A Ratiometric Fluorescence Probe Based on Silver Nanoclusters and CdSe/ZnS Quantum dots for the Detection of Hydrogen Peroxide by Aggregation and Etching.

In this study, a ratiometric fluorescence nanoprobe is developed for the analysis of hydrogen peroxide (H2O2). Silver nanoclusters (AgNCs) were synthesized by chemical reduction method using sodium borohydride (NaBH4) as reducing agent, and were coupled with CdSe/ZnS quantum dots (QDs) to form the ratiometric fluorescence nanoprobe silver nanoclusters-quantum dots (AgNCs-QDs). The effect of the volume ratio of CdSe/ZnS QDs to AgNCs on the fluorescence ratio of AgNCs-QDs was investigated. The fluorescence characterization results show that two emission peaks of AgNCs-QDs are located at 473 nm and 661 nm, respectively. Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) results show that H2O2 can cause the fluorescence probe to aggregate, while etching AgNCs to produce silver ions, which together cause the fluorescence of the QDs in the ratiometric fluorescent probe to be quenched. Based on this strategy, the fluorescence intensity ratio of the two emission peaks F473/F661 exhibits a strong linear correlation with the concentration of H2O2. The detection range is 3.32 µM ~ 2.65 mM with a detection limit of 3.32 µM. In addition, the ratiometric fluorescence probe can specifically recognize H2O2 and has excellent anti-interference performance and good fluorescence stability. Importantly, the probe was utilized for the detection of H2O2 in serum, showing the possibility of the probe in clinical detection applications.

An Integrated Clinical and Computerized Tomography-Based Radiomic Feature Model to Separate Benign from Malignant Pleural Effusion.

INTRODUCTION: Distinguishing between malignant pleural effusion (MPE) and benign pleural effusion (BPE) poses a challenge in clinical practice. We aimed to construct and validate a combined model integrating radiomic features and clinical factors using computerized tomography (CT) images to differentiate between MPE and BPE. METHODS: A retrospective inclusion of 315 patients with pleural effusion (PE) was conducted in this study (training cohort: n = 220; test cohort: n = 95). Radiomic features were extracted from CT images, and the dimensionality reduction and selection processes were carried out to obtain the optimal radiomic features. Logistic regression (LR), support vector machine (SVM), and random forest were employed to construct radiomic models. LR analyses were utilized to identify independent clinical risk factors to develop a clinical model. The combined model was created by integrating the optimal radiomic features with the independent clinical predictive factors. The discriminative ability of each model was assessed by receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA). RESULTS: Out of the total 1,834 radiomic features extracted, 15 optimal radiomic features explicitly related to MPE were picked to develop the radiomic model. Among the radiomic models, the SVM model demonstrated the highest predictive performance [area under the curve (AUC), training cohort: 0.876, test cohort: 0.774]. Six clinically independent predictive factors, including age, effusion laterality, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 125 (CA125), and neuron-specific enolase (NSE), were selected for constructing the clinical model. The combined model (AUC: 0.932, 0.870) exhibited superior discriminative performance in the training and test cohorts compared to the clinical model (AUC: 0.850, 0.820) and the radiomic model (AUC: 0.876, 0.774). The calibration curves and DCA further confirmed the practicality of the combined model. CONCLUSION: This study presented the development and validation of a combined model for distinguishing MPE and BPE. The combined model was a powerful tool for assisting in the clinical diagnosis of PE patients.

A comprehensive review of toxicity of coal fly ash and its leachate in the ecosystem.

Coal fly ash (CFA), a byproduct of coal combustion, is a hazardous industrial solid waste. Its excessive global production, coupled with improper disposal practices, insufficient utilization and limited awareness of its inherent hazards, poses a significant threat to both ecological environment and human health. Based on the physicochemical properties of CFA and its leachates, we elucidate the forms of CFA and potential pathways for its entry into the human body, as well as the leaching behavior, maximum tolerance and biological half-life of toxic elements present in CFA. Furthermore, we provide an overview of current strategies and methods for mitigating the leaching of these harmful elements from CFA. Moreover, we systemically summarize toxic effect of CFA on organisms across various tiers of complexity, analyze epidemiological findings concerning the human health implications resulting from CFA exposure, and delve into the biotoxicological mechanisms of CFA and its leachates at cellular and molecular levels. This review aims to enhance understanding of the potential toxicity of CFA, thereby promoting increased public awareness regarding the disposal and management of this industrial waste.

