Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.937
Filtrar
2.
Sci Rep ; 14(1): 13365, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862686

RESUMEN

In additive manufacturing (AM), process defects such as keyhole pores are difficult to anticipate, affecting the quality and integrity of the AM-produced materials. Hence, considerable efforts have aimed to predict these process defects by training machine learning (ML) models using passive measurements such as acoustic emissions. This work considered a dataset in which keyhole pores of a laser powder bed fusion (LPBF) experiment were identified using X-ray radiography and then registered both in space and time to acoustic measurements recorded during the LPBF experiment. Due to AM's intrinsic process controls, where a pore-forming event is relatively rare, the acoustic datasets collected during monitoring include more non-pores than pores. In other words, the dataset for ML model development is imbalanced. Moreover, this imbalanced and sparse data phenomenon remains ubiquitous across many AM monitoring schemes since training data is nontrivial to collect. Hence, we propose a machine learning approach to improve this dataset imbalance and enhance the prediction accuracy of pore-labeled data. Specifically, we investigate how data augmentation helps predict pores and non-pores better. This imbalance is improved using recent advances in data augmentation called Mixup, a weak-supervised learning method. Convolutional neural networks (CNNs) are trained on original and augmented datasets, and an appreciable increase in performance is reported when testing on five different experimental trials. When ML models are trained on original and augmented datasets, they achieve an accuracy of 95% and 99% on test datasets, respectively. We also provide information on how dataset size affects model performance. Lastly, we investigate the optimal Mixup parameters for augmentation in the context of CNN performance.

3.
Am Surg ; : 31348241262424, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38870480

RESUMEN

The aim was to determine whether on-call case volumes differ amongst colorectal surgeons, and what cases are performed on-call in an academic colorectal surgery practice. The on-call schedule for the year 2021 of a colorectal surgery practice was analyzed. Details of the case origin and operative details were collected. Average cases performed per call per surgeon were compared. Ten surgeons were included, and average cases per call ranged from .5 to 1.4 with 1.0 the overall average (P = .007). Analyzing individual pairs, differences existed between the 2 busiest and the least busy on-call surgeon (both P < .05). Most patients operated on-call were admitted via the emergency department (59%), and the most common operations were exams under anesthesia (39%) and bowel resections (33%). On average, 1 on-call case was performed per day. Surgeon on-call volume was similar aside from the busiest and least busy on-call surgeons.

5.
PeerJ ; 12: e17406, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38860213

RESUMEN

Amphibians are experiencing declines globally, with emerging infectious diseases as one of the main causes. Haematological parameters present a useful method for determining the health status of animals and the effects of particular diseases, but the interpretation of differential cell counts relies on knowing the normal ranges for the species and factors that can affect these counts. However, there is very little data on either normal haematological parameters or guides for blood cell types for free-ranging frog species across the world. This study aims to 1) create a visual guide for three different Australian frog species: Litoria paraewingi, Limnodynastes dumerilii, and Crinia signifera, 2) determine the proportions of erythrocytes to leukocytes and 3) differential leukocytes within blood smears from these three species and 4) assess the association between parasites and differential counts. We collected blood samples from free-ranging frogs and analysed blood smears. We also looked for ectoparasites and tested for the fungal disease chytridiomycosis. Overall, we found that the differentials of erythrocytes to leukocytes were not affected by species, but the proportions of different leukocytes did vary across species. For example, while lymphocytes were the most common type of leukocyte across the three species, eosinophils were relatively common in Limnodynastes dumerilii but rarely present in the other two species. We noted chytridiomycosis infection as well as ectoparasites present in some individuals but found no effect of parasites on blood parameters. Our results add baseline haematological parameters for three Australian frog species and provide an example of how different frog species can vary in their differential blood cell counts. More information is needed on frog haematological data before these parameters can be used to determine the health status of wild or captive frogs.


Asunto(s)
Anuros , Animales , Anuros/sangre , Anuros/parasitología , Anuros/microbiología , Australia , Valores de Referencia , Eritrocitos/parasitología , Recuento de Células Sanguíneas/veterinaria , Pruebas Hematológicas/veterinaria , Especificidad de la Especie , Recuento de Leucocitos , Masculino
6.
Artículo en Inglés | MEDLINE | ID: mdl-38864424

