Behavioral encoding across timescales by region-specific dopamine dynamics.

The dorsal (DS) and ventral striatum (VS) receive dopaminergic projections that control motor functions and reward-related behavior. It remains poorly understood how dopamine release dynamics across different temporal scales in these regions are coupled to behavioral outcomes. Here, we employ the dopamine sensor dLight1.3b together with multiregion fiber photometry and machine learning-based analysis to decode dopamine dynamics across the striatum during self-paced exploratory behavior in mice. Our data show a striking coordination of rapidly fluctuating signal in the DS, carrying information across dopamine levels, with a slower signal in the VS, consisting mainly of slow-paced transients. Importantly, these release dynamics correlated with discrete behavioral motifs, such as turns, running, and grooming on a subsecond-to-minute time scale. Disruption of dopamine dynamics with cocaine caused randomization of action selection sequencing and disturbance of DS-VS coordination. The data suggest that distinct dopamine dynamics of DS and VS jointly encode behavioral sequences during unconstrained activity with DS modulating the stringing together of actions and VS the signal to initiate and sustain the selected action.

Ab Initio Design of Molecular Qubits with Electric Field Control.

Current scalable quantum computers require large footprints and complex interconnections due to the design of superconducting qubits. While this architecture is competitive, molecular qubits offer a promising alternative due to their atomic scale and tuneable properties through chemical design. The use of electric fields to precisely, selectively and coherently manipulate molecular spins with resonant pulses has the potential to solve the experimental limitations of current molecular spin manipulation techniques such as electron paramagnetic resonance (EPR) spectroscopy. EPR can only address a macroscopic ensemble of molecules, defeating the inherent benefits of molecule-based quantum information. Hence, numerous experiments have been performed using EPR in combination with electric fields to demonstrate coherent spin manipulation. In this work, we explore the underlying theory of spin-electric coupling in lanthanide molecules, and outline ab initio methods to design molecules with enhanced electric field responses. We show how structural distortions arising from electric fields generate coupling elements in the crystal field Hamiltonian within a Kramers doublet ground state and demonstrate the impact of molecular geometry on this phenomenon. We use perturbation theory to rationalize the magnetic and electric field orientation dependence of the spin-electric coupling. We use pseudo-symmetry point groups to decompose molecular distortions to understand the role that symmetry has on spin-electric coupling. Finally, we present an analytical electric field model of structural perturbations that provides large savings in computational expense and allows for the investigation of experimentally accessible electric field magnitudes which cannot be accessed using common ab initio methods.

Coercive Fields Exceeding 30 T in the Mixed-Valence Single-Molecule Magnet (CpiPr5)2Ho2I3.

Mixed-valence dilanthanide complexes of the type (CpiPr5)2Ln2I3 (CpiPr5 = pentaisopropylcyclopentadienyl; Ln = Gd, Tb, Dy) featuring a direct Ln-Ln σ-bonding interaction have been shown to exhibit well-isolated high-spin ground states and, in the case of the Tb and Dy variants, a strong axial magnetic anisotropy that gives rise to a large magnetic coercivity. Here, we report the synthesis and characterization of two new mixed-valence dilanthanide compounds in this series, (CpiPr5)2Ln2I3 (1-Ln; Ln = Ho, Er). Both compounds feature a Ln-Ln bonding interaction, the first such interaction in any molecular compounds of Ho or Er. Like the Tb and Dy congeners, both complexes exhibit high-spin ground states arising from strong spin-spin coupling between the lanthanide 4f electrons and a single σ-type lanthanide-lanthanide bonding electron. Beyond these similarities, however, the magnetic properties of the two compounds diverge. In particular, 1-Er does not exhibit observable magnetic blocking or slow magnetic relaxation, while 1-Ho exhibits magnetic blocking below 28 K, which is the highest temperature among Ho-based single-molecule magnets, and a spin reversal barrier of 556(4) cm-1. Additionally, variable-field magnetization data collected for 1-Ho reveal a coercive field of greater than 32 T below 8 K, more than 6-fold higher than observed for the bulk magnets SmCo5 and Nd2Fe14B, and the highest coercive field reported to date for any single-molecule magnet or molecule-based magnetic material. Multiconfigurational calculations, supported by far-infrared magnetospectroscopy data, reveal that the stark differences in magnetic properties of 1-Ho and 1-Er arise from differences in the local magnetic anisotropy of the lanthanide centers.

