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1.
Small ; 19(26): e2301413, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36929203

RESUMO

In multienzymes cascade reaction, the inter-enzyme spacing is supposed to be a factor affecting the cascade activity. Here, a simple and efficient Y-shaped DNA scaffold is assembled using two partially complementary DNA single strands on magnetic microspheres, which is used to coimmobilize glucose oxidase (GOD) and horseradish peroxidase (HRP). As a result, on poly(vinyl acetate) magnetic microspheres (PVAC), GOD/HRP-DNA@PVAC multienzyme system is obtained, which can locate GOD and HRP accurately and control the inter-enzyme distance precisely. The distance between GOD and HRP is regulated by changing the length of DNA strand. It showed that the cascade activity is significantly distance-dependent. Moreover, the inter-enzyme spacing is not the closer the better, and too short distance would generate steric hindrance between enzymes. The cascade activity reached the maximum value of 967 U mg-1 at 13.6 nm, which is 3.5 times higher than that of free enzymes. This is ascribed to the formation of substrate channeling.


Assuntos
Enzimas Imobilizadas , Glucose Oxidase , Peroxidase do Rábano Silvestre , Microesferas , DNA
2.
Entropy (Basel) ; 25(3)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36981331

RESUMO

Fault diagnosis of complex equipment has become a hot field in recent years. Due to excellent uncertainty processing capability and small sample problem modeling capability, belief rule base (BRB) has been widely used in the fault diagnosis. However, previous BRB models almost did not consider the diverse distributions of observation data which may reduce diagnostic accuracy. In this paper, a new fault diagnosis model based on BRB is proposed. Considering that the previous triangular membership function cannot address the diverse distribution of observation data, a new nonlinear membership function is proposed to transform the input information. Then, since the model parameters initially determined by experts are inaccurate, a new parameter optimization model with the parameters of the nonlinear membership function is proposed and driven by the gradient descent method to prevent the expert knowledge from being destroyed. A fault diagnosis case of laser gyro is used to verify the validity of the proposed model. In the case study, the diagnosis accuracy of the new BRB-based fault diagnosis model reached 95.56%, which shows better fault diagnosis performance than other methods.

3.
J Urban Health ; 99(1): 55-66, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35031943

RESUMO

The objective of this study is to evaluate the life course effects of racism on depressive symptoms in young Black women and to identify particularly sensitive periods. Guided by life-course theory and using logistic regression, we analyzed baseline data on racism frequency and stress from racism at two time periods (before age 20 and during the 20s) and follow-up data (at approximate 20-month intervals) on depressive symptoms (using a modified 11-item Center for Epidemiologic Studies Depression Scale, CES-D) among 1612 Black women participants aged 23-34 years living in Detroit, MI. Of the 1612 women, 65% reported experiencing some racism at baseline, and 36.5% had high depressive symptoms at follow-up. Those who experienced high frequency of racism before age 20 had an increased risk for high depressive symptoms (RR = 1.26, 95% CI: 1.07, 1.46) compared to participants in the low racism frequency group. We observed similar associations for high vs. low stress from racism (RR = 1.30, 95% CI : 1.06, 1.54) and high vs. low combination of racism frequency and stress (RR = 1.38, 95% CI: 1.13, 1.64). These findings did not hold or were weaker when assessing racism during the 20s. Among women who experienced high racism across the two time periods, the risk of high depressive symptoms was higher than those who experienced low racism during both periods (RR = 1.49, 95% CI: 1.14, 1.86). The slightly stronger associations between racism and depressive symptoms in childhood and adolescence than in young adulthood suggest that early life might be a sensitive period for experiencing racism.