RESUMEN

DISCLAIMER: In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. PURPOSE: This article identifies, prioritizes, and summarizes published literature on the medication-use process (MUP) from calendar year 2021 that can impact health-system pharmacy daily practice. The MUP is the foundational system that provides the framework for safe medication utilization within the healthcare environment. The MUP is defined in this article as having the following components: prescribing/transcribing, dispensing, administration, and monitoring, and monitoring/medication reconciliation. Articles evaluating at least one step of the MUP were assessed for their usefulness toward practice improvement. SUMMARY: A PubMed search was conducted in January 2022 for articles published in calendar year 2021 using targeted Medical Subject Headings (MeSH) keywords, and searches of the table of contents of selected pharmacy journals were conducted, providing a total of 7,178 articles. A thorough review identified 79 potentially practice-enhancing articles: 15 for prescribing/transcribing, 17 for dispensing, 4 for administration, 21 for monitoring, and 22 for monitoring/medication reconciliation. Ranking of the articles for importance by peers led to the selection of key articles from each category. The highest-ranked articles are briefly summarized, with a mention of their importance within health-system pharmacy. The other articles are listed for further review and evaluation. CONCLUSION: It is important to routinely review the published literature and to incorporate significant findings into daily practice. This article assists in identifying and summarizing the most impactful publications. Health-system pharmacists have an active role in improving the MUP in their institution, and awareness of the significant published studies can assist in changing practice at the institutional level.

8.
mBio ; : e0119824, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38832773

RESUMEN

Stenotrophomonas maltophilia expresses a type IV protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria and does so partly by secreting the effector TfcB. Here, we report the structure of TfcB, comprising an N-terminal domain similar to the catalytic domain of glycosyl hydrolase (GH-19) chitinases and a C-terminal domain for recognition and translocation by the T4SS. Utilizing a two-hybrid assay to measure effector interactions with the T4SS coupling protein VirD4, we documented the existence of five more T4SS substrates. One of these was protein 20845, an annotated nuclease. A S. maltophilia mutant lacking the gene for 20845 was impaired for killing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Moreover, the cloned 20845 gene conferred robust toxicity, with the recombinant E. coli being rescued when 20845 was co-expressed with its cognate immunity protein. The 20845 effector was an 899 amino-acid protein, comprised of a GHH-nuclease domain in its N-terminus, a large central region of indeterminant function, and a C-terminus for secretion. Engineered variants of the 20845 gene that had mutations in the predicted catalytic site did not impede E. coli, indicating that the antibacterial effect of 20845 involves its nuclease activity. Using flow cytometry with DNA staining, we determined that 20845, but not its mutant variants, confers a loss in DNA content of target bacteria. Database searches revealed that uncharacterized homologs of 20845 occur within a range of bacteria. These data indicate that the S. maltophilia T4SS promotes interbacterial competition through the action of multiple toxic effectors, including a potent, novel DNase.IMPORTANCEStenotrophomonas maltophilia is a multi-drug-resistant, Gram-negative bacterium that is an emerging pathogen of humans. Patients with cystic fibrosis are particularly susceptible to S. maltophilia infection. In hospital water systems and various types of infections, S. maltophilia co-exists with other bacteria, including other pathogens such as Pseudomonas aeruginosa. We previously demonstrated that S. maltophilia has a functional VirB/D4 type VI protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria. Since most work on antibacterial systems involves the type VI secretion system, this observation remains noteworthy. Moreover, S. maltophilia currently stands alone as a model for a human pathogen expressing an antibacterial T4SS. Using biochemical, genetic, and cell biological approaches, we now report both the discovery of a novel antibacterial nuclease (TfdA) and the first structural determination of a bactericidal T4SS effector (TfcB).

9.
Nat Commun ; 15(1): 4912, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38851738

RESUMEN

Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative agent of Legionnaires' disease, these processes are not well understood. The Legionella collagen-like protein (Lcl) is an extracellular peripheral membrane protein that recognises sulphated glycosaminoglycans on the surface of eukaryotic cells, but also stimulates bacterial aggregation in response to divalent cations. Here we report the crystal structure of the Lcl C-terminal domain (Lcl-CTD) and present a model for intact Lcl. Our data reveal that Lcl-CTD forms an unusual trimer arrangement with a positively charged external surface and negatively charged solvent exposed internal cavity. Through molecular dynamics simulations, we show how the glycosaminoglycan chondroitin-4-sulphate associates with the Lcl-CTD surface via distinct binding modes. Our findings show that Lcl homologs are present across both the Pseudomonadota and Fibrobacterota-Chlorobiota-Bacteroidota phyla and suggest that Lcl may represent a versatile carbohydrate-binding mechanism.


