Characteristic Pattern Research Articles

Cross-sectional study to evaluate the utility of elastic tissue staining in primary cicatricial alopecia

Background and aimsDiagnosing end-stage primary cicatricial alopecia (PCA) on routine histology is challenging since the major diagnostic feature (inflammatory infiltrate) may be minimal or absent. This study aimed to assess...

Preterm Piglets Born by Cesarean Section as a Suitable Animal Model for the Study of Iron Metabolism in Premature Infants.

Preterm infants are most at risk of iron deficiency. However, our knowledge of the regulation of iron homeostasis in preterm infants is poor. The main goal of our research was to develop and validate an animal model of human prematurity to assess iron status in preterm infants. We performed a cesarean section on sows on the 109th day of pregnancy, which corresponds to the last trimester of human pregnancy. Preterm piglets showed decreased body weight, red blood cell indices, plasma iron level and transferrin saturation. Interestingly, higher hepatic and splenic non-heme iron content and plasma and hepatic ferritin levels were found in premature piglets compared with term ones. In addition, premature piglets showed higher mRNA levels of iron-regulatory hormone hepcidin in the liver than term animals, which have not been reflected in higher plasma hepcidin-25 levels. We also showed changes in hepcidin regulators, including hepatic bone morphogenetic protein 6, plasma erythroferrone and growth differentiation factor 15 in preterm piglets. Consequently, no difference was observed in iron-exporter ferroportin levels in the spleen and liver. Overall, it seems that premature piglets show a pattern of iron metabolism characteristic of functional iron deficiency and iron accumulation in the tissue.

Green synthesis of magnetic silver nanocomposite: the photocatalytic performance of nanocomposite to decolorize organic dyes

ABSTRACT The magnetite-silver nanocomposites (Fe3O4-Ag NCs) were synthesized via a facile and green process by Citrus sinensis peel extract. The deposition of silver nanoparticles (NPs) was confirmed by observing an absorption peak at the maximum wavelength at 422 nm in the suspension solution of samples, which is related to silver surface plasmon resonance (SPR). The characteristic diffraction patterns of Fe3O4 and Ag phases were characterized utilizing the XRD patterns and the average size of the crystals was 21 nm. The photocatalytic behavior of Fe3O4-Ag NCs was studied for the destruction of three organic dyes methyl green (MG), methyl orange (MO), and methylene blue (MB) below UV radiation. The effect of the amount of photocatalyst and volume of hydrogen peroxide as an oxidant in the process of dye degradation was also investigated. The complete degradation time of dyes MB, MG, and MO under UV irradiation in the presence of 0.002 g Fe3O4-Ag NCs were 57, 33, and 49 min, respectively. The time of degradation reactions showed the high photocatalytic performance of Fe3O4-Ag NCs. These results proved that the synergistic effect of magnetite in the role of supporting the silver NPs was a significant contribution to the excellent decolorization behavior of Fe3O4-Ag NCs.

Ethnic stereotypes and prejudices of modern Russian youth

The article examines the theoretical foundations of the analysis of ethnic stereotypes and prejudices that have developed in modern sociological and socio-psychological science. The patterns of this phenomenon characteristic of modern society are highlighted. The results of the authors’ own empirical study of ethnic stereotypes and prejudices of modern Russian youth are presented that made it possible to identify the regional specificity of the manifestation of this phenomenon among Perm youth and to compared it with the Moscow youth. The specificity was identified according to behavioural (behaviour in the process of interethnic conflict; existence of interpersonal relationships with representatives of another ethnic group; orientation towards a certain type of relationship with representatives of another ethnic group), cognitive (knowledge about representatives of their own and other ethnic groups; trust in services provided by representatives of different ethnic groups and by migrants; trust in representatives of different ethnic groups) and emotional parameters (emotional attitude to the culture and traditions of another ethnic group; emotional attitude to interethnic conflict). The main factors influencing the formation of ethnic stereotypes and prejudices among Perm and Moscow youth are clarified. These results can be used for further study of regional characteristics of interethnic relations and ethnic stereotypes, prejudices, their dynamics and effective interaction of ethnophors as well as to optimise the process of interethnic relations.

