Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Bioinformatics ; 40(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38960861

RESUMO

MOTIVATION: The alignment of sequencing reads is a critical step in the characterization of ancient genomes. However, reference bias and spurious mappings pose a significant challenge, particularly as cutting-edge wet lab methods generate datasets that push the boundaries of alignment tools. Reference bias occurs when reference alleles are favoured over alternative alleles during mapping, whereas spurious mappings stem from either contamination or when endogenous reads fail to align to their correct position. Previous work has shown that these phenomena are correlated with read length but a more thorough investigation of reference bias and spurious mappings for ancient DNA has been lacking. Here, we use a range of empirical and simulated palaeogenomic datasets to investigate the impacts of mapping tools, quality thresholds, and reference genome on mismatch rates across read lengths. RESULTS: For these analyses, we introduce AMBER, a new bioinformatics tool for assessing the quality of ancient DNA mapping directly from BAM-files and informing on reference bias, read length cut-offs and reference selection. AMBER rapidly and simultaneously computes the sequence read mapping bias in the form of the mismatch rates per read length, cytosine deamination profiles at both CpG and non-CpG sites, fragment length distributions, and genomic breadth and depth of coverage. Using AMBER, we find that mapping algorithms and quality threshold choices dictate reference bias and rates of spurious alignment at different read lengths in a predictable manner, suggesting that optimized mapping parameters for each read length will be a key step in alleviating reference bias and spurious mappings. AVAILABILITY AND IMPLEMENTATION: AMBER is available for noncommercial use on GitHub (https://github.com/tvandervalk/AMBER.git). Scripts used to generate and analyse simulated datasets are available on Github (https://github.com/sdolenz/refbias_scripts).


Assuntos
DNA Antigo , Análise de Sequência de DNA , DNA Antigo/análise , Humanos , Análise de Sequência de DNA/métodos , Software , Animais , Alinhamento de Sequência/métodos , Biologia Computacional/métodos , Algoritmos
2.
Macromol Rapid Commun ; 44(10): e2200972, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36913681

RESUMO

Polymer blending is an efficient way to obtain extraordinary polymeric materials. However, once permanently cross-linked thermosets are involved in blending, there are challenges in designing and optimizing the structures and interfacial compatibility of blends. Vitrimer with dynamic covalent polymer networks provides an innovative opportunity for blending thermoplastics and thermosets. Herein, a reactive blending strategy is proposed to develop thermoplastic-thermoset blend with enhanced compatibility on the basis of dynamic covalent chemistry. Specifically, polybutylene terephthalate (PBT) and polymerized epoxy vitrimer can be directly melt blended to obtain tough and thermostable blends with desirable microstructures and interfacial interaction. Bond exchange facilitates the grafting of PBT and epoxy vitrimer chains, thus enhancing the interfacial compatibility and thermal stability of blends. The obtained blend balances the strength and stretchability of PBT and epoxy vitrimer, resulting in enhanced toughness. This work offers a new way of designing and fabricating new polymeric materials by blending thermoplastics and thermosets. It also suggests a facile direction towards upcycling thermoplastics and thermosets.


Assuntos
Poliésteres , Polímeros , Resinas Epóxi , Polimerização
3.
J Chem Phys ; 158(22)2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37290088

RESUMO

We perform numerical and experimental studies on the melting process of thin films initiated by a small hole in the continuum regime. The presence of a nontrivial capillary surface, namely the liquid/air interface, leads to a few counterintuitive results: (1) The melting point is elevated if the film surface is partially wettable, even with a small contact angle. (2) For a film that is finite in size, melting may prefer to start from the outer boundary rather than a hole inside. (3) More complex melting scenarios may arise, including morphology transitions and the "de facto" melting point being a range instead of a single value. These are verified by experiments on melting alkane films between silica and air. This work continues a series of investigations on the capillary aspects of melting. Both our model and analysis approach can be easily generalized to other systems.


