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1.
Commun Med (Lond) ; 4(1): 79, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702451

RESUMO

BACKGROUND: Bulk transcriptional profiles of early colorectal cancer (CRC) can fail to detect biological processes associated with disease-free survival (DFS) if the transcriptional patterns are subtle and/or obscured by other processes' patterns. Consensus-independent component analysis (c-ICA) can dissect such transcriptomes into statistically independent transcriptional components (TCs), capturing both pronounced and subtle biological processes. METHODS: In this study we (1) integrated transcriptomes (n = 4228) from multiple early CRC studies, (2) performed c-ICA to define the TC landscape within this integrated data set, 3) determined the biological processes captured by these TCs, (4) performed Cox regression to identify DFS-associated TCs, (5) performed random survival forest (RSF) analyses with activity of DFS-associated TCs as classifiers to identify subgroups of patients, and 6) performed a sensitivity analysis to determine the robustness of our results RESULTS: We identify 191 TCs, 43 of which are associated with DFS, revealing transcriptional diversity among DFS-associated biological processes. A prominent example is the epithelial-mesenchymal transition (EMT), for which we identify an association with nine independent DFS-associated TCs, each with coordinated upregulation or downregulation of various sets of genes. CONCLUSIONS: This finding indicates that early CRC may have nine distinct routes to achieve EMT, each requiring a specific peri-operative treatment strategy. Finally, we stratify patients into DFS patient subgroups with distinct transcriptional patterns associated with stage 2 and stage 3 CRC.


While treatments for patients with colorectal cancer have improved, many patients (around 30-50%) have cancers that will eventually relapse and these patients will die due to their disease. Researchers have been studying the genes involved in colorectal cancer to help us understand why some cancers might relapse. However, current methods to do this may miss subtle or hidden patterns in the gene activity related to cancer relapse. To deal with this, we used a special method called consensus-independent component analysis (c-ICA) to dig more deeply into the activity of genes. This helped us to uncover some potential biological processes underpinning colorectal cancer relapse, which ultimately could help researchers to identify better treatments for patients with colorectal cancer.

2.
Clin Ophthalmol ; 18: 1157-1169, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707771

RESUMO

Purpose: To compare the outcomes of the Tecnis Eyhance ICB00 IOL, designed to enhance intermediate vision, to a conventional Tecnis Monofocal ZCB00 IOL. Methods: This retrospective analysis compared two cohorts of patients undergoing lens replacement surgery with bilateral implantation of the Tecnis ICB00 or the Tecnis ZCB00 IOL (383 patients in each group). Monocular and binocular uncorrected distance (UDVA), intermediate (UIVA; 66cm), and near (UNVA; 40cm) visual acuities, refractive predictability, and patient-reported outcomes were compared. A sub-analysis of patients with the Eyhance IOL was performed to compare patients who achieved bilateral emmetropia to those with mini-monovision. One-month postoperative outcomes were analyzed. Results: Both groups had comparable UDVA outcomes. On average, both monocular and binocular UIVAs were approximately one Snellen line better in patients implanted with Eyhance IOL (monocular UIVA: ICB00 0.23 ± 0.18 logMAR, ZCB00 0.33 ± 0.19 logMAR; binocular UIVA: ICB00 0.18 ± 0.18 logMAR, ZCB00 0.26 ± 0.20 logMAR, p < 0.01). Likewise, the mean UNVA was also one Snellen line better with the ICB00 model (monocular UNVA: ICB00 0.51 ± 0.20 logMAR, ZCB00 0.61 ± 0.18 logMAR; binocular UNVA: ICB00 0.42 ± 0.19 logMAR, ZCB00 0.51 ± 0.22 logMAR, p < 0.01). There was no difference between the two groups in overall satisfaction or visual phenomena. A subgroup of patients who achieved mini-monovision with Eyhance IOL had, on average, one Snellen line better UIVA and UNVA compared to patients with bilateral emmetropia. Conclusion: Patients receiving the enhanced monofocal IOL had better intermediate and near vision compared to those receiving the conventional monofocal IOL, with similar levels of patient-reported photic phenomena in both groups.