Assuntos
Depressão , Racismo , Adolescente , Adulto , Negro ou Afro-Americano , População Negra , Depressão/epidemiologia , Depressão/etiologia , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Adulto Jovem
4.
Int J Mol Sci ; 23(22)2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36430342

RESUMO

Surface-enhanced Raman spectroscopy (SERS) is powerful for structural characterization of biomolecules under physiological condition. Owing to its high sensitivity and selectivity, SERS is useful for probing intrinsic structural information of proteins and is attracting increasing attention in biophysics, bioanalytical chemistry, and biomedicine. This review starts with a brief introduction of SERS theories and SERS methodology of protein structural characterization. SERS-active materials, related synthetic approaches, and strategies for protein-material assemblies are outlined and discussed, followed by detailed discussion of SERS spectroscopy of proteins with and without cofactors. Recent applications and advances of protein SERS in biomarker detection, cell analysis, and pathogen discrimination are then highlighted, and the spectral reproducibility and limitations are critically discussed. The review ends with a conclusion and a discussion of current challenges and perspectives of promising directions.


Assuntos
Proteínas , Análise Espectral Raman , Análise Espectral Raman/métodos , Reprodutibilidade dos Testes , Proteínas/química
5.
Entropy (Basel) ; 24(12)2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36554216

RESUMO

It is of great significance to obtain the performance state of complex equipment to protect equipment and maintain its normal operation. The majority of the performance evaluation methods are based on test data, but resume information is not considered. With its wide applicability and completeness, the resume information can be used in the comprehensive evaluation of equipment in various non-testing situations. By incorporating resume information into the performance evaluation of complex equipment, the flexible use of test data and resume information can result in a more comprehensive and accurate evaluation. Therefore, this paper focuses on the evaluation method of complex equipment performance based on evidential reasoning (ER) considering resume information. In order to unify the test data and resume information in the same framework, a novel method is proposed to transform them into the ER-based performance evaluation. On this basis, according to the index types, different reliability calculation methods are put forward, with one being based on the first-order fitting coefficient of variation, and the other being based on average time to failure; the index weight is analyzed based on the method of expert weight construction. Then, the transformed information with reliability and weight are fused by the ER rule. Finally, a performance evaluation case of a certain inertial measurement unit (IMU) is conducted to verify the effectiveness of the proposed method.

6.
J Cardiothorac Vasc Anesth ; 35(9): 2607-2612, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33441271

RESUMO

OBJECTIVES: Transcaval transcatheter aortic valve replacement (TC-TAVR) is an alternative approach to transcatheter aortic valve replacement involving deployment of the bioprosthetic valve via a conduit created from the inferior vena cava to the descending aorta in patients for whom the traditional transfemoral approach is not feasible. By analyzing the largest known cohort of TC-TAVR patients, the authors wished to compare hospital length of stay and post-procedure outcomes between patients who underwent the procedure under deep sedation (DS) and patients who underwent general anesthesia with an endotracheal tube. DESIGN: Retrospective, single-center study. SETTING: Henry Ford Hospital in Detroit, MI. PARTICIPANTS: Patients undergoing TC-TAVR from 2015 to 2018. MEASUREMENTS AND MAIN RESULTS: Seventy-nine patients were included in the analysis, which consisted of 38 under general anesthesia with an endotracheal tube and 41 under DS. The sample was divided into a general anesthesia (GA) group and DS group. There were no significant differences in implant success rate or post-procedure outcomes, including in-hospital mortality (p = 0.999) and major vascular complication rate (p = 0.481), between the two groups. Patients in the GA group stayed a median of 24 hours longer in the intensive care unit (ICU) (p < 0.001) and one day longer in the hospital (p = 0.046) after the procedure compared to patients in the DS group. The median procedure time was significantly lower (135 minutes) in the DS group compared to the GA group (167 minutes, p < 0.001). CONCLUSIONS: Patients undergoing TC-TAVR under DS had similar postoperative outcomes and shorter post-procedure hospital and ICU lengths of stay compared to general anesthesia. In the authors' experience, DS is the preferred anesthetic technique for TC-TAVR.


