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1.
Global Spine J ; : 21925682241260642, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861501

RESUMO

STUDY DESIGN: Prospective Cohort Study. OBJECTIVE: Untreated pre-surgical depression may prolong post-surgical pain and hinder recovery. However, research on the impact of untreated pre-surgical depression on post-spinal surgery pain is lacking. Therefore, this study aimed to assess pre-surgical depression in patients and analyze its relationship with post-surgical pain and overall post-surgical outcomes. METHODS: We recruited 100 patients scheduled for lumbar spine surgery due to spondylolisthesis, degenerative lumbar disc diseases, and herniated lumbar disc diseases. Psychiatrists evaluated them for the final selection. We assessed the Beck Depression Inventory (BDI), Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), and EuroQoL 5 Dimensions (EQ-5D) scores, numerical back and leg pain scales, and medication dosage data collected before and at 6 weeks, 3 months, and 6 months after surgery. RESULTS: Ninety-one patients were included in this study; 40 and 51 were allocated to the control and depression groups, respectively. The pre- and post-surgical leg pain, back pain, and functional scores were not different. However, the depression group showed higher ODI and EQ-5D and lower JOA scores than the control group 3 months post-surgery. Partial correlation analysis revealed an inverse correlation between the JOA and BDI scores and a positive correlation between the EQ-5D and BDI scores at 3 months postoperatively. CONCLUSION: Untreated depression can prolong postoperative pain and hinder recovery. Detecting and treating depression in patients before spine surgery may improve their overall quality of life and functional recovery.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38576263

RESUMO

STUDY DESIGN: Retrospective observational study. OBJECTIVE: To determine the proximity between screw and endplate of the upper instrumented vertebra (UIV) using a cortical bone trajectory (CBT) screw as a predictive factor for radiographic adjacent segment degeneration (ASD) in patients surgically treated with transforaminal lumbar interbody fusion (TLIF) with CBT screws (CBT-TLIF) with lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: The risk factors for radiographic ASD after CBT-TLIF remain unknown. METHODS: Among patients surgically treated with CBT-TLIF at a single institute, 239 consecutive patients (80 males and 159 females) were enrolled. ASD was defined by the presence of one or more of the following three radiologic criteria on the adjacent segment: >3 mm anteroposterior translation, >10° segmental kyphosis, or >50% loss of disc height comparing immediate postoperative and 1-year follow-up radiographs. Clinical and radiological features associated with the development of ASD were retrospectively measured. Univariate and multivariate analyses were performed to identify risk factors associated with radiographic ASD. RESULTS: Radiographic ASD was observed in 71 (29.7%) cases at 1-year postoperative follow-up. The preoperative Pfirrmann grade of the adjacent segment (>grade 2), multi-level fusion (>2 levels), and proximity between the tip of CBT screws and endplate on the UIV were significantly associated with radiographic ASD (OR = 3.98, 95% CI [1.06-15.05], P=0.042 versus OR = 3.03, 95% CI [1.00-9.14], P=0.049 versus OR = 0.53, 95% CI [0.40-0.72], P<0.001). The cut-off value of the distance between the tip of the screw and endplate on UIV for radiographic ASD was approximately 2.5 mm (right-sided CBT screw; cut-off value 2.48 mm/ left-sided CBT screw; cut-off value 2.465 mm). CONCLUSION: Radiographic adjacent segment degeneration progression can occur when the cortical trajectory bone screw is close to the endplate of the upper instrumented vertebrae in patients with lumbar spinal stenosis undergoing fusion surgery.

3.
medRxiv ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38496585

RESUMO

The Long Life Family Study (LLFS) enrolled 4,953 participants in 539 pedigrees displaying exceptional longevity. To identify genetic mechanisms that affect cardiovascular risks in the LLFS population, we developed a multi-omics integration pipeline and applied it to 11 traits associated with cardiovascular risks. Using our pipeline, we aggregated gene-level statistics from rare-variant analysis, GWAS, and gene expression-trait association by Correlated Meta-Analysis (CMA). Across all traits, CMA identified 64 significant genes after Bonferroni correction (p ≤ 2.8×10-7), 29 of which replicated in the Framingham Heart Study (FHS) cohort. Notably, 20 of the 29 replicated genes do not have a previously known trait-associated variant in the GWAS Catalog within 50 kb. Thirteen modules in Protein-Protein Interaction (PPI) networks are significantly enriched in genes with low meta-analysis p-values for at least one trait, three of which are replicated in the FHS cohort. The functional annotation of genes in these modules showed a significant over-representation of trait-related biological processes including sterol transport, protein-lipid complex remodeling, and immune response regulation. Among major findings, our results suggest a role of triglyceride-associated and mast-cell functional genes FCER1A, MS4A2, GATA2, HDC, and HRH4 in atherosclerosis risks. Our findings also suggest that lower expression of ATG2A, a gene we found to be associated with BMI, may be both a cause and consequence of obesity. Finally, our results suggest that ENPP3 may play an intermediary role in triglyceride-induced inflammation. Our pipeline is freely available and implemented in the Nextflow workflow language, making it easily runnable on any compute platform (https://nf-co.re/omicsgenetraitassociation).

