Quantitative analysis of apparent diffusion coefficients to predict neurological prognosis in cardiac arrest survivors: an observational derivation and internal-external validation study.

BACKGROUND: This study aimed to validate apparent diffusion coefficient (ADC) values and thresholds to predict poor neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors by quantitatively analysing the ADC values via brain magnetic resonance imaging (MRI). METHODS: This observational study used prospectively collected data from two tertiary academic hospitals. The derivation cohort comprised 70% of the patients randomly selected from one hospital, whereas the internal validation cohort comprised the remaining 30%. The external validation cohort used the data from another hospital, and the MRI data were restricted to scans conducted at 3 T within 72-96 h after an OHCA experience. We analysed the percentage of brain volume below a specific ADC value at 50-step intervals ranging from 200 to 1200 × 10-6 mm2/s, identifying thresholds that differentiate between good and poor outcomes. Poor neurological outcomes were defined as cerebral performance categories 3-5, 6 months after experiencing an OHCA. RESULTS: A total of 448 brain MRI scans were evaluated, including a derivation cohort (n = 224) and internal/external validation cohorts (n = 96/128, respectively). The proportion of brain volume with ADC values below 450, 500, 550, 600, and 650 × 10-6 mm2/s demonstrated good to excellent performance in predicting poor neurological outcomes in the derivation group (area under the curve [AUC] 0.89-0.91), and there were no statistically significant differences in performances among the derivation, internal validation, and external validation groups (all P > 0.5). Among these, the proportion of brain volume with an ADC below 600 × 10-6 mm2/s predicted a poor outcome with a 0% false-positive rate (FPR) and 76% (95% confidence interval [CI] 68-83) sensitivity at a threshold of > 13.2% in the derivation cohort. In both the internal and external validation cohorts, when using the same threshold, a specificity of 100% corresponded to sensitivities of 71% (95% CI 58-81) and 78% (95% CI 66-87), respectively. CONCLUSIONS: In this validation study, by consistently restricting the MRI types and timing during quantitative analysis of ADC values in brain MRI, we observed high reproducibility and sensitivity at a 0% FPR. Prospective multicentre studies are necessary to validate these findings.

Association between quantitative analysis of cerebral edema using CT imaging and neurological outcomes in cardiac arrest survivors.

BACKGROUND: To determine if the density distribution proportion of Hounsfield unit (HUdp) in head computed tomography (HCT) images can be used to quantitatively measure cerebral edema in survivors of out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective observational study included adult comatose OHCA survivors who underwent HCT within 6 h (first) and 72-96 h (second), all performed using the same CT scanner. Semi-automated quantitative analysis was used to identify differences in HUdp at specific HU ranges across the intracranial component based on neurological outcome. Cerebral edema was defined as the increased displacement of the sum of HUdp values (ΔHUdp) at a specific range between two HCT scans. Poor neurological outcome was defined as cerebral performance categories 3-5 at 6 months after OHCA. RESULTS: Twenty-three (42%) out of 55 patients had poor neurological outcome. Significant HUdp differences were observed between good and poor neurological outcomes in the second HCT scan at HU = 1-14, 23-35, and 39-56 (all P < 0.05). Only the ΔHUdp = 23-35 range showed a significant increase and correlation in the poor neurological outcome group (4.90 vs. -0.72, P < 0.001) with the sum of decreases in the other two ranges (r = 0.97, P < 0.001). Multivariate logistic regression analysis demonstrated a significant association between ΔHUdp = 23-35 range and poor neurological outcomes (adjusted OR, 1.12; 95% CI: 1.02-1.24; P = 0.02). CONCLUSION: In this cohort study, the increased displacement in ΔHUdp = 23-35 range is independently associated with poor neurological outcome and provides a quantitative assessment of cerebral edema formation in OHCA survivors.

Association of ultra-early diffusion-weighted magnetic resonance imaging with neurological outcomes after out-of-hospital cardiac arrest.