Assuntos
Anestesia Geral , Estenose da Valva Aórtica , Sedação Profunda , Substituição da Valva Aórtica Transcateter , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Humanos , Intubação Intratraqueal , Tempo de Internação , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
7.
Lifetime Data Anal ; 27(2): 195-215, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33507457

RESUMO

With recent advancement in cancer screening and treatment, many patients with cancers are identified at early stage and clinically cured. Importantly, uncured patients should be treated timely before the cancer progresses to advanced stages for which therapeutic options are rather limited. It is also crucial to identify uncured subjects among patients with early-stage cancers for clinical trials to develop effective adjuvant therapies. Thus, it is of interest to develop statistical predictive models with as high accuracy as possible in predicting the latent cure status. The receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC) are among the most widely used statistical metrics for assessing predictive accuracy or discriminatory power for a dichotomous outcome (cured/uncured). Yet the conventional AUC cannot be directly used due to incompletely observed cure status. In this article, we proposed new estimates of the ROC curve and its AUC for predicting latent cure status in Cox proportional hazards (PH) cure models and transformation cure models. We developed explicit formulas to estimate sensitivity, specificity, the ROC and its AUC without requiring to know the patient cure status. We also developed EM type estimates to approximate sensitivity, specificity, ROC and AUC conditional on observed data. Numerical studies were used to assess their finite-sample performance of the proposed methods. Both methods are consistent and have similar efficiency as shown in our numerical studies. A melanoma dataset was used to demonstrate the utility of the proposed estimates of the ROC curve for the latent cure status. We also have developed an [Formula: see text] package called [Formula: see text] to efficiently compute the proposed estimates.


Assuntos
Modelos Estatísticos , Neoplasias , Área Sob a Curva , Humanos , Modelos de Riscos Proporcionais , Curva ROC
8.
J Environ Sci (China) ; 99: 143-150, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183691

RESUMO

Phosphorus is a vital nutrient for algal growth, thus, a better understanding of phosphorus availability is essential to mitigate harmful algal blooms in lakes. Wind waves are a ubiquitous characteristic of lake ecosystems. However, its effects on the cycling of organic phosphorus and its usage by phytoplankton remain poorly elucidated in shallow eutrophic lakes. A mesocosm experiment was carried out to investigate the responses of alkaline phosphatase activity fractions to wind waves in large, shallow, eutrophic Lake Taihu. Results showed that wind-driven waves induced the release of alkaline phosphatase and phosphorus from the sediment, and dramatically enhanced phytoplanktonic alkaline phosphatase activity. However, compared to the calm conditions, bacterial and dissolved alkaline phosphatase activity decreased in wind-wave conditions. Consistently, the gene copies of Microcystis phoX increased but bacterial phoX decreased under wind-wave conditions. The ecological effects of these waves on phosphorus and phytoplankton likely accelerated the biogeochemical cycling of phosphorus and promoted phytoplankton production in Lake Taihu. This study provides an improved current understanding of phosphorus availability and the phosphorus strategies of plankton in shallow, eutrophic lakes.


Assuntos
Lagos , Fósforo , Fosfatase Alcalina , China , Ecossistema , Monitoramento Ambiental , Eutrofização , Fósforo/análise , Vento
9.
Carcinogenesis ; 41(8): 1074-1082, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32614434

RESUMO

M2 (tumor-supportive) macrophages may upregulate growth differentiation factor 15 (GDF15), which is highly expressed in prostate tumors, but the combined utility of these markers as prognostic biomarkers are unclear. We retrospectively studied 90 prostate cancer cases that underwent radical prostatectomy as their primary treatment and were followed for biochemical recurrence (BCR). These cases also had a benign prostate biopsy at least 1 year or more before their prostate cancer surgery. Using computer algorithms to analyze digitalized immunohistochemically stained slides, GDF15 expression and the presence of M2 macrophages based on the relative density of CD204- and CD68-positive macrophages were measured in prostate: (i) benign biopsy, (ii) cancer and (iii) tumor-adjacent benign (TAB) tissue. Both M2 macrophages (P = 0.0004) and GDF15 (P < 0.0001) showed significant inter-region expression differences. Based on a Cox proportional hazards model, GDF15 expression was not associated with BCR but, in men where GDF15 expression differences between cancer and TAB were highest, the risk of BCR was significantly reduced (hazard ratio = 0.26; 95% confidence interval = 0.09-0.94). In addition, cases with high levels of M2 macrophages in prostate cancer had almost a 5-fold increased risk of BCR (P = 0.01). Expression of GDF15 in prostate TAB was associated with M2 macrophage levels in both prostate cancer and TAB and appeared to moderate M2-macrophage-associated BCR risk. In summary, the relationship of GDF15 expression and CD204-positive M2 macrophage levels is different in a prostate tumor environment compared with an earlier benign biopsy and, collectively, these markers may predict aggressive disease.