5.
Sci Rep ; 13(1): 15599, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37730856

RESUMO

Guidelines from the World Health Organization strongly recommend the use of a high fraction of inspired oxygen (FiO2) in adult patients undergoing general anesthesia to reduce surgical site infection (SSI). However, previous meta-analyses reported inconsistent results. We aimed to address this controversy by focusing specifically on abdominal surgery with relatively high risk of SSI. Medline, EMBASE, and Cochrane CENTRAL databases were searched. Randomized trials of abdominal surgery comparing high to low perioperative FiO2 were included, given that the incidence of SSI was reported as an outcome. Meta-analyses of risk ratios (RR) were performed using a fixed effects model. Subgroup analysis and meta-regression were employed to explore sources of heterogeneity. We included 27 trials involving 15977 patients. The use of high FiO2 significantly reduced the incidence of SSI (n = 27, risk ratio (RR): 0.87; 95% confidence interval (CI): 0.79, 0.95; I2 = 49%, Z = 3.05). Trial sequential analysis (TSA) revealed that z-curve crossed the trial sequential boundary and data are sufficient. This finding held true for the subgroup of emergency operations (n = 2, RR: 0.54; 95% CI: 0.35, 0.84; I2 = 0%, Z = 2.75), procedures using air as carrier gas (n = 9, RR: 0.79; 95% CI: 0.69, 0.91; I2 = 60%, Z = 3.26), and when a high level of FiO2 was maintained for a postoperative 6 h or more (n = 9, RR: 0.68; 95% CI: 0.56, 0.83; I2 = 46%, Z = 3.83). Meta-regression revealed no significant interaction between SSI with any covariates including age, sex, body-mass index, diabetes mellitus, duration of surgery, and smoking. Quality of evidence was assessed to be moderate to very low. Our pooled analysis revealed that the application of high FiO2 reduced the incidence of SSI after abdominal operations. Although TSA demonstrated sufficient data and cumulative analysis crossed the TSA boundary, our results should be interpreted cautiously given the low quality of evidence.Registration: https://www.crd.york.ac.uk/prospero (CRD42022369212) on October 2022.


Assuntos
Anestesia Geral , Infecção da Ferida Cirúrgica , Adulto , Humanos , Infecção da Ferida Cirúrgica/prevenção & controle , Anestesia Geral/efeitos adversos , Índice de Massa Corporal , Bases de Dados Factuais , Oxigênio
6.
Front Neurol ; 14: 1221892, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37719763

RESUMO

Background and purpose: To develop and validate a deep learning-based automatic segmentation model for assessing intracranial volume (ICV) and to compare the accuracy determined by NeuroQuant (NQ), FreeSurfer (FS), and SynthSeg. Materials and methods: This retrospective study included 60 subjects [30 Alzheimer's disease (AD), 21 mild cognitive impairment (MCI), 9 cognitively normal (CN)] from a single tertiary hospital for the training and validation group (50:10). The test group included 40 subjects (20 AD, 10 MCI, 10 CN) from the ADNI dataset. We propose a robust ICV segmentation model based on the foundational 2D UNet architecture trained with four types of input images (both single and multimodality using scaled or unscaled T1-weighted and T2-FLAIR MR images). To compare with our model, NQ, FS, and SynthSeg were also utilized in the test group. We evaluated the model performance by measuring the Dice similarity coefficient (DSC) and average volume difference. Results: The single-modality model trained with scaled T1-weighted images showed excellent performance with a DSC of 0.989 ± 0.002 and an average volume difference of 0.46% ± 0.38%. Our multimodality model trained with both unscaled T1-weighted and T2-FLAIR images showed similar performance with a DSC of 0.988 ± 0.002 and an average volume difference of 0.47% ± 0.35%. The overall average volume difference with our model showed relatively higher accuracy than NQ (2.15% ± 1.72%), FS (3.69% ± 2.93%), and SynthSeg (1.88% ± 1.18%). Furthermore, our model outperformed the three others in each subgroup of patients with AD, MCI, and CN subjects. Conclusion: Our deep learning-based automatic ICV segmentation model showed excellent performance for the automatic evaluation of ICV.