Assuntos
Dióxido de Silício , Propriedades de Superfície , Molhabilidade , Congelamento
4.
Molecules ; 28(14)2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37513228

RESUMO

Smartphone-assisted fluorescence and colorimetric methods for the on-site detection of Hg2+ and Cl- were established based on the oxidase-like activity of the Au-Hg alloy on the surface of Au/Cu/Ti3C2 NSs. The Au nanoparticles (NPs) were constructed via in-situ growth on the surface of Cu/Ti3C2 NSs and characterized by different characterization techniques. After the addition of Hg2+, the formation of Hg-Au alloys could promote the oxidization of o-phenylenediamine (OPD) to generate a new fluorescence emission peak of 2,3-diaminopenazine (ADP) at 570 nm. Therefore, a turn-on fluorescence method for the detection of Hg2+ was established. As the addition of Cl- can influence the fluorescence of ADP, the fluorescence intensity was constantly quenched to achieve the continuous quantitative detection of Cl-. Therefore, a turn-off fluorescence method for the detection of Cl- was established. This method had good linear ranges for the detection of Hg2+ and Cl- in 8.0-200.0 nM and 5.0-350.0 µM, with a detection limit of 0.8 nM and 27 nM, respectively. Depending on the color change with the detection of Hg2+ and Cl-, a convenient on-site colorimetric method for an analysis of Hg2+ and Cl- was achieved by using digital images combined with smartphones (color recognizers). The digital picture sensor could analyze RGB values in concentrations of Hg2+ or Cl- via a smartphone app. In summary, the proposed Au/Cu/Ti3C2 NSs-based method provided a novel and more comprehensive application for environmental monitoring.

5.
Angew Chem Int Ed Engl ; 61(50): e202213431, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36214646

RESUMO

Silanes are important in chemistry and material science. The self-redistribution of HSiCl3 is an industrial process to prepare SiH4 , which is widely used in electronics and automobile industries. However, selective silane cross-redistribution to prepare advanced silanes is challenging. We now report an enthalpy-driven silane cross-redistribution to access bis-silanes that contain two different types of Si-H bonds in the same molecule. Compared with entropy-driven reactions, the enthalpy-driven reaction shows high regioselectivity, broad substrate scope (62 examples) and high atom economy. Our combined experimental and computational study indicates that the reaction proceeds through a Ni0 -NiII -NiIV catalytic cycle.

6.
Phys Rev Lett ; 127(8): 088006, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477448

RESUMO

Microswimmers can serve as cargo carriers that move deep inside complex flow networks. When a school collectively entrains the surrounding fluid, their transport capacity can be enhanced. This effect is quantified with good agreement between experiments with self-propelled droplets and a confined Brinkman squirmer model. The volume of liquid entrained can be much larger than the droplet itself, amplifying the effective cargo capacity over an order of magnitude, even for dilute schools. Hence, biological and engineered swimmers can efficiently transport materials into confined environments.

7.
Proc Natl Acad Sci U S A ; 114(20): 5089-5094, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28465433

RESUMO

Chemotaxis and autochemotaxis play an important role in many essential biological processes. We present a self-propelling artificial swimmer system that exhibits chemotaxis as well as negative autochemotaxis. Oil droplets in an aqueous surfactant solution are driven by interfacial Marangoni flows induced by micellar solubilization of the oil phase. We demonstrate that chemotaxis along micellar surfactant gradients can guide these swimmers through a microfluidic maze. Similarly, a depletion of empty micelles in the wake of a droplet swimmer causes negative autochemotaxis and thereby trail avoidance. We studied autochemotaxis quantitatively in a microfluidic device of bifurcating channels: Branch choices of consecutive swimmers are anticorrelated, an effect decaying over time due to trail dispersion. We modeled this process by a simple one-dimensional diffusion process and stochastic Langevin dynamics. Our results are consistent with a linear surfactant gradient force and diffusion constants appropriate for micellar diffusion and provide a measure of autochemotactic feedback strength vs. stochastic forces. This assay is readily adaptable for quantitative studies of both artificial and biological autochemotactic systems.