Assuntos
Carcinogênese/metabolismo , Fator 15 de Diferenciação de Crescimento/metabolismo , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/metabolismo , Macrófagos Associados a Tumor/metabolismo , Idoso , Contagem de Células , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo
10.
Anal Chem ; 92(21): 14325-14329, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33085474

RESUMO

The use of silver nanoparticles (Ag NPs) as substrates to obtain satisfactory Raman spectra of native proteins is a simple and valuable but challenging process. Herein, the Ag NPs modified with aluminum and iodide ions (Ag IANPs) were introduced for Raman detection of proteins, including acidic BSA (PI 4.7), catalase (PI 5.4), ß-casein (PI 4.5), α-casein (PI 4.0), insulin (PI 5.35), basic myoglobin (PI 6.99), and lysozyme (PI 11.2). The Raman signals of all the detected proteins were significantly improved in comparison with the reported spectra obtained by using Ag NPs containing Na2SO4, I-, and Mg2+. Specifically, detection sensitivities of the acidic proteins were drastically increased. The limit of detection (LOD) of bovine serum albumin (BSA), α-casein, and ß-casein was 0.03 ng/mL. The LOD of insulin and catalase were 0.3 and 3 ng/mL, respectively. As the bands corresponding to disulfide bonds, α-helices, residues of Phe, Trp, and Tyr, and carboxyl groups were also greatly enhanced, it was easy to monitor the folding of native protein and the denaturation of protein under acidic and heated conditions. Thus, Ag IANPs as substrates open a way for surface-enhanced Raman spectroscopy (SERS) detection of proteins. Hence, the method can provide more valuable information about protein and, therefore, has the potential for wide applications.


Assuntos
Limite de Detecção , Nanopartículas Metálicas/química , Proteínas/análise , Prata/química , Análise Espectral Raman , Animais
11.
Blood Cells Mol Dis ; 80: 102355, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31525610

RESUMO

A low erythropoietin (EPO) level is a minor diagnostic criterion for polycythemia vera (PV). Controversies exist regarding the diagnostic value of a low EPO level when considering increasing availability of advanced molecular testing. We assessed the role of low EPO level for PV diagnosis in the context of positive JAK2 mutation status as well as other diagnostic parameters. Of 138 patients, 75 patients had PV and 63 had secondary erythrocytosis. Of the 75 patients with PV, 32% had EPO levels within the normal range. EPO level positively correlated with obesity and smoking status, making it an unreliable diagnostic marker in those patients. Although EPO level below normal as a standalone diagnostic modality was significantly associated with PV (odds ratio [OR] 0.857; p < 0.001), when JAK2V617F mutation status was included in the prediction model, the association of low EPO was not statistically significant (OR 0.962, p = 0.269). Positive JAK2V617F demonstrated a strong predictive value for PV (OR 670.5, p = 0.006) either alone or in combination with other variables. Results show that EPO level is not a reliable diagnostic marker due to physiologic variation in association with obesity and smoking.