Asunto(s)
Proteínas Bacterianas , Colágeno , Glicosaminoglicanos , Legionella pneumophila , Simulación de Dinámica Molecular , Unión Proteica , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Legionella pneumophila/metabolismo , Colágeno/metabolismo , Colágeno/química , Cristalografía por Rayos X , Sulfatos de Condroitina/metabolismo , Sulfatos de Condroitina/química , Adhesión Bacteriana , Dominios Proteicos , Enfermedad de los Legionarios/microbiología , Enfermedad de los Legionarios/metabolismo , Humanos , Secuencia de Aminoácidos
10.
Psychophysiology ; : e14629, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886908

RESUMEN

Social anxiety (SA) is characterized by anxious symptomology and fear during social situations, but recent work suggests that SA may not necessarily be associated with negative interpersonal and intrapersonal outcomes in support contexts. The current research investigates the discrepancies between self-perceptions, behavior, and physiological responses associated with SA in social support conversations with close friends. Specifically, we examined the associations between SA and positive and negative affect, perceptions of demands and resources, and responsiveness. Additionally, we used the biopsychosocial model of challenge and threat to understand the physiological responses associated with SA. Participants (79.9% White, 9.8% Black or African American, 10.3% Multiple races or other; 78.7% Female), totaling 172 undergraduate friend dyads, completed self-report measures and had physiological responses recorded while they discussed a problem unrelated to the friendship. Trained coders rated responsive behaviors exhibited during the conversation. Results revealed that greater SA was associated with greater negative perceptions of social interactions (greater negative affect, fewer perceived resources, and greater perceived demands). However, cardiovascular reactivity and behavioral responses within the conversation, as well as perceptions of partners' behavior after the conversation, contrasted with these negative perceptions. Indeed, greater SA was associated with greater sympathetic arousal (indicative of greater task engagement), but not with greater challenge or threat, and SA was not associated with perceived partner responsiveness or responsive behaviors. These results add to the growing body of research that suggests people with greater SA show inconsistencies between their conscious appraisals of social situations and their physiological responses.

11.
bioRxiv ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38895400

RESUMEN

Coordinated assembly of individual components into higher-order structures is a defining theme in biology, but underlying principles are not well-understood. In neurons, α/ß spectrins, adducin, and actinfilaments assemble into a lattice wrapping underneath the axonal plasma membrane, but mechanistic events leading to this periodic axonal structure (PAS) are unclear. Visualizing PAS components in axons as they develop, we found focal patches in distal axons containing spectrins and adducin (but sparse actin filaments) with biophysical properties reminiscent of biomolecular condensation. Overexpressing spectrin-repeats - constituents of α/ß-spectrins - in heterologous cells triggered condensate formation, and preventing association of ßII-spectrin with actin-filaments/membranes also facilitated condensation. Finally, overexpressing condensate-triggering spectrin repeats in neurons before PAS establishment disrupted the lattice, presumably by competing with innate assembly, supporting a functional role for biomolecular condensation. We propose a condensation-assembly model where PAS components form focal phase-separated condensates that eventually unfurl into a stable lattice-structure by associating with subplasmalemmal actin. By providing local 'depots' of assembly parts, biomolecular condensation may play a wider role in the construction of intricate cytoskeletal structures.

12.
Sci Rep ; 14(1): 13209, 2024 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-38851835

RESUMEN

Hypertension remains a leading cause of cardiovascular and kidney diseases. Failure to control blood pressure with ≥ 3 medications or control requiring ≥ 4 medications is classified as resistant hypertension (rHTN) and new therapies are needed to reduce the resulting increased risk of morbidity and mortality. Here, we report genetic evidence that relaxin family peptide receptor 2 (RXFP2) is associated with rHTN in men, but not in women. This study shows that adrenal gland gene expression of RXFP2 is increased in men with hypertension and the RXFP2 natural ligand, INSL3, increases adrenal steroidogenesis and corticosteroid secretion in human adrenal cells. To address the hypothesis that RXFP2 activation is an important mechanism in rHTN, we discovered and characterized small molecule and monoclonal antibody (mAb) blockers of RXFP2. The novel chemical entities and mAbs show potent, selective inhibition of RXFP2 and reduce aldosterone and cortisol synthesis and release. The RXFP2 mAbs have suitable rat pharmacokinetic profiles to evaluate the role of RXFP2 in the development and maintenance of rHTN. Overall, we identified RXFP2 activity as a potential new mechanism in rHTN and discovered RXFP2 antagonists for the future interrogation of RXFP2 in cardiovascular and renal diseases.


