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Breath analysis is a promising technique for lung cancer screening. Despite the rapid development of breathomics in the last four decades, no consistent, robust, and validated volatile organic compound (VOC) signature for lung cancer has been identified. This review summarizes the identified VOC biomarkers from both exhaled breath analysis and in vitro cultured lung cell lines. Both clinical and in vitro studies have produced inconsistent, and even contradictory, results. Methodological issues that lead to these inconsistencies are reviewed and discussed in detail. Recommendations on addressing specific issues for more accurate biomarker studies have also been made.

Research in bilingual healthy controls (BHC) has illustrated that detailed characterization of verbal fluency along with separate measures of executive control stand to inform our understanding of the lexical and cognitive underpinnings of the task. Such data are currently lacking in bilinguals with aphasia (BWA). We aimed to compare the characteristics of verbal fluency performance (semantic, letter) in Bengali–English BWA and BHC, in terms of cross-linguistic differences, variation on the parameters of bilingualism, and cognitive underpinnings. BWA showed significant differences on verbal fluency variables where executive control demands were higher (fluency difference score, number of switches, between-cluster pauses); whilst performed similarly on variables where executive control demands were lower (cluster size, within-cluster pauses). Despite clear cross-linguistic advantage in Bengali for BHC, no cross-linguistic differences were noted in BWA. BWA who were most affected in the independent executive control measures also showed greater impairment in letter fluency condition. Correlation analyses revealed a significant relationship for BWA between inhibitory control and number of correct responses, initial retrieval time, and number of switches. This research contributes to the debate of underlying mechanisms of word retrieval deficits in aphasia, and adds to the nascent literature of BWA in South Asian languages.

Carbon nanotubes' (CNTs) hollow interior space has been explored for biomedical applications, such as drug repository against undesirable inactivation. To further devise CNTs as smart material for controlled release of cargo molecules, we propose the concept of \"gold-carbon nanobottles\". After encapsulating cis-diammineplatinum(II) dichloride (cisplatin, CDDP) in CNTs, we covalently attached gold nanoparticles (AuNPs) at the open-tips of CNTs via different cleavable linkages, namely hydrazine, ester, and disulfide-containing linkages. Compared with our previous study in which more than 80% of CDDP leaked from CNTs in 2 hours, AuNPs were found to significantly decrease such spontaneous release to <40%. In addition, CDDP release from AuNP-capped CNTs via disulfide linkage was selectively enhanced by twofolds in reducing conditions (namely with 1 mM dithiothreitol [DTT]), which mimic the intracellular environment. We treated human colon adenocarcinoma cells HCT116 with our CDDP-loaded gold-carbon nanobottles and examined the cell viability using lactate dehydrogenase assay. Interestingly, we found that our nanobottles with cleavable disulfide linkage exerted stronger cytotoxic effect in HCT116 compared with normal human fetal lung fibroblast cells IMR-90. Therefore, we infer that our nanobottles strategy with inbuilt disulfide linkage could attain selective release of payload in highly reductive tumor tissues while avoiding collateral damage to normal tissues.

Research has shown that bilinguals can perform similarly, better or poorly on verbal fluency task compared to monolinguals. Verbal fluency data for semantic (animals, fruits and vegetables, and clothing) and letter fluency (F, A, S) were collected from 25 Bengali–English bilinguals and 25 English monolinguals in English. The groups were matched for receptive vocabulary, age, education and non-verbal intelligence. We used a wide range of measures to characterize fluency performance: number of correct, fluency difference score, time-course analysis (1 st RT, Sub-RT, initiation, slope), clustering, and switching. Participants completed three executive control measures tapping into inhibitory control, mental-set shifting and working memory. Differences between the groups were significant when executive control demands were higher such as number of correct responses in letter fluency, fluency difference score, Sub-RT, slope and cluster size for letter fluency, such that bilinguals outperform the monolinguals. Stroop performance correlated positively with the slope only for the bilinguals.

Profuse dendritic-synaptic interconnections among neurons in the neocortex embed intricate logic structures enabling sophisticated decision-making that vastly outperforms any artificial electronic analogues 1 – 3 . The physical complexity is far beyond existing circuit fabrication technologies: moreover, the network in a brain is dynamically reconfigurable, which provides flexibility and adaptability to changing environments 4 – 6 . In contrast, state-of-the-art semiconductor logic circuits are based on threshold switches that are hard-wired to perform predefined logic functions. To advance the performance of logic circuits, we are re-imagining fundamental electronic circuit elements by expressing complex logic in nanometre-scale material properties. Here we use voltage-driven conditional logic interconnectivity among five distinct molecular redox states of a metal–organic complex to embed a ‘thicket’ of decision trees (composed of multiple if-then-else conditional statements) having 71 nodes within a single memristor. The resultant current–voltage characteristic of this molecular memristor (a 'memory resistor', a globally passive resistive-switch circuit element that axiomatically complements the set of capacitor, inductor and resistor) exhibits eight recurrent and history-dependent non-volatile switching transitions between two conductance levels in a single sweep cycle. The identity of each molecular redox state was determined with in situ Raman spectroscopy and confirmed by quantum chemical calculations, revealing the electron transport mechanism. Using simple circuits of only these elements, we experimentally demonstrate dynamically reconfigurable, commutative and non-commutative stateful logic in multivariable decision trees that execute in a single time step and can, for example, be applied as local intelligence in edge computing 7 – 9 . Multiple redox transitions in a molecular memristor can be harnessed as ‘decision trees’ to undertake complex and reconfigurable logic operations in a single time step.