Assuntos
Eritropoetina/sangue , Policitemia Vera/sangue , Policitemia Vera/diagnóstico , Biomarcadores , Biópsia , Medula Óssea/patologia , Diagnóstico Diferencial , Feminino , Humanos , Janus Quinase 2/genética , Masculino , Mutação , Policitemia Vera/etiologia , Prognóstico , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos
12.
Phys Chem Chem Phys ; 21(24): 12850-12858, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31179479

RESUMO

The exploitation of new types of non-metal surface-enhanced Raman scattering (SERS) substrates with high performances and the exploration of enhancement mechanisms are of vital importance for the development of the SERS technology due to its potential prospects in both the spectroscopy and material fields. Here, a magnetic SERS-active substrate hybridized by reduced graphene oxide (rGO), TiO2 and Fe3O4 (rGO-TiO2-Fe3O4) was successfully prepared via the combination of a simple sol-hydrothermal method and a co-precipitation method. The as-synthesized rGO-TiO2-Fe3O4 nanohybrid not only exhibited outstanding SERS detection ability with high sensitivity and spectral reproducibility, but also could be recycled with high stability based on its self-cleaning capacity and magnetism. Exploiting these features, it could be used for the SERS detection of 4-mercaptobenzoic acid (4-MBA), 4-mercaptopyridine (4-MPy), 6-mercaptopurine monohydrate (6-MP), 1,2-di(4-pyridyl) ethylene (BPE) and p-aminobenzoic acid (PABA) with the detection limits of 1.0 × 10-10, 1.0 × 10-8, 1.0 × 10-10, 1.0 × 10-10 and 1.0 × 10-9 mol L-1, respectively; these are the highest SERS sensitivity values among those reported for semiconductor substrates and are even lower than that of noble metal substrates. Meanwhile, an SERS enhancement mechanism from the synergistic effects of the rGO, TiO2 and Fe3O4 components was proposed to explain the observed considerable SERS enhancement on rGO-TiO2-Fe3O4.

13.
Environ Res ; 172: 266-272, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30822559

RESUMO

The effects of childhood exposure to perfluoroalkyl substances (PFASs) on lung function remain mostly unknown. Previous research indicates that children living or going to school near the World Trade Center (WTC) disaster were exposed to high levels of PFASs, among other toxic chemicals. To explore the effects of PFAS exposure on lung function, we measured serum PFASs in a cohort of children from the WTC Health Registry and a matched control group. Perfluorooctanesulfonate had the highest median concentrations in both groups (WTCHR = 3.72 ng/mL, Comparison = 2.75 ng/mL), while the lowest median concentrations were seen for perfluoroundecanoic acid (WTCHR = 0.12 ng/mL, Comparison = 0.01 ng/mL). Lung function outcomes were measured by spirometry, plethysmography, and oscillometry. Asthma diagnosis and serum eosinophil count were also recorded. We examined the relationships of each PFAS with lung function parameters and eosinophil count using linear regressions. Odds ratios for asthma were obtained for each PFAS using logistic regression. The effect of total PFASs on these outcomes was also assessed. All regression models were adjusted for sex, race/ethnicity, age, body mass index (BMI) and tobacco smoke exposure. We found that serum PFASs were not statistically associated with the measured lung function parameters, asthma diagnosis, or eosinophil count in this cohort (p < 0.05). These findings highlight the need for more longitudinal studies to explore the long-term effects of childhood PFAS exposure on lung function past adolescence and early adulthood.


Assuntos
Exposição Ambiental , Poluentes Ambientais , Fluorocarbonos , Pulmão , Ataques Terroristas de 11 de Setembro , Adolescente , Adulto , Asma/epidemiologia , Criança , Estudos de Coortes , Poluentes Ambientais/sangue , Poluentes Ambientais/toxicidade , Fluorocarbonos/sangue , Fluorocarbonos/toxicidade , Humanos , Pulmão/efeitos dos fármacos , Cidade de Nova Iorque/epidemiologia , Testes de Função Respiratória
14.
J Cardiothorac Vasc Anesth ; 33(12): 3303-3308, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30850225

