Browse Articles

Enhancement of indigotin and indirubin production in root cultures of Isatis species by H2O2: biochemical and molecular responses

Isoprene chemistry under upper-tropospheric conditions

Abstract Isoprene (C5H8) is the non-methane hydrocarbon with the highest emissions to the atmosphere. It is mainly produced by vegetation, especially broad-leaved trees, and efficiently transported to the upper troposphere in deep convective clouds, where it is mixed with lightning NO x . Isoprene oxidation products drive rapid formation and growth of new particles in the tropical upper troposphere. However, isoprene oxidation pathways at low temperatures are not well understood. Here, in experiments at the CERN CLOUD chamber at 223 K and 243 K, we find that isoprene oxygenated organic molecules (IP-OOM) all involve two successive $${{{\rm{OH}}}}^{\bullet}$$ OH ∙ oxidations. However, depending on the ambient concentrations of the termination radicals ( $${{{{\rm{HO}}}}_{2}}^{\bullet},\,{{{\rm{NO}}}}^{\bullet}$$ HO 2 ∙ , NO ∙ , and $${{{\rm{NO}}}}_{2}^{\bullet}$$ NO 2 ∙ ), vastly-different IP-OOM emerge, comprising compounds with zero, one or two nitrogen atoms. Our findings indicate high IP-OOM production rates for the tropical upper troposphere, mainly resulting in nitrate IP-OOM but with an increasing non-nitrate fraction around midday, in close agreement with aircraft observations.

Genome editing strategies to generate working models of polycystic kidney disease

Influence of conventional and sustainable electroless baths on autocatalytic copper deposition

Chromosome segregation dynamics during the cell cycle of Staphylococcus aureus

Evidences of topological nodal line semimetal in Mn3GaC: Anomalous Hall effect, thermal transport and DFT studies

Abstract The non-trivial electronic transport in magnetic topological materials have attracted significant attention. Here, we present evidences of a topological nodal line semimetal in antiperovskite $$\hbox {Mn}_{{3}}$$ GaC along with the experimental studies such as the anomalous Hall effect (AHE), Kondo effect and thermal transport properties (Seebeck and Nernst effects). The upturn in the low-temperature electrical resistivity follows Hamann expression with the Kondo temperature $$T_{K}$$ = 16 K. The scaling analysis of the anomalous Hall conductivity ( $$\sigma _{AHE}$$ ) suggests that the AHE in $$\hbox {Mn}_{{3}}$$ GaC is primarily governed by coexistence of both intrinsic Berry curvature and skew scattering mechanisms. The experimentally observed value of $$\sigma _{AHE}$$ ( $$\sim$$ 50 $$\Omega ^{-1} \text {cm}^{-1}$$ ) is close to the theoretically calculated value. The low temperature Seebeck data suggests the presence of significant contribution of electron–magnon scattering, and a large value of Nernst coefficient is consistent with finite Berry curvature effects in $$\hbox {Mn}_{{3}}$$ GaC. The electronic band structure calculations with spin-orbit coupling, shows the formation of a drumhead-shaped surface states, and the existence of finite number of Weyl nodes, in consistence with the experimental findings.

Distinctive GABA A receptor subunit expression modulates cell specific EMT and functional responses in glioblastoma breast and ovarian cancer

Prolonged glucagon exposure rewires lipid oxidation and drives diabetic kidney disease progression

Sibling species differently distributed around a CO2 vent show transplantation proteomic remodelling, while displaying metabolomic signatures associated with their origin

Abstract The cellular homeostatic response (CHR) and cellular stress response (CSR) work together to maintain homeostasis. Studying phylogenetically closely-related species inhabiting different environments can help investigate the interplay between the CHR and CSR. We conducted reciprocal in situ transplant experiments in a natural CO2 vent (Ischia, Italy), using the sibling annelid species Platynereis cf.. dumerilii and Platynereis cf.. massiliensis which have been shown to have different preferential distributions around the CO2 vent. Following transplantations, we characterised the response of each individual’s proteome, metabolome, and lipidome, to short or long-term exposure to different pCO2 regimes (i.e., high and low), and confirmed its genetic identity. Here we show that different components of the CHR and CSR are utilised at different rates when Platynereis spp. are exposed to different pCO2 regimes, with cellular responses shown to be conserved across species. Metabolome and lipidome responses were dependent on regime of origin, and changed relatively slowly, whereas proteome responses were dependent on transplant type and changed more rapidly. Our results provide new insights to improve our understanding of the interplay between different cellular physiological responses involved in defining the functional phenotype of marine species, and their ability to acclimatise to future projected high pCO2 conditions.

Nephrologists’ perception of the French national guidelines in nephrology

Abstract In France, the “Haute Autorité de Santé” (HAS), an independent public scientific authority, regularly publishes guidelines targeted to healthcare professionals. As their implementation is left to the healthcare professionals’ discretion, their perception could influence their application. The aim of this study was to assess the nephrologists’ perception of the HAS guidelines on nephrology in general and on the access to the kidney transplant waiting list. We used a mixed methods approach with an exploratory design combining analysis of qualitative and quantitative data. Nephrologists practicing in France were included. We collected qualitative data in face-to-face semi-structured interviews and identified the main themes through an inductive thematic analysis. We collected quantitative data through an online questionnaire designed based on the qualitative findings. The analysis of interviews with 45 nephrologists (22 women) identified three main themes: (i) nephrologists’ knowledge and sources of information on HAS guidelines in nephrology; (ii) their perception of these guidelines and relevance to medical practice; (iii) age limit to access the kidney transplant waiting list in the 2015 guidelines. The quantitative analysis included 126 nephrologists (47.6% women), among whom 84.1% had already heard about these guidelines. Respectively, 85.8% and 80.2% found the guidelines “clear” and “complete”. Overall, the quantitative data confirmed the qualitative findings. This study shows how nephrologists perceive the HAS guidelines. This will inform discussions on how to make these guidelines more accessible to nephrologists. New studies could be carried out to better quantify and qualify the effect of these guidelines