7.
Eur Radiol ; 33(9): 6145-6156, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37059905

RESUMO

OBJECTIVES: To develop and validate a nomogram based on MRI features for predicting iNPH. METHODS: Patients aged ≥ 60 years (clinically diagnosed with iNPH, Parkinson's disease, or Alzheimer's disease or healthy controls) who underwent MRI including three-dimensional T1-weighted volumetric MRI were retrospectively identified from two tertiary referral hospitals (one hospital for derivation set and the other for validation set). Clinical and imaging features for iNPH were assessed. Deep learning-based brain segmentation software was used for 3D volumetry. A prediction model was developed using logistic regression and transformed into a nomogram. The performance of the nomogram was assessed with respect to discrimination and calibration abilities. The nomogram was internally and externally validated. RESULTS: A total of 452 patients (mean age ± SD, 73.2 ± 6.5 years; 200 men) were evaluated as the derivation set. One hundred eleven and 341 patients were categorized into the iNPH and non-iNPH groups, respectively. In multivariable analysis, high-convexity tightness (odds ratio [OR], 35.1; 95% CI: 4.5, 275.5), callosal angle < 90° (OR, 12.5; 95% CI: 3.1, 50.0), and normalized lateral ventricle volume (OR, 4.2; 95% CI: 2.7, 6.7) were associated with iNPH. The nomogram combining these three variables showed an area under the curve of 0.995 (95% CI: 0.991, 0.999) in the study sample, 0.994 (95% CI: 0.990, 0.998) in the internal validation sample, and 0.969 (95% CI: 0.940, 0.997) in the external validation sample. CONCLUSION: A brain morphometry-based nomogram including high-convexity tightness, callosal angle < 90°, and normalized lateral ventricle volume can help accurately estimate the probability of iNPH. KEY POINTS: • The nomogram with MRI findings (high-convexity tightness, callosal angle, and normalized lateral ventricle volume) helped in predicting the probability of idiopathic normal-pressure hydrocephalus. • The nomogram may facilitate the prediction of idiopathic normal-pressure hydrocephalus and consequently avoid unnecessary invasive procedures such as the cerebrospinal fluid tap test, drainage test, and cerebrospinal fluid shunt surgery.


Assuntos
Doença de Alzheimer , Hidrocefalia de Pressão Normal , Masculino , Humanos , Idoso , Nomogramas , Estudos Retrospectivos , Hidrocefalia de Pressão Normal/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
8.
Sci Rep ; 13(1): 6951, 2023 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-37117258

RESUMO

Corticosteroids remain the mainstay of immunosuppression for liver transplant recipients despite several serious complications including infection, hepatitis C virus (HCV) recurrence, diabetes mellitus (DM), and hypertension. We attempted to compare the safety and efficacy of T-cell specific antibody induction with complete corticosteroid avoidance. We searched MEDLINE, EMBASE, and Cochrane central library. Randomized controlled trials comparing T-cell specific antibody induction with corticosteroid induction immunosuppression were included. Our primary outcome was the incidence of biopsy-proven acute rejection. Eleven trials involving 1683 patients were included. The incidence of acute rejection was not significantly different between the antibody and steroid induction groups (risk ratio [RR] 0.85, 95% confidence interval [CI] 0.72, 1.01, P = 0.06, I2 = 0%). However, T-cell specific antibody induction significantly reduced the risk of cytomegalovirus infection (RR 0.48, 95% CI 0.33, 0.70, P = 0.0002, I2 = 3%), HCV recurrence (RR 0.89, 95% CI 0.80, 0.99, P = 0.03, I2 = 0%), DM (RR 0.41, 95% CI 0.32, 0.54, P < 0.0001, I2 = 0%) and hypertension (RR 0.71, 95% CI 0.55, 0.90, P = 0.005, I2 = 35%). Trial sequential analysis for acute rejection showed that the cumulative z-curve did not cross the Trial sequential boundary and the required information size was not reached. T-cell specific antibody induction compared to corticosteroid induction seems to significantly reduce opportunistic infections including cytomegalovirus infection and HCV recurrence and metabolic complications including DM and hypertension. However, given the insufficient study power, low quality of evidence, and heterogeneous immunosuppressive regimens, our results should be cautiously appreciated.