RESUMO

OBJECTIVE: To compare outcomes among patients with and without preprocedural radial arterial catheters who underwent transfemoral transcatheter aortic valve replacement (TF-TAVR) under deep intravenous (IV) sedation and to assess predictive variables for preprocedural placement. DESIGN: Single-center, retrospective, cohort analysis. SETTING: Department of Anesthesiology, Pain Management and Perioperative Medicine, Henry Ford Hospital, which is a tertiary care, university-affiliated hospital. PARTICIPANTS: The study comprised 157 patients. The primary focus was the 106 patients who underwent TF-TAVR when routine placement of preprocedure radial arterial catheters was abandoned. They were analyzed for hospital length of stay, 30-day mortality, and predictive factors of preprocedure placement. The remaining patients served as historical controls when routine radial artery catheter placement was practiced. INTERVENTIONS: Patient, procedure, and provider factors were analyzed. The transitional period consisted of 169 consecutive days from April 13 to September 28, 2017. A reference group of historical patients served as a control. MEASUREMENTS AND MAIN RESULTS: Seventy-five of 106 patients did not have a preprocedural radial arterial catheter. The primary outcome measures of length of stay and 30-day mortality within the transitional group were not different. Secondary outcome measures included identification of predictive variables for preprocedure placement and outcome comparisons between the transitional and historical groups. Anesthesia provider (p = 0.015) and ejection fraction (p = 0.039) were significant factors. There were no differences in outcome measures. CONCLUSION: There was no difference in primary outcomes in patients with or without radial arterial catheters for TF-TAVR. The findings of this study suggest anesthesia provider and ejection fraction were significant factors for preprocedural placement.


Assuntos
Estenose da Valva Aórtica/cirurgia , Pressão Sanguínea/fisiologia , Cateterismo Periférico/métodos , Sedação Consciente/métodos , Monitorização Fisiológica/métodos , Substituição da Valva Aórtica Transcateter/métodos , Idoso , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico , Ecocardiografia Transesofagiana , Feminino , Artéria Femoral , Seguimentos , Humanos , Tempo de Internação/tendências , Masculino , Artéria Radial , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
15.
J Cardiothorac Vasc Anesth ; 33(9): 2414-2418, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31076296

RESUMO

OBJECTIVE: The purposes of this study were to establish whether implementing a curriculum of perioperative point-of-care ultrasound (POCUS) of the heart and lungs for current in-training anesthesia residents during their required month of cardiac anesthesia was feasible and whether an evaluation tool would demonstrate improvement in the residents' baseline knowledge of POCUS. DESIGN: Single-center, prospective, cohort, and observational study. SETTING: A tertiary-care, university-affiliated hospital. PARTICIPANTS: The study comprised 16 anesthesia residents on their third postgraduate training year during their required cardiac anesthesia rotation. INTERVENTIONS: The implementation of a curriculum to educate anesthesia residents in perioperative POCUS of the heart and lungs on patients undergoing elective cardiothoracic procedures that included both theoretical and practical approaches. A 21-question, multiple-choice, electronic-generated test was developed to gauge performance improvement from before ("pretest") to after ("posttest") the 4-week period. MEASUREMENTS AND MAIN RESULTS: Of the 16 residents, 13 (81.3%) showed improved scores between the pretest and posttest periods after the 4-week rotation. The difference between pretest and posttest mean score was 5 (p = 0.001). CONCLUSIONS: This study demonstrates that integrating a curriculum dedicated to perioperative POCUS of the heart and lungs as part of the goals and objectives during the rotation of cardiac anesthesia is feasible and that anesthesia residents who received the training proposed by the authors improved their cognitive and technical skills.


