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1.
J Imaging Inform Med ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491236

RESUMO

In this article, we propose an AI-based low-risk visualization framework for lung health monitoring using low-resolution ultra-low-dose CT (LR-ULDCT). We present a novel deep cascade processing workflow to achieve diagnostic visualization on LR-ULDCT (<0.3 mSv) at par high-resolution CT (HRCT) of 100 mSV radiation technology. To this end, we build a low-risk and affordable deep cascade network comprising three sequential deep processes: restoration, super-resolution (SR), and segmentation. Given degraded LR-ULDCT, the first novel network unsupervisedly learns restoration function from augmenting patch-based dictionaries and residuals. The restored version is then super-resolved (SR) for target (sensor) resolution. Here, we combine perceptual and adversarial losses in novel GAN to establish the closeness between probability distributions of generated SR-ULDCT and restored LR-ULDCT. Thus SR-ULDCT is presented to the segmentation network that first separates the chest portion from SR-ULDCT followed by lobe-wise colorization. Finally, we extract five lobes to account for the presence of ground glass opacity (GGO) in the lung. Hence, our AI-based system provides low-risk visualization of input degraded LR-ULDCT to various stages, i.e., restored LR-ULDCT, restored SR-ULDCT, and segmented SR-ULDCT, and achieves diagnostic power of HRCT. We perform case studies by experimenting on real datasets of COVID-19, pneumonia, and pulmonary edema/congestion while comparing our results with state-of-the-art. Ablation experiments are conducted for better visualizing different operating pipelines. Finally, we present a verification report by fourteen (14) experienced radiologists and pulmonologists.

2.
J Chromatogr B Analyt Technol Biomed Life Sci ; 852(1-2): 374-81, 2007 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-17324642

RESUMO

A high throughput and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of bisoprolol in human plasma using multiplexing technique (two HPLC units connected to one MS). Bisoprolol was extracted from human plasma using solid-phase extraction technique using metoprolol as internal standard. A Betabasic 8 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion-pair was followed as m/z 326.2-->116.1 for bisoprolol and m/z 268.2-->191.0 for metoprolol. The method involves a simple multiplexing, rapid solid-phase extraction, simple isocratic chromatography conditions and mass spectrometric detection which enable detection at sub-nanogram levels. The proposed method has been validated for a linear range of 0.5-70.0 ng/mL with correlation coefficient > or =0.9991. The precision and accuracy were within 10% for intra-HPLC runs and inter-HPLC runs. The overall recoveries for bisoprolol and metoprolol were 93.89% and 77.65%, respectively. Total MS run time was 0.90 min only. The developed method was applied for the determination of pharmacokinetic parameters of bisoprolol following a single oral administration of a 10mg bisoprolol tablet in 18 healthy male volunteers.


Assuntos
Antagonistas Adrenérgicos beta/sangue , Bisoprolol/sangue , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Humanos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
3.
J Chromatogr B Analyt Technol Biomed Life Sci ; 852(1-2): 115-21, 2007 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-17296337

RESUMO

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of rivastigmine in human plasma. Rivastigmine was extracted from human plasma by using solid-phase extraction technique. Zolpidem was used as the internal standard. A Betabasic-8 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion-pair was followed as m/z 251.20-->206.10, 86.20 for rivastigmine and m/z 308.10-->235.10 for zolpidem. The method involves a rapid solid-phase extraction from plasma, simple isocratic chromatographic conditions and mass spectrometric detection that enables detection at sub-nanogram levels. The proposed method has been validated for a linear range of 0.2-20.0 ng/ml with a correlation coefficient > or =0.9988. The intra-run and inter-run precision and accuracy were within 10.0%. The overall recoveries for rivastigmine and zolpidem were 86.28% and 87.57%, respectively. The total run time was 2.0 min. The developed method was applied for the determination of the pharmacokinetic parameters of rivastigmine following a single oral administration of a 3 mg rivastigmine capsule in 20 healthy male volunteers.