Identification of a CTX-M-255 ß-lactamase containing a G239S substitution selectively conferring resistance to penicillin/ß-lactamase inhibitor combinations.

OBJECTIVES: An Escherichia coli isolate, WGS1363, showed resistance to piperacillin/tazobactam but susceptibility to cephalosporins and contained a previously unrecognized ß-lactamase, CTX-M-255, as the only acquired ß-lactamase. CTX-M-255 was identical to CTX-M-27 except for a G239S substitution. Here, we characterize the hydrolytic spectrum of CTX-M-255 and a previously reported ß-lactamase, CTX-M-178, also containing a G239S substitution and compare it to their respective parental enzymes, CTX-M-27 and CTX-M-15. METHODS: All ß-lactamase genes were expressed in E. coli TOP10 and MICs to representative ß-lactam-antibiotics were determined. Furthermore, blaCTX-M-15,  blaCTX-M-27, blaCTX-M-178 and blaCTX-M-255 with C-terminal His-tag fusions were affinity purified for enzyme kinetic assays determining Michaelis-Menten kinetic parameters against representative ß-lactam-antibiotics and IC50s of clavulanate, sulbactam, tazobactam and avibactam. RESULTS: TOP10-transformants expressing blaCTX-M-178 and blaCTX-M-255 showed resistance to penicillin/ß-lactamase combinations and susceptibility to cephalothin and cefotaxime in contrast to transformants expressing blaCTX-M-15 and blaCTX-M-27. Determination of enzyme kinetic parameters showed that CTX-M-178 and CTX-M-255 both lacked hydrolytic activity against cephalosporins and showed impaired hydrolytic efficiency against penicillin antibiotics compared to their parental enzymes. Both enzymes appeared more active against piperacillin compared to benzylpenicillin and ampicillin. Compared to their parental enzymes, IC50s of ß-lactamase-inhibitors were increased more than 1000-fold for CTX-M-178 and CTX-M-255. CONCLUSIONS: CTX-M-178 and CTX-M-255, both containing a G239S substitution, conferred resistance to piperacillin/tazobactam and may be characterized as inhibitor-resistant CTX-M ß-lactamases. Inhibitor resistance was accompanied by loss of activity against cephalosporins and monobactams. These findings add to the necessary knowledge base for predicting antibiotic susceptibility from genotypic data.

Improved Dielectric Response of Solids: Combining the Bethe-Salpeter Equation with the Random Phase Approximation.

The Bethe-Salpeter equation (BSE) can provide an accurate description of low-energy optical spectra of insulating crystals-even when excitonic effects are important. However, due to high computational costs it is only possible to include a few bands in the BSE Hamiltonian. As a consequence, the dielectric screening given by the real part of the dielectric function can be significantly underestimated by the BSE. Here, we show that universally accurate optical response functions can be obtained by combining a four-point BSE-like equation for the irreducible polarizability with a two-point Dyson equation that includes the higher-lying transitions within the random phase approximation. The new method is referred to as BSE+. It has a computational cost comparable to the BSE but a much faster convergence with respect to the size of the electron-hole basis. We use the method to calculate refractive indices and electron energy loss spectra for a test set of semiconductors and insulators. In all cases the BSE+ yields excellent agreement with experimental data across a wide frequency range and outperforms both the BSE and the random phase approximation.

Intramolecular bridging strategies to suppress two-phonon Raman spin relaxation in dysprosocenium single-molecule magnets.