Asunto(s)
Hipertensión , Receptores Acoplados a Proteínas G , Receptores de Péptidos , Humanos , Masculino , Hipertensión/tratamiento farmacológico , Hipertensión/genética , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Animales , Receptores de Péptidos/genética , Receptores de Péptidos/metabolismo , Receptores de Péptidos/antagonistas & inhibidores , Ratas , Femenino , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Glándulas Suprarrenales/metabolismo , Glándulas Suprarrenales/efectos de los fármacos , Resistencia a Medicamentos/genética , Antihipertensivos/farmacología , Aldosterona/metabolismo
14.
J Chem Phys ; 160(22)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38860680

RESUMEN

This paper evaluates the accuracy of the Hermitian form of the downfolding procedure using the double unitary coupled cluster (DUCC) ansatz on the benchmark systems of linear chains of hydrogen atoms, H6 and H8. The computational infrastructure employs the occupation-number-representation codes to construct the matrix representation of arbitrary second-quantized operators, allowing for the exact representation of exponentials of various operators. The tests demonstrate that external amplitudes from standard single-reference coupled cluster methods that sufficiently describe external (out-of-active-space) correlations reliably parameterize the Hermitian downfolded effective Hamiltonians in the DUCC formalism. The results show that this approach can overcome the problems associated with losing the variational character of corresponding energies in the corresponding SR-CC theories.

15.
bioRxiv ; 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38853987

RESUMEN

Infection with clade I Mpox virus (MPXV) results in adverse pregnancy outcomes, yet the potential for vertical transmission resulting in fetal harm with clade IIb MPXV, the clade that is currently circulating in the Western Hemisphere, remains unknown. We established a rhesus macaque model of vertical MPXV transmission with early gestation inoculation. Three pregnant rhesus macaques were inoculated intradermally with 1.5 × 10^5 plaque forming units (PFU) of clade IIb MPXV near gestational day (GD) 30 and animals were monitored for viremia and maternal and fetal well-being. Animals were euthanized to collect tissues at 5, 14, or 25 days post-inoculation (dpi). Tissues were evaluated for viral DNA (vDNA) loads, infectious virus titers, histopathology, MPXV mRNA and protein localization, as well as MPXV protein co-localization with placental cells including, Hofbauer cells, mesenchymal stromal cells, endothelial cells, and trophoblasts. vDNA was detected in maternal blood and skin lesions by 5 dpi. Lack of fetal heartbeat was observed at 14 or 25 dpi for two dams indicating fetal demise; the third dam developed significant vaginal bleeding at 5 dpi and was deemed an impending miscarriage. vDNA was detected in placental and fetal tissue in both fetal demise cases. MPXV localized to placental villi by ISH and IHC. Clade IIb MPXV infection in pregnant rhesus macaques results in vertical transmission to the fetus and adverse pregnancy outcomes, like clade I MPXV. Further studies are needed to determine whether antiviral therapy with tecovirimat will prevent vertical transmission and improve pregnancy outcomes. One Sentence Summary: Clade IIb Mpox virus infection of pregnant rhesus macaques results in vertical transmission from mother to fetus and adverse pregnancy outcomes.

16.
Phys Chem Chem Phys ; 26(23): 16859-16870, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38832453

RESUMEN

We report the preparation of a co-crystal formed between the energetic molecule 3-nitro-1,2,4-triazol-5-one (NTO) and 4,4'-bipyridine (BIPY), that has been structurally characterised by high-pressure single crystal and neutron powder diffraction data up to 5.93 GPa. No phase transitions or proton transfer were observed up to this pressure. At higher pressures the crystal quality degraded and the X-ray diffraction patterns showed severe twinning, with the appearance of multiple crystalline domains. Computational modelling indicates that the colour changes observed on application of pressure can be attributed to compression of the unit cell that cause heightened band dispersion and band gap narrowing that coincides with a shortening of the BIPY π⋯π stacking distance. Modelling also suggests that the application of pressure induces proton migration along an N-H⋯N intermolecular hydrogen bond. Impact-sensitivity measurements show that the co-crystal is less sensitive to initiation than NTO, whereas computational modelling suggests that the impact sensitivities of NTO and the co-crystal are broadly similar.