BACKGROUND: This study aimed to investigate the association between ultra-early (within 6 h after return of spontaneous circulation [ROSC]) brain diffusion-weighted magnetic resonance imaging (DW-MRI) and neurological outcomes in comatose survivors after out-of-hospital cardiac arrest. METHODS: We conducted a registry-based observational study from May 2018 to February 2022 at a Chungnam national university hospital in Daejeon, Korea. Presence of high-signal intensity (HSI) (PHSI) was defined as a HSI on DW-MRI with corresponding hypoattenuation on the apparent diffusion coefficient map irrespective of volume after hypoxic ischemic brain injury; absence of HSI was defined as AHSI. The primary outcome was the dichotomized cerebral performance category (CPC) at 6 months, defined as good (CPC 1-2) or poor (CPC 3-5). RESULTS: Of the 110 patients (30 women [27.3%]; median (interquartile range [IQR]) age, 58 [38-69] years), 48 (43.6%) had a good neurological outcome, time from ROSC to MRI scan was 2.8 h (IQR 2.0-4.0 h), and the PHSI on DW-MRI was observed in 46 (41.8%) patients. No patients in the PHSI group had a good neurological outcome compared with 48 (75%) patients in the AHSI group. In the AHSI group, cerebrospinal fluid (CSF) neuron-specific enolase (NSE) levels were significantly lower in the group with good neurological outcome compared to the group with poor neurological outcome (20.1 [14.4-30.7] ng/mL vs. 84.3 [32.4-167.0] ng/mL, P < 0.001). The area under the curve for PHSI on DW-MRI was 0.87 (95% confidence interval [CI] 0.80-0.93), and the specificity and sensitivity for predicting a poor neurological outcome were 100% (95% CI 91.2%-100%) and 74.2% (95% CI 62.0-83.5%), respectively. A higher sensitivity was observed when CSF NSE levels were combined (88.7% [95% CI 77.1-95.1%]; 100% specificity). CONCLUSIONS: In this cohort study, PHSI findings on ultra-early DW-MRI were associated with poor neurological outcomes 6 months following the cardiac arrest. The combined CSF NSE levels showed higher sensitivity at 100% specificity than on DW-MRI alone. Prospective multicenter studies are required to confirm these results.

Quantitative analysis of early apparent diffusion coefficient values from MRIs for predicting neurological prognosis in survivors of out-of-hospital cardiac arrest: an observational study.

BACKGROUND: This study aimed to quantitatively analyse ultra-early brain diffusion-weighted magnetic resonance imaging (DW-MRI) findings to determine the apparent diffusion coefficient (ADC) threshold associated with neurological outcomes in comatose survivors of out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective study included adult survivors of comatose OHCA who underwent DW-MRI imaging scans using a 3-T MRI scanner within 6 h of the return of spontaneous circulation (ROSC). We investigated the association between neurological outcomes and ADC values obtained through voxel-based analysis on DW-MRI. Additionally, we constructed multivariable logistic regression models with pupillary light reflex (PLR), serum neuron-specific enolase (NSE), and ADC values as independent variables to predict poor neurological outcomes. The primary outcome was poor neurological outcome 6 months after ROSC, determined by the Cerebral Performance Category 3-5. RESULTS: Overall, 131 patients (26% female) were analysed, of whom 74 (57%) showed poor neurological outcomes. The group with a poor neurological outcome had lower mean whole brain ADC values (739.1 vs. 787.1 × 10-6 mm/s) and higher percentages of voxels with ADC below threshold in all ranges (250-1150) (all P < 0.001). The mean whole brain ADC values (area under the receiver operating characteristic curve [AUC] 0.83) and the percentage of voxels with ADC below 600 (AUC 0.81) had the highest sensitivity of 51% (95% confidence interval [CI] 39.4-63.1; cut-off value ≤ 739.2 × 10-6 mm2/s and > 17.2%, respectively) when the false positive rate (FPR) was 0%. In the multivariable model, which also included PLR, NSE, and mean whole brain ADC values, poor neurological outcome was predicted with the highest accuracy (AUC 0.91; 51% sensitivity). This model showed more accurate prediction and sensitivity at an FPR of 0% than did the combination of PLR and NSE (AUC 0.86; 30% sensitivity; P = 0.03). CONCLUSIONS: In this cohort study, early voxel-based quantitative ADC analysis after ROSC was associated with poor neurological outcomes 6 months after cardiac arrest. The mean whole brain ADC value demonstrated the highest sensitivity when the FPR was 0%, and including it in the multivariable model improved the prediction of poor neurological outcomes.

Capsule-based colorimetric temperature monitoring system for customizable cold chain management.

