Construction of a BiOCl/Bi2O2CO3 S-Scheme Heterojunction Photocatalyst via Sharing [Bi2O2]2+ Slabs with Enhanced Photocatalytic H2O2 Production Performance.

The construction of a close contact interface is key to enhancing the photocatalytic activity in heterojunctions. In the work, the BiOCl/Bi2O2CO3 of sharing [Bi2O2]2+ slabs S-scheme heterojunction was prepared by a HCl in situ etching method. The optimal composite photocatalyst could accomplish sizable productivity of H2O2 to 2562.95 µmol g-1 h-1 under simulated solar irradiation, higher than that of primitive Bi2O2CO3 and BiOCl. Moreover, the synthesized catalysts showed good stability. The band structures of BiOCl and Bi2O2CO3 were determined, confirming the formation of BiOCl/Bi2O2CO3 S-scheme heterojunction The BiOCl/Bi2O2CO3, which obviously improved the separation efficiency of photoinduced carriers and effectively enhanced the redox ability of the photocatalyst. In addition, density functional theory (DFT) calculations were utilized to analyze the electron transfer properties and the constitution of the built-in electric field at the interface of BiOCl and Bi2O2CO3. The photocatalytic reaction process was further researched by electron paramagnetic resonance (EPR), indicating the active species in the photocatalytic production of hydrogen peroxide. Eventually, a feasible S-scheme electron transfer mechanism on the BiOCl/Bi2O2CO3 heterojunction during the photocatalytic H2O2 production process was proposed and discussed. This work provides a reliable strategy for the fine design of the S-scheme heterojunction.

Th17/Treg cells regulated by interleukin 6 in the pathogenesis of chronic rhinosinusitis with nasal polyps.

PURPOSE: To be investigated whether Th17/Treg cells regulated by Interleukin-6 in the pathogenesis of chronic rhinosinusitis with nasal polyps. METHODS: The distributions of Th17 and Treg cells in peripheral blood mononuclear cells (PBMCs) and tissues got from 46 CRSwNP patients and 14 controls were evaluated. Th17 and Treg cells and cells-related cytokines in serum were assessed in means of cytometric bead array (CBA) multiplex assays and enzyme-linked immunosorbent assays (ELISAs). Spleen cells were isolated from spleen of 20 normal BALB/c mice (male), isolated and purified with CD4 antibody immunomagnetic bead kit. CD4+ cells were divided into three groups, including TGF-ß1, TGF-ß1+ IL-6 and control (PBS). Treg and Th17 cells and cells related cytokines were detected by flow cytometry (FCM) after collecting spleen cells. The level of IL-10 and IL-17 in supernatant was measured by ELISA. RESULTS: Th17/Treg ratio and the level of IL-6 in both ECRSwNP (P < 0.05) and non-ECRSwNP (P < 0.05) were significantly increased when compared with control group, these were consistent with the previous findings. Experiments in vitro suggested that the level of Th17 cells in IL-6+ TGF-ß1 group was significantly increased than TGF-ß1 group and control group (P < 0.05). The ratio of cells expressed RoRγt in IL-6+ TGF-ß1 group was much higher than TGF-ß1 group (P < 0.05). CONCLUSION: IL-6 might regulate the function of Th17 and Treg cells and the Th17/Treg ratio and have a role in the pathogenesis of CRSwNP.

[Molecular mechanism of Bupleuri Radix and Scutellariae Radix drug pair for depression based on integrative pharmacology platform of traditional Chinese medicine].