Assuntos
Infecções por Citomegalovirus , Diabetes Mellitus , Hepatite C , Hipertensão , Transplante de Fígado , Humanos , Transplante de Fígado/efeitos adversos , Terapia de Imunossupressão/métodos , Imunossupressores/efeitos adversos , Soro Antilinfocitário , Corticosteroides/uso terapêutico , Linfócitos T
9.
G3 (Bethesda) ; 12(8)2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35666184

RESUMO

The ability to predict which genes will respond to the perturbation of a transcription factor serves as a benchmark for our systems-level understanding of transcriptional regulatory networks. In previous work, machine learning models have been trained to predict static gene expression levels in a biological sample by using data from the same or similar samples, including data on their transcription factor binding locations, histone marks, or DNA sequence. We report on a different challenge-training machine learning models to predict which genes will respond to the perturbation of a transcription factor without using any data from the perturbed cells. We find that existing transcription factor location data (ChIP-seq) from human cells have very little detectable utility for predicting which genes will respond to perturbation of a transcription factor. Features of genes, including their preperturbation expression level and expression variation, are very useful for predicting responses to perturbation of any transcription factor. This shows that some genes are poised to respond to transcription factor perturbations and others are resistant, shedding light on why it has been so difficult to predict responses from binding locations. Certain histone marks, including H3K4me1 and H3K4me3, have some predictive power when located downstream of the transcription start site. However, the predictive power of histone marks is much less than that of gene expression level and expression variation. Sequence-based or epigenetic properties of genes strongly influence their tendency to respond to direct transcription factor perturbations, partially explaining the oft-noted difficulty of predicting responsiveness from transcription factor binding location data. These molecular features are largely reflected in and summarized by the gene's expression level and expression variation. Code is available at https://github.com/BrentLab/TFPertRespExplainer.


Assuntos
Regulação da Expressão Gênica , Fatores de Transcrição , Redes Reguladoras de Genes , Humanos , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Sítio de Iniciação de Transcrição
10.
Arch Orthop Trauma Surg ; 138(9): 1257-1263, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29777344

RESUMO

PURPOSE: The purpose of this study was to compare clinical outcomes and development of post-infectious arthritis of the shoulder joint after single (Group S) or repeated (Group R) arthroscopic debridement surgeries. We hypothesized that (1) repeated surgeries might be attributable to initial subchondral involvement resulting from septic arthritis and (2) the repeated surgery group would exhibit a higher incidence of post-infectious arthritic changes and inferior clinical outcomes due to prolonged resolution of the infection. METHODS: This study included 42 patients (single surgery, n = 29; repeated surgery, n = 13) who underwent arthroscopic debridement for septic arthritis and had a minimum of 2 years of postoperative follow-up data. All patients underwent preoperative magnetic resonance imaging (MRI) with gadolinium enhancement to evaluate subchondral bone involvement suspicious for osteomyelitis secondary to septic arthritis and extension of infection around the glenohumeral joint. Functional and radiological outcomes were assessed. RESULTS: Group S experienced a shorter duration (25.4 days) of infection than Group R (39.7 days) (p = 0.002). Increased signal intensity in the subchondral bone on preoperative MRI was identified in 9 patients (31%) in Group S and 5 patients (38%) in Group R. Post-infectious arthritic changes developed in 6 (21%) and 5 (38%) in Groups S and R, respectively. However, there were no significant differences between groups. At the final follow-up, there were no significant differences in functional assessments. CONCLUSION: Despite a prolonged period of infection in the repeated surgery group, there was no significant difference in development of post-infectious arthritic changes or clinical outcomes in patients requiring single or repeated surgeries. LEVEL OF EVIDENCE: Retrospective comparative study, III.