The COVID-19 pandemic and the resulting supply chain disruption have rekindled crucial needs for safe storage and transportation of essential items. Despite recent advances, existing temperature monitoring technologies for cold chain management fall short in reliability, cost, and flexibility toward customized cold chain management for various products with different required temperature. In this work, we report a novel capsule-based colorimetric temperature monitoring system with precise and readily tunable temperature ranges. Triple emulsion drop-based microfluidic technique enables rapid production of monodisperse microcapsules with an interstitial phase-change oil (PCO) layer with precise control over its dimension and composition. Liquid-solid phase transition of the PCO layer below its freezing point triggers the release of the encapsulated payload yielding drastic change in color, allowing user-friendly visual monitoring in a highly sensitive manner. Simple tuning of the PCO layer's compositions can further broaden the temperature range in a precisely controlled manner. The proposed simple scheme can readily be formulated to detect both temperature rise in the frozen environment and freeze detection as well as multiple temperature monitoring. Combined, these results support a significant step forward for the development of customizable colorimetric monitoring of a broad range of temperatures with precision.

Health-related quality of life using WHODAS 2.0 and associated factors 1 year after stroke in Korea: a multi-centre and cross-sectional study.

BACKGROUND: Little is known about the self-perceived level of disability of stroke survivors in the community. We aimed to characterise Health-related quality of life (HRQoL) 1 year after stroke and investigate how sociodemographic and stroke-related factors and medical adherence explain the self-perceived level of disability in a Korean stroke population. METHODS: This was a multicentre cross-sectional study. A total of 382 ischaemic stroke survivors at 1 year after onset from 11 university hospitals underwent a one-session assessment, including socioeconomic variables, the modified Rankin Scale (mRS), various neurological sequelae, the Morisky, Green and Levin-Medication Adherence Questionnaire (MGL), and the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) 36-items. The relationship between disability and different variables was analysed using ordinal logistic regression. RESULTS: The prevalence of disability based on global WHODAS 2.0 was 62.6% (mild, 41.6%; moderate, 16.0%; severe, 5.0%). The prevalence of severe disability was higher in participation in society (16.8%) and getting around (11.8%) than in other domains. Low MGL- motivation was the only factor determining a significant association between all six domains of disability after adjustment. Different predictors for specific domains were age, mRS, dysarthria, trouble seeing, cognition problems, and MGL-motivation for understanding and communicating; age, recurrent stroke, mRS, hemiplegia, facial palsy, general weakness, and MGL-motivation for getting around; age, education, mRS, hemiplegia, and MGL-motivation for self-care; education, recurrent stroke, hemiplegia, dysarthria, and MGL-motivation for getting along with people; age, education, income, mRS, hemiplegia, dysarthria, MGL-knowledge, and MGL-motivation for life activities; living without a spouse, mRS, hemiplegia, dysarthria, trouble seeing, cognition problems, general weakness, and MGL-motivation for participation in society. CONCLUSIONS: Self-perceived disability according to the WHODAS 2.0 at 1 year after stroke was highly prevalent. Each disability domain showed a different prevalence and associated factors. Interventions promoting medical adherence to motivation seemed to help achieve high HRQoL in all domains.

Association of plasma level of growth differentiation factor-15 and clinical outcome after intraarterial thrombectomy.

BACKGROUND AND PURPOSE: As intraarterial thrombectomy (IAT) has been actively practiced, blood biomarkers that can predict outcomes after IAT have drawn attention. Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine and the levels are increased during inflammation or other pathological conditions of various tissues, including the brain. However, GDF-15 levels have not been reported as a biomarker for IAT outcomes. This study was performed to evaluate whether GDF-15 was related to the extent of brain damage and whether it could predict patient prognosis after IAT. METHODS: Patients who showed large arterial occlusion and significant diffusion-perfusion mismatch on imaging underwent IAT. A total of 62 patients who underwent IAT and had blood samples for GDF-15 measurements were enrolled from July 2013 to May 2015. We assessed the infarct severity by consecutive changes on the National Institutes of Health Stroke Scale (NIHSS) during admission and the size of the infarction on brain imaging. Modified Rankin Scale scores (mRS) from 0 to 2 were considered good outcomes, representing functional independence at discharge and three months later. RESULTS: The levels of GDF-15 at the time of admission were significantly correlated with the NIHSS scored at 24 hours (r = 0.306, p = 0.016), three days after IAT (r = 0.261, p = 0.041), and at discharge (r = 0.266, p = 0.037), as well as the infarct size on diffusion-weighted image taken 24 h after IAT (r = 0.452, p = 0.001), but the levels were not correlated with the initial NIHSS or the infarct size before IAT. Multiple logistic regression showed that GDF-15 levels were an independent predictor of functional independence (mRS 0 - 2) at discharge (p = 0.028) and three months after IAT (p = 0.019). Other factors that could predict prognosis were good collateral status on the initial brain angiography and rapid recanalization within six hours from symptom onset. CONCLUSION: The GDF-15 level at the time of admission showed a significant positive correlation with the severity of cerebral damage and clinical outcome after IAT. This suggests that GDF-15 can provide useful prognostic information for patients who successfully underwent IAT in an emergency setting.