Influence of implant distribution on the biomechanical behaviors of mandibular implant-retained overdentures: a three-dimensional finite element analysis.

OBJECTIVE: To assess stress distribution in peri-implant bone and attachments of mandibular overdentures retained by small diameter implants, and to explore the impact of implant distribution on denture stability. METHODS: Through three-dimensional Finite Element Analysis (3D FEA), four models were established: three models of a two mandibular implants retained overdenture (IOD) and one model of a conventional complete denture (CD). The three IOD models consisted of one with two implants in the bilateral canine area, another with implants in the bilateral lateral incisor area, and the third with one implant in the canine area, and another in the lateral incisor area. Three types of loads were applied on the overdenture for each model: a 100 N vertical load and a inclined load on the left first molar, and a100N vertical load on the lower incisors. The stress distribution in the peri-implant bone, attachments, and the biomechanical behaviors of the overdentures were analyzed. RESULTS: Despite different distribution of implants, the maximum stress values in peri-implant bone remained within the physiological threshold for all models across three loading conditions. The dispersed implant distribution design (implant in the canine area) exhibited the highest maximum stress in peri-implant bone (822.8 µe) and the attachments (275 MPa) among the three IOD models. The CD model demonstrated highest peak pressure on mucosa under three loading conditions (0.8188 Mpa). The contact area between the denture and mucosa of the CD model was smaller than that in the IOD models under molar loading, yet it was larger in the CD model compared to the IOD model under anterior loading. However, the contact area between the denture and mucosa under anterior loading in all models was significantly smaller than those under molar loading. The IOD in all three models exhibited significantly less rotational movement than the complete denture. Different implant positions had minimal impact on the rotational movement of the IOD. CONCLUSION: IOD with implants in canine area exhibited the highest maximum stress in the peri-implant bone and attachments, and demonstrated increased rotational movement. The maximum principal stress was concentrated around the neck of the small diameter one-piece implant, rather than in the abutment. An overdenture retained by two implants showed better stability than a complete denture.

Stainless Steel Screen Modified with Renatured Xerogel for Efficient and Highly Stable Oil/Water Separation via Gravity.

The application of hydrogel coatings to surface-modified metallic materials has gained considerable attention in engineering practice such as water-oil separation. However, the low coating adhesion and poor coating stability restrict its application. In this study, to obtain special wettability and durable filter materials, polyacrylamide (PAM)/sodium alginate (SA) xerogel particles were first prepared and adhered to a stainless steel screen by using an epoxy resin as a linker. Subsequently, the xerogel particles of the screen rehydrates in water to form a PAM-SA double-network hydrogel. The results show that the screen modified by PAM-SA xerogel of 20-30 µm particle size and a linker concentration of 0.1 g/mL resulted in a chimeric structure and subsequently transformed a uniform double-network hydrogel coating in water. According to the experimental results, the rough hydrogel coating exhibits superhydrophilicity and superoleophobicity under water; in particular, it has excellent wear resistance as well as physical and chemical stability. Under gravity-driven action, the PAM-SA-modified screen demonstrates high separation efficiency values of up to 99% in separating a wide range of oil/water mixtures and maintaining a water flux of (2-6) × 104 L·m-2·h-1. There was no significant reduction in efficiency of separation and water flux after 10 cycles, indicating that the PAM-SA-modified screen is capable of offering outstanding separation performance and durability. Moreover, the hydrogel-modified screen demonstrated corrosion and swelling resistance in some extreme environments, paving a way for practical applications in water treatment. The novel hydrogel-coating-modified screen with ease of preparation holds great promise for oil/water separation and other engineering applications.

Matrix stiffness, endothelial dysfunction and atherosclerosis.