Assuntos
Anestesiologia/educação , Anestesiologia/normas , Competência Clínica/normas , Internato e Residência/normas , Sistemas Automatizados de Assistência Junto ao Leito/normas , Ultrassonografia de Intervenção/normas , Anestesia/normas , Estudos de Coortes , Feminino , Hospitais Universitários/normas , Humanos , Masculino , Estudos Prospectivos
16.
J Appl Clin Med Phys ; 20(9): 95-103, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31538718

RESUMO

Model-based iterative reconstruction (MBIR) reduces CT imaging dose while maintaining image quality. However, MBIR reduces noise while preserving edges which may impact intensity-based tasks such as auto-segmentation. This work evaluates the sensitivity of an auto-contouring prostate atlas across multiple MBIR reconstruction protocols and benchmarks the results against filtered back projection (FBP). Images were created from raw projection data for 11 prostate cancer cases using FBP and nine different MBIR reconstructions (3 protocols/3 noise reduction levels) yielding 10 reconstructions/patient. Five bony structures, bladder, rectum, prostate, and seminal vesicles (SVs) were segmented using an auto-segmentation pipeline that renders 3D binary masks for analysis. Performance was evaluated for volume percent difference (VPD) and Dice similarity coefficient (DSC), using FBP as the gold standard. Nonparametric Friedman tests plus post hoc all pairwise comparisons were employed to test for significant differences (P < 0.05) for soft tissue organs and protocol/level combinations. A physician performed qualitative grading of 396 MBIR contours across the prostate, bladder, SVs, and rectum in comparison to FBP using a six-point scale. MBIR contours agreed with FBP for bony anatomy (DSC ≥ 0.98), bladder (DSC ≥ 0.94, VPD < 8.5%), and prostate (DSC = 0.94 ± 0.03, VPD = 4.50 ± 4.77% (range: 0.07-26.39%). Increased variability was observed for rectum (VPD = 7.50 ± 7.56% and DSC = 0.90 ± 0.08) and SVs (VPD and DSC of 8.23 ± 9.86% range (0.00-35.80%) and 0.87 ± 0.11, respectively). Over the all protocol/level comparisons, a significant difference was observed for the prostate VPD between BSPL1 and BSTL2 (adjusted P-value = 0.039). Nevertheless, 300 of 396 (75.8%) of the four soft tissue structures using MBIR were graded as equivalent or better than FBP, suggesting that MBIR offered potential improvements in auto-segmentation performance when compared to FBP. Future work may involve tuning organ-specific MBIR parameters to further improve auto-segmentation performance. Running title: Impact of CT Reconstruction Algorithm on Auto-segmentation Performance.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Órgãos em Risco/efeitos da radiação , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Humanos , Masculino , Prognóstico , Dosagem Radioterapêutica , Estudos Retrospectivos
17.
Anal Chem ; 90(5): 2996-3000, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29425026

RESUMO

Surface-enhanced Raman spectroscopy (SERS) can probe DNA primary structure; however, the direct analysis of DNA secondary structure is still technically challenging. In this study, we developed a novel method based on introducing aluminum ion as the aggregation agent for silver nanoparticles, affording high-quality SERS signals of tetramolecular DNA. Thus, the formation of tetramolecular i-motifs was precisely analyzed by SERS signals for the first time and structural features involving glycosidic torsion, protonated cytosine, and cytosine rings were investigated. Moreover, the number of intercalated base pairs in i-motifs were quantified based on the relative intensities of the characteristic SERS bands. The proposed approach would have widespread applications in DNA analysis, especially for detecting various DNA secondary structures.