17.
Artículo en Inglés | MEDLINE | ID: mdl-38853648

RESUMEN

Cancer Cachexia (CC) is a multifactorial and complex syndrome experienced by up to 80% of cancer patients and implicated in ~40% of cancer-related deaths. Given its significant impact on patients' quality of life and prognosis, there has been a growing emphasis on elucidating the underlying mechanisms of CC using pre-clinical models. However, the mechanisms of cachexia appear to differ across several variables including tumor type and model and biologic variables such as sex. These differences may be exacerbated by variance in experimental approaches and data reporting. This review examines literature spanning from 2011 to March 2024, focusing on common pre-clinical models of CC, including Lewis Lung Carcinoma, pancreatic KPC, and colorectal colon-26 and Apcmin/+ models. Our analysis reveals considerable heterogeneity in phenotypic outcomes, and investigated mechanisms within each model, with particular attention to sex differences which may be exacerbated through methodological differences. While searching for unified mechanisms is critical, we posit that effective treatment approaches are likely to leverage the heterogeneity presented by the tumor and pertinent biological variables to direct specific interventions. In exploring this heterogeneity, it becomes critical to consider methodological and data reporting approaches to best inform further research.

18.
Nat Commun ; 15(1): 4456, 2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38796494

RESUMEN

Charge, spin and Cooper-pair density waves have now been widely detected in exotic superconductors. Understanding how these density waves emerge - and become suppressed by external parameters - is a key research direction in condensed matter physics. Here we study the temperature and magnetic-field evolution of charge density waves in the rare spin-triplet superconductor candidate UTe2 using scanning tunneling microscopy/spectroscopy. We reveal that charge modulations composed of three different wave vectors gradually weaken in a spatially inhomogeneous manner, while persisting to surprisingly high temperatures of 10-12 K. We also reveal an unexpected decoupling of the three-component charge density wave state. Our observations match closely to the temperature scale potentially related to short-range magnetic correlations, providing a possible connection between density waves observed by surface probes and intrinsic bulk features. Importantly, charge density wave modulations become suppressed with magnetic field both below and above superconducting Tc in a comparable manner. Our work points towards an intimate connection between hidden magnetic correlations and the origin of the unusual charge density waves in UTe2.

19.
Front Bioeng Biotechnol ; 12: 1394704, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38798956

RESUMEN

Genetically modified (GM) crops that have been engineered to express transgenes have been in commercial use since 1995 and are annually grown on 200 million hectares globally. These crops have provided documented benefits to food security, rural economies, and the environment, with no substantiated case of food, feed, or environmental harm attributable to cultivation or consumption. Despite this extensive history of advantages and safety, the level of regulatory scrutiny has continually increased, placing undue burdens on regulators, developers, and society, while reinforcing consumer distrust of the technology. CropLife International held a workshop at the 16th International Society of Biosafety Research (ISBR) Symposium to examine the scientific basis for modernizing global regulatory frameworks for GM crops. Participants represented a spectrum of global stakeholders, including academic researchers, GM crop developers, regulatory consultants, and regulators. Concurrently examining the considerations of food and feed safety, along with environmental safety, for GM crops, the workshop presented recommendations for a core set of data that should always be considered, and supplementary (i.e., conditional) data that would be warranted only on a case-by-case basis to address specific plausible hypotheses of harm. Then, using a case-study involving a hypothetical GM maize event expressing two familiar traits (insect protection and herbicide tolerance), participants were asked to consider these recommendations and discuss if any additional data might be warranted to support a science-based risk assessment or for regulatory decision-making. The discussions during the workshop highlighted that the set of data to address the food, feed, and environmental safety of the hypothetical GM maize, in relation to a conventional comparator, could be modernized compared to current global regulatory requirements. If these scientific approaches to modernize data packages for GM crop regulation were adopted globally, GM crops could be commercialized in a more timely manner, thereby enabling development of more diverse GM traits to benefit growers, consumers, and the environment.

20.
Cureus ; 16(4): e59027, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38800193

RESUMEN

Pediatric arterial ischemic stroke is a rare but increasingly acknowledged disorder. Large vessel occlusions in this population have been treated off-label with endovascular thrombectomy. However, there is limited evidence to guide management. Small children, before the age of five when the cerebrovasculature reaches adult size, present additional challenges. We report the case of cardioembolic basilar occlusion in a two-year-old and the technical details of endovascular management, currently lacking in published literature. We employed a 5 French slender sheath, typically used for radial access, as a femoral short sheath. We accessed the dominant vertebral artery with a 5 French intermediate catheter, navigated with a typical 0.027-inch microcatheter and 0.014-inch microwire, and performed direct aspiration thrombectomy of the basilar clot. No closure device was employed. The patient had a near-complete and durable recovery. Small children present additional challenges for the endovascular management of stroke. Pre-procedural imaging can be used to design an aspiration-capable system appropriate for the child's size. Endovascular thrombectomy in children is feasible with some modifications to adult protocols.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...