Atherosclerosis (AS) is the leading cause of the human cardiovascular diseases (CVDs). Endothelial dysfunction promotes the monocytes infiltration and inflammation that participate fundamentally in atherogenesis. Endothelial cells (EC) have been recognized as mechanosensitive cells and have different responses to distinct mechanical stimuli. Emerging evidence shows matrix stiffness-mediated EC dysfunction plays a vital role in vascular disease, but the underlying mechanisms are not yet completely understood. This article aims to summarize the effect of matrix stiffness on the pro-atherosclerotic characteristics of EC including morphology, rigidity, biological behavior and function as well as the related mechanical signal. The review also discusses and compares the contribution of matrix stiffness-mediated phagocytosis of macrophages and EC to AS progression. These advances in our understanding of the relationship between matrix stiffness and EC dysfunction open the avenues to improve the prevention and treatment of now-ubiquitous atherosclerotic diseases.

RGD peptide modified RBC membrane functionalized biomimetic nanoparticles for thrombolytic therapy.

In recent years, the fabrication of nano-drug delivery systems for targeted treatment of thrombus has become a research hotspot. In this study, we intend to construct a biomimetic nanomedicine for targeted thrombus treatment. The poly lactic-co-glycolic acid (PLGA) was selected as the nanocarrier material. Then, urokinase and perfluoro-n-pentane (PFP) were co-loaded into PLGA by the double emulsification solvent evaporation method to prepare phase change nanoparticles PPUNPs. Subsequently, the RGD peptide-modified red blood cell membrane (RBCM) was coated on the surface of PPUNPs to prepare a biomimetic nano-drug carrier (RGD-RBCM@PPUNPs). The as-prepared RGD-RBCM@PPUNPs possessed a "core-shell" structure, have good dispersibility, and inherited the membrane protein composition of RBCs. Under ultrasound stimulation, the loaded urokinase could be rapidly released. In vitro cell experiments showed that RGD-RBCM@PPUNPs had good hemocompatibility and cytocompatibility. Due to the coated RGD-RBC membrane, RGD-RBCM@PPUNPs could effectively inhibit the uptake of macrophages. In addition, RGD-RBCM@PPUNPs showed better thrombolytic function in vitro. Overall, the results suggested that this biomimetic nanomedicine provided a promising therapeutic strategy for the targeted therapy of thrombosis.

[Clinical Features and Surgical Outcomes of 15 Cases of Intracranial Alveolar Echinococcosis]. / 15ä¾‹é¢ å† æ³¡åž‹æ£˜çƒèš´ç— çš„ä¸´åºŠç‰¹ç‚¹åŠæ‰‹æœ¯ç–—æ•ˆåˆ†æž.

Objective: To investigate the surgical treatment strategy of intracranial alveolar echinococcosis (AE) and the clinical outcomes. Methods: The clinical and follow-up data of 15 intracranial AE patients who underwent surgical treatment in the Departments of Neurosurgery of Sichuan Provincial People's Hospital (SPPH) and People's Hospital of Aba Tibetan and Qiang Autonomous Prefecture (a branch hospital of SPPH) between March 2017 and January 2021 were retrospectively analyzed. Full follow-up data were available for each of the 15 cases. The clinical and imaging characteristics, general surgical information, and surgical outcomes were analyzed. Results: In the 15 patients, there were a total of 50 intracranial lesions, with an average of (3.3±3.1)/case. Four cases had solitary intracranial lesions, while 11 cases had multiple lesions, with the number of intracranial lesions per case ranging from 2 to 13. All patients with solitary intracranial lesions received total resection. In 6 patients with multiple intracranial lesions, only the largest lesion was surgically removed, and in 5 patients, 2 to 3 adjacent lesions were surgically removed. All but one patient had extracranial lesions in their liver, lungs, kidneys, adrenal glands, and thoracic vertebrae. The patients were followed up for 12 to 58 months after surgery, with the mean follow-up time being (28.1±13.4) months. Among the 15 cases, 13 showed stable intracranial condition during postoperative follow-up. Intracranial lesions recurred in 2 patients who had deep lesions accompanied by dissemination to the subarachnoid space. Two patients died during follow-up. Conclusion: Microsurgical treatment of intracranial AE is effective, but total surgical resection is difficult to accomplish when patients have echinococcosis lesions located at a depth, especially when the lesions are spreading to the subarachnoid space. The prognosis of patients is closely associated with the extent of lesion invasion and the control of systemic hydatid lesions, especially those in the liver.

