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1.
Opt Express ; 32(7): 12303-12317, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571057

RESUMO

Non-line-of-sight (NLOS) imaging retrieves the hidden scenes by utilizing the signals indirectly reflected by the relay wall. Benefiting from the picosecond-level timing accuracy, time-correlated single photon counting (TCSPC) based NLOS imaging can achieve theoretical spatial resolutions up to millimeter level. However, in practical applications, the total temporal resolution (also known as total time jitter, TTJ) of most current TCSPC systems exceeds hundreds of picoseconds due to the combined effects of multiple electronic devices, which restricts the underlying spatial resolution of NLOS imaging. In this paper, an instrument response function deconvolution (IRF-DC) method is proposed to overcome the constraints of a TCSPC system's TTJ on the spatial resolution of NLOS imaging. Specifically, we model the transient measurements as Poisson convolution process with the normalized IRF as convolution kernel, and solve the inverse problem with iterative deconvolution algorithm, which significantly improves the spatial resolution of NLOS imaging after reconstruction. Numerical simulations show that the IRF-DC facilitates light-cone transform and frequency-wavenumber migration solver to achieve successful reconstruction even when the system's TTJ reaches 1200 ps, which is equivalent to what was previously possible when TTJ was about 200 ps. In addition, the IRF-DC produces satisfactory reconstruction outcomes when the signal-to-noise ratio (SNR) is low. Furthermore, the effectiveness of the proposed method has also been experimentally verified. The proposed IRF-DC method is highly applicable and efficient, which may promote the development of high-resolution NLOS imaging.

2.
Opt Express ; 32(7): 12318-12339, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571058

RESUMO

The increasing risk posed by space debris highlights the need for accurate localization techniques. Spaceborne single photon Lidar (SSPL) offers a promising solution, overcoming the limitations of traditional ground-based systems by providing expansive coverage and superior maneuverability without being hindered by weather, time, or geographic constraints. This study introduces a novel approach leveraging non-parametric Bayesian inference and the Dirichlet process mixture model (DPMM) to accurately determine the distance of space debris in low Earth orbit (LEO), where debris exhibits nonlinear, high dynamic motion characteristics. By integrating extended Kalman filtering (EKF) for range gating, our method captures the temporal distribution of reflected photons, employing Markov chain Monte Carlo (MCMC) for iterative solutions. Experimental outcomes demonstrate our method's superior accuracy over conventional statistical techniques, establishing a clear correlation between radial absolute velocity and ranging error, thus significantly enhancing monostatic space debris localization.

3.
Gerontology ; 70(5): 479-490, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38461816

RESUMO

BACKGROUND: Epidemiologic studies have indicated an association of motoric cognitive risk syndrome (MCR), a pre-dementia stage characterized by the presence of cognitive complaints and a slow gait, with increased risk of incident dementia. OBJECTIVES: We aimed to clarify this association using meta-analysis. METHODS: We systematically searched the PubMed, Embase, and Web of Science databases up to December 2022 for relevant studies that investigated the association between MCR and incident all-cause dementia and Alzheimer's disease (AD). The random-effects model was used to determine a pooled-effect estimate of the association. RESULTS: We identified seven articles that corresponded with nine cohort studies investigating the association between MCR and the risk of dementia. Pooled analysis showed that MCR was associated with a significantly increased risk of incident all-cause dementia (HR = 2.28; 95% CI: 1.90-2.73) and AD (HR = 2.05; 95% CI: 1.61-2.61). Sensitivity analysis showed that there was no evidence that individual studies influenced the pooled-effect estimate, verifying the robustness of the results. CONCLUSIONS: Our results confirm that MCR is an independent risk factor of incident all-cause dementia and AD. Future studies are needed to better understand the mechanisms underlying this association.