18.
J Pediatr ; 201: 134-140.e6, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30029866

RESUMO

OBJECTIVES: To compare lung function in a representative sample of World Trade Center (WTC)-exposed children with matched comparisons, and examine relationships with reported exposures. STUDY DESIGN: Study population consisted of 402 participants. Oscillometry, spirometry, and plethysmography were performed on WTC Health Registry (WTCHR) respondents who were ≤8 years of age on September 11, 2001 (n = 180) and a sociodemographically matched group of New York City residents (n = 222). We compared lung function by study arm (WTCHR and comparison group) as well as dust cloud (acute); home dust (subchronic); and other traumatic, nondust exposures. RESULTS: In multivariable models, post-9/11 risk of incident asthma was higher in the WTCHR participants than in the comparison group (OR 1.109, 95% CI 1.021, 1.206; P = .015). Comparing by exposure rather than by group, dust cloud (OR 1.223, 95% CI 1.095, 1.365; P < .001) and home dust (OR 1.123, 95% CI 1.029, 1.226; P = .009) exposures were also associated with a greater risk of incidence of post-9/11 asthma. No differences were identified for lung function measures. CONCLUSIONS: Although we cannot exclude an alternative explanation to the null findings, these results may provide some measure of reassurance to exposed children and their families regarding long-term consequences. Further study with bronchodilation and/or methacholine challenge may be needed to identify and further evaluate effects of WTC exposure. Biomarker studies may also be more informative in delineating exposure-outcome relationships. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02068183.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Desastres , Exposição Ambiental/efeitos adversos , Nível de Saúde , Sistema de Registros , Fenômenos Fisiológicos Respiratórios , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Criança , Pré-Escolar , Poeira , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Cidade de Nova Iorque/epidemiologia , Estudos Retrospectivos , Transtornos de Estresse Pós-Traumáticos/fisiopatologia
19.
Neural Comput ; 30(9): 2472-2499, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29949460

RESUMO

A hippocampal prosthesis is a very large scale integration (VLSI) biochip that needs to be implanted in the biological brain to solve a cognitive dysfunction. In this letter, we propose a novel low-complexity, small-area, and low-power programmable hippocampal neural network application-specific integrated circuit (ASIC) for a hippocampal prosthesis. It is based on the nonlinear dynamical model of the hippocampus: namely multi-input, multi-output (MIMO)-generalized Laguerre-Volterra model (GLVM). It can realize the real-time prediction of hippocampal neural activity. New hardware architecture, a storage space configuration scheme, low-power convolution, and gaussian random number generator modules are proposed. The ASIC is fabricated in 40 nm technology with a core area of 0.122 mm[Formula: see text] and test power of 84.4 [Formula: see text]W. Compared with the design based on the traditional architecture, experimental results show that the core area of the chip is reduced by 84.94% and the core power is reduced by 24.30%.


Assuntos
Eletrônica Médica/instrumentação , Hipocampo/citologia , Modelos Neurológicos , Neurônios/fisiologia , Dinâmica não Linear , Potenciais de Ação/fisiologia , Algoritmos , Animais , Eletrônica Médica/métodos , Humanos , Rede Nervosa/fisiologia , Redes Neurais de Computação , Próteses Neurais
20.
Phys Chem Chem Phys ; 20(22): 15149-15157, 2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29789850

RESUMO

Ag simultaneously deposited and doped TiO2 (Ag-TiO2) hybrid nanoparticles (NPs) were prepared via a sol-hydrothermal method, as both a sensitive surface-enhanced Raman scattering (SERS) substrate and a superior photocatalyst for the first time. Ag-TiO2 hybrid NPs exhibit excellent SERS performance for several probe molecules and the enhancement factor is calculated to be 1.86 × 105. The detection limit of the 4-mercaptobenzoic acid (4-MBA) probe on the Ag-TiO2 substrate is 1 × 10-9 mol L-1, which is four orders of magnitude lower than that on pure TiO2 as a consequence of the synergistic effects of TiO2 and Ag. This is the highest SERS sensitivity among the reported semiconductor substrates and even comparable to noble metal substrates, and a SERS enhancement mechanism from the synergistic contribution of the semiconductor and noble metal was proposed. And importantly, the Ag-TiO2 hybrid shows excellent photocatalytic degradation activity for the detected species under UV light irradiation at lower concentration conditions, even for the hard to degrade 4-MBA molecule. This makes the Ag-TiO2 hybrid promising as a dual-function platform for both highly sensitive SERS detection and photocatalytic degradation of a pollutant system. Moreover, it also proves that the Ag-TiO2 hybrid can serve as a promising recyclable SERS-active substrate by virtue of its photocatalytic self-cleaning properties for some specific applications, for instance comparative studies of different species on the same SERS platform, in addition to the economic benefit.

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