Dy(III) bis-cyclopentadienyl (Cp) sandwich compounds exhibit extremely strong single-ion magnetic anisotropy which imbues them with magnetic memory effects such as magnetic hysteresis, and has put them at the forefront of high-performance single-molecule magnets (SMMs). Owing to the great success of design principles focused on maximising the anisotropy barrier, ever higher Ueff values have been reported leading to significant slow down of single-phonon Orbach spin relaxation. However, anisotropy-based SMM design has largely ignored two-phonon Raman spin relaxation, which is still limiting the temperatures at which a memory effect can be observed. In this work, we study the suppression of Raman relaxation through covalent bridging of the Cp ligands by alkyl chains, testing the hypothesis that increasing the rigidity of the ligand framework results in a blue shift of low frequency vibrations in the first coordination sphere of the Dy(III) ion. This reshaping of the vibrational low-energy density of states (DOS) results in lower occupation of pseudo-acoustic phonons available to drive Raman relaxation at low temperatures. We simulate Orbach and Raman spin relaxation in a series of zero-, mono-, di- and tri-bridged [Dy(Cpttt)2]+ analogues fully ab initio, using a quantum mechanics (QM)/molecular mechanics (MM) condensed phase embedding protocol in a periodic solvent matrix as a generic and experimentally testable environment model that can include (pseudo-)acoustic phononic degrees of freedom. We show that this approach can simulate magnetic relaxation dynamics in the condensed phase for the existing non-bridged [Dy(Cpttt)2]+ compound with quantitative experimental accuracy. Subsequently, we find a significant slowing down of Raman relaxation can be achieved for the singly-bridged SMM, while the introduction of further bridges leads to faster relaxation. A key result being that we find the two-phonon Raman rates correlate with the purity of the first-excited Kramers doublet in terms of its mJ = ±13/2 content. Even though the bridging design principle is successful at progressively reshaping the low-energy DOS, the introduction of linker atoms in the equatorial plane successively degrades magnetic anisotropy, suggesting the importance of refined design of the linker chemistry. The accuracy of our results emphasises the value of a generic periodic solvent embedding model, such that it permits the modelling of molecular spin dynamics in the condensed phase without knowledge of a crystal structure. This allows the study of hypothetical molecules or aggregates under real-world conditions, which we expect to have utility beyond the field of molecular magnetism.

Spin-phonon coupling and magnetic relaxation in single-molecule magnets.

Electron-phonon coupling is important in many physical phenomena, e.g. photosynthesis, catalysis and quantum information processing, but its impacts are difficult to grasp on the microscopic level. One area attracting wide interest is that of single-molecule magnets, which is motivated by searching for the ultimate limit in the miniaturisation of binary data storage media. The utility of a molecule to store magnetic information is quantified by the timescale of its magnetic reversal processes, also known as magnetic relaxation, which is limited by spin-phonon coupling. Several recent accomplishments of synthetic organometallic chemistry have led to the observation of molecular magnetic memory effects at temperatures above that of liquid nitrogen. These discoveries have highlighted how far chemical design strategies for maximising magnetic anisotropy have come, but have also highlighted the need to characterise the complex interplay between phonons and molecular spin states. The crucial step is to make a link between magnetic relaxation and chemical motifs, and so be able to produce design criteria to extend molecular magnetic memory. The basic physics associated with spin-phonon coupling and magnetic relaxation was outlined in the early 20th century using perturbation theory, and has more recently been recast in the form of a general open quantum systems formalism and tackled with different levels of approximations. It is the purpose of this Tutorial Review to introduce the topics of phonons, molecular spin-phonon coupling, and magnetic relaxation, and to outline the relevant theories in connection with both the traditional perturbative texts and the more modern open quantum systems methods.

[Statement on the lower age limit for outpatient adenotomies and tonsillotomies]. / Stellungnahme zur Altersuntergrenze bei der ambulanten Durchführung von Adenotomien und Tonsillotomien.

At the beginning of 2023, there have been significant changes to the regulations for outpatient surgery in Germany, which were set out in a trilateral self-administration agreement between the umbrella association of statutory health insurance companies, the German Hospital Association and the Federal Association of Statutory Health Insurance Physicians. Among other things, a catalog stated circumstances under which an operation should not be carried out on an outpatient basis or should only be carried out with doubt. This catalog explains the patient's age: up to the first year of life, inpatient performance of a service can be justified. This formulation in itself means that children from one year of age on should regularly undergo outpatient surgery.In the german scientific societies for otolaryngology, head and neck surgery as well as for anesthesiology and intensive care medicine, doubts arose as to whether this age limit could also be scientifically justified for operations in the throat such as adenotomy or tonsillotomy.A search was carried out in international guidelines and in the international literature and the statements were evaluated. The results of this literature search were discussed with representatives of the Pediatric Otorhinolaryngology Working Group (AG PädHNO) of the German Society for Otorhinolaryngology, Head and Neck Surgery (DGHNO-KHC) and the scientific working group for pediatric anesthesia (WAKKA) of the German Society for Anesthesiology and Intensive Care Medicine (DGAI) in conferences.The consensus revealed that a strict age limit of the first year of life is not appropriate for the outpatient performance of adenotomies and tonsillotomies. First of all, specifying a strict age limit is questionable because, regardless of age, a number of other medical and social factors influence the responsible performance of outpatient operations. Furthermore, the age limit of one year is not considered appropriate in view of literature, guidelines and practical experience in the international area. The assessment of the literature and the consideration of the implementation in the international area make an age limit in the range of 2-3 years seem more appropriate.This review provides the responsible doctors with a variety of insights, aspects and arguments so that they can make their decision to carry out these operations on an outpatient or inpatient basis appropriately and responsibly.