ОСОБЕННОСТИ ВЗАИМООТНОШЕНИЙ МАРГИНАЛЬНЫХ ЭЛЕМЕНТОВ И ОБЩЕСТВА НА ПРИМЕРЕ ФЕНОМЕНА ПРОСТИТУЦИИ В XIX ВЕКЕ (ПО МАТЕРИАЛАМ ЕНИСЕЙСКОЙ ГУБЕРНИИ)

The paper is devoted to the study of various models of relations between the phenomenon of prostitution and society in the 19th century using the example of the local experience of the Yenisei Province. The specific socio-economic institution of legalized commercial sex with its specificity and intra-system connections is a unique phenomenon of pre-revolutionary Russia. While remaining a viable element of public life, part of provincial everyday life, the “industry of debauchery” was not an unambiguous phenomenon. In this context, it is relevant to consider the mutual perception of society and the phenomenon of prostitution during the period of regulation to form ideas about the versatility of everyday life in the province. The article is an attempt to understand the models and judgments of public institutions in relation to prostitution, as well as the behavioral patterns of women involved in the sphere of intimate services from a phenomenological point of view. The source base for the study consisted of office documents from various departments, journalistic works of a medical nature, as well as periodicals. The result of the study is the identification of several models of mutual perception of prostitution by society, which indicate polar opinions regarding this phenomenon. Speaking about the attitude of women involved in sexual commerce to society and its norms, it is worth noting the problem of the lack of sources of personal origin. However, it can be concluded that prostitution developed certain patterns of behavior characteristic of participants in the system.

Computed tomography and magnetic resonance imaging findings in central nervous system listeriosis.

To describe the imaging findings and determine the incidence of a characteristic worm-like pattern along the white matter tracts in neurolisteriosis on CT/MRI. An IRB-approved retrospective study in 21 consecutive neurolisteriosis cases during January 2002-July 2020. At least one of the following is required: (1) Positive Listeria monocytogenes (LM) in blood with clinical signs of meningeal irritation and/or abnormal CSF profile, (2) positive LM in blood with signs of encephalitis, (3) positive LM in CSF, (4) positive LM from brain biopsy/aspiration. Six cases were excluded due to the lack of contrast-enhanced images, leaving a total of 15 cases for analysis (mean age 53.5years ± 18.8 SD). The imaging studies were independently reviewed by two blinded readers. Demographic data, imaging findings, and incidence of the worm-like pattern were reported. The Cohen's kappa was used to calculate interrater reproducibility. Of the 12 patients with relevant imaging findings, nine cases (75%) had parenchymal lesions (eight cases in supratentorial compartment and one case in infratentorial compartment), four cases (33.3%) had leptomeningeal enhancement and two cases (16.7%) had hydrocephalus. Brain abscesses were found in eight cases and nodules evocative of abscess in one case. Restricted diffusion in the central area and hemosiderin deposition were observed in all cases. The involvement of white matter tract in a worm-like pattern was demonstrated in eight of nine patients with parenchymal lesions (88.9%). Abnormal findings in brain CT/MRI images are common in neurolisteriosis. The incidence of worm-like spread along the white matter tracts is high and may help diagnose suspicious patients.

Static and dynamic damping mechanical performance of architected metal-epoxy interpenetrating phase composites

The present contribution investigates the static and dynamic damping mechanical response of architected aluminum-epoxy interpenetrating phase composites (IPCs), engineered with strut, triply periodic minimal surfaces (TPMS), and stochastic spinodal AlSi10Mg reinforcement phases. Both single-phase metamaterials and co-continuous, multi-phase composites are analyzed, assessing the role of the reinforcement phase design and the addition of silicon carbide (SiC) nano-whisker epoxy enhancements in the effective mechanical performance. Aluminum-epoxy IPCs yield a constitutive response with peak, plateau stress, and overall energy absorptions up to 25 times higher than the ones recorded for the underlying single-phase metamaterials. Inner plastic strains, probed through dedicated finite element analysis, provide insights into the inner damage evolution, leading to characteristic ductile failure patterns, as revealed by computer tomography analysis. The exceptional specific energy absorption attributes are complemented by outstanding dynamic performance characteristics, with significant loss moduli over a broad range of frequencies and damping ratios up to 0.29.