3.
Ecol Evol ; 14(5): e11373, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38711489

RESUMO

Megaherbivore carcasses represent sporadic but energetically rewarding resources for carnivores, offering a unique opportunity to study coexistence dynamics between facultative scavengers. South African fenced protected areas, such as Madikwe Game Reserve (Madikwe hereafter), host viable populations of large carnivores and high densities of elephants, Loxodonta africana. However, high carnivore densities can lead to potentially fatal interspecific encounters and increased competition, particularly around high-quality trophic resources. This study explores the temporal partitioning and co-detection strategies of carnivores at six elephant carcasses in Madikwe, aiming to understand how the increased carrion biomass available at elephant carcasses influences coexistence dynamics. Camera traps were deployed to monitor carcasses during two periods (2019 and 2020), revealing occurrences of six carnivore species. Carnivores, particularly black-backed jackals, Lupulella mesomelas, (hereafter jackal), lions, Panthera leo, and spotted hyaenas, Crocuta crocuta, comprised 56.7% of carcass observations, highlighting their pivotal roles in scavenging dynamics. Pairwise co-detection analysis demonstrated consistent association and shared peak activity periods between jackals and spotted hyaenas, indicating potential resource sharing. However, the minimal co-detection rates between lions and other carnivores highlight their resource domination. There was some evidence of temporal partitioning between carnivores, with most species exhibiting earlier peaks in nocturnal activity to avoid temporal overlap with lions. This study emphasises the importance of elephant carcasses in the diet of multiple species and coexistence techniques utilised to exploit this ephemeral resource. As fenced protected areas become crucial for conserving intact carnivore guilds globally, further research into carnivore behavioural adaptations at carcasses is recommended to shed light on their coexistence strategies.

4.
Birth ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38716628

RESUMO

BACKGROUND: Standardization of health systems often hinders client-centered care. This study investigates whether allowing more flexibility in the planning range of the Dutch home-based postpartum care service improves its quality of care, as innovative approach to client-centered care. METHODS: A randomized controlled trial was conducted (2017-2019), in which pregnant women who intended to breastfeed were assigned into two groups (1:1). The intervention group was allowed to receive care up to the 14th-day postpartum, instead of the first 8-10 consecutive days ("usual care"). Primary outcome measure was the proportion of newborns still receiving exclusively breastmilk on final caring day of the service. This so-called successful breastfeeding rate is currently used by the Dutch health sector to measure the quality of care. Secondary outcome measures were self-care experience, overall care experience, and exclusive breastfeeding duration rate. RESULTS: Based on data from 1275 participants, there was no difference in exclusive breastfeeding on final caring day (86,7% intervention group vs. 88,9% control group, RR: 1.03, 95% CI: 0.98-1.07). Both groups showed similar self-care experiences. Women in the intervention group had slightly poorer overall care experience and lower exclusive breastfeeding duration rates. CONCLUSIONS: This study found no effect on the quality of care when allowing more flexibility in the planning range of home-based postpartum care. Women can, therefore, be offered more flexibility to suit them. Given the confusion in interpreting the sector's current main quality indicator, we call for an inclusive dialogue on how to best measure the quality of home-based postpartum care.

5.
Haematologica ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38721739

RESUMO

Anti T-lymphocyte globulin (ATLG) is used in hematopoietic stem cell transplantation (HSCT) to prevent graft-versus-host disease (GvHD) and graft failure. To date, insight in ATLG pharmacokinetics and -dynamics (PK/PD) is limited, and population PK (POPPK) models are lacking. In this prospective study, we describe ATLG POPPK using NONMEM® and the impact of ATLG exposure on clinical outcome and immune reconstitution in a homogeneous cohort of pediatric acute lymphoblastic leukemia (ALL) patients transplanted with a matched unrelated donor and receiving uniform ATLG dosing. Based on 121 patients and 812 samples for POPPK analysis, a two-compartmental model with parallel linear and non-linear clearance and bodyweight as covariate, best described the ATLG concentrationtime data. The level of ATLG exposure (day active ATLG day 16 8.2%, p.