Taming Super-Reduced Bi23- Radicals with Rare Earth Cations.

Here, we report the synthesis of two new sets of dibismuth-bridged rare earth molecules. The first series contains a bridging diamagnetic Bi22- anion, (Cp*2RE)2(µ-η2:η2-Bi2), 1-RE (where Cp* = pentamethylcyclopentadienyl; RE = Gd (1-Gd), Tb (1-Tb), Dy (1-Dy), Y (1-Y)), while the second series comprises the first Bi23- radical-containing complexes for any d- or f-block metal ions, [K(crypt-222)][(Cp*2RE)2(µ-η2:η2-Bi2•)]·2THF (2-RE, RE = Gd (2-Gd), Tb (2-Tb), Dy (2-Dy), Y (2-Y); crypt-222 = 2.2.2-cryptand), which were obtained from one-electron reduction of 1-RE with KC8. The Bi23- radical-bridged terbium and dysprosium congeners, 2-Tb and 2-Dy, are single-molecule magnets with magnetic hysteresis. We investigate the nature of the unprecedented lanthanide-bismuth and bismuth-bismuth bonding and their roles in magnetic communication between paramagnetic metal centers, through single-crystal X-ray diffraction, ultraviolet-visible/near-infrared (UV-vis/NIR) spectroscopy, SQUID magnetometry, DFT and multiconfigurational ab initio calculations. We find a πz* ground SOMO for Bi23-, which has isotropic spin-spin exchange coupling with neighboring metal ions of ca. -20 cm-1; however, the exchange coupling is strongly augmented by orbitally dependent terms in the anisotropic cases of 2-Tb and 2-Dy. As the first examples of p-block radicals beneath the second row bridging any metal ions, these studies have important ramifications for single-molecule magnetism, main group element, rare earth metal, and coordination chemistry at large.

Structural Evolution of Paramagnetic Lanthanide Compounds in Solution Compared to Time- and Ensemble-Average Structures.

Anisotropy in the magnetic susceptibility strongly influences the paramagnetic shifts seen in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) experiments. A previous study on a series of C3-symmetric prototype MRI contrast agents showed that their magnetic anisotropy was highly sensitive to changes in molecular geometry and concluded that changes in the average angle between the lanthanide-oxygen (Ln-O) bonds and the molecular C3 axis due to solvent interactions had a significant impact on the magnetic anisotropy and, consequently, the paramagnetic shift. However, this study, like many others, was predicated on an idealized C3-symmetric structural model, which may not be representative of the dynamic structure in solution at the single-molecule level. Here, we address this by using ab initio molecular dynamics simulations to simulate how the molecular geometry, in particular the angles between the Ln-O bonds and the pseudo-C3 axis, evolves over time in the solution, mimicking typical experimental conditions. We observe large-amplitude oscillations in the O-Ln-C̃3 angles, and complete active space self-consistent field spin-orbit calculations show that this leads to similarly large oscillations in the pseudocontact (dipolar) paramagnetic NMR shifts. The time-averaged shifts show good agreement with experimental measurements, while the large fluctuations suggest that an idealized structure provides an incomplete description of the solution dynamics. Our observations have significant implications for modeling the electronic and nuclear relaxation times in this and other systems where the magnetic susceptibility is exquisitely sensitive to the molecular structure.

Accurate and Efficient Spin-Phonon Coupling and Spin Dynamics Calculations for Molecular Solids.