Assuntos
Doença de Alzheimer , Demência , Humanos , Demência/epidemiologia , Demência/etiologia , Fatores de Risco , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/etiologia , Estudos de Coortes , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Incidência , Idoso
4.
Clin Interv Aging ; 19: 255-263, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38380228

RESUMO

Background: The concomitant rise in the prevalence of obstructive sleep apnea (OSA) and frailty among the elderly population has been linked to an increase in mortality rates. Despite continuous positive airway pressure (CPAP) being the gold standard treatment for OSA, its impact on incident frailty remains inadequately explored. Methods: In this cohort study, we analyzed data from 1290 patients diagnosed with OSA, aged 60 years and older. A subset of 71 patients who demonstrated high adherence to CPAP therapy were categorized as the CPAP group. Propensity score matching (PSM) was employed at a 1:4 ratio, matching for variables such as age, gender, body mass index (BMI), and sleep apnea-hypopnea index (AHI), to establish a non-CPAP group for comparison. The FRAIL scale was utilized to evaluate the frailty status of participants. Logistic regression analysis examined the relationship between CPAP therapy and incident frailty, as well as its individual components, in elderly patients with OSA. Results: During a median follow-up period of 52 months, incident frailty was observed in 70 patients (19.7%). Patients with OSA receiving CPAP therapy exhibited a lower incidence of frailty compared to those not receiving CPAP (11.26% vs 21.83%, P=0.045). In the multivariate model, CPAP therapy was significantly correlated with a reduced risk of incident frailty (OR = 0.36, 95% CI, 0.15-0.88; P = 0.025). Subcomponent analyses revealed that CPAP was associated with a lower risk of fatigue (OR=0.35, 95% CI, 0.19-0.63; P < 0.001), resistance (OR = 0.32, 95% CI, 0.14-0.74; P=0.008), and weight loss (OR = 0.38, 95% CI, 0.19-0.75; P = 0.007). Conclusion: CPAP therapy was associated with a reduced risk of incident frailty among elderly patients with OSA.


Assuntos
Fragilidade , Apneia Obstrutiva do Sono , Humanos , Idoso , Pessoa de Meia-Idade , Estudos de Coortes , Pressão Positiva Contínua nas Vias Aéreas , Fragilidade/epidemiologia , Fragilidade/complicações , Pontuação de Propensão , Apneia Obstrutiva do Sono/epidemiologia , Apneia Obstrutiva do Sono/terapia
5.
J Nutr Health Aging ; 28(4): 100191, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38359750

RESUMO

OBJECTIVES: This study aimed to explore the associations between different types of meat consumption and mortality risk among people with frailty. DESIGN: Longitudinal study. SETTING AND PARTICIPANTS: We included 19,913 physically frail participants from the UK Biobank. MEASUREMENTS: We used the validated brief food frequency questionnaire (FFQ) to measure meat consumption. Baseline diet data from 2006 to 2010 were collected, and participants were followed up until March 23, 2021. Cox proportional hazards regression models were conducted to examine the associations of meat consumption with mortality risk. RESULTS: We identified 3,622 all-cause deaths, 1,453 cancer deaths, and 1,663 cardiovascular deaths during a median follow-up time of 11.2 years. Higher consumption of unprocessed poultry (per 25 g/day increment) was associated with a lower risk of all-cause mortality (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.75-0.88), cancer mortality (HR 0.84, 95% CI 0.74-0.96), and cardiovascular mortality (HR 0.72, 95% CI 0.63-0.81). Consumption of unprocessed red meat had a U-shaped relationship with mortality. Moderate consumption of unprocessed red meat 1.0-1.9 times/week was associated with a 14% (95% CI: 3 %-24%) lower risk of all-cause mortality than the lowest consumption frequency group (0-0.9 times/week). The hazard of cancer and CV mortality was also lower in the 1.0-1.9 times/week group, though the associations were not statistically significant. More frequent consumption of processed meat was associated with an increased risk of all-cause mortality (HR 1.20, 95% CI 1.07-1.34) and cardiovascular mortality (HR 1.20, 95% CI 1.02-1.42). Fish consumption was not associated with all types of mortality. CONCLUSIONS: Higher consumption of processed meat, not fish, was associated with increased all-cause and cardiovascular mortality. In contrast, higher consumption of unprocessed poultry and moderate consumption of unprocessed red meat was associated with reduced all-cause, cancer, and cardiovascular mortality. These findings warrant further investigation to establish optimal dietary patterns for frail individuals.