Gamma-glutamyl transferase levels are associated with the occurrence of post-stroke cognitive impairment: a multicenter cohort study.

BACKGROUND: Gamma-glutamyl transferase (GGT) is involved in maintenance of physiological concentrations of glutathione in cells, and protects them from oxidative stress-induced damage. However, its role in post-stroke cognitive impairment (PSCI) remains unknown. Here, we investigated the effects of serum GGT on PSCI. METHODS: We conducted a prospective, multicenter cohort study. A total of 1, 957 participants with a minor ischemic stroke or transient ischemic attack whose baseline GGT levels were measured were enrolled from the Impairment of Cognition and Sleep (ICONS) study of the China National Stroke Registry-3 (CNSR-3). They were categorized into four groups according to quartiles of baseline GGT levels. Cognitive functions were assessed using the Montreal Cognitive Assessment (MoCA) approach. Multiple logistic regression models were performed to evaluate the relationship between GGT and PSCI at 3 months follow-up. RESULTS: Among the 1957 participants, 671 (34.29%) patients suffered PSCI at 3 months follow-up. The highest GGT level quartile group exhibited a lower risk of PSCI in the fully adjusted model [OR (95% CI): 0.69 (0.50-0.96)], relative to the lowest group. Moreover, incorporation of GGT to the conventional model resulted in slight improvements in PSCI outcomes after 3 months (NRI: 12.00%; IDI: 0.30%). CONCLUSIONS: Serum GGT levels are inversely associated with the risk of PSCI, with extremely low levels being viable risk factors for PSCI.

Persisting cognitive impairment predicts functional dependence at 1 year after stroke and transient ischemic attack: a longitudinal, cohort study.

OBJECTIVE: Minor stroke or transient ischemic attack (TIA) usually have mild and nondisabling symptoms, and these functional deficits may recover fully e.g., TIA, however, part of them still suffer from cognitive impairment and poor outcomes. We conducted a study to determine the relationship between cognition evaluated by Montreal Cognitive Assessment (MoCA) and poor functional outcomes assessed by the Modified Rankin Scale (mRS) (mRS ≥ 2) and Stroke Impact Scale (SIS)-16(SIS-16<25%). METHODS: The data of this study come from the impairment of cognition and Sleep (ICONS) after acute ischemic stroke or transient ischemic attack in Chinese patients study. A total of 1675 minor stroke patients and TIA patients were finally recruited. Patients' cognition were evaluated by Montreal Cognitive Assessment (MoCA) scale at 2-week (2w), 3 months (3 m) and 1 year(1y). Cognitive impairment (CI) was defined as MoCA score ≤ 22. According to MoCA score, patients were divided into 4 groups: no PSCI group: with MoCA-2w>22 and MoCA-3 m>22; improved PSCI group: with MoCA-2w ≤ 2 and MoCA-3 m>22;delayed PSCI group: MoCA-2w>22 and MoCA-3 m ≤ 22; persisting PSCI group: with MoCA-2w ≤ 22 and MoCA-3 m ≤ 22. RESULTS: A total of 1675 stroke patients were recruited in this study. There were 818 patients (48.84%) who had PSCI at baseline. Of these, 123 patients (15%) had mRS ≥2 at 3 months. The persisting PSCI group was a significant predictor of functional dependence at 3 months and 1 year after stroke and when adjusted for covariates such as gender, age, history of stroke, depression and intracranial atherosclerotic stenosis, stroke subtype and acute infarction type. CONCLUSION: Persisting PSCI increased the risk of poor functional outcome after 3 months and 1 year follow-up. These high-risk individuals should be identified for targeted rehabilitation and counseling to improve longer-term post-stroke outcome.

Light-deformable dynamic surface fabricated by ink-jet printing.