Use of microcatheters for suction thrombectomy of acute distal occlusions.

We report our initial experience of using a microcatheter for contact aspiration of acute distal occlusions for recanalization. Endovascular technique and a case using Excelsior XT-27 microcatheter are presented. After manual suction within distal middle cerebral artery segments using a 50-ml syringe, instant and complete recanalization was obtained. Microcatheter suction thrombectomy using a 50-ml syringe can be considered a feasible treatment option for acute distal small artery occlusions.

The Effect of Inter-Departmental Stroke Meetings on Rehabilitation in a Comprehensive Cerebrovascular Center.

BACKGROUND: Stroke is the number one cause of adulthood disability in Korea. Rehabilitation after stroke can minimize functional disability, enhance recovery toward independence, and optimize community reintegration. The inter-departmental stroke meeting (IDSM) is a potential method to improve rehabilitation outcomes in patients with stroke. We aimed to analyze the effect of IDSM on rehabilitation after acute ischemic stroke management. METHODS: Medical records of 753 patients with acute ischemic stroke admitted to the neurology department of our medical center between January and December 2014 were reviewed retrospectively. In May 2014, weekly IDSMs were initiated. All physicians responsible for the patient's care reviewed patient treatment, methods of secondary prevention, and future rehabilitation plans. RESULTS: The transfer rate significantly increased after initiation of IDSM (phase 2, 3) and the length of stay (LOS) before transfer to the rehabilitation department decreased significantly from 9.68 ± 8.50 days to 5.75 ± 2.12 days. There was a reduction in the total LOS from 52 ± 28.57 days to 35 ± 27.21 days after IDSMs were introduced. In non-transferred patients also, the total LOS reduced significantly. The transfer rate increased significantly and the LOS before transfer to the rehabilitation department decreased significantly after implementation of IDSM in a subgroup of patients with moderate to severe stroke. CONCLUSION: The introduction of IDSM was significantly correlated with improvements in transfer rates and reduction of LOS in hospital. This finding shows that IDSMs are an important intervention to improve therapeutic progress and outcomes for patients with stroke.

Brachial-ankle PWV for predicting clinical outcomes in patients with acute stroke.

BACKGROUND: Although brachial-ankle pulse wave velocity (baPWV) is well-known for predicting the cardiovascular mortality and morbidity, its anticipated value is not demonstrated well concerning acute stroke. METHODS: Total 1557 patients with acute stroke who performed baPWV were enrolled. We evaluated the prognostic value of baPWV predicting all-cause death and vascular death in patients with acute stroke Results: Highest quartile of baPWV was ≥23.64 m/s. All-caused deaths (including vascular death; 71) were 109 patients during follow-up periods (median 905 days). Multivariate Cox regression analysis revealed that patients with the highest quartile of baPWV had higher risk for vascular death when they are compared with patients with all other three quartiles of baPWV (Hazard ratio with 95% confidence interval [CI] 1.879 [1.022-3.456], p = .042 for vascular death). CONCLUSION: High baPWV was a strong prognostic value of vascular death in patients with acute stroke.

Prognostic Relationships between Microbleed, Lacunar Infarction, White Matter Lesion, and Renal Dysfunction in Acute Ischemic Stroke Survivors.