Assuntos
Doenças Cardiovasculares , Causas de Morte , Dieta , Fragilidade , Carne , Neoplasias , Humanos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Estudos Longitudinais , Dieta/estatística & dados numéricos , Dieta/efeitos adversos , Doenças Cardiovasculares/mortalidade , Neoplasias/mortalidade , Fragilidade/mortalidade , Reino Unido/epidemiologia , Modelos de Riscos Proporcionais , Fatores de Risco , Idoso Fragilizado/estatística & dados numéricos , Carne Vermelha/efeitos adversos , Idoso de 80 Anos ou mais , Aves Domésticas
6.
ACS Omega ; 9(3): 3691-3700, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38284004

RESUMO

The growth parameters of the underground coal gasification (UCG) combustion cavity are important for the regulation of its gasification process. The irregular cavities formed in the early stages of ignition can affect the stability of the gasification process. In this study, a heat-solid coupling model is used to determine the combustion cavity boundary at the early stage of coal seam ignition to simulate the movement of the combustion cavity boundary by indirectly inheriting the coal seam temperature. It reveals the evolution of the temperature field, stress field, and plasticity zone at the combustion cavity boundary at the early stage of ignition in the UCG process and compares with the ex situ small-scale experiments. The simulation results show that in the early stage of ignition, the temperature transfer to the top of the coal seam and the direction of the gasification agent outlet pipeline is faster, while the transfer rate to the direction of the gasification agent inlet pipeline is slower. The main stresses are mainly distributed in the left and right sides of the combustion cavity and gradually increase directly above. The plastic zone is mainly distributed directly above the combustion cavity and arc-shaped plastic zones. The experimental results show that the temperature directly above the combustion cavity is higher than in the other directions, and the ash layer hinders the temperature transfer to the bottom. Therefore, the combustion cavity has a longer elliptical shape in the upper part, which is consistent with the simulation results. The model better reveals the extension law of the combustion cavity at the early stage of UCG ignition and provides theoretical guidance for the study of combustion cavity formation.

7.
bioRxiv ; 2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38293120

RESUMO

Gliomas are highly aggressive brain tumors characterized by poor prognosis and composed of diffusely infiltrating tumor cells that intermingle with non-neoplastic cells in the tumor microenvironment, including neurons. Neurons are increasingly appreciated as important reactive components of the glioma microenvironment, due to their role in causing hallmark glioma symptoms, such as cognitive deficits and seizures, as well as their potential ability to drive glioma progression. Separately, mTOR signaling has been shown to have pleiotropic effects in the brain tumor microenvironment, including regulation of neuronal hyperexcitability. However, the local cellular-level effects of mTOR inhibition on glioma-induced neuronal alterations are not well understood. Here we employed neuron-specific profiling of ribosome-bound mRNA via 'RiboTag,' morphometric analysis of dendritic spines, and in vivo calcium imaging, along with pharmacological mTOR inhibition to investigate the impact of glioma burden and mTOR inhibition on these neuronal alterations. The RiboTag analysis of tumor-associated excitatory neurons showed a downregulation of transcripts encoding excitatory and inhibitory postsynaptic proteins and dendritic spine development, and an upregulation of transcripts encoding cytoskeletal proteins involved in dendritic spine turnover. Light and electron microscopy of tumor-associated excitatory neurons demonstrated marked decreases in dendritic spine density. In vivo two-photon calcium imaging in tumor-associated excitatory neurons revealed progressive alterations in neuronal activity, both at the population and single-neuron level, throughout tumor growth. This in vivo calcium imaging also revealed altered stimulus-evoked somatic calcium events, with changes in event rate, size, and temporal alignment to stimulus, which was most pronounced in neurons with high-tumor burden. A single acute dose of AZD8055, a combined mTORC1/2 inhibitor, reversed the glioma-induced alterations on the excitatory neurons, including the alterations in ribosome-bound transcripts, dendritic spine density, and stimulus evoked responses seen by calcium imaging. These results point to mTOR-driven pathological plasticity in neurons at the infiltrative margin of glioma - manifested by alterations in ribosome-bound mRNA, dendritic spine density, and stimulus-evoked neuronal activity. Collectively, our work identifies the pathological changes that tumor-associated excitatory neurons experience as both hyperlocal and reversible under the influence of mTOR inhibition, providing a foundation for developing therapies targeting neuronal signaling in glioma.