Assuntos
Artrite Infecciosa/cirurgia , Artroscopia/métodos , Desbridamento/métodos , Articulação do Ombro/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Artrite Infecciosa/complicações , Artroscopia/efeitos adversos , Desbridamento/efeitos adversos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Articulação do Ombro/patologia , Resultado do Tratamento
11.
J Orthop Surg Res ; 13(1): 80, 2018 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-29642925

RESUMO

BACKGROUND: No previously published studies have examined recurrent traumatic incomplete events in patients with excessive joint laxity. The purpose of this study is to investigate outcomes after arthroscopic stabilization for recurrent traumatic shoulder subluxation in patients with excessive joint laxity but no history of dislocation. METHODS: This study included 23 patients with glenoid bone defects less than 20% who underwent arthroscopic stabilization of recurrent shoulder subluxation and were available for at least 2 years follow-up. Outcomes were assessed with the subjective shoulder value (SSV), University of California Los Angeles (UCLA) shoulder score, Rowe score, and sports/recreation activity level. RESULTS: Postoperatively, overall functional scores improved significantly (p <  0.001), compared to preoperative scores: SSV improved from 49.1 to 90.4; Rowe score improved from 36.7 to 90.2; and UCLA shoulder score improved from 26.3 to 32.5. Patient satisfaction rate was 87% (20/23 patients). Sports/recreation activity level (return to premorbid activity level; grade I = 100% to grade IV = less than 70%) was grade I in 7 patients, grade II in 11, grade III in 3, grade IV in 2. The incidence of any glenoid bone defect was 61% (14/23 patients), and the mean glenoid bone defect size was 8%; among these 14 patients, 8 (35%) exhibited 15-20% glenoid bone defects. Instability reoccurred in 2 patients (9%) who had 15-20% glenoid bone defect. CONCLUSION: Despite excessive joint laxity, overall functional outcomes after arthroscopic stabilization of recurrent shoulder subluxation were satisfactory. However, arthroscopic Bankart repair may not be reliable in patients with excessive joint laxity plus a glenoid bone defect size of more than approximately 15%.


Assuntos
Instabilidade Articular/cirurgia , Luxação do Ombro/cirurgia , Articulação do Ombro/cirurgia , Adolescente , Adulto , Artroscopia/métodos , Artroscopia/reabilitação , Feminino , Seguimentos , Humanos , Instabilidade Articular/fisiopatologia , Instabilidade Articular/reabilitação , Masculino , Satisfação do Paciente , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Recidiva , Volta ao Esporte , Luxação do Ombro/fisiopatologia , Luxação do Ombro/reabilitação , Lesões do Ombro , Articulação do Ombro/fisiopatologia , Resultado do Tratamento , Adulto Jovem
12.
AJS ; 120(1): 187-225, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25705783

RESUMO

Social movements occupy a shared ideational and resource space, which is often referred to as the social movement sector. This article contributes to the understanding of the relational dynamics of the social movement sector by demonstrating how ideational linkages are formed through protest events. Using a data set of protest events occurring in the United States from 1960 to 1995, the authors model the mechanisms shaping why certain movement issues (e.g., women's and peace or environmental and gay rights) appear together at protest events. They argue that both cultural similarity and status differences between two social movement issues are the underlying mechanisms that shape joint protest and the resultant ideational linkages between issues. Finally, they show that the linking of issues at protest events results in changes in the prominence of a given issue in the social movement sector.


Assuntos
Cultura , Política , Opinião Pública , Mudança Social/história , História do Século XX , Modelos Psicológicos , Estados Unidos
13.
Lab Chip ; 13(23): 4653-62, 2013 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-24121997

RESUMO

A new sample-to-answer polymer lab-on-a-chip, which can perform immunoassay with minimum user intervention through on-chip reservoirs for reagents and single-channel assay system, has been designed, developed and successfully characterized as a point-of-care testing (POCT) cartridge for the detection of thyroid stimulating hormone (TSH). Test results were obtained within 30 minutes after a sample was dropped into the POCT cartridge. The analyzed results of TSH showed a linear range of up to 55 µIU mL(-1) with the limit of detection (LOD) of 1.9 µIU mL(-1) at the signal-to-noise ratio (SNR) of 3. The reagents stored in the on-chip reservoirs maintained more than 97% of their initial volume for 120 days of storage time while the detection antibody retained its activity above 98% for 120 days. The sample-to-answer polymer lab-on-a-chip developed in this work using the mass-producible and low-cost polymer is well suited for the point-of-care testing of rapid in vitro diagnostics (IVD) of TSH.