Spatial distribution, sources, and human health risk assessment of elevated nitrate levels in groundwater of an agriculture-dominant coastal area in Hainan Island, China

In order to comprehend the groundwater nitrate contamination in Hainan Island, which is recognized as China's sole “tropical agricultural production base,” the distribution characteristics of nitrate in different aquifers and land-use types were elucidated through hydrochemical and geostatistical analysis methods. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and absolute principal component score-multiple linear regression (APCS-MLR) were employed for qualitative and quantitative analysis of the nitrate source. The results showed that NO3−-high (>88.57 mg/L) groundwater accounted for about 10 % of the total distribution area of the western coastal area in Hainan Island. Moreover, the proportions of NO3−-high groundwater in pore water and fissure water were 10 % and 7 %, respectively. The order of groundwater nitrate concentration in different land-use types was as follows: bare land, cultivated land, construction land, grassland, and woodland. The main sources of elevated nitrate concentrations in pore water were animal feces and nitrogen/potassium fertilizers, accounting for 45.4 % of the overall contribution. These substances infiltrated through the vadose zone, leaching out and mobilizing selenium within this zone, ultimately leading to the characteristic enrichment patterns observed in pore water, including nitrate, arsenic, potassium, and selenium. Furthermore, the occurrence of high nitrate in fissure water was mainly attributed to the leaching of cultured manure, septic tank leakage, and infiltration of domestic sewage, accounting for a contribution rate of 32.9 %. Simultaneously, under oxidizing conditions, selenium became activated and entered groundwater through water flow, thereby exhibiting common enrichment characteristics with nitrate and potassium in fissure water. In addition, the assessment of human health risks revealed that 16 % and 40 % of groundwater samples posed unacceptable non-carcinogenic risks to adults and children respectively, with a higher risk for local children. The study recommends the reasonable application of chemical fertilizers, as well as the strengthening of sewage treatment capacity and standardized disposal of manure and feces, to reduce nitrate contamination of groundwater at source and ensure the safety of drinking water.

Modulation of early osteoarthritis by tibiofemoral re-alignment in sheep

ObjectiveTo investigate whether tibiofemoral alignment influences early knee osteoarthritis (OA). We hypothesized that varus overload exacerbates early degenerative osteochondral changes, and that valgus underload diminishes early OA. MethodNormal, over- and underload were induced by altering alignment via high tibial osteotomy in adult sheep (n = 8 each). Simultaneously, OA was induced by partial medial anterior meniscectomy. At 6 weeks postoperatively, OA was examined in five individual subregions of the medial tibial plateau using Kellgren-Lawrence grading, quantification of macroscopic OA, semiquantitative histopathological OA and immunohistochemical type-II collagen, ADAMTS-5, and MMP-13 scoring, biochemical determination of DNA and proteoglycan contents, and micro-computed tomographic evaluation of the subchondral bone. ResultsMultivariate analyses revealed that OA cartilaginous changes had a temporal priority over subchondral bone changes. Underload inhibited early cartilage degeneration in a characteristic topographic pattern (P ≥ 0.0983 vs. normal), in particular below the meniscal damage, avoided alterations of the subarticular spongiosa (P ≥ 0.162 vs. normal), and prevented the disturbance of otherwise normal osteochondral correlations. Overload induced early alterations of the subchondral bone plate microstructure towards osteopenia, including significantly decreased percent bone volume and increased bone surface–to–volume ratio (all P ≤ 0.0359 vs. normal). ConclusionThe data provide high-resolution evidence that tibiofemoral alignment modulates early OA induced by a medial meniscus injury in adult sheep. Since underload inhibits early OA, these data also support the clinical value of strategies to reduce the load in an affected knee compartment to possibly decelerate structural OA progression.