Dynamic surfaces which can change their topography with external stimuli have wide application prospects. Liquid crystal network (LCN) is an ideal material for making dynamic surfaces, but traditional methods for LCN dynamic surface manufacturing are difficult to scale up, which limits its applications. This research proposes a new method to fabricate a responsive surface using ink-jet printing technology. Using a liquid crystal monomer mixture as the ink, we printed arrays of droplets onto a glass substrate with a homeotropic alignment layer and polymerized the droplets into deformable LCN hemispheres. An azobenzene diacrylate was copolymerized into the hemispheres to make them photo-responsive to UV light. Because the ink-jet printing method can potentially be used to print countless hemispheres on a large area substrate, large area dynamic surfaces consisting of a multitude of separate dynamic structures can be manufactured. Since the deformation of the entire surface is a periodic repetition of the deformation of a single hemisphere, we characterized the deformation of individual hemispheres, and found that the optical image of hemispheres between crossed polarizers shows a "maltese cross" texture, and 3D surface profiling shows the top surface depresses into a valley after UV-irradiation. This is caused by an order parameter decrease of the homeotropically aligned LC molecules, which leads to a contraction in the alignment direction. The deformation amplitude can be modulated by UV intensity and temperature. This kind of dynamic surface fabricated by ink-jet printing technology can easily be scaled up and is promising for applications such as adjustable micro-lenses or surface wettability.

[The Clinical Efficacy and Possible Mechanism of Combination Treatment of Cerebral Ischemic Stroke with Ginkgo Biloba Extract and Low-Frequency Repetitive Transcranial Magnetic Stimulation].

OBJECTIVE: To study the effect of the combination treatment of ginkgo biloba extract and low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) on the oxidative stress and brain neurotransmitters of patients who had cerebral ischemic stroke (CIS). METHODS: A retrospective analysis was conducted, and 93 CIS patients admitted to the Sichuan Academy of Medical Sciences/Sichuan Provincial People's Hospital from January 2018 to January 2020 were included in the study. They were divided into three groups, the regular treatment group (31 cases), the LF-rTMS group (31 cases), and the combination treatment group (31 cases). Patients in the regular treatment group were given the conventional drug therapy and exercise regimen. The LF-rTMS group received LF-rTMS therapy (for 20-30 min each time, 1 time/d and 5 times/week) in addition to the treatment given to the regular treatment group. The combination treatment group was given ginkgo biloba extract (intravenous drips, once per day) in addition to the treatment given to the LF-rTMS group. The treatment was given continuously for 4 weeks and comparison was made at the end of the 4-week treatment regarding the clinical efficacy, oxidative stress response, cerebral oxygen metabolism, and brain neurotransmitter as shown by the three groups. RESULTS: The treatment efficacy in the combination treatment group (96.77%) was higher than those of the LF-rTMS group (80.65%) and the regular treatment group (54.84%). The LF-rTMS group showed higher treatment efficacy than that of the regular group. The serum superoxide dismutase (SOD) of the combination treatment group was higher than that of the LF-rTMS group and that of the routine group, while the malondialdehyde (MDA) and endothelin-1 (ET-1) of the combination treatment group were lower than those of the LF-rTMS group and the regular treatment group ( P<0.05). The serum SOD of the LF-rTMS group was higher than that of the regular treatment group, while the MDA and ET-1 of the group was lower than those of the regular treatment group ( P<0.05). The arterial oxygen content (CaO 2), arterio-venous oxygen content difference (Ca-vO 2) and cerebral extraction rate of oxygen (CERO 2) in the combination treatment group were lower than those of the LF-rTMS group and the regular treatment group ( P<0.05). The levels of these three indicators of the LF-rTMS group were lower than those of the regular treatment group ( P<0.05). EEG frequencies of gamma-aminobutyric acid (GABA), 5-hydroxytryptamine (5-HT) and dopamine (DA) of the combination treatment group were higher than those of the LF-rTMS group and the regular treatment group, while the acetylcholine (Ach) EEG frequency of the combination treatment group was lower than that of the LF-rTMS group and regular treatment group ( P<0.05). The LF-rTMS group showed higher GABA, 5-HT and DA EEG frequencies than those of the regular treatment group, while the Ach EEG frequency of the group was lower than that of the regular treatment group ( P<0.05). All the patients were followed up for 6 months, and recurrence rate was lower in the combination treatment group (3.23%) than that of the LF-rTMS group (19.35%) and the regular treatment group (25.81%) ( P<0.05). CONCLUSION: The combination treatment of ginkgo biloba extract and LF-rTMS helped to improve the clinical outcome of CIS patients, which may be related to the inhibition of oxidative stress, improvement in cerebral oxygen metabolism, and regulation of brain neurotransmitter.

