahl, 1931)

The sub-montane East African Reed Frog, Hyperolius substriatus Ahl, 1931 (Spotted Reed Frog) has a fragmented highland distribution throughout East Africa. Previous studies show extensive mitochondrial divergence between four lineages of African Spotted Reed Frogs that roughly correspond to previously-recognized subspecies. These may have conservation implications if formally described. However, as mitochondrial-based population models only track maternal patterns, further genomic datasets are necessary to assess the distinctness of these lineages in relation to historically recognized morphological subspecies. In this study, we expanded sampling to newly discovered localities and assessed mitochondrial and genomic data to better understand phylogeography and landscape genomics of this species. We found that genomic clades (biparentally inherited) confirm some of the mitochondrial structure (female inherited), but also revealed multiple cases of mitonuclear discordance particularly within the Udzungwa Mountain block, which may have two separate founding events based on peripatric mitochondrial lineages and panmictic genomic signals. Taken together, the three clades within the geographical range of H. substriatus through Tanzania, Malawi, and Mozambique correspond to three previously-identified subspecies and lineages, and have both spatially cohesive and population-specific patterns of geneflow and isolation with neighboring highland locations.