Xiaochaihu decoction is a classic prescription of traditional Chinese medicine. Modern research has proved its anti-depression effect. However, its pharmacological mechanism for anti-depression effect is difficult to be unveiled because of the complexity of compound Chinese medicines. Bupleuri Radix and Scutellariae Radix is the core drug pair of Xiaochaihu decoction. In this research, Bupleuri Radix and Scutellariae Radix were analyzed by the integrative pharmacology platform to study its molecular mechanism for anti-depression. One hundred and sixteen active ingredients were predicted, 62 for Bupleuri Radix, mainly including saikosaponins, acids, alcohols, and 54 for Scutellariae Radix, mainly including flavonoids and glycosides. Its anti-depression effect was relevant to 118 core targets, including 22 known disease targets, such as serotonin receptor(HTR2C), activating transcription factor(ATF1, ATF2), δ opioid receptor(OPRD1), µ opioid receptor (OPRM1), κ opioid receptor(OPRK1), inositol monophosphatase(IMPA1), Toll-like receptor 4 (TLR4), histamine H1 receptor(HRH1), neurotrophic factor tyrosine kinase receptor1 (NTRK1), Glycogen synthetase kinase 3ß(GSK3ß), etc. The antidepressant effect involved positive regulation of transcription from RNA polymerase Ⅱ promoter, transcription factor binding, cytosol, transcriptional regulation of DNA template, enzyme binding, endocrine system, nervous system, neurotrophin signaling pathway, cell growth and death, signal transduction, thyroid hormone signaling pathway and other related biological processes and metabolic pathways. This study provides a scientific evidence for further study of the anti-depression mechanism of this drug pair.

Two inflammatory phenotypes of nasal polyps and comorbid asthma.

BACKGROUND: Nasal polyps and comorbid asthma (NPCA) is a common united airway disease. However, the inflammatory phenotyes of NPCA are not clear. OBJECTIVE: To identify inflammatory phenotypes of NPCA. METHODS: A total of 106 patients diagnosed with NPCA were recruited from rhinologic clinics. A combined method of biopsies from nasal polyps and fractional exhaled nitric oxide (FeNO) was used to explore inflammatory phenotyes of NPCA. Patients were evaluated with respect to clinical, functional, and inflammatory parameters. Clinical outcomes after medical treatment were also assessed. RESULTS: Two distinct inflammatory phenotypes (eosinophilic [64.15%] and noneosinophilic phenotypes [35.85%]) were identified. Inflammatory patterns of upper and lower airways were consistent in NPCA. Patients with eosinophilic NPCA had a higher nasal polyps recurrence rate than did patients with noneosinophilic NPCA, a more severe asthma phenotype (P < .001), higher exhaled nitric oxide levels (P < .001), higher IgE levels (P < .001), higher Lund-Mackay scores (P < .05), and more blood eosinophilia (P < .001). In addition, eosinophilic NPCA was associated with worse pulmonary function and responded well to an 8-week course of medical treatment based on computed tomographic findings and the ratio of forced expiratory volume in 1 second to forced vital capacity. The total IgE concentration was a marker for eosinophilic NPCA (optimal cutoff, >55.5 kU/L; sensitivity, 86.2%; specificity, 85.4%). CONCLUSION: Patients with NPCA had 2 inflammatory phenotypes with distinct clinical profiles. Total IgE is a marker of eosinophilic NPCA.

Three-dimensional printing of tissue phantoms for biophotonic imaging.

We have investigated the potential of tissue phantoms fabricated with thermosoftening- and photopolymerization-based three-dimensional (3D) printers for use in evaluation of biophotonic imaging systems. The optical properties of printed polymer samples were measured and compared to biological tissues. Phantoms with subsurface channels as small as 0.2 mm in diameter were fabricated and imaged with microscopy, x-ray microtomography, and optical coherence tomography to characterize morphology. These phantoms were then implemented to evaluate the penetration depth of a hyperspectral reflectance imaging system used in conjunction with a near-infrared contrast agent. Results indicated that 3D printing may provide a suitable platform for performance testing in biophotonics, although subsurface imaging is critical to mitigate printer-to-printer variability in matrix homogeneity and feature microstructure.

Conditionally activating optical contrast agent with enhanced sensitivity via gold nanoparticle plasmon energy transfer: feasibility study.