BACKGROUND: It is well known that renal dysfunction and cerebral small-vessel disease (SVD), including microbleed, lacunar infarction, and white matter lesion (WML), are associated with poor prognosis after ischemic stroke. However, the prognostic relationship between renal dysfunction and SVD has not been well evaluated in acute ischemic stroke survivors. Therefore, in this study, we evaluated the prognostic relationships between estimated glomerular filtration rate (eGFR) and cerebral SVD after acute ischemic stroke. METHODS: We retrospectively reviewed the clinical and radiological data of acute ischemic stroke survivors with decreased eGFR (<60 mL/min/1.73 m2, n = 128) and controls (eGFR ≥60 mL/min/1.73 m2, n = 128). The presence of SVD was evaluated according to magnetic resonance imaging performed on admission. Mortality data were obtained from medical chart reviews and telephone interviews. RESULTS: Patients with silent lacunar infarction, WML, or microbleed had lower eGFR than patients without such lesions (60.4 ± 34.8 versus 87.5 ± 28.4 mL/min/1.73 m2, 60.5 ± 37.1 versus 73.9 ± 33.3 mL/min/1.73 m2, and 57.6 ± 33.3 versus 73.9 ± 32.9 mL/min/1.73 m2, respectively). In addition, the multivariate adjusted odds ratio for the presence of SVD increased inversely with eGFR. Three-year survival was lower in patients with renal dysfunction and each type of SVD. The presence of WML was an independent risk factor for cardiovascular death. CONCLUSIONS: Renal impairment was associated with the presence of SVD in acute ischemic stroke survivors. Both renal impairment and the presence of SVD were predictors of poor poststroke survival.

The Impact of Hemodialysis and Arteriovenous Access Flow on Extracranial Hemodynamic Changes in End-Stage Renal Disease Patients.

In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure.

Therapeutic hypothermia after recanalization in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Therapeutic hypothermia improves outcomes in experimental stroke models, especially after ischemia-reperfusion injury. We investigated the clinical and radiological effects of therapeutic hypothermia in acute ischemic stroke patients after recanalization. METHODS: A prospective cohort study at 2 stroke centers was performed. We enrolled patients with acute ischemic stroke in the anterior circulation with an initial National Institutes of Health Stroke Scale≥10 who had successful recanalization (≥thrombolysis in cerebral ischemia, 2b). Patients at center A underwent a mild hypothermia (34.5°C) protocol, which included mechanical ventilation, and 48-hour hypothermia and 48-hour rewarming. Patients at center B were treated according to the guidelines without hypothermia. Cerebral edema, hemorrhagic transformation, good outcome (3-month modified Rankin Scale, ≤2), mortality, and safety profiles were compared. Potential variables at baseline and during the therapy were analyzed to evaluate for independent predictors of good outcome. RESULTS: The hypothermia group (n=39) had less cerebral edema (P=0.001), hemorrhagic transformation (P=0.016), and better outcome (P=0.017) compared with the normothermia group (n=36). Mortality, hemicraniectomy rate, and medical complications were not statistically different. After adjustment for potential confounders, therapeutic hypothermia (odds ratio, 3.0; 95% confidence interval, 1.0-8.9; P=0.047) and distal occlusion (odds ratio, 7.3; 95% confidence interval; 1.3-40.3; P=0.022) were the independent predictors for good outcome. Absence of cerebral edema (odds ratio, 5.4; 95% confidence interval, 1.6-18.2; P=0.006) and no medical complications (odds ratio, 9.3; 95% confidence interval, 2.2-39.9; P=0.003) were also independent predictors for good outcome during the therapy. CONCLUSIONS: In patients with ischemic stroke, after successful recanalization, therapeutic hypothermia may reduce risk of cerebral edema and hemorrhagic transformation, and lead to improved clinical outcomes.

Predictive factors for early clinical improvement after intra-arterial thrombolytic therapy in acute ischemic stroke.

BACKGROUND: In acute ischemic stroke, the speed of improvement after intra-arterial thrombolytic therapy (IAT)-mediated recanalization varies. This study aimed to identify clinical and radiological variables that are predictive of early improvement (EI) after IAT in acute ischemic stroke. METHODS: This single-center retrospective cohort study included 141 consecutive patients who underwent IAT for terminal internal carotid and/or middle cerebral artery (MCA) occlusions. EI was defined as a National Institutes of Health Stroke Scale (NIHSS) score less than 3 or NIHSS score improvement of 8 points or more within 72 hours of IAT. The EI and non-EI groups were compared in terms of clinical and radiological findings before and after IAT. RESULTS: Forty-nine patients showed EI (34.8%). Multivariate analysis revealed that atrial fibrillation (odds ratio [OR] .35, 95% confidence interval [CI] .14-.89, P = .028) and hyperdense MCA sign (OR .39, CI .15-.97, P = .042) were related with lack of EI. The independent EI predictors were less extensive parenchymal lesion on baseline computed tomography (OR 4.92, CI 1.74-13.9, P = .003), intermediate to good collaterals (OR 3.28, CI 1.16-9.31, P = .026), and recanalization within 6 hours of symptom onset (OR 5.2, CI 1.81-14.94, P = .002). EI associated with favorable outcomes (modified Rankin scale score 0-2) at discharge (88% versus 7%; P < .001) and 3 months after discharge (92% versus 18%; P < .001). CONCLUSIONS: The clinical and radiological variables maybe useful for predicting EI and favorable long-term outcomes after IAT.