6.
Heart ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38729636

RESUMO

OBJECTIVE: Heart failure (HF) is characterised by collagen deposition. Urinary proteomic profiling (UPP) followed by peptide sequencing identifies parental proteins, for over 70% derived from collagens. This study aimed to refine understanding of the antifibrotic action of spironolactone. METHODS: In this substudy (n=290) to the Heart 'Omics' in Ageing Study trial, patients were randomised to usual therapy combined or not with spironolactone 25-50 mg/day and followed for 9 months. The analysis included 1498 sequenced urinary peptides detectable in ≥30% of patients and carboxyterminal propeptide of procollagen I (PICP) and PICP/carboxyterminal telopeptide of collagen I (CITP) as serum biomarkers of COL1A1 synthesis. After rank normalisation of biomarker distributions, between-group differences in their changes were assessed by multivariable-adjusted mixed model analysis of variance. Correlations between the changes in urinary peptides and in serum PICP and PICP/CITP were compared between groups using Fisher's Z transform. RESULTS: Multivariable-adjusted between-group differences in the urinary peptides with error 1 rate correction were limited to 27 collagen fragments, of which 16 were upregulated (7 COL1A1 fragments) on spironolactone and 11 downregulated (4 COL1A1 fragments). Over 9 months of follow-up, spironolactone decreased serum PICP from 81 (IQR 66-95) to 75 (61-90) µg/L and PICP/CITP from 22 (17-28) to 18 (13-26), whereas no changes occurred in the control group, resulting in a difference (spironolactone minus control) expressed in standardised units of -0.321 (95% CI 0.0007). Spironolactone did not affect the correlations between changes in urinary COL1A1 fragments and in PICP or the PICP/CITP ratio. CONCLUSIONS: Spironolactone decreased serum markers of collagen synthesis and predominantly downregulated urinary collagen-derived peptides, but upregulated others. The interpretation of these opposite UPP trends might be due to shrinking the body-wide pool of collagens, explaining downregulation, while some degree of collagen synthesis must be maintained to sustain vital organ functions, explaining upregulation. Combining urinary and serum fibrosis markers opens new avenues for the understanding of the action of antifibrotic drugs. TRIAL REGISTRATION NUMBER: NCT02556450.

8.
J Bone Jt Infect ; 9(2): 117-119, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38779580

RESUMO

Unilateral osteoarthritis of the knee can be treated by osteotomy. In case of postoperative infection after high tibial osteotomy, treatment can be challenging and often requires implant removal with the risk of loss of reduction. In the presented case, a 47-year old patient suffered postoperative infection after high tibial osteotomy using an angular stable plate with the need for multiple revision surgeries and anti-infective therapy. Implant exchange to a silver-coated angular plate led to infection control with undisturbed wound healing and further bone consolidation. Full bone consolidation could be achieved radiographically 12 months after the last revision surgery. One-step implant exchange using silver-coated implants could be a promising approach to address postoperative infections after high tibial osteotomy.

9.
J Hypertens ; 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38690919

RESUMO

OBJECTIVES: Hypertension is a common condition worldwide; however, its underlying mechanisms remain largely unknown. This study aimed to identify urinary peptides associated with hypertension to further explore the relevant molecular pathophysiology. METHODS: Peptidome data from 2876 individuals without end-organ damage were retrieved from the Human Urinary Proteome Database: general population (discovery) or type 2 diabetic (validation) cohorts. Participants were divided based on systolic blood pressure (SBP) and diastolic BP (DBP) into hypertensive (SBP ≥140 mmHg and/or DBP ≥90 mmHg) and normotensive (SBP <120 mmHg and DBP <80 mmHg, without antihypertensive treatment) groups. Differences in peptide abundance between the two groups were confirmed using an external cohort (n = 420) of participants without end-organ damage, matched for age, BMI, eGFR, sex, and the presence of diabetes. Furthermore, the association of the peptides with BP as a continuous variable was investigated. The findings were compared with peptide biomarkers of chronic diseases and bioinformatic analyses were conducted to highlight the underlying molecular mechanisms. RESULTS: Between hypertensive and normotensive individuals, 96 (mostly COL1A1 and COL3A1) peptides were found to be significantly different in both the discovery (adjusted) and validation (nominal significance) cohorts, with consistent regulation. Of these, 83 were consistently regulated in the matched cohort. A weak, yet significant, association between their abundance and standardized BP was also observed. CONCLUSION: Hypertension is associated with an altered urinary peptide profile with evident differential regulation of collagen-derived peptides. Peptides related to vascular calcification and sodium regulation were also affected. Whether these modifications reflect the pathophysiology of hypertension and/or early subclinical organ damage requires further investigation.