Assuntos
Inibidores da Colinesterase/sangue , Fenilcarbamatos/sangue , Espectrometria de Massas em Tandem/métodos , Administração Oral , Inibidores da Colinesterase/farmacocinética , Humanos , Masculino , Fenilcarbamatos/farmacocinética , Padrões de Referência , Reprodutibilidade dos Testes , Rivastigmina , Sensibilidade e Especificidade
4.
J Chromatogr Sci ; 45(2): 91-6, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17425138

RESUMO

A new, rapid, and sensitive liquid chromatography-tandem mass spectrometry method is developed and validated to quantitate the sibutramine active metabolites mono desmethyl sibutramine (M1) and di-desmethyl sibutramine (M2) using imipramine as the internal standard in human plasma samples for routine bioequivalence studies. The method involves rapid solid-phase extraction from plasma, eliminating the drying and reconstitution steps. The analytes are chromatographed on a C8 reversed-phase chromatographic column and analyzed by mass spectrometry in the multiple reaction monitoring mode, which enables a quantitation limit at the sub-nanogram level. The method has a chromatographic run time of 2.8 min. The proposed method is validated with a linear range of 0.1-8.0 and 0.2-16.0 ng/mL for M1 and M2, respectively, with a correlation coefficient of regression > or = 0.9990. The method is sensitive and reproducible, having intra- and inter-assay precision at the lower limit of quantitation (0.1 ng/mL for M1 and 0.2 ng/mL for M2) < 10.0%. The overall recovery for M1 and M2 is 93.5% and 77.9%, respectively. The method has been applied to a bioequivalence clinical study with great success.


Assuntos
Fármacos Antiobesidade/sangue , Cromatografia Líquida/métodos , Ciclobutanos/sangue , Espectrometria de Massas em Tandem/métodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
J Pharm Biomed Anal ; 40(5): 1202-8, 2006 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-16289706

RESUMO

A rapid and robust liquid chromatography-mass spectrometry (LC-MS/MS) method was developed for non-ergoline dopamine D(2)-receptor agonist, ropinirole in human plasma using Es-citalopram oxalate as an internal standard. The method involves solid phase extraction from plasma, reversed-phase simple isocratic chromatographic conditions and mass spectrometric detection that enables a detection limit at picogram levels. The proposed method was validated with linear range of 20-1,200 pg/ml. The extraction recoveries for ropinirole and internal standard were 90.45 and 65.42%, respectively. The R.S.D.% of intra-day and inter-day assay was lower than 15%. For its sensitivity and reliability, the proposed method is particularly suitable for pharmacokinetic studies.


Assuntos
Agonistas de Dopamina/sangue , Indóis/sangue , Calibragem , Cromatografia Líquida , Citalopram/sangue , Citalopram/química , Agonistas de Dopamina/química , Humanos , Indicadores e Reagentes , Indóis/química , Espectrometria de Massas , Controle de Qualidade , Padrões de Referência , Reprodutibilidade dos Testes , Inibidores Seletivos de Recaptação de Serotonina/sangue , Inibidores Seletivos de Recaptação de Serotonina/química , Soluções
6.
J Chromatogr B Analyt Technol Biomed Life Sci ; 829(1-2): 75-81, 2005 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-16249126

RESUMO

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for simultaneous quantification of venlafaxine (VEN) and O-desmethyl venlafaxine (ODV) in human plasma. The analytes were extracted from human plasma by using solid-phase extraction (SPE) technique. Escitalopram (ESC) was used as the internal standard. A Betasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion-pair has been followed as m/z 278.27-->121.11 for VEN, m/z 264.28-->107.10 for ODV and m/z 325.00-->262.00 for ESC. The method involves a solid phase extraction from plasma, simple isocratic chromatography conditions and mass spectrometric detection that enables detection at nanogram levels. The proposed method has been validated with linear range of 3-300 ng/ml for VEN and 6-600 ng/ml for ODV. The intrarun and interrun precision and accuracy values are within 10%. The overall recoveries for VEN and ODV were 95.9 and 81.7%, respectively. Total elution time as low as 3 min only.