Impact of discontinuous grain size distributions on the spectral energy distribution of debris disks

Context. The collisional evolution of debris disks is expected to cause the characteristic wavy pattern, that is, an under- or overabundance of particles of specific sizes, of grain size distributions. This perturbed grain size distribution potentially leaves characteristic patterns in the spectral energy distribution (SED) of the disk system. Aims. We aim to quantify and understand the specific influence of discontinuous particle size distributions on the appearance of debris disks. For this purpose, we considered dust emission models based on two different grain size distributions, namely, one with a single power law and one with a broken power law. In particular, our study is focused on the impact of an overabundance of small grains and an underabundance of medium-sized grains on the far-IR and (sub-)millimeter regime on the dust reemission radiation and the potential to constrain discontinuities in the grain size distribution from (sub-)millimeter photometric measurements of debris disks. Methods. We compared the spectral index α (Fν ∝ να) in the case of a continuous grain size distribution with that of a discontinuous grain size distribution. We performed this comparison for central stars with different spectral types and two different disk structures (e.g., slim and broad debris dust rings). Results. Within the considered parameter space, we found a characteristic difference between the spectral slopes of the SED in the different scenarios. In particular, the overabundance of small grains resulting from collisional events and thus parameters defining the outcome of disk events in debris disks is potentially observable by comparison with the SED corresponding to a grain size distribution resulting from an ideal collisional cascade. More specifically, the overabundance of small grains leads to a steeper slope in the far-IR and sub-millimeter regime, while the spectral index in the millimeter regime is hardly affected. On the other hand, the underabundance of medium-sized grains results in a slight steepening of the far-IR slope of the SED, but its primary effect is on the millimeter slope of the SED, causing it to become shallower. We also found that the impact of an overabundance of small dust particles is more pronounced than that of an underabundance of medium-sized dust particles. We also found that the difference between the spectral indices for the two different grain size distributions is largest for debris disks around brighter central stars and broader disks. However, the impact of the considered spatial distributions described by the fractional width of the disk system is weak. Our results also show that the dust composition is not the sole physical mechanism responsible for the spectral inversion observed in the far-IR to millimeter part of the SED of debris disk systems. Furthermore, the location of the spectral break is placed at different wavelength regimes if the grain size distribution is considered as a function of blowout size and stellar type.

Abstract IA021: Novel genomic features of POLE-mutant tumors: the utility for tumor classification and identification of new driver alleles

Abstract Alterations in the exonuclease domain of POLE drive the development of ultramutated endometrial tumors with better prognosis. A hallmark of these tumors is the accumulation of G>T mutations in AGA sequences; however, understanding of their genomic features beyond the trinucleotide motifs is limited. We applied a novel computational framework to the whole-exome sequencing data of 524 endometrial tumors reported by The Cancer Genome Atlas network to analyze the extended DNA sequence context of ultramutation. We found that the presence of POLE driver alleles is associated with an increased frequency of G>T mutations in polypurine tracts. Sequences containing three consecutive purines, including the classic AGA context, are only moderately mutable, but the mutability increased abruptly as the tract length reached six or more purines. Moreover, mutations showed a strong preference for certain positions within the tracts, creating a characteristic quantifiable pattern. Using this signature, we developed a machine learning classifier to identify tumors with hitherto unknown POLE drivers and validated two new drivers, POLE-E978G and POLE-S461L, by functional assays in yeast. Unlike previously known pathogenic variants, the E978G substitution affects the DNA polymerase rather than exonuclease domain of POLE. We further show that the extended genomic signature of POLE ultramutation is shared by tumors with POLD1 drivers. These findings uncover new mechanisms of ultramutation and highlight the limitations of the current focus on POLE exonuclease domain variants when stratifying patients. Citation Format: Daria Ostroverkhova, Kathryn Tyryshkin, Annette K. Beach, Elizabeth A. Moore, Yosef Masoudi-Sobhanzadeh, Stephanie R. Barbari, Igor B Rogozin, Konstantin V Shaitan, Anna R Panchenko, Polina V. Shcherbakova. Novel genomic features of POLE-mutant tumors: the utility for tumor classification and identification of new driver alleles [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr IA021.