BACKGROUND: Molecular sensing/imaging utilizing fluorophores has been one of the most frequently used techniques in biomedical research. As for any molecular imaging techniques, fluorescence mediated sensing always seeks for greater specificity and sensitivity. Since fluorophores emit fluorescence while their electron energy state changes, manipulating the local electromagnetic field around the fluorophores may be a way to enhance the specificity and sensitivity. Gold nanoparticles (GNPs) are known to form a very strong electromagnetic field on their surface [i.e., surface plasmon field (SPF)], upon receiving photonic energy. The level of fluorescence change by GNP-SPF may range from complete quenching to extensive enhancement, depending upon the SPF strength, excitation and emission wavelengths, and quantum yield of the fluorophore. METHOD: Here, we report a novel design that utilizes BOTH fluorescence quenching and enhancement abilities of the GNP in one single nano-entity, providing high specificity and sensitivity. The construct utilizes a specially designed molecular dual-spacer that places the fluorphore at the location with an appropriate GNP-SFP strength before and after exposed to the biomarker. A model system to test the concept was an optical signal mediator activated by urokinase-type plasminogen activator (uPA; breast cancer secreting enzyme). RESULTS: The resulting contrast agent shows less than 10% of the natural fluorescence but, in the presence of uPA, its fluorescence emission is triggered and emits its fluorescence approximately twice of the natural form. CONCLUSION: This study demonstrated that our novel design of an optical contrast agent can be conditionally activated with enhanced sensitivity, using both quenching and enhancement phenomena of fluorophores in the electromagnetic field of the appropriate strengths (in this case, locally generated by the GNP-SPF). This entity is similar to molecular beacon in terms of specificity but with greater sensitivity. In addition, it is not restricted to only DNA or RNA sensing but for any designs that cause the change in the distance between the fluorophore and GNP, upon the time of encountering biomarker of interest.

Self-assembled phytosterol-fructose-chitosan nanoparticles as a carrier of anticancer drug.

Self-assembled nanoparticles were synthesized from water-soluble fructose-chitosan, substituted by succinyl linkages with phytosterols as hydrophobic moieties for self-assembly. The physicochemical properties of the prepared self-assembled nanoparticles were characterized by Fourier transform infrared spectroscopy, fluorescence spectroscopy, and transmission electron microscopy. Doxorubicin (DOX), as a model anticancer drug, was physically entrapped inside prepared self-assembled nanoparticles by the dialysis method. With increasing initial levels of the drug, the drug loading content increased, but the encapsulation efficiency decreased. The release profiles in vitro demonstrated that the DOX showed slow sustained released over 48 h, and the release rate in phosphate buffered saline (PBS) solution (pH 7.4) was much slower than in PBS solution (pH 5.5 and pH 6.5), indicating the prepared self-assembled nanoparticles had the potential to be used as a carrier for targeted delivery of hydrophobic anticancer drugs with declined cytotoxicity to normal tissues.

NIR fluorophore-hollow gold nanosphere complex for cancer enzyme-triggered detection and hyperthermia.

Hollow gold nanospheres (HGN) may be delicately tuned to absorb near infrared light (NIR) by tailoring the diameter-to-shell ratio. This unique property can be utilized for enhancing the contrast for the NIR and X-ray/CT imaging, and also noninvasive and local, photothermal hyperthermia by conjugating cancer-targeting molecules on the particle surface. In addition, when an NIR fluorophore is placed on the surface of the NIR-tuned HGNs, the fluorescence can be significantly quenched due to the emitted light absorption by the HGNs. Combining the NIR fluorescence quenching property of HGNs and the enzyme secreting nature of cancer, we have developed a novel enzyme-triggered NIR contrast agent for cancer detection with high specificity. NIR fluorophore Cypate (Indocyanine Green based) was conjugated to HGN via a short spacer for fluorescence quenching. The spacer contains an enzyme-substrate-motif (G-G-R) that can be cleaved by urokinase-type plasminogen activator (uPA, a breast cancer enzyme). The nano-complex normally does not emit fluorescence but, in the presence of uPA, the fluorescence was restored, providing high specificity. The enzyme-specific emission allows us to characterize the nature of the cancer (e.g., invasive, metastatic, etc.). Once the cancer is detected, the same HGNs can be used to deliver heat to the cancer site for cancer-specific hyperthermia.

Deep learning technique to detect craniofacial anatomical abnormalities concentrated on middle and anterior of face in patients with sleep apnea.