Assuntos
Quimiotaxia , Dispositivos Lab-On-A-Chip , Óleos/química , Tensoativos/química , Modelos Químicos
8.
J Cell Physiol ; 234(11): 20161-20173, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30953357

RESUMO

The human absent in melanoma 2 (AIM2) is considered as a DNA recognizer. AIM2 has been described as a tumor suppressor gene in the early years. But recent studies suggested that it functions as an oncogene in several cancers. However, its roles in non-small-cell lung cancer (NSCLC) remain unclear. Here we reported that AIM2 highly expressed in NSCLC cells and exhibited a tumor-promoting property both in vitro and in vivo. Besides, AIM2 short hairpin RNA (shRNA)-mediated suppression of cell proliferation was triggered by the accumulation of cells at the G2/M phase. Knockdown of AIM2 reduced the inflammasome formation, while overexpression of AIM2 or stimulation by poly(dA:dT) induced the inflammasome formation. Interestingly, blockade of the inflammasome by caspase-1 inhibitor VX-765 or ASC small interfering RNA (siRNA) abolished the effects brought by AIM2 shRNA and AIM2 plasmid. In summary, our results revealed that AIM2 functioned as an oncogene in NSCLC in an inflammasome-dependent way.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Inflamassomos/genética , Neoplasias Pulmonares/genética , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/patologia , Caspase 1/genética , Divisão Celular/genética , Linhagem Celular Tumoral , Fase G2/genética , Genes Supressores de Tumor/fisiologia , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , RNA Interferente Pequeno/genética
9.
J Cell Biochem ; 120(10): 17744-17756, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31210372

RESUMO

Absent in melanoma 2 (AIM2) is a critical component in natural immunity system and is closely related to cancer initiation and development. It has been shown that AIM2 inhibited colorectal cancer (CRC) development and cell proliferation. It remains unresolved how AIM2 acts on CRC metastasis. In this study, we assessed migration, invasion ability, and epithelial-mesenchymal transition (EMT) program upon AIM2 overexpression or knockdown in human CRC cells. Transwell assay demonstrated that upregulation of AIM2 reduced cell migration and invasion. Epithelial marker E-cadherin was augmented and mesenchymal markers vimentin, as well as Snail, were examined decreased by Western blot, real-time polymerase chain reaction, and immunofluorescence. Correspondingly, knockdown of AIM2 led to a reverse consequence. In addition, AIM2 regulated Akt phosphorylation and effects of AIM2 on cell invasion and EMT were recovered after administration of Akt inhibitor, suggesting that AIM2 suppressed EMT dependent on Akt pathway. In addition, caspase-1 inhibitor exposure indicated that AIM2 abrogated EMT through the inflammasome pathway as well. In summary, AIM2 suppressed EMT via Akt and inflammasome pathways in human CRC cells.


Assuntos
Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/patologia , Proteínas de Ligação a DNA/metabolismo , Transição Epitelial-Mesenquimal , Inflamassomos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Invasividade Neoplásica , Fosforilação/efeitos dos fármacos , Transdução de Sinais
10.
Environ Sci Technol ; 53(9): 5124-5132, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30969102