Molecular materials are poised to play a significant role in the development of future optoelectronic and quantum technologies. A crucial aspect of these areas is the role of spin-phonon coupling and how it facilitates energy transfer processes such as intersystem crossing, quantum decoherence, and magnetic relaxation. Thus, it is of significant interest to be able to accurately calculate the molecular spin-phonon coupling and spin dynamics in the condensed phase. Here, we demonstrate the maturity of ab initio methods for calculating spin-phonon coupling by performing a case study on a single-molecule magnet and showing quantitative agreement with the experiment, allowing us to explore the underlying origins of its spin dynamics. This feat is achieved by leveraging our recent developments in analytic spin-phonon coupling calculations in conjunction with a new method for including the infinite electrostatic potential in the calculations. Furthermore, we make the first ab initio determination of phonon lifetimes and line widths for a molecular magnet to prove that the commonplace Born-Markov assumption for the spin dynamics is valid, but such "exact" phonon line widths are not essential to obtain accurate magnetic relaxation rates. Calculations using this approach are facilitated by the open-source packages we have developed, enabling cost-effective and accurate spin-phonon coupling calculations on molecular solids.

Tectonic and geological setting influence hot spring microbiology.

Hydrothermal systems form at divergent and convergent boundaries of lithospheric plates and within plates due to weakened crust and mantle plumes, playing host to diverse microbial ecosystems. Little is known of how differences in tectonic setting influence the geochemical and microbial compositions of these hydrothermal ecosystems. Here, coordinated geochemical and microbial community analyses were conducted on 87 high-temperature (>65°C) water and sediment samples from hot springs in Yellowstone National Park, Wyoming, USA (n = 41; mantle plume setting), Iceland (n = 41, divergent boundary), and Japan (n = 5; convergent boundary). Region-specific variation in geochemistry and sediment-associated 16S rRNA gene amplicon sequence variant (ASV) composition was observed, with 16S rRNA gene assemblages being nearly completely distinguished by region and pH being the most explanatory parameter within regions. Several low abundance ASVs exhibited cosmopolitan distributions across regions, while most high-abundance ASVs were only identified in specific regions. The presence of some cosmopolitan ASVs across regions argues against dispersal limitation primarily shaping the distribution of taxa among regions. Rather, the results point to local tectonic and geologic characteristics shaping the geochemistry of continental hydrothermal systems that then select for distinct microbial assemblages. These results provide new insights into the co-evolution of hydrothermal systems and their microbial communities.

The associations of sodium-glucose cotransporter-2 inhibitors versus dipeptidyl peptidase-4 inhibitors as add-on to metformin with fracture risk in patients with type 2 diabetes mellitus.

AIM: To investigate whether sodium-glucose cotransporter-2 (SGLT2) inhibitor use as compared to dipeptidyl peptidase-4 (DPP-4) inhibitor use as add-on to metformin is associated with the risk of any fracture or major osteoporotic fractures (MOFs). METHODS: A cohort study using the Clinical Practice Research Datalink (CPRD) Aurum database was conducted. All patients aged 18 years and older with a first-ever prescription for a DPP-4 inhibitor or an SGLT2 inhibitor as add-on to metformin between January 1, 2013 and June 30, 2020 were selected. Patients starting with SGLT2 inhibitors were matched (up to 1:3) on propensity scores to patients starting with DPP-4 inhibitors. Propensity scores were calculated based on sex, age, body mass index, comorbidities, comedication and lifestyle factors. Cox proportional hazard models were used to estimate the risk of fracture with SGLT2 inhibitor use as compared to DPP-4 inhibitor use. RESULTS: A total of 13 807 SGLT2 inhibitor users (age 55.4 ± 10.6 years, 36.7% female) were included in this study, matched with 28 524 DPP-4 inhibitor users (age 55.4 ± 8.0 years, 36.4% female). The risk of any fracture with current SGLT2 inhibitor use was similar compared with current DPP-4 inhibitor use (adjusted hazard ratio [aHR] 1.09, 95% confidence interval [CI] 0.91-1.31), as was the risk of MOFs (aHR 0.89, 95% CI 0.64-1.22) and the risk of fractures at any of the individual MOF sites. Additionally, no association was found with duration of SGLT2 inhibitor use (longest duration >811 days) for any of the individual SGLT2 inhibitor agents, or after stratification by sex and age. CONCLUSION: Use of SGLT2 inhibitors was not associated with the risk of any fracture, MOFs or fracture at the individual MOF sites when compared to DPP-4 inhibitor use.

Microbiome and photoperiod interactively determine thermal sensitivity of polar and temperate diatoms.