OBJECTIVES: The aim of this study is to propose a deep learning-based model using craniofacial photographs for automatic obstructive sleep apnea (OSA) detection and to perform design explainability tests to investigate important craniofacial regions as well as the reliability of the method. METHODS: Five hundred and thirty participants with suspected OSA are subjected to polysomnography. Front and profile craniofacial photographs are captured and randomly segregated into training, validation, and test sets for model development and evaluation. Photographic occlusion tests and visual observations are performed to determine regions at risk of OSA. The number of positive regions in each participant is identified and their associations with OSA is assessed. RESULTS: The model using craniofacial photographs alone yields an accuracy of 0.884 and an area under the receiver operating characteristic curve of 0.881 (95% confidence interval, 0.839-0.922). Using the cutoff point with the maximum sum of sensitivity and specificity, the model exhibits a sensitivity of 0.905 and a specificity of 0.941. The bilateral eyes, nose, mouth and chin, pre-auricular area, and ears contribute the most to disease detection. When photographs that increase the weights of these regions are used, the performance of the model improved. Additionally, different severities of OSA become more prevalent as the number of positive craniofacial regions increases. CONCLUSIONS: The results suggest that the deep learning-based model can extract meaningful features that are primarily concentrated in the middle and anterior regions of the face.

Fluorophore-gold nanoparticle complex for sensitive optical biosensing and imaging.

Fluorophores have been extensively used as the signal mediator in biosensing and bioimaging for a long time. Enhancement of fluorescence can amplify the signal, thus improving the sensitivity, enabling earlier and accurate disease detection and diagnosis. Some metal nanoparticles, such as gold and silver, can generate a strong electromagnetic field on their surface (surface plasmon field) upon receiving photonic energy. When a fluorophore is placed in the field, the field can affect the fluorophore electrons participating in fluorescence emission and change the fluorescence output. The change can be from complete quenching to significant enhancement, depending on the metal type, particle size and shape, excitation/emission wavelengths and quantum yield of the fluorophore, and the distance between the fluorophore and the particle surface. In this study, the effects of these parameters on the fluorescence enhancement of commonly used fluorophores by gold nanoparticles (GNPs) are theoretically analyzed. Experimentally, an NIR contrast agent with enhanced fluorescence was developed by carefully tailoring the distance between Cypate (ICG based fluorophore) and a GNP, via biocompatible spacer constructs. The effect of the GNP size (3.7-16.4 nm) and spacer length (3.2-4.6 nm) on fluorescence enhancement was studied, and the spacer length that provided the significant enhancement was determined. The spacer of 3.9 nm with 16.4 nm GNP provided the fluorescence of 360% of the control. The experimental data qualitatively agreed with the theoretical results and, thus, the theoretical analysis can be used as a guide for significantly improving the sensitivity of existing fluorescent contrast agents by properly utilizing GNPs and spacers.

Statins Have an Anti-Inflammation in CKD Patients: A Meta-Analysis of Randomized Trials.

Background: Persistent inflammation has been recognized as an important comorbid condition in patients with chronic kidney disease (CKD) and is associated with many complications, mortality, and progression of CKD. Previous studies have not drawn a clear conclusion about the anti-inflammatory effects of statins in CKD. This meta-analysis is aimed at assessing the anti-inflammatory effects of statins therapy in patients with CKD. Methods: A comprehensive literature search was conducted in these databases (Medline, Embase, Cochrane library, and clinical trials) to identify the randomized controlled trials that assess the anti-inflammatory effects of statins. Subgroup, sensitivity, and trim-and-fill analysis were conducted to determine the robustness of pooled results of the primary outcome. Results: 25 eligible studies with 7921 participants were included in this meta-analysis. The present study showed that statins therapy was associated with a decreased C-reactive protein (CRP) (-2.06 mg/L; 95% CI: -2.85 to -1.27, p < 0.01). Subgroup, sensitivity, and trim-and-fill analysis showed that the pooled results of CPR were stable. Conclusion: This meta-analysis demonstrates that statins supplementation has anti-inflammatory effects in patients with CKD. Statins exert an anti-inflammatory effect that is clinically important in improving complications, reducing mortality, and slowing progression in CKD. We believe that the benefits of statins to CKD are partly due to their anti-inflammatory effects. However, stains usually are prescribed in the CKD patients with dyslipidemia, whether statins can reduce inflammation in CKD patients with normal serum lipid needed to explore in the future. Therefore, we suggest that randomized clinical trials need to assess the effect of statins in CKD patients with normal serum lipid. Whether statins can be prescribed for aiming to inhibit inflammation in CKD also needed further study. Trial Registration. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO); registration number: CRD42022310334.