RESUMO

In flooded soils, soil-water interface (SWI) is the key zone controlling biogeochemical dynamics. Chemical species and concentrations vary greatly at micro- to cm-scales. Techniques able to track these changing element profiles both in space and over time with appropriate resolution are rare. Here, we report a patent-pending technique, the Integrated Porewater Injection (IPI) sampler, which is designed for soil porewater sampling with minimum disturbance to saturated soil environment. IPI sampler employs a single hollow fiber membrane tube to passively sample porewater surrounding the tube. When working, it can be integrated into the sample introduction system, thus the sample preparation procedure is dramatically simplified. In this study, IPI samplers were coupled to ICP-MS at data-only mode. The limits of detection of IPI-ICP-MS for Ni, As, Cd, Sb, and Pb were 0.12, 0.67, 0.027, 0.029, and 0.074 µg·L-1, respectively. Furthermore, 25 IPI samplers were assembled into an SWI profiler using 3D printing in a one-dimensional array. The SWI profiler is able to analyze element profiles at high spatial resolution (∼2 mm) every ≥24 h. When deployed in arsenic-contaminated paddy soils, it depicted the distributions and dynamics of multiple elements at anoxic-oxic transition. The results show that the SWI profiler is a powerful and robust technique in monitoring dynamics of element profile in soil porewater at high spatial resolution. The method will greatly facilitate studies of elements behaviors in sediments of wetland, rivers, lakes, and oceans.


Assuntos
Arsênio , Poluentes do Solo , Monitoramento Ambiental , Solo , Água
11.
J Chem Phys ; 143(16): 164707, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26520543

RESUMO

We use thermal annealing to improve smoothness and to increase the lateral size of crystalline islands of n-tetratetracontane (TTC, C44H90) films. With in situ x-ray diffraction, we find an optimum temperature range leading to improved texture and crystallinity while avoiding an irreversible phase transition that reduces crystallinity again. We employ real-time optical phase contrast microscopy with sub-nm height resolution to track the diffusion of TTC across monomolecular step edges which causes the unusual smoothing of a molecular thin film during annealing. We show that the lateral island sizes increase by more than one order of magnitude from 0.5 µm to 10 µm. This desirable behavior of 2d-Ostwald ripening and smoothing is in contrast to many other organic molecular films where annealing leads to dewetting, roughening, and a pronounced 3d morphology. We rationalize the smoothing behavior with the highly anisotropic attachment energies and low surface energies for TTC. The results are technically relevant for the use of TTC as passivation layer and as gate dielectric in organic field effect transistors.

12.
J Obstet Gynaecol Res ; 41(10): 1653-60, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26446417

RESUMO

AIM: AKT signaling regulates multiple biological processes and expresses in various cancers. miR-205 plays complex roles in tumorigenesis and tumor progression by acting either as a tumor suppressor or an oncogene depending on the tumor type. Here we describe the molecular mechanism of miR-205 regulating epithelial-mesenchymal transition by activation of AKT signaling in endometrial cancer cells HEC-50B and HEC-1-A. MATERIAL AND METHODS: The proliferation of HEC-50B cells transfected with miR-205 mimic was assessed by WST-1 assay. The migration and invasion were evaluated by BD transwell migration and matrigel invasion assays. The EMT markers were detected by Western blot. RESULTS: We found that miR-205 increased the proliferation in HEC-50B cells. The migration and invasion of HEC-50B cells and HEC-1-A cells were enhanced by miR-205. When HEC-50B cells and HEC-1-A cells were treated with anti-miR-205 inhibitor, the migration and invasion were decreased as compared with the negative control. The overexpression of miR-205 inhibited E-cadherin expression and promoted Snail expression by activation of AKT and downregulation of glycogen synthase kinase 3ß. However, after the HEC-50B cells and HEC-1-A cells were treated with anti-miR-205 inhibitor, E-cadherin expression was increased and Snail protein level was decreased by inhibition of AKT expression. CONCLUSION: Our data strongly suggest that miR-205 plays an important role in endometrial cancer migration and invasion by targeting the AKT pathway. Our data highlight miR-205 as a potential molecular target for endometrial cancer treatment.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias do Endométrio/metabolismo , Transição Epitelial-Mesenquimal , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Metástase Neoplásica
13.
Biophys Rev ; 16(2): 173-188, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38737203

RESUMO

Microbes thrive in diverse porous environments-from soil and riverbeds to human lungs and cancer tissues-spanning multiple scales and conditions. Short- to long-term fluctuations in local factors induce spatio-temporal heterogeneities, often leading to physiologically stressful settings. How microbes respond and adapt to such biophysical constraints is an active field of research where considerable insight has been gained over the last decades. With a focus on bacteria, here we review recent advances in self-organization and dispersal in inorganic and organic porous settings, highlighting the role of active interactions and feedback that mediates microbial survival and fitness. We discuss open questions and opportunities for using integrative approaches to advance our understanding of the biophysical strategies which microbes employ at various scales to make porous settings habitable.