Cervical spinal cord hemisection impacts sigh and the respiratory reset in male rats.

Cervical spinal cord injury impacts ventilatory and non-ventilatory functions of the diaphragm muscle (DIAm) and contributes to clinical morbidity and mortality in the afflicted population. Periodically, integrated brainstem neural circuit activity drives the DIAm to generate a markedly augmented effort or sigh-which plays an important role in preventing atelectasis and thus maintaining lung function. Across species, the general pattern of DIAm efforts during a normal sigh is variable in amplitude and the extent of post-sigh "apnea" (i.e., the post-sigh inter-breath interval). This post-sigh inter-breath interval acts as a respiratory reset, following the interruption of regular respiratory rhythm by sigh. We examined the impact of upper cervical (C2 ) spinal cord hemisection (C2 SH) on the transdiaphragmatic pressure (Pdi ) generated during sighs and the post-sigh respiratory reset in rats. Sighs were identified in Pdi traces by their characteristic biphasic pattern. We found that C2 SH results in a reduction of Pdi during both eupnea and sighs, and a decrease in the immediate post-sigh breath interval. These results are consistent with partial removal of descending excitatory synaptic inputs to phrenic motor neurons that results from C2 SH. Following cervical spinal cord injury, a reduction in the amplitude of Pdi during sighs may compromise the maintenance of normal lung function.

The Need of Differential Diagnosis Between Vulvar Lichen Sclerosus and Autoimmune Dermatoses in Adolescent Girls.

Vulvar lichen sclerosus (VLS) is a chronic inflammatory condition affecting the anogenital region, which can manifest in prepubertal or adolescent patients. The prevailing theories point to autoimmune and genetic factors. The primary symptoms of VLS typically include vulvar itching, discomfort, dysuria, and constipation. Physical examination often reveals a characteristic figure8 pattern, involving the labia minora, clitoral hood, and perianal region. However, these symptoms and the age of onset are nonspecific and require differentiation from autoimmune dermatoses such as bullous diseases, pemphigus diseases, epidermolysis bullosa acquisita, and dermatitis herpetiformis. We performed this study to distinguish VLS from autoimmune dermatoses, and in doing so, uncover the underlying causes of chronic vulvar changes. This knowledge will enable healthcare providers to offer appropriate medical care to affected patients. The study was conducted between July 2020 and February 2021, with a sample of 55 girls aged 2-18years who did not have any systemic diseases. The study group was composed of 20 girls previously diagnosed with vulvar lichen sclerosus, while the control group included 35 girls without VLS. Questionnaires regarding the medical history of the children were completed by their legal guardians. Blood samples were collected and analyzed biochemically to assess human immunoglobulin A (IgA), IgG, and IgM antibodies against various substrates, including the desmosome of stratum spinosum, basement membrane zone, desmoglein 1 (DSG1), desmoglein 3 (DSG3), BP180-NC16A-4X, BP230gC, pemphigoid antigen, collagen type VII NC1, transitional epithelium, gliadin (GAF-3X), endomysium (EMA), and cellular nucleus (ANA). The analysis of the study group revealed that the most commonly observed signs and symptoms included: itching, soreness, burning sensations, and excoriation, as well as erythema or/and pallor of the skin and perineal mucosa. Among the assessed antibodies, only anti-GAF3x antibodies and ANA antibodies were detected. However, the results did not reach statistical significance (p > 0.5).

Relationship Between Hand Function and Handheld Ultrasound Imaging in Inclusion Body Myositis.