10.
Nat Commun ; 15(1): 4107, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750042

RESUMO

Many wide-gap organic semiconductors exhibit imbalanced electron and hole transport, therefore efficient organic light-emitting diodes require a multilayer architecture of electron- and hole-transport materials to confine charge recombination to the emissive layer. Here, we show that even for emitters with imbalanced charge transport, it is possible to obtain highly efficient single-layer organic light emitting diodes (OLEDs), without the need for additional charge-transport and blocking layers. For hole-dominated emitters, an inverted single-layer device architecture with ohmic bottom-electron and top-hole contacts moves the emission zone away from the metal top electrode, thereby more than doubling the optical outcoupling efficiency. Finally, a blue-emitting inverted single-layer OLED based on thermally activated delayed fluorescence is achieved, exhibiting a high external quantum efficiency of 19% with little roll-off at high brightness, demonstrating that balanced charge transport is not a prerequisite for highly efficient single-layer OLEDs.

11.
BMC Res Notes ; 17(1): 137, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750530

RESUMO

OBJECTIVE: The concept of lines of therapy (LOT) in cancer treatment is often considered for decision making in tumor boards and clinical management, but lacks a common definition across medical specialties. The complexity and heterogeneity of malignancies and treatment modalities contribute to an inconsistent understanding of LOT among physicians. This study assesses the heterogeneity of understandings of the LOT concept, its major dimensions, and criteria from the perspective of physicians of different specialties with an oncological focus in Germany. Semi-structured expert interviews with nine physicians were conducted and evaluated using qualitative content analysis. RESULTS: Most interviewees agreed that there is no single definition for LOT and found it difficult to explicate their understanding. A majority of experts stated that they had already encountered misunderstandings with colleagues regarding LOT and that they had problems with deciphering LOT from the medical records of their patients. Disagreement emerged about the roles of the following within the LOT concept: maintenance therapy, treatment intention, different therapy modalities, changing pharmaceutical agents, and therapy breaks. Respondents predominantly considered the same criteria as decisive for the definition of LOT as for a change in LOT (e.g., the occurrence of a progression event or tumor recurrence).


Assuntos
Neoplasias , Humanos , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Masculino , Feminino , Entrevistas como Assunto , Alemanha , Pessoa de Meia-Idade , Pesquisa Qualitativa , Adulto , Médicos/psicologia
12.
Eur J Heart Fail ; 2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38734982

RESUMO

AIM: In a randomized controlled trial, we recently showed that a natriuresis-guided diuretic approach improved natriuresis and diuresis in patients with acute heart failure (HF). In this pre-specified analysis, we investigated the association between (worsening) renal function, outcomes and the effect of intensive natriuresis-guided loop diuretic therapy as compared with standard of care. METHODS AND RESULTS: The Pragmatic Urinary Sodium-based algoritHm in Acute Heart Failure (PUSH-AHF) trial randomized patients to natriuresis-guided diuretic therapy or standard of care. Serum creatinine and estimated glomerular filtration rate (eGFR) were assessed at fixed timepoints, and worsening renal function (WRF) was assessed at 72 h. The primary outcome was the interaction between randomized treatment allocation, baseline eGFR and the dual primary outcome of PUSH-AHF: total natriuresis at 24 h and time to all-cause mortality or HF rehospitalization at 180 days. In 309 patients, median baseline eGFR was 53 (35-73) ml/min/1.73 m2, and 58% had eGFR <60 ml/min/1.73 m2. Baseline eGFR did not significantly modify the treatment effect of natriuresis-guided diuretic therapy on natriuresis at 24 h (p for interaction = 0.730). However, baseline eGFR significantly modified the effect on all-cause mortality and HF rehospitalization (p for interaction = 0.017): the risk of this second primary outcome was lower in patients with lower eGFR who were randomized to the natriuresis-guided group. In the natriuresis-guided arm, eGFR decreased more (-11.0 vs. -6.91 ml/min/1.73 m2; p = 0.002) during the first 3 days, but this effect was attenuated at discharge (-10.3 vs. -8.69 ml/min/1.73 m2; p = 0.38). WRF was more frequently observed in patients randomized to natriuresis-guided treatment, but was not associated with worse clinical outcomes. CONCLUSIONS: Natriuresis-guided diuretic treatment improved diuresis and natriuresis irrespective of baseline eGFR and occurrence of WRF, was effective even in patients with low eGFR, and the observed effect on eGFR was transient and not associated with worse clinical outcomes.