14.
Hepatobiliary Surg Nutr ; 13(2): 258-272, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38617474

RESUMO

Background: Visceral pain induced by pancreatic cancer seriously affects patients' quality of life, and there is no effective treatment, because the mechanism of its neural circuit is unknown. Therefore, the aim of this study is to explore the main neural circuit mechanism regulating visceral pain induced by pancreatic cancer in mice. Methods: The mouse model of pancreatic cancer visceral pain was established on C57BL/6N mice by pancreatic injection of mPAKPC-luc cells. Abdominal mechanical hyperalgesia and hunch score were performed to assess visceral pain; the pseudorabies virus (PRV) was used to identify the brain regions innervating the pancreas; the c-fos co-labeling method was used to ascertain the types of activated neurons; in vitro electrophysiological patch-clamp technique was used to record the electrophysiological activity of specific neurons; the calcium imaging technique was used to determine the calcium activity of specific neurons; specific neuron destruction and chemogenetics methods were used to explore whether specific neurons were involved in visceral pain induced by pancreatic cancer. Results: The PRV injected into the pancreas was detected in the paraventricular nucleus of the hypothalamus (PVN). Immunofluorescence staining showed that the majority of c-fos were co-labeled with glutamatergic neurons in the PVN. In vitro electrophysiological results showed that the firing frequency of glutamatergic neurons in the PVN was increased. The calcium imaging results showed that the calcium activity of glutamatergic neurons in the PVN was enhanced. Both specific destruction of glutamatergic neurons and chemogenetics inhibition of glutamatergic neurons in the PVN alleviated visceral pain induced by pancreatic cancer. Conclusions: Glutamatergic neurons in the PVN participate in the regulation of visceral pain induced by pancreatic cancer in mice, providing new insights for the discovery of effective targets for the treatment of pancreatic cancer visceral pain.

15.
J Gastrointest Oncol ; 15(1): 468-477, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38482229

RESUMO

Background: Given the pivotal role of neuroinflammation in chronic pain and that the paraventricular nucleus of the hypothalamus (PVN) is a crucial brain region involved in visceral pain regulation, we sought to investigate whether the targeted modulation of microglia and astrocytes in the PVN could ameliorate pancreatic cancer-induced visceral pain (PCVP) in mice. Methods: Using a mouse model of PCVP, achieved by tumor cell injection at the head of the pancreas, we measure the number of glial cells, and at the same time we employed minocycline to inhibit microglia and chemogenetic methods to suppress astrocytes in order to investigate the respective roles of microglia and astrocytes within the PVN in PCVP. Results: Mice exhibited visceral pain at 12, 15 and 18 days post-tumor cell injection. We observed a significant increase in the population of both microglia and astrocytes. Inhibition of microglial activity through minocycline microinjection into the PVN resulted in alleviation of visceral pain within 30 and 60 min. Similarly, chemogenetic inhibition of astrocyte function at 14 and 21 days post-injection also led to relief from visceral pain. Conclusions: This study found that PVN microglia and astrocytes were involved in regulating PCVP. Our results suggest that targeting glia may be a potential approach for alleviating visceral pain in patients with pancreatic cancer.