Assuntos
Imunoensaio/instrumentação , Imunoensaio/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Polímeros/química , Tireotropina/análise , Anticorpos/imunologia , Sistemas Automatizados de Assistência Junto ao Leito , Razão Sinal-Ruído , Tireotropina/imunologia
14.
Biomed Microdevices ; 15(2): 241-53, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23150205

RESUMO

A new micro blood sampling system has been designed, fabricated, and characterized to reduce iatrogenic blood loss from the catheterized neonates and pediatrics in intensive care unit by providing micro-volume of blood to analytical biomedical microdevices which can do point-of-care testing for their critical care. The system can not only save enormous iatrogenic blood loss through 1 to 10 µL of blood sampling and re-infusion of 1 to 5 mL of discard blood but also reduce the infection risk through the closed structure while satisfying the key criteria of the blood sampler. The sampled blood preserved its quality without rupturing of red blood cells verified by blood potassium concentrations of 3.86 ± 0.07 mM on the sampled blood which is similar to 3.81 ± 0.04 mM measured from the blood which did not go through the system. The sampling volume among the sampling channels showed consistency with the relative standard deviation of 1.41 %. In addition to the micro blood sampling capability, the sampling system showed negligible sample cross-contamination. The analyte-free samples collected after aspirating 7,500 times higher signal sample showed the same output signal as blank. The system was also demonstrated not to cause air-embolism by having no bubble generation during flushing procedure and the system was verified as leak-free since there was no fluid leakage under 30 times higher pressure than central venous pressure for 24 h.


Assuntos
Coleta de Amostras Sanguíneas/instrumentação , Cateteres Venosos Centrais , Unidades de Terapia Intensiva Neonatal , Unidades de Terapia Intensiva Pediátrica , Microfluídica/instrumentação , Manejo de Espécimes/instrumentação , Criança , Pré-Escolar , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Lactente , Recém-Nascido , Masculino
15.
Artigo em Inglês | MEDLINE | ID: mdl-19964635

RESUMO

An innovative sensing tube with an integrated piezoelectric flow sensor to measure flow rate in portal vein during liver transplantation has been developed and characterized in this work. This smart tube aims to measure flow rates in the portal vein in a real-time continuous format with high reliability. The PVDF-TrFE piezoelectric flow sensor integrated in a tube was able to measure flow rates with the sensitivity of 0.02 mVpp per 20 mL/min in the range of portal vein flow rate. It also showed excellent operational stability for 120 minutes with a standard deviation of 0.084 mVpp. The tube can be used as a clinical tool for assessing the need for portal vein inflow modification during liver transplantation.


Assuntos
Técnicas Biossensoriais , Campos Eletromagnéticos , Transplante de Fígado/instrumentação , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Velocidade do Fluxo Sanguíneo/fisiologia , Desenho de Equipamento , Polivinil/química , Veia Porta/fisiologia
16.
Lab Chip ; 9(20): 2941-6, 2009 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-19789747

RESUMO

In this work, a new method of rapidly fabricating thermopolymer and elastomer microfluidic channels has been developed and characterized for production of microfluidics with fixed aspect ratio and 3D tapered channels. A unique way to attain a desired channel depth by simply altering channel width is demonstrated. This rapid prototyping method is compatible with replication methods such as injection molding, hot embossing and elastomer casting and offers the ability to fabricate multiple channel depths (5 microm-1 mm) simultaneously in a single lithographic step. This method yields facile fabrication of 3-dimensionally tapered channels and polymer lab chips.


Assuntos
Técnicas Analíticas Microfluídicas/instrumentação , Microfluídica/métodos , Desenho de Equipamento , Técnicas Analíticas Microfluídicas/economia , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/economia , Microfluídica/instrumentação , Fatores de Tempo
17.
Lab Chip ; 9(14): 1988-90, 2009 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-19568663

RESUMO

A novel lab-on-a-tube integrated with spirally-rolled pressure, temperature, oxygen and glucose microsensors is described for multimodal neuromonitoring of patients with traumatic brain injury. In addition to measuring various crucial parameters in real-time continuous formats, the newly developed device also works as an intraventricular catheter to lower the elevated intracranial pressure by draining cerebrospinal fluid.


Assuntos
Lesões Encefálicas/diagnóstico , Lesões Encefálicas/fisiopatologia , Dispositivos Lab-On-A-Chip , Procedimentos Analíticos em Microchip/métodos , Técnicas Biossensoriais , Lesões Encefálicas/sangue , Lesões Encefálicas/líquido cefalorraquidiano , Humanos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Sensibilidade e Especificidade , Fatores de Tempo
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