scholarly journals Dispersive Raman spectroscopy for the invitroidentification and quantification of injected vancomycin intra-vitreous

2011 ◽  
Vol 25 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Roney Carlos Lora ◽  
Landulfo Silveira ◽  
Stella Regina Zamuner ◽  
Marcos Tadeu Tavares Pacheco
Keyword(s):  
Raman Spectroscopy ◽  
Latent Variable ◽  
Multivariate Calibration ◽  
Ccd Camera ◽  
Carbon Chain ◽  
Control Group ◽  
Calibration Model ◽  
Time Intervals ◽  
Imaging Spectrograph ◽  
Pls Method

This work presents a study which aimed to quantify the intravitreally-injected vancomycin antibiotic using dispersive Raman spectroscopy and Partial Least Squares multivariate calibration. Eyes of New Zealand rabbits were injected with 5.0 mg vancomycin at different time intervals (8, 24 and 48 h groups). Distilled water was injected into the eyes of rabbits in the control group. The vitreous was then removed from each eyeball, placed into a quartz cuvette and submitted for dispersive Raman spectroscopy. The Raman equipment used a laser (80 mW, 830 nm), an imaging spectrograph and a CCD camera with exposure time of 50 s. A calibration curve was developed using the PLS method with vancomycin diluted in water in the range of 1.0–8.0 mg/ml. The spectrum of vancomycin was present in bands at the positions of C=C, amide I, CH3, amide III and vibrations of the carbon chain (C–C, aromatic ring breathing and C–O–C). The spectra of the injected vitreous bodies showed weak bands which were correlated with the pure drug. The PLS calibration model had a standard error of prediction of 0.8 mg/ml using one latent variable. The PLS showed changes in the predicted concentrations of the injected vitreous bodies depending on the time of injection, with an amount near zero for the water-injected group and ranging between 2 and 3 mg/ml for the drug-injected groups. Raman spectroscopy could be employed in the quantitative evaluation of intravitreally-injected vancomycin in future invivoapplications.

scholarly journals Preliminary Assessment of Parmigiano Reggiano Authenticity by Handheld Raman Spectroscopy

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1563
Author(s):  
Mario Li Vigni ◽  
Caterina Durante ◽  
Sara Michelini ◽  
Marco Nocetti ◽  
Marina Cocchi
Keyword(s):  
Raman Spectroscopy ◽  
Near Infrared ◽  
Multivariate Calibration ◽  
Calibration Model ◽  
Preliminary Assessment ◽  
Model Based ◽  
Intact Sample ◽  
Non Destructive ◽  
Maximum Content ◽  
Parmigiano Reggiano

Raman spectroscopy, and handheld spectrometers in particular, are gaining increasing attention in food quality control as a fast, portable, non-destructive technique. Furthermore, this technology also allows for measuring the intact sample through the packaging and, with respect to near infrared spectroscopy, it is not affected by the water content of the samples. In this work, we evaluate the potential of the methodology to model, by multivariate data analysis, the authenticity of Parmigiano Reggiano cheese, which is one of the most well-known and appreciated hard cheeses worldwide, with protected denomination of origin (PDO). On the other hand, it is also highly subject to counterfeiting. In particular, it is critical to assess the authenticity of grated cheese, to which, under strictly specified conditions, the PDO is extended. To this aim, it would be highly valuable to develop an authenticity model based on a fast, non-destructive technique. In this work, we present preliminary results obtained by a handheld Raman spectrometer and class-modeling (Soft Independent Modeling of Class Analogy, SIMCA), which are extremely promising, showing sensitivity and specificity of 100% for the test set. Moreover, another salient issue, namely the percentage of rind in grated cheese, was addressed by developing a multivariate calibration model based on Raman spectra. It was possible to obtain a prediction error around 5%, with 18% being the maximum content allowed by the production protocol.

Importance of Prediction Outlier Diagnostics in Determining a Successful Inter-Vendor Multivariate Calibration Model Transfer

2007 ◽  
Vol 61 (7) ◽  
pp. 747-754 ◽  
Author(s):  
Robert D. Guenard ◽  
Christine M. Wehlburg ◽  
Randy J. Pell ◽  
David M. Haaland
Keyword(s):  
Least Squares ◽  
Outlier Detection ◽  
Prediction Error ◽  
Near Infrared ◽  
Multivariate Calibration ◽  
Subset Selection ◽  
Calibration Model ◽  
Calibration Transfer ◽  
Significant Difference ◽  
Pls Method