13.
BMJ Open ; 14(5): e078853, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38719323

RESUMO

INTRODUCTION: By implementation of Enhanced Recovery After Bariatric Surgery protocols and day-care surgery, early discharge poses a challenge if excessive bleeding occurs after bariatric surgery. Tranexamic acid (TXA) has demonstrated efficacy in other surgical fields and in bariatric pilot studies. This trial aims to assess the efficacy of peroperative administration of TXA in reducing haemorrhage in patients undergoing gastric bypass surgery. METHOD AND ANALYSIS: This is a multicentre, phase III, double-blind randomised controlled trial in six high-volume bariatric centres in the Netherlands. A total of 1524 eligible patients, aged 18 years or older, undergoing primary gastric bypass surgery (either Roux-en-Y gastric bypass or one-anastomosis gastric bypass) will be randomised between TXA and placebo (1:1, variable block, stratified for centre, day-care/overnight stay and type of surgery) after obtaining informed consent (2.5% less haemorrhage, power 80%, 2-sided-α 0.05 and 10% dropout). Exclusion criteria are pregnancy, amedical history of acute bleeding (without cause), venous thrombotic events (VTEs), epilepsy, anticoagulant use and iatrogenic bleeding during surgery (aside from staple line). The primary outcome is postoperative haemorrhage requiring intervention within 30 days postoperatively. Secondary outcome measures are staple line reinforcement, blood loss, duration of surgery, postoperative haemoglobin, vital parameters, minor and major complications, side effects of TXA (nausea, hypotension and VTE), length of hospital stay and directly made costs. ETHICS AND DISSEMINATION: Written informed consent will be obtained from all participants. The protocol has been approved by the Medical Research Ethics Committees United, Nieuwegein, on 7 February 2023 (registration number: R22.102). Results will be disseminated through peer-reviewed publications and conferences. TRIAL REGISTRATION NUMBER: NCT05464394.


Assuntos
Antifibrinolíticos , Derivação Gástrica , Obesidade Mórbida , Ácido Tranexâmico , Humanos , Ácido Tranexâmico/administração & dosagem , Ácido Tranexâmico/uso terapêutico , Derivação Gástrica/efeitos adversos , Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Antifibrinolíticos/administração & dosagem , Antifibrinolíticos/uso terapêutico , Método Duplo-Cego , Hemorragia Pós-Operatória/prevenção & controle , Hemorragia Pós-Operatória/etiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Feminino , Estudos Multicêntricos como Assunto , Adulto , Países Baixos , Ensaios Clínicos Fase III como Assunto , Masculino
14.
BMJ Open ; 14(5): e079540, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38760032

RESUMO

OBJECTIVES: Patients' preferences, values and contexts are important elements of the shared decision-making (SDM) process. We captured those elements into the concept of 'personal perspective elicitation' (PPE), which reflects the need to elicit patients' preferences, values and contexts in patient-clinician conversations. We defined PPE as: 'the disclosure (either elicited by the clinician or spontaneously expressed by the patient) of information related to the patient's personal preferences, values and/or contexts potentially relevant to decision-making'. Our goal was to operationalise the concept of PPE through the evaluation of preferences, values and contexts and explore how PPE occurs in clinical encounters. DESIGN: Cross-sectional study: observational coding based on a novel coding scheme of audio-recorded outpatient clinical encounters where encounter patient decision aids were applied. SETTING: We audio-recorded patient-clinician interactions at three Dutch outpatient clinics. PPE was analysed using a novel observational coding scheme, distinguishing preferences, contexts and four Armstrong taxonomy value types (global, decisional, external and situational). We measured SDM using the Observer OPTION5. PARTICIPANTS: Twenty patients who suffered from psoriasis or ovarian cysts; four clinicians. RESULTS: We included 20 audio-recordings. The mean Observer OPTION5 score was 57.5 (SD:10.1). The audio-recordings gave a rich illustration of preferences, values and contexts that were discussed in the patient-clinician interactions. Examples of identified global values: appearance, beliefs, personality traits. Decisional values were related to the process of decision-making. External values related to asking advice from for example, the clinician or significant others. An identified situational value: a new job ahead. Contexts related to how the illness impacted the life (eg, sexuality, family, sports, work life) of patients. CONCLUSIONS: The operationalisation of PPE, an important aspect of SDM, explores which preferences, values and contexts were discussed during patient-clinician interactions where an ePDA was used. The coding scheme appeared feasible to apply but needs further refinement.