Assuntos
Antidepressivos de Segunda Geração/sangue , Cromatografia Líquida/métodos , Cicloexanóis/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos , Citalopram/sangue , Succinato de Desvenlafaxina , Humanos , Padrões de Referência , Cloridrato de Venlafaxina
7.
ISA Trans ; 54: 156-68, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25441219

RESUMO

PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported.

8.
AAPS J ; 16(6): 1167-74, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25135836

RESUMO

The A7 harmonization team (A7 HT), a part of the Global Bioanalysis Consortium (GBC), focused on reviewing best practices for repeat analysis and incurred sample reanalysis (ISR) as applied during regulated bioanalysis. With international representation from Europe, Latin America, North America, and the Asia Pacific region, the team first collated common practices and guidance recommendations and assessed their suitability from both a scientific and logistical perspective. Subsequently, team members developed best practice recommendations and refined them through discussions and presentations with industry experts at scientific meetings. This review summarizes the team findings and best practice recommendations. The few topics where no consensus could be reached are also discussed. The A7 HT recommendations, together with those from the other GBC teams, provide the basis for future international harmonization of regulated bioanalytical practices.


Assuntos
Técnicas de Química Analítica/métodos , Técnicas de Química Analítica/normas , Guias de Prática Clínica como Assunto , Estudos de Validação como Assunto , Técnicas de Química Analítica/instrumentação , Comportamento Cooperativo , Cooperação Internacional
9.
Biomed Chromatogr ; 21(2): 169-75, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17221911

RESUMO

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of amlodipine in human plasma. Amlodipine was extracted from human plasma by using a solid-phase extraction technique. Imipramine was used as the internal standard. A Hypersil BDS C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves a rapid solid-phase extraction from plasma, simple isocratic chromatography conditions and mass spectrometric detection that enables detection at sub-nanogram levels. The proposed method has been validated for a linear range of 0.1-10.0 ng/mL with correlation coefficient >or=0.9990. The intrarun and interrun precision and accuracy were within 10.0%. The overall recovery for amlodipine was 63.67%. Total run time was 3.2 min only.


Assuntos
Anlodipino/sangue , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Estabilidade de Medicamentos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/métodos
10.
Rapid Commun Mass Spectrom ; 20(14): 2109-14, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16775814

RESUMO

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed and validated for simultaneous quantification of risperidone (RSP) and its active metabolite 9-hydroxyrisperidone (9-OH-RSP) in human plasma. The analytes were extracted from human plasma by using the protein precipitation extraction technique. Methyl risperidone was used as internal standard for RSP and 9-OH-RSP. A Betasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion-pair was followed as m/z 411.28 --> 191.15 for RSP and m/z 427.30 --> 207.10 for 9-OH-RSP. The method involves a simple extraction, isocratic chromatography conditions and mass spectrometric detection that enable detection at sub-nanogram levels. The proposed method has been validated with a linear range of 0.10-15.0 ng/mL for RSP and 9-OH-RSP. The intrarun and interrun precision and accuracy values were within 15%. The overall recoveries for RSP and 9-OH-RSP were 82.1% and 83.2%, respectively. The total analysis time was as low as 3.0 min only. The developed method was applied for the determination of the pharmacokinetic parameters of RSP and 9-OH-RSP following a single oral administration of a 1 mg RSP tablet in 24 healthy male volunteers.


Assuntos
Antipsicóticos/sangue , Cromatografia Líquida de Alta Pressão/métodos , Isoxazóis/sangue , Pirimidinas/sangue , Risperidona/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Administração Oral , Cromatografia Líquida de Alta Pressão/instrumentação , Humanos , Masculino , Microquímica/métodos , Palmitato de Paliperidona , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Espectrometria de Massas em Tandem/instrumentação
11.
Biomed Chromatogr ; 20(8): 736-42, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16240286