Evaluation of the robustness of cerebral oximetry to variations in skin pigmentation using a tissue-simulating phantom.

Clinical studies have demonstrated that epidermal pigmentation level can affect cerebral oximetry measurements. To evaluate the robustness of these devices, we have developed a phantom-based test method that includes an epidermis-simulating layer with several melanin concentrations and a 3D-printed cerebrovascular module. Measurements were performed with neonatal, pediatric and adult sensors from two commercial oximeters, where neonatal probes had shorter source-detector separation distances. Referenced blood oxygenation levels ranged from 30 to 90%. Cerebral oximeter outputs exhibited a consistent decrease in saturation level with simulated melanin content; this effect was greatest at low saturation levels, producing a change of up to 15%. Dependence on pigmentation was strongest in a neonatal sensor, possibly due to its high reflectivity. Overall, our findings indicate that a modular channel-array phantom approach can provide a practical tool for assessing the impact of skin pigmentation on cerebral oximeter performance and that modifications to algorithms and/or instrumentation may be needed to mitigate pigmentation bias.

Fluorescence manipulation by gold nanoparticles: from complete quenching to extensive enhancement.

BACKGROUND: When a fluorophore is placed in the vicinity of a metal nanoparticle possessing a strong plasmon field, its fluorescence emission may change extensively. Our study is to better understand this phenomenon and predict the extent of quenching and/or enhancement of fluorescence, to beneficially utilize it in molecular sensing/imaging. RESULTS: Plasmon field intensities on/around gold nanoparticles (GNPs) with various diameters were theoretically computed with respect to the distance from the GNP surface. The field intensity decreased rapidly with the distance from the surface and the rate of decrease was greater for the particle with a smaller diameter. Using the plasmon field strength obtained, the level of fluorescence alternation by the field was theoretically estimated. For experimental studies, 10 nm GNPs were coated with polymer layer(s) of known thicknesses. Cypate, a near infrared fluorophore, was placed on the outermost layer of the polymer coated GNPs, artificially separated from the GNP at known distances, and its fluorescence levels were observed. The fluorescence of Cypate on the particle surface was quenched almost completely and, at approximately 5 nm from the surface, it was enhanced ~17 times. The level decreased thereafter. Theoretically computed fluorescence levels of the Cypate placed at various distances from a 10 nm GNP were compared with the experimental data. The trend of the resulting fluorescence was similar. The experimental results, however, showed greater enhancement than the theoretical estimates, in general. The distance from the GNP surface that showed the maximum enhancement in the experiment was greater than the one theoretically predicted, probably due to the difference in the two systems. CONCLUSIONS: Factors affecting the fluorescence of a fluorophore placed near a GNP are the GNP size, coating material on GNP, wavelengths of the incident light and emitted light and intrinsic quantum yield of the fluorophore. Experimentally, we were able to quench and enhance the fluorescence of Cypate, by changing the distance between the fluorophore and GNP. This ability of artificially controlling fluorescence can be beneficially used in developing contrast agents for highly sensitive and specific optical sensing and imaging.

Highly specific, NIR fluorescent contrast agent with emission controlled by gold nanoparticle.

Nanoparticles are currently being intensively studied for in vivo molecular imaging because of their unique and beneficial properties. Among these particles, some metal particles possess strong surface plasmon fields that can effectively alter fluorescence. Using this fluorescence alteration, an NIR fluorophore based, nanosized contrast agent for breast cancer diagnosis is being developed. The fluorophore is conjugated to gold nanoparticles (GNP) via a short spacer whose length was specially adjusted to have the strong plasmon field to quench the fluorescence. The spacer also has a special molecular sequence that can be cleaved by an enzyme secreted by targeted cancer cells. Normally, the entity does not fluoresce. If it is delivered to the cancer site, the short spacer would be cleaved by the enzyme secreted by the cancer cell at which point the fluorescence would be restored. This entity can incorporate a cancer targeting molecule for a cancer specific delivery. The entity specifically targets cancer cells and fluoresce only when the spacer is cleaved by a specific cancer secreting biomolecule, providing dual specificity for cancer diagnosis. In the future, this entity will be combined with cancer drugs for seamless detection and personalized therapy.