Muscle mass and chronic dizziness: a cross-sectional study of a Korean population.

BACKGROUND AND OBJECTIVES: Weight gain is associated with imbalance in older people. In contrast, overweightness or mild obesity is less common in patients with chronic dizziness. This paradox may be, at least in part, related to differences in the body composition indices adopted in the previous studies. This study aimed to determine any association between the predicted body composition and chronic dizziness or imbalance of unknown causes. METHODS: We measured the lean body mass, body fat mass, and appendicular skeletal mass in 9243 people who participated in the Korean National Health and Nutrition Examination Survey 2019-2021. Sarcopenia was defined according to the Asian Working Group for Sarcopenia's guidelines. Obesity was defined as a body fat percentage of ≥ 25% for men and ≥ 35% for women. RESULTS: The participants with chronic dizziness had a lower body mass index than those without (p = 0.001). Furthermore, sarcopenia was more common in those with chronic dizziness. In contrast, the degree of obesity was comparable in both groups. Multiple logistic regression analysis showed that sarcopenia was associated with a higher risk of chronic dizziness (odds ratio = 1.6, 95% confidence interval: 1.1-2.5; p = 0.026). DISCUSSION: Given the association of sarcopenia with chronic dizziness or imbalance, muscle mass may play a role in maintaining balance and stability. Physical exercise could be recommended to increase muscle mass in patients with chronic dizziness/imbalance and sarcopenia. Additional research is required to establish a causal relationship between chronic dizziness and sarcopenia.

Color-encoded multicompartmental hydrogel microspheres for multiplexed bioassays.

We develop color-encoded multicompartmental hydrogel (MH) microspheres tailored for multiplexed bioassays using a drop-based microfluidic approach. Our method involves the creation of triple emulsion drops that feature thin sacrificial oil layers separating two prepolymer phases. This configuration leads to the formation of poly(ethylene glycol) (PEG) multi-compartmental core-shell microspheres through photopolymerization, followed by the removal of the thin oil layers. The core compartments stably incorporate pigments, ensuring their retention within the hydrogel network without leakage, which facilitates reliable color encoding across varying spatial positions. Additionally, we introduce small molecule fluorescent labeling into the chemically functionalized shell compartments, achieving consistent distribution of functional components without the core's contamination. Importantly, our integrated one-pot conjugation of these color-encoded microspheres with affinity peptides enables the highly sensitive and selective detection of influenza virus antigens using a fluorescence bioassay, resulting in an especially low detection limit of 0.18 nM and 0.66 nM for influenza virus H1N1 and H5N1 antigens, respectively. This approach not only highlights the potential of our microspheres in clinical diagnostics but also paves the way for their application in a wide range of multiplexed assays.

Intracranial hemodynamic stabilization patterns after stenting of severe stenosis in the proximal internal carotid artery.

PURPOSE: To evaluate intracranial hemodynamic stabilization patterns after carotid artery stenting (CAS) in patients having variable collateral developments before CAS. METHODS: The hemodynamic and angiographic data of 62 patients (58 men; mean age 68.0±8.4 years) who underwent CAS for unilateral proximal internal carotid artery stenosis were analyzed. The patients had transcranial Doppler examinations before and at 1 and 90 days after CAS. Patients were classified according to pre-CAS mean blood flow velocity (MBFV) of the ipsilateral middle cerebral artery (MCA): low (<30 cm/s; n=17), normal (30 to 48 cm/s; n=26), or high (>48 cm/s; n=19). The collaterals from contralateral anterior and/or posterior circulations prior to CAS, the stabilization pattern of MBFV, and the pulsatility index (PI) after CAS were compared across the 3 groups. RESULTS: The presence of collaterals was lowest in the low MBFV group (17.6% of patients) than in the normal (38.5%) or high (68.4%) MBFV groups (p=0.008). The low MBFV group exhibited an increase in MBFV and PI in the ipsilateral MCA at 1 and 90 days after CAS (p<0.05). By contrast, the high MBFV group exhibited a decrease in MBFV and no change in PI in the ipsilateral MCA up to 90 days after CAS (p<0.05). The normal MBFV group showed an increase in MBFV at post-CAS day 1 but a subsequent decrease at 90 days and an increase in PI in the ipsilateral MCA at 1 and 90 days post-CAS (p<0.05). CONCLUSION: The pattern of post-CAS intracranial hemodynamic stabilization differs according to the pre-CAS MBFV in the ipsilateral MCA.