The spatial complexity of optical computing: toward space-efficient design

Sugemalimab plus chemotherapy versus chemotherapy for advanced gastric cancer in China: a cost-effectiveness analysis

Ultraviolet A absorption coefficients of contact lenses for use in contact lens assisted corneal crosslinking for thin Corneas

Fully chemical interface engineering for statically and dynamically stable perovskite solar cells

Abstract The interfacial modifications between perovskite and charge-transport layers can arise from strong chemisorption bonds or weak physical adsorption interactions. However, modifications based on physical adsorption are susceptible to detachment, which not only disrupts the original energy level alignment and defect passivation but also introduces new charge recombination centers. Here, we report a fully chemical modification strategy in which the interfacial modifiers undergo an in situ crosslinking-like reaction, forming a localized, chemically bonded layer that seamlessly extends from the bulk of the underlying transport layer to the interface. Perovskite solar cells (PSCs) fabricated with this fully chemical modification strategy achieve a power conversion efficiency (PCE) of 25.52% (certified 25.49%) under standard conditions, representing one of the highest PCEs reported for devices fully fabricated in an ambient atmosphere. In terms of static stability, unencapsulated devices exhibit linear extrapolated T 80 lifetimes of 27,000 h during dark shelf storage and 19,000 h under thermal stress at 85 °C, both of which are record-breaking values for dark shelf and thermal stability, respectively. For dynamic stability, the devices maintain a linear extrapolated T 80 lifetime of 2,600 h under light-dark cycling, representing the most dynamically stable PSCs reported to date.

AgriFact framework for modelling the impact of farmers’ information demand on nationwide wheat productivity in India

Gender differences in opioid and stimulant poisoning in the central region of iran: a cross-sectional study

Aligning global mercury mitigation with climate action

Machine learning accelerates Raman computations from molecular dynamics for materials science

Raman spectroscopy is a powerful experimental technique for characterizing molecules and materials that is used in many laboratories. First-principles theoretical calculations of Raman spectra are important because they elucidate the microscopic effects underlying Raman activity in these systems. These calculations are often performed using the canonical harmonic approximation, which cannot capture certain thermal changes in the Raman response. Anharmonic vibrational effects were recently found to play crucial roles in several materials, which motivates theoretical treatments of the Raman effect beyond harmonic phonons. While Raman spectroscopy from molecular dynamics (MD-Raman) is a well-established approach that includes anharmonic vibrations and further relevant thermal effects, MD-Raman computations were long considered to be computationally too expensive for practical materials computations. In this perspective article, we highlight that recent advances in the context of machine learning have now dramatically accelerated the involved computational tasks without sacrificing accuracy or predictive power. These recent developments highlight the increasing importance of MD-Raman and related methods as versatile tools for theoretical prediction and characterization of molecules and materials.

A Davydov <i>Ansatz</i> approach to accurate system–bath dynamics in the presence of multiple baths with distinct temperatures

We perform benchmark simulations using the time-dependent variational approach with the multiple Davydov Ansatz (mDA) to study real-time nonequilibrium dynamics in a single qubit model coupled to two thermal baths with distinct temperatures. A broad region of the parameter space has been investigated, accompanied by a detailed analysis of the convergence behavior of the mDA method. In addition, we have compared our mD2 results to those from two widely adopted, numerically “exact” techniques: the methods of hierarchical equations of motion (HEOM) and the quasi-adiabatic path integral (QUAPI). It is found that the mDA approach in combination with thermal field dynamics yields numerically accurate, convergent results in nearly all regions of the parameter space examined, including those that pose serious challenges for QUAPI and HEOM. Our results reveal that mDA offers a highly adaptable framework capable of capturing long-time dynamics, even in challenging regimes where other methods face limitations. These findings underscore the potential of mDA as a versatile tool for exploring quantum thermodynamics, energy transfer processes, and non-equilibrium quantum systems.

Small matrix path integral in imaginary time

Thermal equilibrium properties are usually obtained from the imaginary-time path integral representation of the Boltzmann operator in combination with Monte Carlo integration methods. In some situations (identical fermions or frustrated Hamiltonians), the Boltzmann matrix leads to terms of alternating sign, which leads to a sign problem that severely impacts convergence. In this paper, we develop a robust and efficient quadrature-based method suitable for computing the Boltzmann matrix for discrete systems coupled to common or local harmonic baths. By expressing the discretized path integral with the influence functional in terms of a sum of matrix products, we develop a small matrix path integral (SMatPI) decomposition that allows iterative propagation in imaginary time while circumventing the storage of tensors employed in earlier work. The method is illustrated with several examples that involve two- and three-level systems coupled to common or local baths. We show that cyclic tight-binding Hamiltonians with positive coupling parameters give rise to Boltzmann matrix elements with alternating signs, presenting a severe sign problem to Monte Carlo approaches, while the SMatPI algorithm is stable and efficient.