Differential phosphorylation regulates the shear stress-induced polar activity of Rho-specific guanine nucleotide dissociation inhibitor α.

The activity of Rho-specific guanine nucleotide dissociation inhibitor α (RhoGDIα) is regulated by its own phosphorylation at different amino acid sites. These phosphorylation sites may have a crucial role in local Rho GTPases activation during cell migration. This paper is designed to explore the influence of phosphorylation on shear stress-induced spatial RhoGDIα activation. Based on the fluorescence resonance energy transfer biosensor sl-RhoGDIα, which was constructed to test the RhoGDIα activity in living cells, new RhoGDIα phosphomimetic mutation (sl-S101E/S174E, sl-Y156E, sl-S101E, sl-S174E) and phosphorylation-deficient mutation (sl-S101A/S174A, sl-Y156A, sl-S101A, sl-S174A) biosensors were designed to test their effects on RhoGDIα activation upon shear stress application in human umbilical vein endothelial cells (HUVECs). The results showed lower RhoGDIα activity at the downstream of HUVECs (the region from the edge of the nucleus to the edge of the cell along with the flow). The overall decrease in RhoGDIα activity was inhibited by Y156A-mutant, whereas the polarized RhoGDIα and Rac1 activity were blocked by S101A/S174A mutant. It is concluded that the Tyr156 phosphorylation mainly mediates shear stress-induced overall RhoGDIα activity, while Ser101/Ser174 phosphorylation mediates its polarization. This study demonstrates that differential phosphorylation of RhoGDIα regulates shear stress-induced spatial RhoGDIα activation, which could be a potential target to control cell migration.

High-sensitivity Detection of Cysteine and Glutathione Using Au Nanoclusters Based on Aggregation-induced Emission.

Gold nanoclusters (AuNCs) stabilized by glutathione (GSH) have been synthesized using a simple one-pot method, which were used as a fluorescence-enhanced probe for the detection of cysteine (Cys) and GSH. The detection is based on the finding that the weak yellow fluorescence of the AuNCs, with excitation/emission maxima of 430/600 nm, can be enhanced by Cys and GSH via NCs aggregation. This method is selective for Cys and GSH. According to the fluorescence enhancement, the detection ranges of AuNCs for Cys and GSH are 2.49 µM ~ 0.80 mM and 1.99 µM ~ 0.44 mM, with the detection limit of 0.42 µM and 0.27 µM, respectively. In addition, the probe has good anti-interference performance over other common biomolecules. Importantly, the probe is successfully used for the determination of Cys in human serum samples, displaying the potential application of the probe in the detection of biological sulfhydryl molecules in actual samples.

Fabrication of protease XIV-loaded microspheres for cell spreading in silk fibroin hydrogels.

Due to their excellent mechanical strength and biocompatibility, silk fibroin(SF) hydrogels can serve as ideal scaffolds. However, their slow rate of natural degradation limits the space available for cell proliferation, which hinders their application. In this study, litchi-like calcium carbonate@hydroxyapatite (CaCO3@HA) porous microspheres loaded with proteases from Streptomyces griseus (XIV) were used as drug carriers to regulate the biodegradation rate of SF hydrogels. The results showed that litchi-like CaCO3@HA microspheres with different phase compositions could be prepared by changing the hydrothermal reaction time. The CaCO3@HA microspheres controlled the release of Ca ions, which was beneficial for the osteogenic differentiation of mesenchymal stem cells (MSCs). The adsorption and release of protease XIV from the CaCO3@HA microcarriers indicated that the loading and release amount can be controlled with the initial drug concentration. The weight loss test and SEM observation showed that the degradation of the fibroin hydrogel could be controlled by altering the amount of protease XIV-loaded CaCO3@HA microspheres. A three-dimensional (3D) cell encapsulation experiment proved that incorporation of the SF hydrogel with protease XIV-loaded microspheres promoted cell dispersal and spreading, suggesting that the controlled release of protease XIV can regulate hydrogel degradation. SF hydrogels incorporated with protease XIV-loaded microspheres are suitable for cell growth and proliferation and are expected to serve as excellent bone tissue engineering scaffolds.