FRET-like fluorophore-nanoparticle complex for highly specific cancer localization.

Fluorophore mediated bio-signal retrieval has been extensively used in molecular imaging. However, only a limited number of fluorophores can be used for humans and their quantum yield is usually low. Another important issue is emitting fluorescence at the disease site, with a minimal non-specific emission at any other sites. Artificial quenching and enhancing of fluorescence was found to be possible by manipulating the distance between a fluorophore and a certain type of nanometal particle. Utilizing this unique property, we have designed a novel, FRET-like, fluorophore-nanoparticle complex. The complex emits fluorescence conditionally only at a disease site at an enhanced level. As a model system, our complex is designed to target breast cancer. As an initial step for developing this cancer locator, fluorescence alteration was studied when a spacer at various lengths is placed between a nanogold particle and a safe fluorophore.

[Effects of protein kinase CK2α on apoptosis and ultrastructure of laryngeal carcinoma cells].

OBJECTIVE: To investigate the effect of protein kinase CK2α on apoptosis and ultrastructure of human laryngeal carcinoma cells and its possible mechanism. METHODS: The siRNA expression plasmid psiRNA-hH1neo-CK2α specific to protein kinase CK2α and non-specific siRNA expression plasmid psiRNA-hH1neo-cont were transfected into Hep-2 cells respectively by lipofectamine method. Western blot was used to detect the expression of kinase CK2α protein. The apoptotic rate was measured by Annexin V-FITC/PI double-staining. The morphological changes of Hep-2 cells were observed under transmission electron microscope (TEM). The expressions of bcl-2 and Bax protein were measured by Western blot. RESULTS: The expression of protein kinase CK2α protein significantly decreased in the Hep-2 cells transfected with psiRNA-hH1neo-CK2α (P < 0.01). Compared with the untransfected cells and siRNA-hH1neo-cont transfected group, psiRNA-hH1neo-CK2α transfected group presented with classical ultrastructural features of apoptosis, such as karyopyknosis, chromatic agglutination adjacent to nuclear membrane and apoptotic body. The apoptotic rate of psiRNA-hH1neo-CK2α transfected group was obviously higher than that in untransfected cells and siRNA-hH1neo-cont transfected group (25.66% ± 0.83% vs 3.66% ± 0.43%, 5.18% ± 0.22%, both P < 0.05). Compared with two other groups, the bcl-2 protein expression of psiRNA-hH1neo-CK2α transfected group decreased (0.20 ± 0.09 vs 0.72 ± 0.16, 0.56 ± 0.11, both P < 0.01), the Bax protein expression increased (0.81 ± 0.17 vs 0.26 ± 0.12, 0.33 ± 0.17, both P < 0.01) while the ratio of bcl-2 to Bax decreased (0.25 ± 0.05 vs 2.76 ± 0.21, 1.70 ± 0.22, both P < 0.01). CONCLUSION: Protein kinase CK2a plays an important role in the apoptosis of human laryngeal carcinoma cells possibly by decreasing bcl-2/Bax. Protein kinase CK2a may provide a potential therapeutic target against human laryngeal carcinoma.

Mini sensing chip for point-of-care acute myocardial infarction diagnosis utilizing micro-electro-mechanical system and nano-technology.

A rapid and accurate diagnosis of acute myocardial infarction (AMI) is crucial for saving lives. For this purpose, we have been developing a rapid, automatic, point-of-care, biosensing system for simultaneous four cardiac marker quantification. This system performs a fluorophore mediated immuno-sensing on optical fibers. To improve the sensitivity of the sensor, novel nanoparticle reagents enhancing fluorescence were implemented. Micro-electro-mechanical system (MEMS) technology was applied in the sensing chip development and automatic sensing operation was implemented to ensure a reliable and user-friendly assay. The resulting system is a point-of-care, automatic four cardiac marker sensing system with a 2 x 2.5 cm sensing chip. An assay requires a 200 microL plasma sample and 15-minute assay time.