8.
Environ Monit Assess ; 196(1): 42, 2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38102303

RESUMO

Black and odorous water is an extreme pollution phenomenon. This article reviews the formation process, formation conditions, and evaluation methods of black and odorous water. The results indicate that N, P, and TOC are the key nutrients inducing black and odorous water while S, Fe, and Mn are key elements forming blackening and odorizing pollutants. In addition, Cyanobacteria, Proteobacteria, Firmicutes, Verrucomicrobia, Planctomycetes, and Actinobacteria participate in the biogeochemistry cycles of key elements and play important roles in the blackening and odorizing process of water. The black and odorous thresholds that need further verification are as follows: 1.0 g/L of organic matrix, 2.0-8.0 mg/L of NH3-N, 0.6-1.2 mg/L of TP, 0.05 mg/L of Fe2+, 0.3 mg/L of Mn2+, 1.2-2.0 mg/L of DO, and -50 to 50 mV of the ORP. In order to propose a universal assessment method, it is suggested that NH3-N, DO, COD, BOD, and TP serve as the assessment indicators, and the levels of pollutions are I (not black odor), II (mild black odor), III (moderate black odor), IV (severe black odor), and inferior IV (extremely black odor).


Assuntos
Cianobactérias , Água , Monitoramento Ambiental , Odorantes , Poluição da Água
9.
Clin Interv Aging ; 18: 2129-2139, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38143488

RESUMO

Background: Frailty is a risk factor for acute myocardial infarction (AMI). This study examined the association between the modified frailty index (MFI) and adverse outcomes in patients with critical AMI. Methods: Data were obtained from the Medical Information Mart for Intensive Care IV database. Logistic and Cox regression models and a competing risk model were applied. Results: Of 5003 patients, 1496 were non-frail and 3507 were frail. Frailty was significantly associated with in-hospital mortality (per point, OR 1.13, 95% CI: 1.05-1.21; frail vs non-frail, OR 1.31, 95% CI: 1.04-1.65) and 1-year mortality (per point, HR 1.15, 95% CI: 1.11-1.20; frail vs non-frail, HR 1.37, 95% CI: 1.20-1.58). Frailty was significantly associated with post-discharge care needs (per point, OR 1.23, 95% CI: 1.14-1.33; frail vs non-frail, OR 1.47, 95% CI: 1.22-1.78). In the competing risk models, frailty was significantly associated with a lower probability of being discharged from the ICU (per point, HR 0.87, 95% CI: 0.85-0.90; frail vs non-frail, HR 0.73, 95% CI: 0.68-0.79) and hospital (per point, HR 0.82, 95% CI: 0.80-0.85; frail vs non-frail, HR 0.62, 95% CI: 0.57-0.68). Subgroup analyses showed the association of frailty with in-hospital and 1-year mortality was stronger in patients with a SOFA score ≤2 than in those with a SOFA score >2 (both p<0.05 for interaction). Conclusion: Frailty assessed by the MFI was an independent predictor of adverse outcomes in patients with critical AMI and may be helpful for prognostic risk stratification.


Assuntos
Fragilidade , Infarto do Miocárdio , Humanos , Idoso , Idoso Fragilizado , Estudos Retrospectivos , Assistência ao Convalescente , Alta do Paciente
10.
Clin Nutr ; 42(12): 2569-2577, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37967504