Selective, Sensitive and Label-Free Detection of Fe3+ Ion in Tap Water Using Highly Fluorescent Graphene Quantum Dots.

Graphene quantum dots (GQDs) as a new type of fluorescent carbon nanomaterials, showing excellent photoluminescence properties, biocompatibility, photoelectric properties, have become the current research focus. Iron element as an essential element in the human body and an important part of hemoglobin, is very important for human health, so the detection of ferric ions has great significance. In this paper, GQDs with strong blue light emission were prepared through pyrolysis treatment using citric acid as a carbon source. Through characterization by transmission electron microscopy (TEM) and fluorescence spectrometer, it was observed that the GQDs have a uniform particle size distribution and highly fluorescent intensity with a quantum yield of 27.4%. Due to the strong quenching effect of Fe3+ on GQDs fluorescence, GQDs was used as a green and facile fluorescence sensor to detect Fe3+ selectively and sensitively. The GQDs fluorescence sensor shows a sensitive response to Fe3+ in a wide linear range (3.5 × 10-6-6.7 × 10-4 M), a low detection limit of 1.6 µM (S/N = 3) and good selectivity. Importantly, the new sensor realizes the detection of Fe3+ ions in tap water because of its low detection limit, wide linear range, and high sensitivity.

Cerebral Vascular Changes During Acute Intracranial Pressure Drop.

OBJECTIVE: This study applied a new external ventricular catheter, which allows intracranial pressure (ICP) monitoring and cerebral spinal fluid (CSF) drainage simultaneously, to study cerebral vascular responses during acute CSF drainage. METHODS: Six patients with 34 external ventricular drain (EVD) opening sessions were retrospectively analyzed. A published algorithm was used to extract morphological features of ICP recordings, and a template-matching algorithm was applied to calculate the likelihood of cerebral vasodilation index (VDI) and cerebral vasoconstriction index (VCI) based on the changes of ICP waveforms during CSF drainage. Power change (∆P) of ICP B-waves after EVD opening was also calculated. Cerebral autoregulation (CA) was assessed through phase difference between arterial blood pressure (ABP) and ICP using a previously published wavelet-based algorithm. RESULTS: The result showed that acute CSF drainage reduced mean ICP (P = 0.016) increased VCI (P = 0.02) and reduced ICP B-wave power (P = 0.016) significantly. VCI reacted to ICP changes negatively when ICP was between 10 and 25 mmHg, and VCI remained unchanged when ICP was outside the 10-25 mmHg range. VCI negatively (r = - 0.44) and VDI positively (r = 0.82) correlated with ∆P of ICP B-waves, indicating that stronger vasoconstriction resulted in bigger power drop in ICP B-waves. Better CA prior to EVD opening triggered bigger drop in the power of ICP B-waves (r = - 0.612). CONCLUSIONS: This study demonstrates that acute CSF drainage reduces mean ICP, and results in vasoconstriction which can be detected through an index, VCI. Cerebral vessels actively respond to ICP changes or cerebral perfusion pressure (CPP) changes in a certain range; beyond which, the vessels are insensitive to the changes in ICP and CPP.

Evaluation of a New Catheter for Simultaneous Intracranial Pressure Monitoring and Cerebral Spinal Fluid Drainage: A Pilot Study.