Ultrasound studies in inclusion body myositis (IBM) have reported a characteristic pattern of increased echointensity in the flexor digitorum profundus (FDP) with relative sparing of the flexor carpi ulnaris (FCU). We examined the relationship between echointensity of the FDP and FCU muscles and hand strength or patient-reported outcomes (PROs). A total of 15 patients with IBM were recruited. Ultrasound images of the FDP and FCU muscles were obtained by a point-of-care ultrasound and graded using the modified Heckmatt score. Hand grip and neutral pinch strength were measured by dynamometry. PROs were assessed by the IBM Upper Extremity Function Scale. FDP and/or FCU modified Heckmatt score showed a significant relationship with grip, neutral pinch strength, and PROs. Point-of-care ultrasound examination of the forearm may serve as an extension of the neuromuscular examination. The semi-qualitative echointensity rating based on modified Heckmatt score seems to correlate well with the objective strength measurement and PROs.

Elastic deformation as a tool to investigate watershed storage connectivity

Storage-discharge relationships and dynamic changes in storage connectivity remain key unknowns in understanding and predicting watershed behavior. In this study, we use Global Positioning System measurements of load-induced Earth surface displacement as a proxy for total water storage change in four climatologically diverse mountain watersheds in the western United States. Comparing total water storage estimates with stream-connected storage derived from hydrograph analysis, we find that each of the investigated watersheds exhibits a characteristic seasonal pattern of connection and disconnection between total and stream-connected storage. We investigate how the degree and timing of watershed-scale connectivity is related to the timing of precipitation and seasonal changes in dominant hydrologic processes. Our results show that elastic deformation of the Earth due to water loading is a powerful new tool for elucidating dynamic storage connectivity and watershed discharge response across scales in space and time.

Atypical Presentation of Metastatic Castrate-resistant Prostate Cancer in a Middle Aged African Male with Good Response to Radioligand Therapy.

Prostate cancer typically follows a characteristic pattern of metastatic spread to the pelvic lymph nodes and bone. Atypical patterns of metastasis are rare but have been documented. In African men, this disease tends to follow a more aggressive course, with the possibility of an atypical site of metastatic spread. We present a case of a 58-year- old African male with metastatic castrate-resistant prostate cancer who presented with both typical and atypical patterns of metastatic disease detected by a fluorine 18 prostate-specific membrane antigen positron emission tomography/computed tomography scan. This patient also had a good response to radioligand therapy.

The role of high-resolution impedance manometry to identify rumination syndrome in children with unexplained foregut symptoms.

Diagnosis of rumination syndrome (RS) relies on Rome IV criteria. Oesophageal high-resolution impedance manometry (HRIM) can objectively demonstrate the episodes of rumination, but its role in the diagnostic pathway is not yet established. We aimed to demonstrate the clinical contribution of this tool for the timely diagnosis of RS and diagnostic work-up of children with unexplained foregut symptoms deemed to be due to other conditions. HRIMs performed between 2012 and 2021 were searched to retrieve all diagnoses of RS. Medical records were reviewed for clinical data. Out of 461 HRIMs performed, 76 children had manometric diagnosis of RS (35 male, median age: 13 years). Of them, 47% were not clinically suspected as the symptoms did not fulfil clinical criteria for RS. The indications for HRIM in these cases were investigation of unexplained foregut symptoms (37%), suspected refractory gastroesophageal reflux disease (8%) and dysphagia (2%). Among all HRIMs performed for investigations of unexplained foregut symptoms (n = 80), 35% demonstrated rumination episodes. Identification of characteristic patterns of rumination on HRIM in children with unexplained foregut symptoms enables the immediate diagnosis of RS. Thus, in situations of diagnostic uncertainty, the use of HRIM at early stages of the diagnostic pathway would reduce unnecessary investigations and treatments.