RESUMO

BACKGROUND: Evidence regarding how dietary patterns (DPs) from mid- (60 years old) to later-life (over 80 years old) affect sarcopenia risk in old age is scarce. METHODS: We included 7267 participants aged ≥80 years from the Chinese Longitudinal Healthy Longevity Survey in 2018. The Simplified Healthy Eating Index (SHE index) based on nine dietary variables was used to measured DPs and changes in DPs, with a higher score indicating better diet quality. The term "Mid-life" DPs denoted dietary habits at the age of 60 whereas "Later-life" DPs referred to dietary habits acquired over 80 years old. Sarcopenia risk was evaluated using the SARC-CalF questionnaire. We applied multivariable adjusted logistic regression models to investigate the cross-sectional association between DPs in a life course and sarcopenia risk in 2018 after adjusting for potential confounders including sociodemographic characteristics, lifestyle risk factors, and unfavorable health conditions. Several sensitivity analyses were conducted to verify the robustness of the results. RESULTS: We found that healthier DPs during both mid- and later-life were associated with a decreased odds of sarcopenia risk, with adjusted odds ratios (ORs) of 0.69 (95 % confidence interval [CI]: 0.54-0.88) and 0.84 (95 % CI: 0.71-0.99), respectively. The odds of sarcopenia risk were also decreased among those with healthier DPs over a period of 20 years (OR = 0.80, 95 % CI: 0.69-0.93). For each nutrient consumption, participants who had high-quality fish consumption both in mid- and later-life had a 23 % decreased odds of sarcopenia risk (OR = 0.77, 95 % CI: 0.67-0.88) compared with those who had low-quality fish consumption all the time. The results were largely unchanged in sensitivity analyses. CONCLUSIONS: Our findings highlight the importance of maintaining healthy dietary habits throughout life to reduce the risk of sarcopenia in old age.


Assuntos
Dieta , Sarcopenia , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Estudos Transversais , População do Leste Asiático , Vida Independente , Sarcopenia/epidemiologia
11.
Opt Lett ; 48(21): 5487-5490, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910684

RESUMO

A ranging high-speed moving target with a high accuracy is challenging for a single-photon ranging system (SPRS). In this Letter, the dynamic instrument response function (IRF) is proposed to establish a dynamic discrete model (DDM) by introducing a velocity and a system timing resolution, which leads to better accuracy of cross-correlation results. And with the data of a dynamic Monte Carlo (DMC), the ranging accuracy can be improved with DDM.

12.
Mucosal Immunol ; 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38007004

RESUMO

Dry eye disease (DED) is a prevalent chronic eye disease characterized by an aberrant inflammatory response in ocular surface mucosa. The immunological alterations underlying DED remain largely unknown. In this study, we employed single-cell transcriptome sequencing of conjunctival tissue from environment-induced DED mice to investigate multicellular ecosystem and functional changes at different DED stages. Our results revealed an epithelial subtype with fibroblastic characteristics and pro-inflammatory effects emerging in the acute phase of DED. We also found that T helper (Th)1, Th17, and regulatory T cells (Treg) were the dominant clusters of differentiation (CD)4+ T-cell types involved in regulating immune responses and identified three distinct macrophage subtypes, with the CD72+CD11c+ subtype enhancing chronic inflammation. Furthermore, bulk transcriptome analysis of video display terminal-induced DED consistently suggested the presence of the pro-inflammatory epithelial subtype in human conjunctiva. Our findings have uncovered a DED-associated pro-inflammatory microenvironment in the conjunctiva, centered around epithelial cells, involving interactions with macrophages and CD4+ T cells, which deepens our understanding of ocular surface mucosal immune responses during DED progression.

13.
Clin Transl Sci ; 16(12): 2507-2518, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37969034

RESUMO

Investigating the influencing factors of new-onset hypertension in the elderly with obstructive sleep apnea (OSA). 450 Chinese older patients with OSA who were non-hypertensive at baseline were enrolled. All patients had undergone polysomnography monitoring in the multicenter study. The primary endpoint was incident hypertension. Kaplan-Meier survival analysis was performed, and multivariate Cox proportional hazards models were generated to determine the factors influencing new-onset hypertension. A total of 176 (39.1%) patients developed hypertension. The hypertension group had older age, higher hemoglobin (Hb) level and apnea-hypopnea index (AHI) values than the non-hypertension group (all p < 0.05). During the median 33-month follow-up period, multivariate Cox analysis showed age (hazard ratio (HR) = 1.039, 95% confidence interval (95% CI): 1.016-1.062), AHI (HR = 1.015, 95% CI: 1.007-1.023) and Hb level (HR = 1.016, 95% CI: 1.008-1.025) were independent predictors of new-onset hypertension. However, continuous positive airway pressure (CPAP; HR = 0.508, 95% CI: 0.271-0.951) reduced the risk of developing hypertension. Notably, the subgroup analysis demonstrated that the plasma glucose level (HR = 1.168, 95% CI: 1.029-1.326) was a risk factor for male patients. Besides length of time with the pulse oxygen saturation less than 90% (Tsat90; HR = 1.005, 95% CI: 1.003-1.007), body mass index (BMI; HR = 1.170, 95% CI: 1.043-1.311), and dyslipidemia (HR = 2.335, 95% CI: 1.144-4.766) had statistically significant effects on the incidence of hypertension in certain subgroups. Although this study lacked analysis of items such as living habits and medication, it did show age, AHI, Hb and CPAP affected the development of hypertension in elderly OSA patients. These findings suggested that targeted interventions in specific populations may be more effective in preventing hypertension.