RESUMO

A simple and robust method for quantification of zolpidem in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS). Es-citalopram was used as an internal standard. Zolpidem and internal standard in plasma sample were extracted using solid-phase extraction cartridges (Oasis HLB, 1 cm3/30 mg). The samples were injected into a C8 reversed-phase column and the mobile phase used was acetonitrile-ammonium acetate (pH 4.6; 10 mm) (80:20, v/v) at a flow rate of 0.7 mL/min. Using MS/MS in the selected reaction-monitoring (SRM) mode, zolpidem and Es-citalopram were detected without any interference from human plasma matrix. Zolpidem produced a protonated precursor ion ([M+H]+) at m/z 308.1 and a corresponding product ion at m/z 235.1. The internal standard produced a protonated precursor ion ([M+H]+) at m/z 325.1 and a corresponding product ion at m/z 262.1. Detection of zolpidem in human plasma by the LC-ESI MS/MS method was accurate and precise with a quantification limit of 2.5 ng/mL. The proposed method was validated in the linear range 2.5-300 ng/mL. Reproducibility, recovery and stability of the method were evaluated. The method has been successfully applied to bioequivalence studies of zolpidem.


Assuntos
Cromatografia Líquida/métodos , Piridinas/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos , Estabilidade de Medicamentos , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Zolpidem
12.
Biomed Chromatogr ; 20(9): 864-9, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16425345

RESUMO

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of nicorandil in human plasma. Nicorandil was extracted from human plasma using solid-phase extraction technique. Imipramine was used as the internal standard. A Betasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves a rapid solid-phase extraction from plasma, simple isocratic chromatography conditions and mass spectrometric detection that enables detection at nanogram levels. The proposed method has been validated for a linear range of 1.0-500.0 ng/mL with a correlation coefficient of > or =0.9993. The intra-run and inter-run precision and accuracy was within 10.0%. The overall recovery for nicorandil was 63.81%. The total run time was just 3.0 min.


Assuntos
Nicorandil/sangue , Vasodilatadores/sangue , Humanos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray
13.
Rapid Commun Mass Spectrom ; 20(19): 2921-31, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16941726

RESUMO

A rapid and sensitive liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method for the determination of isosorbide-5-mononitrate (5-ISMN), used in the treatment of angina pectoris, in human plasma is described. The quantification of 5-ISMN was performed via stable acetate adduct formation with a high relative abundance. The plasma filtrate obtained after solid-phase extraction (SPE), using a polymer based, hydrophilic-lipophilic balanced (HLB) cartridge, was submitted directly to reversed-phase high-performance liquid chromatography separation followed by ESI and detection of the resulting ions using triple-quadrupole mass spectrometry in selected reaction monitoring (SRM) mode. There was no significant matrix effect on the analysis. For validation of the method, the recovery of the free analyte response was compared to that obtained from an optimized extraction method. The analyte stability was examined under conditions mimicking the sample storage, handling, and analytical procedures. The extraction procedure yielded extremely clean extracts with a recovery of 95.51% and 93.98% for iossorbide-5-mononitrate and topiramate (internal standard (IS)), respectively. The calibration curves were linear for the dynamic range of 10.0 to 1000.0 ng/mL with a correlation coefficient r > or = 0.9985. The intra-assay and inter-assay precision for the samples at the lower limit of quantification (LLOQ) were 9.02 and 13.30%, respectively. The intra-assay accuracies at LLOQ, LQC, MQC and HQC levels varied from 98.13 to 118.15, 102.34 to 105.21, 100.69 to 109.68, and 95.76 to 102.92%, respectively, while the inter-assay accuracies ranged from 93.10 to 118.15, 93.03 to 107.04, 86.97 to 109.68 and 86.18 to 105.85%, respectively, at these levels. The method is rugged and fast with a total run time of 2 min. The method was successfully applied for a bioequivalence study in 24 human subject samples after oral administration of 60 mg extended release (ER) formulations.


Assuntos
Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada , Dinitrato de Isossorbida/análogos & derivados , Doadores de Óxido Nítrico/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos , Acetilação , Administração Oral , Humanos , Dinitrato de Isossorbida/sangue , Dinitrato de Isossorbida/química , Dinitrato de Isossorbida/farmacocinética , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/farmacocinética , Reprodutibilidade dos Testes , Extração em Fase Sólida , Equivalência Terapêutica
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