Study on neural stem cell transplantation into natural rat cochlea via round window.

OBJECTIVE: The aim of the study is to investigate the survival of neural stem cells (NSCs) in normal rat cochlea and their potential effect on auditory function and cochlea structures via round window transplantation. METHODS: In comparison with the normal rats without any transplantation (group III), normal rat cochleae were transplanted with NSCs infected with adenovirus carrying green fluorescence protein (GFP) gene (group I) or the artificial perilymph (group II) via round windows. Auditory functions were monitored by thresholds of auditory brain stem responses (ABRs); the cochlea structures were examined by hematoxylin and eosin staining; survivals of implanted NSCs were determined by the expression of GFP; survivals of hair cells were accessed by whole mount preparation; and ultrastructures of hair cells were examined by scanning electron microscopy. RESULT: There were significant differences in the click-ABR thresholds in rats among all 3 groups neither at pretransplantation nor at posttransplantation; there were no significant differences in these values before and after transplantation in the same rats from each group. After transplantation, the cochlea structures were normal in both group I and group II. Grafted NSCs were visualized by the GFP expression in every turn of the cochlea in all animals of group I. There were no significant differences in the losses of outer hair cells (OHCs) among 3 groups. The inner hair cells and most OHCs were normal in every turns of cochleae of all groups. CONCLUSION: Neural stem cells survived in normal rat cochlea after transplantation via round window and showed no obvious effects on auditory functions and inner ear pathologic examination of the rat cochlea.

Phantom-based evaluation of near-infrared intracranial hematoma detector performance.

Near-infrared spectroscopy (NIRS) is emerging as a rapid, low-cost approach for point-of-care triage of hematomas resulting from traumatic brain injury. However, there remains a lack of standardized test methods for benchtop performance assessment of these devices and incomplete understanding of relevant light-tissue interactions. We propose a phantom-based test method for systems operating near the 800-nm oxy-/deoxy-hemoglobin isosbestic point and implement it to evaluate a clinical system. Semi-idealized phantom geometries are designed to represent epidural/subdural, subarachnoid, and intracerebral hemorrhages. Measurements of these phantoms are made with a commercial NIRS-based hematoma detector to quantify the effect of hematoma type, depth, and size, as well as measurement repeatability and detector positioning relative to the hematoma. Results indicated high sensitivity to epidural/subdural and subarachnoid hematomas. Intracerebral hematomas are detectable to a maximum depth of ∼2.5 cm, depending on thickness and diameter. The maximum lateral detection area for the single-emitter/single-collector device studied here appears elliptical and decreases strongly with inclusion depth. Overall, this study provides unique insights into hematoma detector function and indicates the utility of modular polymer tissue phantoms in performance tests for emerging NIRS-based cerebral diagnostic technology.

Cerebral oximetry performance testing with a 3D-printed vascular array phantom.

Cerebral oximetry based on near-infrared spectroscopy represents a unique noninvasive tool for real-time surgical monitoring, yet studies have shown a significant discrepancy in accuracy among commercial systems. Towards the establishment of a standardized method for performance testing, we have studied a solid phantom approach - based on a 3D-printed cerebrovascular module (CVM) incorporating an array of 148 cylindrical channels - that has several advantages over liquid phantoms. Development and characterization of a CVM prototype are described, including high-resolution imaging and spectrophotometry measurements. The CVM was filled with whole bovine blood tuned over an oxygen saturation range of 30-90% and molded-silicone layers simulating extracerebral tissues were used to evaluate penetration depth. Saturation measurement accuracy was assessed in two commercially-available clinical cerebral oximeters. For one oximeter, both neonatal and pediatric sensors showed a high degree of precision, whereas accuracy was strongly dependent on saturation level and extracerebral geometry. The second oximeter showed worse precision, yet greater robustness to variations in extracerebral layers. These results indicate that 3D-printed channel array phantoms represent a promising new approach for standardized testing of clinical oximeters.