Assuntos
Tomada de Decisão Compartilhada , Relações Médico-Paciente , Humanos , Feminino , Estudos Transversais , Países Baixos , Masculino , Pessoa de Meia-Idade , Adulto , Preferência do Paciente , Participação do Paciente , Gravação em Fita , Idoso , Comunicação
15.
Metabolites ; 14(5)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38786758

RESUMO

Volatile organic compounds (VOCs) might be associated with pulmonary oxygen toxicity (POT). This pilot study aims to identify VOCs linked to oxidative stress employing an in vitro model of alveolar basal epithelial cells exposed to hyperbaric and hyperoxic conditions. In addition, the feasibility of this in vitro model for POT biomarker research was evaluated. The hyperbaric exposure protocol, similar to the U.S. Navy Treatment Table 6, was conducted on human alveolar basal epithelial cells, and the headspace VOCs were analyzed using gas chromatography-mass spectrometry. Three compounds (nonane [p = 0.005], octanal [p = 0.009], and decane [p = 0.018]), of which nonane and decane were also identified in a previous in vivo study with similar hyperbaric exposure, varied significantly between the intervention group which was exposed to 100% oxygen and the control group which was exposed to compressed air. VOC signal intensities were lower in the intervention group, but cellular stress markers (IL8 and LDH) confirmed increased stress and injury in the intervention group. Despite the observed reductions in compound expression, the model holds promise for POT biomarker exploration, emphasizing the need for further investigation into the complex relationship between VOCs and oxidative stress.

16.
Entropy (Basel) ; 26(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38785650

RESUMO

Long-range interactions are relevant for a large variety of quantum systems in quantum optics and condensed matter physics. In particular, the control of quantum-optical platforms promises to gain deep insights into quantum-critical properties induced by the long-range nature of interactions. From a theoretical perspective, long-range interactions are notoriously complicated to treat. Here, we give an overview of recent advancements to investigate quantum magnets with long-range interactions focusing on two techniques based on Monte Carlo integration. First, the method of perturbative continuous unitary transformations where classical Monte Carlo integration is applied within the embedding scheme of white graphs. This linked-cluster expansion allows extracting high-order series expansions of energies and observables in the thermodynamic limit. Second, stochastic series expansion quantum Monte Carlo integration enables calculations on large finite systems. Finite-size scaling can then be used to determine the physical properties of the infinite system. In recent years, both techniques have been applied successfully to one- and two-dimensional quantum magnets involving long-range Ising, XY, and Heisenberg interactions on various bipartite and non-bipartite lattices. Here, we summarise the obtained quantum-critical properties including critical exponents for all these systems in a coherent way. Further, we review how long-range interactions are used to study quantum phase transitions above the upper critical dimension and the scaling techniques to extract these quantum critical properties from the numerical calculations.

17.
Sci Rep ; 14(1): 11940, 2024 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789658

RESUMO

The classic ketogenic diet is an effective treatment option for drug-resistant epilepsy, but its high fat content challenges patient compliance. Optimizing liver ketone production guided by a method comparing substrates for their ketogenic potential may help to reduce the fat content of the diet without loss in ketosis induction. Here, we present a liver cell assay measuring the ß-hydroxybutyrate (ßHB) yield from fatty acid substrates. Even chain albumin-conjugated fatty acids comprising between 4 and 18 carbon atoms showed a sigmoidal concentration-ßHB response curve (CRC) whereas acetate and omega-3 PUFAs produced no CRC. While CRCs were not distinguished by their half-maximal effective concentration (EC50), they differed by maximum response, which related inversely to the carbon chain length and was highest for butyrate. The assay also suitably assessed the ßHB yield from fatty acid blends detecting shifts in maximum response from exchanging medium chain fatty acids for long chain fatty acids. The assay further detected a dual role for butyrate and hexanoic acid as ketogenic substrate at high concentration and ketogenic enhancer at low concentration, augmenting the ßHB yield from oleic acid and a fatty acid blend. The assay also found propionate to inhibit ketogenesis from oleic acid and a fatty acid blend at low physiological concentration. Although the in vitro assay shows promise as a tool to optimize the ketogenic yield of a fat blend, its predictive value requires human validation.