Assuntos
Hipertensão , Apneia Obstrutiva do Sono , Idoso , Humanos , Masculino , Estudos de Coortes , Hipertensão/epidemiologia , Modelos de Riscos Proporcionais , Fatores de Risco , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/epidemiologia , Feminino
14.
ACS Omega ; 8(43): 40153-40161, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37929149

RESUMO

During deep underground coal gasification, the semicoke produced by the pyrolysis of dense coal cores is an important material for its gasification and combustion. In this paper, pressurized pyrolysis experiments were carried out on dense coal cores at 700 °C and pressures of 1, 2, and 3 MPa using a shaft furnace. The resulting semicoke and raw coal were analyzed using the characterization methods such as the N2 isothermal adsorption/desorption and scanning electron microscopy, Fourier transform infrared spectrometry (FTIR), and a pressurized thermogravimetric analyzer coupled with a FTIR spectrometer. The pyrolysis gas generation characteristics during pressurized pyrolysis were studied. The mechanisms of evolution of aliphatic functional groups and pore structures in semicoke during pressurized pyrolysis were revealed. The results indicate that the increase in pressure obviously changed the gas composition, most notably, the relative content of CH4 and H2 in the pyrolysis gas. The methane in the pyrolysis gas during pressurized pyrolysis of dense coal cores is mainly from the secondary reaction. As the pyrolysis pressure increased, the ratio of -CH2-/-CH3 became smaller, indicating that the pressure promoted the breakage of the long fat chains. With the increase of the pyrolysis pressure, the surface deformation of pressurized pyrolysis semicoke increases, and the pore structure becomes more abundant.

15.
Opt Express ; 31(19): 30588-30603, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37710599

RESUMO

Mono-static system benefits from its more flexible field of view and simplified structure, however, the backreflection photons from mono-static system lead to count loss for target detection. Counting loss engender range-blind, impeding the accurate acquisition of target depth. In this paper, count loss is reduced by introducing a polarization-based underwater mono-static single-photon imaging method, and hence reduced blind range. The proposed method exploits the polarization characteristic of light to effectively reduce the count loss of the target, thus improving the target detection efficiency. Experiments demonstrate that the target profile can be visually identified under our method, while the unpolarization system can not. Moreover, the ranging precision of system reaches millimeter-level. Finally, the target profile is reconstructed using non-local pixel correlations algorithm.

16.
Int J Antimicrob Agents ; 62(4): 106925, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37451649

RESUMO

Klebsiella pneumoniae is one of the most common opportunistic pathogens causing hospital- and community-acquired infections. Antibiotic resistance in K. pneumoniae has emerged as a major clinical and public health threat. Persisters are specific antibiotic-tolerant bacterial cells. Studies on the mechanism underlying their formation mechanism and growth status are scarce. Therefore, it is urgent to explore the key genes and signalling pathways involved in the formation and recovery process of K. pneumoniae persisters to enhance the understanding and develop relevant treatment strategies. In this study, we treated K. pneumoniae with a lethal concentration of levofloxacin. It resulted in a distinct plateau of surviving levofloxacin-tolerant persisters. Subsequently, we obtained bacterial samples at five different time points during the formation and recovery of K. pneumoniae persisters to perform transcriptome analysis. ptsH gene was observed to be upregulated during the formation of persisters, and down-regulated during the recovery of the persisters. Further, we used CRISPR-Cas9 to construct ΔptsH, the ptsH-knockout K. pneumoniae strain, and to investigate the effect of ptsH on the persister formation. We observed that ptsH can promote the formation of persisters, reduce accumulation of reactive oxygen species, and enhance antioxidant capacity by reducing cyclic adenosine monophosphate (cAMP) levels. To the best of our knowledge, this is the first study to report that ptsH plays a vital role in forming K. pneumoniae persisters. This study provided important insights to further explore the mechanism underlying the formation of K. pneumoniae persisters and provided a potential target for treating infection with K. pneumoniae persisters.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Humanos , Levofloxacino/farmacologia , Antibacterianos/farmacologia , Monofosfato de Adenosina , Fosfotransferases/farmacologia , Infecções por Klebsiella/microbiologia
17.
Aging Clin Exp Res ; 35(10): 2145-2155, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37477792

RESUMO

BACKGROUND: Cognitive frailty (CF) is a complex and heterogeneous clinical syndrome that indicates the onset of neurodegenerative processes and poor prognosis. In order to prevent the occurrence and development of CF in real world, we intended to develop and validate a simple and timely diagnostic instrument based on comprehensive geriatric assessment that will identify patients with potentially reversible CF (PRCF). METHODS: 750 community-dwelling individuals aged over 60 years were randomly allocated to either a training or validation set at a 4:1 ratio. We used the operator regression model offering the least absolute data dimension shrinkage and feature selection among candidate predictors. PRCF was defined as the presence of physical pre-frailty, frailty, and mild cognitive impairment (MCI) occurring simultaneously. Multivariate logistic regression was conducted to build a diagnostic tool to present data as a nomogram. The performance of the tool was assessed with respect to its calibration, discrimination, and clinical usefulness. RESULTS: PRCF was observed in 326 patients (43%). Predictors in the tool were educational background, coronary heart disease, handgrip strength, gait speed, instrumental activity of daily living (IADL) disability, subjective cognitive decline (SCD) and five-times-sit-to-stand test. The diagnostic nomogram-assisted tool exhibited good calibration and discrimination with a C-index of 0.805 and a higher C-index of 0.845 in internal validation. The calibration plots demonstrated strong agreement in both the training and validation sets, while decision curve analysis confirmed the nomogram's efficacy in clinical practice. CONCLUSIONS: This tool can effectively identify older adults at high risk for PRCF, enabling physicians to make informed clinical decisions and implement proper patient-centered individual interventions.


Assuntos
Disfunção Cognitiva , Fragilidade , Nomogramas , Idoso , Humanos , Pessoa de Meia-Idade , Cognição , Disfunção Cognitiva/diagnóstico , População do Leste Asiático , Fragilidade/diagnóstico , Força da Mão , Vida Independente
18.
BMC Geriatr ; 23(1): 360, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-37296410

RESUMO

BACKGROUND: The allostatic load (AL) refers to the cumulative weakening of multiple physiological systems caused by repeated adaptation of the body to stressors There are still no studies have focused on the association between AL and the prognosis of patients with heart failure with preserved ejection fraction (HFpEF). The present study aimed to investigate the association between AL and adverse outcomes, including mortality and HF admission, among elderly male patients with HFpEF. METHODS: We conducted a prospective cohort study of 1111 elderly male patients with HFpEF, diagnosed between 2015 and 2019 and followed up through 2021. We constructed an AL measure using a combination of 12 biomarkers. The diagnosis of HFpEF was made according to the 2021 European Society of Cardiology guidelines. A Cox proportional hazards model was used to determine the associations between AL and adverse outcomes. RESULTS: In multivariate analysis, AL was significantly associated with increased risk of all-cause mortality (medium AL: adjusted hazard ratio [HR] = 2.53; 95% confidence interval [CI] 1.37-4.68; high AL: HR = 4.21; 95% CI 2.27-7.83; per-score increase: HR = 1.31; 95% CI 1.18-1.46), cardiovascular mortality (medium AL: HR = 2.67; 95% CI 1.07-6.68; high AL: HR = 3.13; 95% CI 1.23-7.97; per-score increase: HR = 1.20; 95% CI 1.03-1.40), non-cardiovascular mortality (medium AL: HR = 2.45; 95% CI 1.06-5.63; high AL: HR = 5.81; 95% CI 2.55-10.28; per-score increase: HR = 1.46; 95% CI 1.26-1.69), and HF admission (medium AL: HR = 2.68; 95% CI 1.43-5.01; high AL: HR = 3.24; 95% CI 1.69-6.23; per-score increase: HR = 1.24; 95% CI 1.11-1.39). Consistent results were found in multiple subgroup analyses. CONCLUSIONS: A higher AL was associated with poor prognosis in elderly men with HFpEF. AL relies on information that is easily obtained in physical examinations and laboratory parameters and can be assessed in various care and clinical settings to help risk stratification of HFpEF patients.


Assuntos
Alostase , Insuficiência Cardíaca , Humanos , Masculino , Idoso , Insuficiência Cardíaca/diagnóstico , Volume Sistólico/fisiologia , Estudos Prospectivos , Prognóstico
19.
Age Ageing ; 52(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37326605

RESUMO

BACKGROUND: studies comparing different frailty measures in intensive care unit settings are lacking. We aimed to compare the frailty index based on physiological and laboratory tests (FI-Lab), modified frailty index (MFI) and hospital frailty risk score (HFRS) to predict short-term outcomes for critically ill patients. METHODS: we conducted a secondary analysis of data from the Medical Information Mart for Intensive Care IV database. Outcomes of interest included in-hospital mortality and discharge with need for nursing care. RESULTS: the primary analysis was conducted with 21,421 eligible critically ill patients. After adjusting for confounding variables, frailty as diagnosed by all three frailty measures was found to be significantly associated with increased in-hospital mortality. In addition, frail patients were more likely to receive further nursing care after being discharged. All three frailty scores could improve the discrimination ability of the initial model generated by baseline characteristics for adverse outcomes. The FI-Lab had the best predictive ability for in-hospital mortality, whereas the HFRS had the best predictive performance for discharge with need for nursing care amongst the three frailty measures. A combination of the FI-Lab with either the HFRS or MFI improved the identification of critically ill patients at increased risk of in-hospital mortality. CONCLUSIONS: frailty, as assessed by the HFRS, MFI and FI-Lab, was associated with short-term survival and discharge with need for nursing care amongst critically ill patients. The FI-Lab was a better predictor of in-hospital mortality than the HFRS and MFI. Future studies focusing on FI-Lab are warranted.


Assuntos
Fragilidade , Humanos , Idoso , Fragilidade/diagnóstico , Idoso Fragilizado , Estado Terminal , Cuidados Críticos , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos
20.
Cell Rep ; 42(6): 112527, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37243588

RESUMO

Although resting-state functional magnetic resonance imaging (fMRI) studies have observed dynamically changing brain-wide networks of correlated activity, fMRI's dependence on hemodynamic signals makes results challenging to interpret. Meanwhile, emerging techniques for real-time recording of large populations of neurons have revealed compelling fluctuations in neuronal activity across the brain that are obscured by traditional trial averaging. To reconcile these observations, we use wide-field optical mapping to simultaneously record pan-cortical neuronal and hemodynamic activity in awake, spontaneously behaving mice. Some components of observed neuronal activity clearly represent sensory and motor function. However, particularly during quiet rest, strongly fluctuating patterns of activity across diverse brain regions contribute greatly to interregional correlations. Dynamic changes in these correlations coincide with changes in arousal state. Simultaneously acquired hemodynamics depict similar brain-state-dependent correlation shifts. These results support a neural basis for dynamic resting-state fMRI, while highlighting the importance of brain-wide neuronal fluctuations in the study of brain state.


Assuntos
Mapeamento Encefálico , Encéfalo , Animais , Camundongos , Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Imageamento por Ressonância Magnética/métodos , Neurônios/fisiologia , Hemodinâmica , Descanso/fisiologia , Vias Neurais/fisiologia
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