16.
J Gastrointest Oncol ; 15(1): 458-467, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38482250

RESUMO

Background: For patients with pancreatic cancer, visceral pain is a debilitating symptom that significantly compromises their quality of life. Unfortunately, the lack of effective treatment options can be attributed to our limited understanding of the neural circuitry underlying this phenomenon. The primary objective of this study is to elucidate the fundamental mechanisms governing visceral pain induced by pancreatic cancer in murine models. Methods: A mouse model of pancreatic cancer visceral pain was established in C57BL/6N mice through the intrapancreatic injection of mPAKPC-luc cells. Abdominal mechanical hyperalgesia and hunch score were employed to evaluate visceral pain, whereas the in vitro electrophysiological patch-clamp technique was utilized to record the electrophysiological activity of GABAergic neurons. Specific neuron ablation and chemogenetics methods were employed to investigate the involvement of GABAergic neurons in pancreatic cancer-induced visceral pain. Results: In vitro electrophysiological results showed that the firing frequency of GABAergic neurons in the paraventricular nucleus of the hypothalamus (PVN) was decreased. Specific destruction of GABAergic neurons in the PVN exacerbated visceral pain induced by pancreatic cancer. Chemogenetics activation of GABAergic neurons in the PVN alleviated visceral pain induced by pancreatic cancer. Conclusions: GABAergic neurons located in PVN play a crucial role in precipitating visceral pain induced by pancreatic cancer in mice, thereby offering novel insights for identifying effective targets to treat pancreatic cancer-related visceral pain.

17.
Front Med (Lausanne) ; 10: 1203023, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37636580

RESUMO

Background: Unanticipated difficult mask ventilation (DMV) is a potentially life-threatening event in anesthesia. Nevertheless, predicting DMV currently remains a challenge. This study aimed to verify whether three dimensional (3D) facial scans could predict DMV in patients scheduled for general anesthesia. Methods: The 3D facial scans were taken on 669 adult patients scheduled for elective surgery under general anesthesia. Clinical variables currently used as predictors of DMV were also collected. The DMV was defined as the inability to provide adequate and stable ventilation. Spatially dense landmarks were digitized on 3D scans to describe sufficient details for facial features and then processed by 3D geometric morphometrics. Ten different machine learning (ML) algorithms, varying from simple to more advanced, were introduced. The performance of ML models for DMV prediction was compared with that of the DIFFMASK score. The area under the receiver operating characteristic curves (AUC) with its 95% confidence interval (95% CI) as well as the specificity and sensitivity were used to evaluate the predictive value of the model. Results: The incidence of DMV was 35/669 (5.23%). The logistic regression (LR) model performed best among the 10 ML models. The AUC of the LR model was 0.825 (95% CI, 0.765-0.885). The sensitivity and specificity of the model were 0.829 (95% CI, 0.629-0.914) and 0.733 (95% CI, 0.532-0.819), respectively. The LR model demonstrated better predictive performance than the DIFFMASK score, which obtained an AUC of 0.785 (95% CI, 0.710-0.860) and a sensitivity of 0.686 (95% CI, 0.578-0.847). Notably, we identified a significant morphological difference in the mandibular region between the DMV group and the easy mask ventilation group. Conclusion: Our study indicated a distinct morphological difference in the mandibular region between the DMV group and the easy mask ventilation group. 3D geometric morphometrics with ML could be a rapid, efficient, and non-invasive tool for DMV prediction to improve anesthesia safety.