OBJECTIVES: Intracranial pressure (ICP) monitoring is a common practice when treating intracranial pathology with risk of elevated ICP. External ventricular drain (EVD) insertion is a standard approach for both monitoring ICP and draining cerebrospinal fluid (CSF). However, the conventional EVD cannot serve these two purposes simultaneously because it cannot accurately measure ICP and its pulsatile waveform while the EVD is open to CSF drainage. A new Integra® Camino® FLEX Ventricular Catheter (Integra Lifesciences, County Offaly, Ireland) with a double-lumen construction has been recently introduced into the market, and it can monitor ICP waveforms even during CSF drainage. The aim of this study was to evaluate and validate this new FLEX catheter for ICP monitoring in a neurological intensive care unit. METHODS: Six patients with 34 EVD open/close episodes were retrospectively analyzed. Continuous ICP was detected in two ways: through the FLEX sensor at the tip (ICPf) and through a fluid-coupled manometer within the FLEX catheter, functioning as a conventional EVD (ICPe). The morphologies of ICPf and ICPe pulses were extracted using Morphological Clustering and Analysis of ICP algorithm, an algorithm that has been validated in previous publications. The mean ICP and waveform shapes of ICP pulses detected through the two systems were compared. Bland-Altman plots were used to assess the agreement of the two systems. RESULTS: A significant linear relationship existed between mean ICPf and mean ICPe, which can be described as: mICPf = 0.81 × mICPe + 1.67 (r = 0.79). The Bland-Altman plot revealed that no significant difference existed between the two ICPs (average of [ICPe-ICPf] was - 1.69 mmHg, 95% limits of agreement: - 7.94 to 4.56 mmHg). The amplitudes of the landmarks of ICP pulse waveforms from the two systems showed strong, linear relationship (r ranging from 0.89 to 0.94). CONCLUSIONS: This study compared a new FLEX ventricular catheter with conventional fluid-coupled manometer for ICP waveform monitoring. Strong concordance in ICP value and waveform morphology between the two systems indicates that this catheter can be used for reliability for both clinical and research applications.

Amperometric hydrogen peroxide sensor using a glassy carbon electrode modified with a nanocomposite prepared from ferumoxytol and reduced graphene oxide decorated with platinum nanoparticles.

A high-performance electrochemical H2O2 sensor was prepared by constructing multiple interfaces using platinum nanoparticles (Pt NPs), ferumoxytol (Fer) and reduced graphene oxide (rGO) on a glassy carbon electrode (GCE). The morphology of Fer/rGO and Fer/rGO-Pt was characterized by field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. Cyclic voltammetry and chronoamperometry were adopted to characterize the electrochemical properties of the sensor. Because of the synergistic catalytic effect of the compositions (rGO, Fer and Pt NPs) on the multiple interfaces, the sensor exhibits particularly high electrocatalytic activity toward the reduction of H2O2 with a low detection limit (~0.38 µM), a linear range (0.0004-0.01, 0.0075-4.3 and 4.9-10.8 mM), and a high sensitivity (340 µA mM-1 cm-2, n = 4) operated at a typical working voltage of +0.1 V (vs. Ag/AgCl). The electrode is selective and long-term stable. It was successfully applied to the determination of H2O2 in (spiked) milk samples. Graphical abstract Schematic presentation of an electrochemical H2O2 sensor using platinum nanoparticles (Pt NPs), ferumoxytol (Fer) and reduced graphene oxide (rGO) nanocomposites modified glassy carbon electrode (GCE). The sensor was applied to the determination of H2O2 in (spiked) milk samples.

Risk Factors for Pressure Sores in Hospitalized Acute Ischemic Stroke Patients.

BACKGROUND: Acute ischemic stroke patients are a group at high risk for pressure sores. It is important to identify risk factors for pressure sores in acute ischemic stroke patients in order to facilitate early adoption of appropriate preventive and treatment measures. METHODS: Data were derived from the China National Stroke Registry. Acute ischemic stroke patients aged >18 years who presented at the hospital within 14 days after the onset of symptoms were eligible for this study. Comprehensive baseline data were collected. The definition of pressure sores was based on assessment at discharge of whether the patient had pressure sores at any time during hospitalization. RESULTS: 12,415 patients with a mean age of 67 years and a mean length of hospitalization of 14 days were included in the study. Among these patients, 97 (0.8%) had pressure sores during hospitalization. In the multivariate analysis of risk factors for pressure sores, age (each increment of 5 years), being unmarried, NIHSS at admission (each increment of 3 points), mRS at admission (3-5 points), diabetes mellitus, hemoglobin at admission (each incremental reduction of 10 units), and history of peripheral vascular disease all were significantly correlated with the occurrence of pressure sores among acute ischemic stroke patients during hospitalization. CONCLUSIONS: Old age, severe neurological disability, being unmarried, low hemoglobin, and history of diabetes mellitus and peripheral vascular disease were risk factors for pressure sores in acute ischemic stroke patients.