Broad-temperature-range mechanically tunable hydrogel microcapsules for controlled active release.

Here, we report PNIPAm-co-PEGDA hydrogel shelled microcapsules with a thin oil layer to achieve tunable thermo-responsive release of the encapsulated small hydrophilic actives. We use a microfluidic device integrated with a temperature-controlled chamber for consistent and reliable production of the microcapsules by utilizing triple emulsion drops (W/O/W/O) with a thin oil layer as capsule templates. The interstitial oil layer between the aqueous core and the PNIPAm-co-PEGDA shell provides a diffusion barrier for the encapsulated active until the temperature reaches a critical point above which the destabilization of interstitial oil layer occurs. We find that the destabilization of the oil layer with temperature increase is caused by outward expansion of the aqueous core due to volume increase and the radial inward compression from the deswelling of the thermo-responsive hydrogel shell. The copolymerization of NIPAm with PEGDA increases the biocompatibility of the resulting microcapsule while offering the ability to alter the compressive modulus in broad ranges by simply varying crosslinker concentrations thereby to precisely tune the onset release temperature. Based on this concept, we further demonstrate that the release temperature can be enhanced up to 62 °C by adjusting the shell thickness even without varying the chemical composition of the hydrogel shell. Moreover, we incorporate gold nanorods within the hydrogel shell to spatiotemporally regulate the active release from the microcapsules by illuminating with non-invasive near infrared (NIR) light.

Affinity Peptide-Tethered Suspension Hydrogel Sensor for Selective and Sensitive Detection of Influenza Virus.

Influenza viruses are known to cause pandemic flu outbreaks through both inter-human and animal-to-human transmissions. Therefore, the rapid and accurate detection of such pathogenic viruses is crucial for effective pandemic control. Here, we introduce a novel sensor based on affinity peptide-immobilized hydrogel microspheres for the selective detection of influenza A virus (IAV) H3N2. To enhance the binding affinity performance, we identified novel affinity peptides using phage display and further optimized their design. The functional hydrogel microspheres were constructed using the drop microfluidic technique, employing a structure composed of natural (chitosan) and synthetic (poly(ethylene glycol) diacrylate and PEG 6 kDa) polymers with the activation of azadibenzocyclooctyne for the subsequent click chemistry reaction. The binding peptide-immobilized hydrogel microsphere (BP-Hyd) was characterized by field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy and exhibited selective detection capability for the IAV H3N2. To capture the detected IAV H3N2, a Cy3-labeled IAV hemagglutinin antibody was utilized. By incorporating the affinity peptide with hydrogel microspheres, we achieved quantitative and selective detection of IAV H3N2 with a detection limit of 1.887 PFU mL-1. Furthermore, the developed suspension sensor exhibited excellent reproducibility and showed reusability potential. Our results revealed that the BP-Hyd-based fluorescence sensor platform could be feasibly employed to detect other pathogens because the virus-binding peptides can be easily replaced with other peptides through phage display, enabling selective and sensitive binding to different targets.

Endovascular recanalization therapy for patients with acute ischemic stroke with hidden aortic dissection: A case series.

Aortic dissection is one of the causes of acute ischemic stroke. Endovascular recanalization therapy (EVT) has emerged as an essential treatment for acute ischemic stroke due to large artery occlusion. However, it is rarely performed in the situation of hidden aortic dissection (AD). Two patients presented to the emergency room with focal neurologic deficits. The first patient was diagnosed with right internal carotid artery (ICA) occlusion. Angiography revealed that the ICA was occluded by the dissection flap. After a stent deployment in the proximal ICA, the antegrade flow was restored. The patient was diagnosed with AD on chest computed tomography (CT) after EVT. For the second patient, intraarterial thrombectomy was performed to treat left middle cerebral artery occlusion. AD was first detected on echocardiography, which was performed after EVT. Herein, we report successful endovascular recanalization therapy performed in two patients with acute ischemic stroke in the situation of undiagnosed aortic dissection. We also reviewed previous case reports and relevant literature.