Assuntos
Ácido 3-Hidroxibutírico , Dieta Cetogênica , Hepatócitos , Cetonas , Dieta Cetogênica/métodos , Humanos , Hepatócitos/metabolismo , Cetonas/metabolismo , Ácido 3-Hidroxibutírico/metabolismo , Epilepsia/dietoterapia , Epilepsia/metabolismo , Ácidos Graxos/metabolismo , Epilepsia Resistente a Medicamentos/dietoterapia , Epilepsia Resistente a Medicamentos/metabolismo
18.
Ecol Evol ; 14(4): e11304, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38628919

RESUMO

Mammals in arid zones have to trade off thermal stress, predation pressure, and time spent foraging in a complex thermal landscape. We quantified the relationship between the environmental heat load and activity of a mammal community in the hot, arid Kalahari Desert. We deployed miniature black globe thermometers within the existing Snapshot Safari camera trap grid on Tswalu Kalahari Reserve, South Africa. Using the camera traps to record species' activity throughout the 24-h cycle, we quantified changes in the activity patterns of mammal species in relation to heat loads in their local environment. We compared the heat load during which species were active between two sites with differing predator guilds, one where lion (Panthera leo) biomass dominated the carnivore guild and the other where lions were absent. In the presence of lion, prey species were generally active under significantly higher heat loads, especially during the hot and dry spring. We suggest that increased foraging under high heat loads highlights the need to meet nutritional requirements while avoiding nocturnal activity when predatory pressures are high. Such a trade-off may become increasingly costly under the hotter and drier conditions predicted to become more prevalent as a result of climate change within the arid and semi-arid regions of southern Africa.

19.
Cell Rep ; 43(4): 114110, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38607912

RESUMO

Transmembrane transporter proteins are essential for maintaining cellular homeostasis and, as such, are key drug targets. Many transmembrane transporter proteins are known to undergo large structural rearrangements during their functional cycles. Despite the wealth of detailed structural and functional data available for these systems, our understanding of their dynamics and, consequently, how they function is generally limited. We introduce an innovative approach that enables us to directly measure the dynamics and stability of interdomain interactions of transmembrane proteins using optical tweezers. Focusing on the osmoregulatory ATP-binding cassette transporter OpuA from Lactococcus lactis, we examine the mechanical properties and potential interactions of its substrate-binding domains. Our measurements are performed in lipid nanodiscs, providing a native-mimicking environment for the transmembrane protein. The technique provides high spatial and temporal resolution and allows us to study the functionally relevant motions and interdomain interactions of individual transmembrane transporter proteins in real time in a lipid bilayer.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Proteínas de Bactérias , Lactococcus lactis , Pinças Ópticas , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Lactococcus lactis/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Ligação Proteica , Domínios Proteicos , Imagem Individual de Molécula , Estabilidade Proteica , Bicamadas Lipídicas/metabolismo , Bicamadas Lipídicas/química
20.
Blood ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684038

RESUMO

The T-box transcription factor T-bet is known as a master regulator of T-cell response but its role in malignant B cells is not sufficiently explored. Here, we conducted single-cell resolved multi-omics analyses of malignant B cells from patients with chronic lymphocytic leukemia (CLL) and studied a CLL mouse model with genetic knockout of TBX21. We found that T-bet acts as a tumor suppressor in malignant B cells by decreasing their proliferation rate. NF-κB activity induced by inflammatory signals provided by the microenvironment, triggered T-bet expression which impacted on promoter proximal and distal chromatin co-accessibility and controlled a specific gene signature by mainly suppressing transcription. Gene set enrichment analysis identified a positive regulation of interferon signaling, and a negative control of proliferation by T-bet. In line, we showed that T-bet represses cell cycling and is associated with longer overall survival of CLL patients. Our study uncovers a novel tumor suppressive role of T-bet in malignant B cells via its regulation of inflammatory processes and cell cycling which has implications for stratification and therapy of CLL patients. Linking T-bet activity to inflammation explains the good prognostic role of genetic alterations in inflammatory signaling pathways in CLL.

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