18.
Quant Imaging Med Surg ; 13(7): 4663-4675, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37456309

RESUMO

Background: Unsuccessful airway management is associated with increased perioperative morbidity and mortality. Difficult laryngoscopy is a leading cause of unanticipated difficult airways and presents a challenge for anesthesiologists. Airway ultrasound assessment can be used as a priority diagnostic strategy for difficult laryngoscopy because of its diagnostic performance in difficult airways. This study was designed to develop a comprehensive model based on multivariate statistical analysis (including bedside examination tests and ultrasonography) for difficult laryngoscopy. Methods: This study was conducted from December 27, 2021, to September 16, 2022. All patients underwent an airway ultrasonographic measurement with a standard operating procedure. The baseline characteristics and bedside examination tests were also recorded. Laryngoscopy with a Cormack-Lehane (CL) grade of 1-2 was defined as "easy laryngoscopy", whereas "difficult laryngoscopy" was based on a CL grade of 3-4. The prediction model was built by using baseline characteristics, bedside examination tests, and ultrasonographic measurements as independent variables and easy/difficult laryngoscopy as the dependent variable. Results: A total of 516 patients were eligible, and 456 patients were finally enrolled in the study. A 4-variable analysis, including inter-incisor gap (IIG), thyromental distance (TMD), the distance from the skin to the tongue root, and airway-related diseases, was performed to construct the optimum prediction model. The area under curve (AUC) value of the prediction model was 0.933 [95% confidence interval (CI): 0.770 to 0.935] in the training set and 0.956 (95% CI: 0.915 to 0.997) in the validation set. Conclusions: The comprehensive model and nomogram, especially the integration of tongue root thickness, can predict the risk of difficult laryngoscopy more accurately and reliably than any other screening method alone, allowing for reasonable individualized regimen decision-making.

19.
Front Med (Lausanne) ; 10: 1197536, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37727768

RESUMO

Background: Airway management failure is associated with increased perioperative morbidity and mortality. Airway-related complications can be significantly reduced if difficult laryngoscopy is predicted with high accuracy. Currently, there are no large-sample studies on difficult airway assessments in Chinese populations. An airway assessment model based on the Chinese population is urgently needed to guide airway rescue strategy. Methods: This prospective nested case-control study took place in a tertiary hospital in Shanghai, China. Information on 10,549 patients was collected, and 8,375 patients were enrolled, including 7,676 patients who underwent successful laryngoscopy and 699 patients who underwent difficult laryngoscopy. The baseline characteristics, medical history, and bedside examinations were included as predictor variables. Laryngoscopy was defined as 'successful laryngoscopy' based on a Cormack-Lehane Grades of 1-2 and as 'difficult laryngoscopy' based on a Cormack-Lehane Grades of 3-4. A model was developed by incorporating risk factors and was presented in the form of a nomogram by univariate logistic regression, least absolute shrinkage and selection operator, and stepwise logistic regression. The main outcome measures were area under the curve (AUC), sensitivity, and specificity of the predictive model. Result: The AUC value of the prediction model was 0.807 (95% confidence interval [CI]: 0.787-0.828), with a sensitivity of 0.730 (95% CI, 0.690-0.769) and a specificity of 0.730 (95% CI, 0.718-0.742) in the training set. The AUC value of the prediction model was 0.829 (95% CI, 0.800-0.857), with a sensitivity of 0.784 (95% CI, 0.73-0.838) and a specificity of 0.722 (95% CI, 0.704-0.740) in the validation set. Conclusion: Our model had accurate predictive performance, good clinical utility, and good robustness for difficult laryngoscopy in the Chinese population.

20.
Sci Adv ; 9(9): eade7375, 2023 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-36867693

RESUMO

Bovine pericardium (BP) has been used as leaflets of prosthetic heart valves. The leaflets are sutured on metallic stents and can survive 400 million flaps (~10-year life span), unaffected by the suture holes. This flaw-insensitive fatigue resistance is unmatched by synthetic leaflets. We show that the endurance strength of BP under cyclic stretch is insensitive to cuts as long as 1 centimeter, about two orders of magnitude longer than that of a thermoplastic polyurethane (TPU). The flaw-insensitive fatigue resistance of BP results from the high strength of collagen fibers and soft matrix between them. When BP is stretched, the soft matrix enables a collagen fiber to transmit tension over a long length. The energy in the long length dissipates when the fiber breaks. We demonstrate that a BP leaflet greatly outperforms a TPU leaflet. It is hoped that these findings will aid the development of soft materials for flaw-insensitive fatigue resistance.


Assuntos
Matriz Extracelular , Longevidade , Animais , Bovinos , Estado Nutricional , Pericárdio , Poliuretanos , Colágeno
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA