RESUMEN
To meet the demand of flexible access for high-precision synchronization frequency, we demonstrate multi-node stable radio frequency (RF) dissemination over a long-distance optical fiber. Stable radio frequency signals can be extracted at any node along the optical fiber, not just at the endpoint. The differential mixing structure (DMS) is employed to avoid the frequency harmonic leakage and enhance the precision. The phase-locked loop (PLL) provides frequency reference for the DMS while improving the signal to noise ratio (SNR) of dissemination signal. We measure the frequency instability of multi-node stable frequency dissemination system (MFDS) at different locations along the 2,000 km optical fiber. The measured short-term instability with average time of 1 s are 1.90 × 10-14 @ 500 km, 2.81 × 10-14 @ 1,000 km, 3.46 × 10-14 @ 1,500 km, and 3.84 × 10-14 @ 2,000 km respectively. The long-term instability with average time of 10,000 s are basically the same at any position of the optical fiber, which is about (6.24 ± 0.05) × 10-17. The resulting instability is sufficient for the propagation of precision active hydrogen masers.
RESUMEN
Controlled atmosphere (CA) has been used to alleviate chilling injury (CI) of horticultural crops caused by cold storage. However, the effects of CA treatment on peach fruit sensory quality and flavor-related chemicals suffering from CI remain largely unknown. Here, we stored peach fruit under CA with 5% O2 and 10% CO2 at 0 °C up to 28 d followed by a subsequent 3 d shelf-life at 20 °C (28S3). CA significantly reduced flesh browning and improved sensory quality at 28S3. Though total volatiles declined during extended cold storage, CA accumulated higher content of volatile esters and lactones than control at 28S3. A total of 14 volatiles were positively correlated with consumer acceptability, mainly including three C6 compounds, three esters and four lactones derived from the fatty acid lipoxygenase (LOX) pathway. Correspondingly, the expression levels of genes including PpLOX1, hyperoxide lyase PpHPL1 and alcohol acyltransferase PpAAT1 were positively correlated with the change of esters and lactones. CA elevated the sucrose content and the degree of fatty acids unsaturation under cold storage, which gave us clues to clarify the mechanism of resistance to cold stress. The results suggested that CA treatment improved sensory quality by alleviating CI of peach fruits under cold storage.
Asunto(s)
Prunus persica , Atmósfera , Frío , Ésteres/metabolismo , Almacenamiento de Alimentos , Frutas/metabolismo , Expresión Génica , Lactonas/metabolismo , Prunus persica/metabolismoRESUMEN
Ventilator-associated pneumonia (VAP) is one of the most severe complications in patients with traumatic brain injury (TBI) and is considered a risk factor for poor outcomes. However, the incidence of VAP among patients with TBI reported in studies varies widely. What is more, the risk factors and outcomes of VAP are controversial. This study estimates the incidence, risk factors, and outcomes of VAP in patients with TBI and provides evidence for prevention and treatment. PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched from the earliest records to May 2018. Data involving the incidence, risk factors, and outcomes were extracted for meta-analysis. The results showed that the incidence of VAP was 36% (95% confidence interval (CI) 31-41%); risk factors analyses showed that smoking [odds ratio (OR) 2.13; 95% CI 1.16-3.92], tracheostomy (OR 9.55; 95% CI 3.24-28.17), blood transfusion on admission (OR 2.54; 95% CI 1.24-5.18), barbiturate infusion (OR 3.52; 95% CI 1.68-7.40), injury severity score (OR 4.65; 95% CI 1.96-7.34), and head abbreviated injury scale (OR 2.99; 95% CI 1.66-5.37) were related to the occurrence of VAP. When patients developed VAP, mechanical ventilation time (OR 5.45; 95% CI 3.78-7.12), ICU length of stay (OR 6.85; 95% CI 4.90-8.79), and hospital length of stay (OR 10.92; 95% CI 9.12-12.72) were significantly increased. However, VAP was not associated with an increased risk of mortality (OR 1.28; 95% CI 0.74-2.21). VAP is common in patients with TBI. It is affected by a series of factors and has a poor prognosis.
Asunto(s)
Barbitúricos/uso terapéutico , Transfusión Sanguínea/estadística & datos numéricos , Lesiones Traumáticas del Encéfalo/terapia , Mortalidad , Neumonía Asociada al Ventilador/epidemiología , Fumar/epidemiología , Traqueostomía/estadística & datos numéricos , Escala Resumida de Traumatismos , Lesiones Traumáticas del Encéfalo/complicaciones , Humanos , Incidencia , Infusiones Parenterales , Puntaje de Gravedad del Traumatismo , Unidades de Cuidados Intensivos , Tiempo de Internación/estadística & datos numéricos , Neumonía Asociada al Ventilador/complicaciones , Respiración Artificial/estadística & datos numéricos , Factores de Riesgo , Factores de TiempoRESUMEN
We demonstrate a radio frequency (RF) phase-stable transmission over fiber based on microwave photonic phase shifter. In the proposed system, both assistant RF signals are applied to drive two arms of a dual-drive Mach-Zehnder modulator (DMZM), respectively. An optical bandpass filter is followed to filter out the first-order sideband of optical modulated signal. Due to the phase independence between two optical sidebands, the phase perturbation caused by fiber-length variations can be compensated automatically via controlling the direct-current bias voltage of the DMZM. We have performed RF transfer in a 155 km single-mode fiber with a frequency instability of 3.05 × 10-17 at 10,000 s averaging time.
RESUMEN
PURPOSE: To evaluate the ability of an arginine-containing dentifrice to occlude dentin tubules. METHODS: Dentin discs were divided equally into premolar and molar groups, which were then utilized in three treatment groups: a blank control group (distilled water treatment), a negative control group (common dentifrice with calcium carbonate) and an experimental group [dentifrice with 8% (w/w) arginine]. Each dentin disk was brushed with the dentifrice twice daily for 7 consecutive days. After this period, each disc was separated into two equal halves. One half was used for scanning electron microscopy (SEM) and energy-dispersive spectrometer (EDS) examinations, while the other half was brushed with distilled water twice daily for another 7 days prior to SEM observation. RESULTS: The plugging rate in the arginine dentifrice group was significantly higher and more sustainable than in the negative control group. The surface deposition of calcium and phosphorus on the dentin discs in the arginine dentifrice group was also significantly higher. CLINICAL SIGNIFICANCE: This study provided evidence that using arginine as an active ingredient in dentifrice can improve its ability to occlude dentin tubules, thus supporting future efforts to improve dentin hypersensitivity.
Asunto(s)
Dentífricos , Desensibilizantes Dentinarios , Arginina , Dentina , Pastas de DientesRESUMEN
In this paper, we propose an active-compensation stable radio frequency (RF) transmission scheme based on a high-performance phase lock loop (PLL). In our PLL, a new structure for phase-detection is designed with only one standard RF signal to obtain a simple structure with no interference from other signals. In addition, different optical wavelengths carrying the same RF signal are utilized in the two directions to suppress Rayleigh scattering. The low phase noise homemade bi-directional erbium doped fiber amplifier (EDFA) module is used to reduce signal-to-noise ratio (SNR) deterioration. Hence, the transmission distance is greatly improved. The effects of polarization mode dispersion and phase noise produced by the EDFA on the transmission distance are discussed. Ultimately, a stable RF signal with 2.4 GHz transmitted over a 1007 km fiber link is obtained. The experimental results demonstrate that frequency instabilities of 1.2×10- 13 at 1s and 5.1×10- 16 at 20000s. Therefore, the system can be used for atomic clocks comparisons and provides frequency standard for time transfer systems over a long-haul fiber.
RESUMEN
An optical comb based stable frequency dissemination system is proposed and experimentally demonstrated over a multi-access optical fiber loop link. In the system, a new technique based on optical-microwave phase locking loop is designed for phase compensation. In the experiment, a mode-locked fiber laser at a repetition rate of 100 MHz is used to provide an optical source at local site, then it transmits along a 150 km fiber loop link. To testify the proposed system, two accessing nodes are measured in the loop link. The dissemination frequency instability is measured at 3.65 × 10-15/1 s and 7.8 × 10-18/1000 s at the intermediate node. The similar performance is shown at the other node. Hence, the system has the potential application in high-precision frequency transmission system via a long-haul multi-access loop link.
RESUMEN
A copper(I) 3,5-diphenyltriazolate metal-organic framework (CuTz-1) was synthesized and extensively characterized by using a multi-technique approach. The combined results provided solid evidence that CuTz-1 features an unprecedented Cu5 tz6 cluster as the secondary building unit (SBU) with channels approximately 8.3â Å in diameter. This metal-organic framework (MOF) material, which is both thermally and chemically (basic and acidic) stable, exhibited semiconductivity and high photocatalytic activity towards the degradation of dyes in the presence of H2 O2 . Its catalytic performance was superior to that of reported MOFs and comparable to some composites, which has been attributed to its high efficiency in generating . OH, the most active species for the degradation of dyes. It is suggested that the photogenerated holes are trapped by CuI , which yields CuII , the latter of which behaves as a catalyst for a Fenton-like reaction to produce an excess amount of . OH in addition to that formed through the scavenging of photogenerated electrons by H2 O2 . Furthermore, it was shown that a dye mixture (methyl orange, methyl blue, methylene blue, and rhodamineâ B) could be totally decolorized by using CuTz-1 as a photocatalyst in the presence of H2 O2 under the irradiation of a Xe lamp or natural sunlight.
RESUMEN
We propose and experimentally demonstrate a stable radio frequency (RF) phase dissemination scheme for a long-haul optical ï¬ber loop link based on frequency mixing. Using a single optical source in both directions of the loop link, additional timing jitter caused by group velocity dispersion (GVD) can be eliminated. Impressive scalability provided by the optical link ensures that arbitrary-access node can obtain an RF signal with a stabilized phase to meet the requirements of multiple users. In our experiment, a 2.4 GHz RF signal is distributed to arbitrary points along a 100 km ï¬ber-optic loop link steadily. Stabilities of the recovered signals from two accessing nodes are recorded. The root-mean-square (RMS) phase jitter of the received signal at either accessing node is reduced from 1.87 rad to no more than 0.027 rad during 1800-second measuring time.
RESUMEN
The nonantimicrobial properties and relatively poor mechanical properties of hydroxyethyl cellulose (HEC) limit its use in packaging. Sulfated rice bran polysaccharides (SRBP) possess significant antioxidant and antimicrobial activities. The purpose of this study was to investigate the effect of different concentrations of SRBP on the physical and mechanical properties and the functional characteristics of HEC/SRBP films. The physical properties of the HEC/20% SRBP films, such as water resistance, water vapor barrier, light barrier, and tensile strength, improved significantly (p < 0.05) compared with those of the HEC films. Scanning electron microscopy and Fourier transform infrared spectrometry showed that HEC formed hydrogen bonds with SRBP and exhibited better compatibility. Thermogravimetric analysis revealed that the addition of SRBP was beneficial to the thermal stability of the films. In addition, the antioxidant and bacteriostatic properties of the films were enhanced by the addition of SRBP to HEC, with the 20% SRBP films showing the most significant enhancement in activity. Therefore, the HEC/20% SRBP films show potential for development for use as active food packaging.
RESUMEN
Seven novel antioxidant peptides (AWF, LWQ, WIY, YLW, LAYW, LPWG, and LYFY) exhibiting a superior activity compared to trolox were identified through in silico screening. Among these, the four peptides (WIY, YLW, LAYW, and LYFY) displayed notably enhanced performance, with ABTS activity 2.58-3.26 times and ORAC activity 5.19-8.63 times higher than trolox. Quantum chemical calculations revealed that the phenolic hydroxyl group in tyrosine and the nitrogen-hydrogen bond in the indole ring of tryptophan serve as the critical sites for antioxidant activity. These findings likely account for the potent chemical antioxidant activity. The corn peptides also exerted a protective effect against AAPH-induced cytomorphologic changes in human erythrocytes by modulating the antioxidant system. Notably, LAYW exhibited the most pronounced cytoprotective effects, potentially due to its high content of hydrophobic amino acids.
Asunto(s)
Antioxidantes , Glútenes , Humanos , Antioxidantes/química , Glútenes/química , Zea mays/química , Péptidos/química , FenolesRESUMEN
Fresh red waxy corn is consumed worldwide because of its unique flavor and rich nutrients, but it is susceptible to deterioration with a short shelf life. This study explored the effect of slightly acidic electrolyzed water (SAEW) treatment on the quality and antioxidant capacity of fresh red waxy corn during postharvest cold storage up to 40 d. The SAEW treatment exhibited lower weight loss, softer firmness, and higher total soluble solids (TSS) and moisture content than the control group. Correspondingly, the SAEW maintained the microstructure of endosperm cell wall and starch granules of fresh red waxy corn kernels well, contributing to good sensory quality. Furthermore, SAEW effectively reduced the accumulation of H2O2 content, elevated the O2 -· scavenging ability, maintained higher CAT and APX activities, and decreased the decline of the flavonoids and anthocyanin during the storage. These results revealed that the SAEW treatment could be a promising preservation method to maintain higher-quality attributes and the antioxidant capacity of fresh red waxy corn during postharvest cold storage.
RESUMEN
Cherry tomatoes are easily damaged due to their high moisture content. A composite coating was developed to delay deterioration and prolong storage by mixing antibacterial sulfated rice bran polysaccharides (SRBP) and edible hydroxyethyl cellulose (HEC) with film-forming properties. The effects of HEC, HEC-5% SRBP, and HEC-20% SRBP preservative coatings on the maintenance of the quality of cherry tomatoes (LycopersivonesculentumMill., Xiaohuang F2) during cold storage were investigated. The HEC-20% SRBP coating significantly reduced tomato deterioration and weight loss, delayed firmness loss, decreased polyphenol oxidase activity, and increased peroxidase activity. Furthermore, cherry tomatoes treated with HEC-20% SRBP maintained high levels of titratable acid, ascorbic acid, total phenols, and carotenoids. Cherry tomatoes coated with HEC-SRBP also had higher levels of volatile substances and a greater variety of these substances compared to uncoated tomatoes. In conclusion, the HEC-20% SRBP coating effectively delayed deterioration and preserved cherry tomatoes' nutrient and flavor qualities during postharvest cold storage, suggesting it could be a novel food preservation method.
RESUMEN
Lupus nephritis (LN) has a high incidence in systemic lupus erythematosus (SLE) patients, but there is a lack of sensitive predictive markers. The purpose of the study was to investigate the association between the CD4 +CD8 + double positive T (DPT) lymphocytes and LN. The study included patients with SLE without renal impairment (SLE-NRI), LN, nephritic syndrome (NS), or nephritis. Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Biochemical measurements were performed with peripheral blood in accordance with the recommendations proposed by the National Center for Clinical Laboratories. The proportions of DPT cells in the LN group were significantly higher than that in the SLE-NRI group ( t=4.012, P<0.001), NS group ( t=3.240, P=0.001), and nephritis group ( t=2.57, P=0.011). In the LN group, the risk of renal impairment increased significantly in a DPT cells proportion-dependent manner. The risk of LN was 5.136 times (95% confidence interval, 2.115-12.473) higher in cases with a high proportion of DPT cells than those whose proportion of DPT cells within the normal range. These findings indicated that the proportion of DPT cells could be a potential marker to evaluate LN susceptibility, and the interference of NS and nephritis could be effectively excluded when assessing the risk of renal impairment during SLE with DPT cell proportion.
RESUMEN
Carotenoids are essential pigments widely distributed in tissues and organs of higher plants, contributing to color, photosynthesis, photoprotection, nutrition, and flavor in plants. White- or yellow-fleshed colors in peach were determined by expression of carotenoids cleavage dioxygenase (PpCCD) genes, catalyzing the degradation of carotenoids. The cracked volatile apocarotenoids are the main contributors to peach aroma and flavor with low sensory threshold concentration. However, the detailed regulatory roles of carotenoids metabolism genes remained unclear under UV-B irradiation. In our study, metabolic balance between carotenoids and apocarotenoids was regulated by the expression of phytoene synthase (PSY), ß-cyclase (LCY-B), ε-cyclase (LCY-E), and PpCCD4 under UV-B irradiation. The transcript levels of PpPSY, PpLCY-B, PpLCY-E, and PpCHY-B were elevated 2- to 10-fold compared with control, corresponding to a nearly 30% increase of carotenoids content after 6 h UV-B irradiation. Interestingly, the total carotenoids content decreased by nearly 60% after 48 h of storage, while UV-B delayed the decline of lutein and ß-carotene. The transcript level of PpLCY-E increased 17.83-fold compared to control, partially slowing the decline rate of lutein under UV-B irradiation. In addition, the transcript level of PpCCD4 decreased to 30% of control after 48 h UV-B irradiation, in accordance with the dramatic reduction of apocarotenoid volatiles and the delayed decrease of ß-carotene. Besides, ß-ionone content was elevated by ethylene treatment, and accumulation dramatically accelerated at full ripeness. Taken together, UV-B radiation mediated the metabolic balance of carotenoid biosynthesis and catabolism by controlling the transcript levels of PpPSY, PpLCY-B, PpLCY-E, and PpCCD4 in peach, and the transcript level of PpCCD4 showed a positive relationship with the accumulation of ß-ionone during the ripening process. However, the detailed catalytic activity of PpCCD4 with various carotenoid substrates needs to be studied further, and the key transcript factors involved in the regulation of metabolism between carotenoids and apocarotenoids need to be clarified.
RESUMEN
OBJECTIVE: To build highly predictive performance models for glioma stratification with radiomics features from non-invasive MRI. METHODS: T2-weighted fluid-attenuated inversion recovery (T2-FLAIR) imaging, diffusion-weighted MRI and diffusion kurtosis imaging were retrospectively collected for 139 glioma cases (2 with grade I, 67 with grade II, 36 with grade III and 34 with grade IV disease). Multi-parameter maps, including the apparent diffusion coefficient (ADC), mean diffusion coefficient (Dmean), fractional anisotropy (FA), and mean kurtosis (MK), were co-registered to T2-FLAIR, and 431 radiomics features for each were extracted within manually segmented tumour regions. Partial correlation analysis revealed correlations between radiomics features and glioma stratification factors (tumour grades and Ki-67 LI). Predictive models were built with adjusted-imbalanced logistic regression. RESULTS: MK radiomics features were more closely correlated with glioma stratification than other modalities analysed. The maximum R in MK was 0.52 for tumour grade and 0.56 for Ki-67 index (compared with 0.36 and 0.34 in FA, and 0.43 and 0.37 in ADC, and 0.48 and 0.42 in T2-FLAIR). The best predictive models for grade II vs. III, grade II vs. IV, low-grade vs. high-grade gliomas and positive vs. highly positive Ki-67 LI were obtained by combining multi-parameter MR radiomics features with AUCs of 0.858, 0.966, 0.853 and 0.870, respectively. However, for grade III vs. IV gliomas, the model obtained from MK radiomics features achieved the highest AUC (0.947), with excellent sensitivity and specificity. CONCLUSION: Compared with the other modalities, MK showed closer correlations with tumour grade and Ki-67 LI. Combined radiomics models integrating multi-parameter MRI allow for the generation of highly predictive models for glioma stratification.
RESUMEN
A meta-analysis was conducted to analyze the literature concerning the effects of paternal perinatal depression (PPND) on socioemotional and behavioral development in children. We assessed the literature using searches in PubMed, Web of Science, the Cochrane Library, and Embase from inception to November 2019 and supplemented it by manual searches. Two authors independently selected the eligible studies and extracted data, and three authors assessed the quality of the studies. To explore the effects of PPND on a child's socioemotional and behavioral development, a random-effects meta-analysis was conducted, followed by the construction of a funnel plot. Nine studies were included for review. The pooled odds ratio (OR) of behavioral problems in children with PPND as compared to non-PPND was 1.209 (95% CI: 1.137-1.285), the pooled OR of emotional problems in children with PPND was 1.265 (95% CI: 1.180-1.356), and the pooled OR of social functions in children with PPND was OR=1.299 (95% CI: 0.972-1.736). PPND may play a significant role in adversely impacting the emotional and behavioral development in children during early childhood. Thus, interventions for PPND should be initiated to make up the negative effect of PPND on a child's emotional and behavioral development.
Asunto(s)
Trastornos de la Conducta Infantil/psicología , Desarrollo Infantil , Trastorno Depresivo/psicología , Padre/psicología , Conducta Paterna/psicología , Niño , Trastornos de la Conducta Infantil/diagnóstico , Trastornos de la Conducta Infantil/etiología , Desarrollo Infantil/fisiología , Preescolar , Trastorno Depresivo/complicaciones , Trastorno Depresivo/diagnóstico , Femenino , Humanos , Masculino , Estudios Observacionales como Asunto/métodos , Conducta Paterna/fisiología , Embarazo , Estudios ProspectivosRESUMEN
Stigma maydis, an ingredient of pharmaceuticals and healthy foods, has a long history of usage in China and some occidental countries. Polysaccharide (SMP) is supposed to be one of the major bioactive compounds in stigma maydis, which possesses immune-enhancement, antitumor, antioxidant, anti-fatigue, diuretic, liver protection, antihyperglycaemic and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics and biological activities of polysaccharides were summarized. Their biological activities were introduced on the basis of vivo experiments, and some possible mechanisms were listed. Furthermore, industrial application of SMPs were reviewed and discussed. New perspectives for the future work of stigma maydis polysaccharide were also proposed.
Asunto(s)
Extractos Vegetales/química , Extractos Vegetales/farmacología , Polisacáridos/química , Polisacáridos/farmacología , Zea mays/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Fraccionamiento Químico , Fenómenos Químicos , Carbohidratos de la Dieta , Humanos , Estructura Molecular , Peso Molecular , Extractos Vegetales/aislamiento & purificación , Plantas Medicinales/química , Polisacáridos/aislamiento & purificación , Sustancias Protectoras/química , Sustancias Protectoras/aislamiento & purificación , Sustancias Protectoras/farmacología , Relación Estructura-ActividadRESUMEN
BACKGROUND: Dexmedetomidine (Dex) was reported to exhibit anti-inflammatory effect in the nervous system. However, the mechanism by which Dex exhibits anti-inflammation effects on LPS-stimulated BV2 microglia cells remains unclear. Thus, this study aimed to investigate the role of Dex in LPS-stimulated BV2 cells. METHODS: The BV2 cells were stimulated by lipopolysaccharides (LPS). BV2 cells were infected with short-hairpin RNAs targeting NF-κB (NF-κB-shRNAs) and NF-κB overexpression lentivirus, respectively. In addition, miR-340 mimics or miR-340 inhibitor was transfected into BV2 cells, respectively. Meanwhile, the dual-luciferase reporter system assay was used to explore the interaction of miR-340 and NF-κB in BV2 cells. CCK-8 was used to detect the viability of BV2 cells. In addition, Western blotting was used to detect the level of NF-κB in LPS-stimulated BV2 cells. The levels of TNF-α, IL-6, IL-1ß, IL-2, IL-12, IL-10 and MCP-1 in LPS-stimulated BV2 cells were measured with ELISA. RESULTS: The level of miR-340 was significantly upregulated in Dex-treated BV2 cells. Meanwhile, the level of NF-κB was significantly increased in BV2 cells following infection with lenti-NF-κB, which was markedly reversed by Dex. LPS markedly increased the expression of NF-κB and proinflammatory cytokines in BV2 cells, which were reversed in the presence of Dex. Moreover, miR-340 mimics enhanced the anti-inflammatory effects of Dex in LPS-stimulated BV2 cells via inhibiting NF-κB and proinflammatory cytokines. Furthermore, Dex obviously inhibited LPS-induced phagocytosis in BV2 cells. CONCLUSION: Taken together, our results suggested that Dex might exert anti-inflammatory effects in LPS-stimulated BV2 cells via upregulation of miR-340. Therefore, Dex might serve as a potential agent for the treatment of neuroinflammation.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Dexmedetomidina/farmacología , Inflamación/tratamiento farmacológico , MicroARNs/metabolismo , Microglía/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Citocinas/análisis , Inflamación/metabolismo , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , MicroARNs/genética , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismoRESUMEN
BACKGROUND: Urinary tract infection (UTI) is thought to be a common complication of stroke and is regarded as a potential risk factor for poor stroke outcomes. However, there is a controversy among predictive factors of stroke-associated UTIs. We aim to estimate the prevalence and predisposing factors of UTIs among patients with stroke. METHODS: PubMed, EMBASE, and Elsevier Science Direct were searched by 2 independent researchers. Sixteen studies with a total of 13,513 patients were included to evaluate the prevalence and predictive factors of stroke-associated UTIs published from the earliest records to March 10, 2017. Pooled effect sizes were calculated using the fixed effect model or random effect model according to I2 and P values. RESULTS: The pooled prevalence of UTI was 19.0% (95% confidence interval [CI], 15%-22%; P <.01). The predisposing factors for UTIs include female sex (odds ratio [OR], 1.93; 95% CI, 1.55-2.41), older age (OR, 1.28; 95% CI, 1.09-1.50), higher modified Rankin Scale score (OR, 1.90; 95% CI, 1.43-2.53), and postvoid residual volume >100 mL (OR, 3.69; 95% CI, 2.09-6.52). CONCLUSIONS: Approximately one-fifth of patients with stroke contracted at least 1 UTI after cerebral apoplexy. Female sex, older age, higher modified Rankin Scale score, and postvoid residual volume >100 mL were associated with higher risk of UTI.