The effect of temperature on ectothermic organisms in the context of climate change has long been considered in isolation (i.e. as a single driver). This is challenged by observations demonstrating that temperature-dependent growth is correlated to further factors. However, little is known how the chronobiological history of an organism reflected in its adaptation to re-occurring cyclic patterns in its environment (e.g. annual range of photoperiods in its habitat) and biotic interactions with its microbiome, contribute to shaping its realized niche. To address this, we conducted a full-factorial microcosm multi-stressor experiment with the marine diatoms Thalassiosira gravida (polar) and Thalassiosira rotula (temperate) across multiple levels of temperature (4°C; 9°C; 13.5°C) and photoperiod (4 h; 16 h; 24 h), both in the presence or absence of their microbiomes. While temperature-dependent growth of the temperate diatom was constrained by short and long photoperiods, the polar diatom coped with a 24 h photoperiod up to its thermal optimum (9°C). The algal microbiomes particularly supported host growth at the margins of their respective fundamental niches except for the combination of the warmest temperature tested at 24 h photoperiod. Overall, this study demonstrates that temperature tolerances may have evolved interactively and that the mutualistic effect of the microbiome can only be determined once the multifactorial abiotic niche is defined.

Factors Affecting Early Cholecystectomy for Acute Cholecystitis in Older People-A Population-Based Study.

OBJECTIVES: Acute cholecystitis is one of the most common surgical presentations in Australia and increases with age. Guidelines recommend early laparoscopic cholecystectomy (within 7 days), as it results in shorter length of stay, reduced costs and readmission rates. Despite this, there is a perception that early cholecystectomy may result in higher morbidity and conversion to open surgery in older patients. Our objective is to report the proportion of early versus delayed cholecystectomy in older patients in New South Wales (NSW), Australia, and to compare health outcomes and factors influencing variation. DESIGN: This is a retrospective population-based cohort study of all cholecystectomies for primary acute cholecystitis in NSW residents aged >50, between 2009 and 2019. The primary outcome was the proportion of early versus delayed cholecystectomy. We used multilevel multivariable logistic regression analyses adjusted for age, sex, comorbidities, insurance status, socio-economic status and hospital characteristics. RESULTS: A high rate (85%) of the 47,478 cholecystectomies in older patients were performed within 7 days of admission. Delayed surgery was associated with increasing age and comorbidity, male sex, Medicare-only insurance and surgery in low- or medium-volume centres. Early surgery was associated with shorter overall length of stay, fewer readmissions, less conversion to open surgery and lower bile duct injury rates. CONCLUSION: A high proportion of adults with cholecystitis are undergoing early cholecystectomy in NSW. Our results support the efficacy of early cholecystectomy in older patients and identify potentially modifiable factors relevant to health care professionals and policymakers.

The Danish landscape of providing support for caregivers of people with potentially life-threatening disease: A cross-sectional study among representatives of health services in Danish municipalities and hospitals.

AIMS: (a) To investigate support for caregivers of people diagnosed with stroke, cancer, chronic obstructive pulmonary disease (COPD), dementia, or heart disease provided across healthcare settings in Denmark; (b) to assess differences in caregiver support across diagnoses and settings. METHODS: A cross-sectional nationwide survey among professionals representing healthcare settings at municipalities (n = 479) and hospital wards and outpatient clinics (n = 425). The survey assessed identification of caregivers and support initiatives. RESULTS: The response rate was 81% for municipalities and 49% for hospitals. Identification of caregivers was frequent in dementia care (81% and 100%) and less frequent in COPD care (58% and 64%) in municipalities and hospitals, respectively. Caregiver support differed significantly across diagnoses within municipalities (p = 0.009) and hospitals (p < 0.001). Systematic identification of vulnerable caregivers was <25% for all diagnoses except dementia. The most common support initiatives involving caregivers were primarily aimed at the ill person and included guidance about the disease and consequences for everyday life and lifestyle changes. Caregivers were least involved in support initiatives addressing physical training, work retention, sexuality, or cohabitation. CONCLUSIONS: Disparities and significant differences across diagnoses exist in the identification of caregivers and the provision of support initiatives. Support initiatives involving caregivers primarily targeted patients. Future studies should investigate how caregivers' needs can be met across different diagnoses and healthcare settings and investigate potential changes in caregivers' needs during disease trajectories. In clinical practice, identification of vulnerable caregivers should be a major focus, and disease-specific clinical guidelines may be required to ensure sufficient support for caregivers.

A Dimerosesquiterpene and Sesquiterpene Lactones from Artemisia argyi Inhibiting Oncogenic PI3K/AKT Signaling in Melanoma Cells.