Radiation-chemical synthesis and characterization of ferrihydrite from iron (III) nitrate

In this study, 2-line ferrihydrite (2L Fh) nanoparticles (NPles)were synthesized by radiation-chemical method from an alcoholic solution of iron (III) nitrate for the first time. The X-ray diffraction analysis confirmed that the synthetic powder exhibited the characteristic pattern of 2L Fh NPles. DSC-TG analysis conducted in air atmosphere further verified the formation of 2L Fh. SEM analysis showed the presence of mesoporous plate-like structures in the 2L Fh powder, consisting of aggregates of NPs with an average size of approximately 20 nm. The absence of impurity peaks on the X-ray diffractograms and energy dispersion spectra (EDX) confirmed the chemical purity of the produced 2L Fh NPles. Additionally, the XPS method detected the presence of nitrogen and carbon adsorbed to the developed surface of the 2L Fh plates. 2L Fh NPles, when dried in air at a temperature of 50 °C, rapidly dissolved in water. 2L Fh NPles alcohol suspensions were stabilized using surfactants polyethylenimine (PEI) and acetylacetone (AcAs). 2L Fh NPles showed good photocatalytic properties when irradiated with ultraviolet light of methyl violet (MV) dye. These 2L Fh NPles, synthesized using an environmentally friendly radiation-chemical method, have immense potential for applications in biomedicine and photocatalysis.

Synthesis of hybrid azobenzene-chalcone dyes and studies on their photophysical properties: Molecular recognition of carbonate and phosphate ions using a novel turn-off fluorescent probe

The work presented here describes the synthesis and comparative physiochemical studies of hybrid compounds C-1 to 5 of azobenzene A-1 and chalcone B-1, which exhibited the characteristic of both. Further, electron-withdrawing and donating substituents analogues have also been synthesized. The hybrid compound is unique in nature because it contains the phenolic -OH, -N = N-, as well as α,β-unsaturated enone functional groups. The photophysical properties of hybrid C-1 behaved more or less like the azobenzene moieties and showed the same pattern of UV–vis absorption as with the change in the polarity of the solvent and the change in the pH of the medium. Thus, in the non-polar solvent or in the water medium, the phenol form dominates with its yellow colour and in polar solvents shows an intense red colour of keto form. They show a dramatic quenching of fluorescence emission in the polar solvent. Furthermore, after screening, C-1 was found to show selective sensing of the aqueous CO32− ion as well as minimally with PO43- and show a characteristic colour change in an organic solvent such as CH3CN. A few ions also changed colour in DMF, but that was due to the only shifting of the tautomerization equilibrium from keto to enol form. The UV–vis as well as fluorescent spectral studies, determination of the detection limits, and binding constants illustrated significant sensing of CO32− ions. A systematic study was performed to understand the binding interactions of the chemosensor by using Job's plot and time-dependent 1H NMR studies that supported the involvement of phenoloc -OH and β carbon of α,β-unsaturated system. The characteristic pattern of UV–vis and interaction mode was confirmed by DFT studies. The applicability of chemosensor C-1 was demonstrated by the development of a paper strip model to check the presence of CO32− ions in different kinds of water in society.

Highly Sensitive Detection of T790 M with a Three-Level Characteristic Current by Thymine-Hg(II)-Thymine in the α-Hemolysin Nanopore.

Sensitive detection of resistance mutation T790 M is of great significance for early diagnosis and prognostic monitoring of non-small-cell lung cancer (NSCLC). In this paper, we showed a highly sensitive detection strategy for T790 M using a three-level characteristic current signal pattern in an α-hemolysin nanopore. A probe was designed that formed a C-T mismatched base pair with wild-type/P and a T-T mismatched with the T790M/P. The T790M/P produced a unique three-level characteristic current signal in the presence of mercury ions(II): first, T790M-Hg2+-P entering the vestibule of α-HL under the transmembrane potential and overhang of probe occupying the β-barrel, then probe unzipping from the T790M/P, T790 M temporally residing inside the nanocavity due to the interaction with Hg(II), and finally T790 M passing through the β-barrel. The blocking current distribution was concentrated with a small relative standard deviation of about 3%, and the signal peaks of T790 M and wild-type can be completely separated with a high separation resolution of more than 2.5, which achieved the highly sensitive detection of T790 M down to 0.001 pM (confidence level P 95%) with a linear range from 0.001 pM to 1 nM in human serum samples. This highly sensitive recognition strategy enables the detection of low abundance T790 M and provides a method for prognostic monitoring in NSCLC patients.