Non-volatile memories will play a decisive role in the next generation of digital technology. Flash memories are currently the key player in the field, yet they fail to meet the commercial demands of scalability and endurance. Resistive memory devices, and in particular memories based on low-cost, solution-processable and chemically tunable organic materials, are promising alternatives explored by the industry. However, to date, they have been lacking the performance and mechanistic understanding required for commercial translation. Here we report a resistive memory device based on a spin-coated active layer of a transition-metal complex, which shows high reproducibility (∼350 devices), fast switching (≤30 ns), excellent endurance (∼10 12  cycles), stability (>10 6  s) and scalability (down to ∼60 nm 2 ). In situ Raman and ultraviolet–visible spectroscopy alongside spectroelectrochemistry and quantum chemical calculations demonstrate that the redox state of the ligands determines the switching states of the device whereas the counterions control the hysteresis. This insight may accelerate the technological deployment of organic resistive memories. Organic resistive memories based on a spin-coated layer of a ruthenium complex with azo-aromatic ligands show high endurance, stability and fast switching speed, as well as good device reproducibility.

Word production is an essential feature of successful communication where semantic information (meaning) of a word is activated first, and this representation then activates the corresponding phonological form followed by the articulation of the target word. However, the production of words becomes effortful and impaired following neurological impairments (e.g., aphasia). The nature of word production impairments in aphasia is poorly understood and inadequately treated. In healthy monolingual speakers, word production involves selection of target word from competing lexical items within the target language. The situation becomes complicated for bilinguals with two sets of lexical systems leading to enhanced lexical competition. Research has shown different executive control processes are involved while resolving lexical competition. There is currently not a consensus in the literature as to whether this lexical competition is resolved in the same way by monolingual and bilingual speakers. Moreover, research on the nature of word production deficits in bilinguals with aphasia (BWA) and their relationship to executive control mechanism is not established in the literature, especially in Indian languages. In this project, we investigate the relationship between word production and executive control in a systematic and stepwise exploration in two phases (Phase I in UK and Phase II in India) by using different participant groups, wide range of linguistic measures, and separate executive control measures. Participants in Phase I were 25 healthy Bengali-English bilinguals and English monolinguals who were matched on age, gender, years of education, non-verbal intelligence, and vocabulary. Participants completed two linguistic experimental tasks (verbal fluency in Chapter 2 and blockedcyclic naming in Chapter 3) in English and three executive control tasks (inhibitory control: Stroop task, mental-set shifting: colour-shape switch task, working memory: backward digit span test). Results revealed bilinguals performed at par with the monolinguals in some linguistic measures (semantic fluency and heterogenous context in blocked-cyclic naming) and outperformed monolinguals in certain linguistic measures (e.g. letter fluency and homogenous context in blockedcyclic naming). Therefore, bilingual disadvantage in the linguistic domain can be negated if vocabulary is controlled for. Also, bilingual advantage in the non-linguistic domain can be extended to the linguistic domain if the linguistic tasks were made more challenging by increasing the executive control demands. Bilingual Participants in Phase II were eight Bengali-English BWA and eight Bengali-English bilingual healthy adults (BHA) who were matched on age, gender, years of education, and measures of bilingualism. Participants completed two linguistic tasks (verbal fluency in Chapter 4 and picture naming involving cognates and non-cognates in Chapter 5) in both languages and same executive control tasks as in Phase I, except for mental-set shifting (Trail Making Test). As expected, we found evidence of linguistic and executive control impairments at the group level for BWA individuals. Similar to the monolingual group in Phase I, we found BWA had more difficulty in the linguistic measures (e.g. fluency difference score, number of switches, between-cluster pause) where executive control demands were higher. However, the underlying executive control deficits in the linguistic tasks may not be visible with the usual analysis techniques. Therefore, we argued in favor of including a more fine-grained analysis of linguistic tasks. In terms of cross-linguistic impairment following a stroke, our results showed similar impairment in both the languages and the post-stroke language ability (e.g. better performance in Bengali) mirrored their pre-stroke language ability (Bengali dominant). Findings from the linguistic tasks revealed that despite showing deficits in lexical access, BWA still mirrored the BHA in terms of the underlying language processing mechanism which is required to perform in the linguistic tasks. In summary, performance differences on the linguistic measures were mediated by various factors such as the participant groups, nature of the task, language proficiency, and executive control abilities. We emphasise the importance of characterising the BWA participants in terms of their linguistic impairments in both languages, bilingualism related variables, separate linguistic and executive control measures and involved analysis approaches. We provide a foundation for future research on understanding the interplay of linguistic and executive control processes during word production in healthy bilinguals as well as in BWA population.

This corrects the article DOI: 10.1038/nmat5009.

Here, we report the presence of defect-related states with magnetic degrees of freedom in crystals of LaAlO 3 and several other rare-earth based perovskite oxides using inelastic light scattering (Raman spectroscopy) at low temperatures in applied magnetic fields of up to 9 T. Some of these states are at about 140 meV above the valence band maximum while others are mid-gap states at about 2.3 eV. No magnetic impurity could be detected in LaAlO 3 by Proton-Induced X-ray Emission Spectroscopy. We, therefore, attribute the angular momentum-like states in LaAlO 3 to cationic/anionic vacancies or anti-site defects. Comparison with the other rare earth perovskites leads to the empirical rule that the magnetic-field-sensitive transitions require planes of heavy elements (e.g. lanthanum) and oxygen without any other light cations in the same plane. These magnetic degrees of freedom in rare earth perovskites with useful dielectric properties may be tunable by appropriate defect engineering for magneto-optic applications.