A library of more than 2500 plant extracts was screened for activity on oncogenic signaling in melanoma cells. The ethyl acetate extract from the aerial parts of Artemisia argyi displayed pronounced inhibition of the PI3K/AKT pathway. Active compounds were tracked with the aid of HPLC-based activity profiling, and altogether 21 active compounds were isolated, including one novel dimerosequiterpenoid (1), one new disesquiterpenoid (2), three new guaianolides (3-5), 12 known sesquiterpenoids (6-17), and four known flavonoids (19-22). A new eudesmanolide derivative (13b) was isolated as an artifact formed by methanolysis. Compound 1 is the first adduct comprising a sesquiterpene lactone and a methyl jasmonate moiety. The absolute configurations of compounds 1 and 3-18 were established by comparison of their experimental and calculated ECD spectra. The absolute configuration for 2 was determined by X-ray diffraction analysis. Guaianolide 8 was the most potent sesquiterpene lactone, inhibiting the PI3K/AKT pathway with an IC50 value of 8.9 ± 0.9 µM.

Combining Activity Profiling with Advanced Annotation to Accelerate the Discovery of Natural Products Targeting Oncogenic Signaling in Melanoma.

The discovery of bioactive natural products remains a time-consuming and challenging task. The ability to link high-confidence metabolite annotations in crude extracts with activity would be highly beneficial to the drug discovery process. To address this challenge, HPLC-based activity profiling and advanced UHPLC-HRMS/MS metabolite profiling for annotation were combined to leverage the information obtained from both approaches on a crude extract scaled down to the submilligram level. This strategy was applied to a subset of an extract library screening aiming to identify natural products inhibiting oncogenic signaling in melanoma. Advanced annotation and data organization enabled the identification of compounds that were likely responsible for the activity in the extracts. These compounds belonged to two different natural product scaffolds, namely, brevipolides from a Hyptis brevipes extract and methoxylated flavonoids identified in three different extracts of Hyptis and Artemisia spp. Targeted isolation of these prioritized compounds led to five brevipolides and seven methoxylated flavonoids. Brevipolide A (1) and 6-methoxytricin (9) were the most potent compounds from each chemical class and displayed AKT activity inhibition with an IC50 of 17.6 ± 1.6 and 4.9 ± 0.2 µM, respectively.

High-Content Screening Pipeline for Natural Products Targeting Oncogenic Signaling in Melanoma.

The incidence of melanoma, the most fatal dermatological cancer, has dramatically increased over the last few decades. Modern targeted therapy with kinase inhibitors induces potent clinical responses, but drug resistance quickly develops. Combination therapy improves treatment outcomes. Therefore, novel inhibitors targeting aberrant proliferative signaling in melanoma via the MAPK/ERK and PI3K/AKT pathways are urgently needed. Biosensors were combined that report on ERK/AKT activity with image-based high-content screening and HPLC-based activity profiling. An in-house library of 2576 plant extracts was screened on two melanoma cell lines with different oncogenic mutations leading to pathological ERK/AKT activity. Out of 140 plant extract hits, 44 were selected for HPLC activity profiling. Active thymol derivatives and piperamides from Arnica montana and Piper nigrum were identified that inhibited pathological ERK and/or AKT activity. The pipeline used enabled an efficient identification of natural products targeting oncogenic signaling in melanoma.

Data-based dynamic compartment model: Modeling of E. coli fed-batch fermentation in a 600 m3 bubble column.

Mathematical modeling is a powerful and inexpensive approach to provide a quantitative basis for improvements that minimize the negative effects of bioreactor heterogeneity. For a model to accurately represent a heterogeneous system, a flow model that describes how mass is channeled between different zones of the bioreactor volume is necessary. In this study, a previously developed compartment model approach based on data from flow-following sensor devices was further developed to account for dynamic changes in volume and flow rates and thus enabling simulation of the widely used fed-batch process. The application of the dynamic compartment model was demonstrated in a study of an industrial fermentation process in a 600 m3 bubble column bioreactor. The flow model was used to evaluate the mixing performance by means of tracer simulations and was coupled with reaction kinetics to simulate concentration gradients in the process. The simulations showed that despite the presence of long mixing times and significant substrate gradients early in the process, improving the heterogeneity did not lead to overall improvements in the process. Improvements could, however, be achieved by modifying the dextrose feeding profile.