This paper reports on the transfer of calibration models between Fourier transform near-infrared (FT-NIR) instruments from four different manufacturers. The piecewise direct standardization (PDS) method is compared with the new hybrid calibration method known as prediction augmented classical least squares/partial least squares (PACLS/PLS). The success of a calibration transfer experiment is judged by prediction error and by the number of samples that are flagged as outliers that would not have been flagged as such if a complete recalibration were performed. Prediction results must be acceptable and the outlier diagnostics capabilities must be preserved for the transfer to be deemed successful. Previous studies have measured the success of a calibration transfer method by comparing only the prediction performance (e.g., the root mean square error of prediction, RMSEP). However, our study emphasizes the need to consider outlier detection performance as well. As our study illustrates, the RMSEP values for a calibration transfer can be within acceptable range; however, statistical analysis of the spectral residuals can show that differences in outlier performance can vary significantly between competing transfer methods. There was no statistically significant difference in the prediction error between the PDS and PACLS/PLS methods when the same subset sample selection method was used for both methods. However, the PACLS/PLS method was better at preserving the outlier detection capabilities and therefore was judged to have performed better than the PDS algorithm when transferring calibrations with the use of a subset of samples to define the transfer function. The method of sample subset selection was found to make a significant difference in the calibration transfer results using the PDS algorithm, while the transfer results were less sensitive to subset selection when the PACLS/PLS method was used.

Simple Multivariate Approach for the Monitoring of Vinylation Reactions Using FT-Raman Spectroscopy

2002 ◽  
Vol 56 (10) ◽  
pp. 1314-1319 ◽  
Author(s):  
Didier A. A. Hutsebaut ◽  
Carl Vercaemst ◽  
Chris Hugelier ◽  
Francis Verpoort
Keyword(s):  
Raman Spectroscopy ◽  
Multivariate Calibration ◽  
Structural Information ◽  
Analytical Techniques ◽  
Production Costs ◽  
Calibration Model ◽  
Multivariate Approach ◽  
Ft Raman Spectroscopy ◽  
Sample Position ◽  
Leave One Out

Catalysts are major partners in industrial reactions. They arrange a higher selectivity, higher specificity, and lower production costs. The development of catalysts is therefore of major importance but the characterization is often time consuming since several analytical techniques are needed to obtain an insight into the process. This paper describes a simple multivariate approach for the acquisition of kinetic data resulting in a decrease of noise in the calibration using FT-NIR Raman spectroscopy. The latter has great potential to replace the classical analytical techniques since they may offer the catalyst-developing scientist a large variety of kinetic and structural information in a simple way. This paper reports on the application of multivariate calibration to extracting kinetic information out of the Raman spectra. Based on an experimental design, a calibration model has been calculated for the monitoring of a vinylation reaction. Due to appropriate data preprocessing, changes in sample position, variations in temperature, and laser fluctuations were corrected. The calculated calibration model was validated using leave-one-out cross validation and resulted in an RMSECV value of 0.013838 M. Based on the calibration model, the conversion for the vinylation was calculated and reported in this work.

scholarly journals Constrained regularization for noninvasive glucose sensing using Raman spectroscopy

2015 ◽  
Vol 08 (04) ◽  
pp. 1550022 ◽  
Author(s):  
Wei-Chuan Shih
Keyword(s):  
Raman Spectroscopy ◽  
Multivariate Calibration ◽  
Experimental Studies ◽  
Principal Component Regression ◽  
Principal Component ◽  
Glucose Sensing ◽  
Model Complexity ◽  
Calibration Model ◽  
Noise Rejection ◽  
Implicit Model

Multivariate calibration is an important tool for spectroscopic measurement of analyte concentrations. We present a detailed study of a hybrid multivariate calibration technique, constrained regularization (CR), and demonstrate its utility in noninvasive glucose sensing using Raman spectroscopy. Similar to partial least squares (PLS) and principal component regression (PCR), CR builds an implicit model and requires knowledge only of the concentrations of the analyte of interest. Calibration is treated as an inverse problem in which an optimal balance between model complexity and noise rejection is achieved. Prior information is included in the form of a spectroscopic constraint that can be obtained conveniently. When used with an appropriate constraint, CR provides a better calibration model compared to PLS in both numerical and experimental studies.

scholarly journals Early impact of the COVID-19 pandemic and social restrictions on ambulance missions

2021 ◽  
Author(s):  
Lauri Laukkanen ◽  
Sanna Lahtinen ◽  
Janne Liisanantti ◽  
Timo Kaakinen ◽  
Ari Ehrola ◽  
...  
Keyword(s):  
Early Phase ◽  
Health Care Services ◽  
Mental Health Problems ◽  
Significant Decline ◽  
Control Group ◽  
Study Group ◽  
Time Intervals ◽  
Care Services ◽  
Group A ◽  
New Strategies

Abstract Background The SARS-CoV-2 coronavirus disease (COVID-19) has had a major impact on health care services globally. Recent studies report that emergency departments have experienced a significant decline in the number of admitted patients in the early phase of the pandemic. To date, research regarding the influence of COVID-19 on emergency medical services (EMS) is limited. The present study investigates a change in the number and characteristics of EMS missions in the early phase of the pandemic. Methods All EMS missions in the Northern Ostrobothnia region, Finland (population 295 500) between 1 March to 30 June 2020 were screened and analyzed as the study group. A control group was composed from the EMS calls between the corresponding months in the years 2016–2019. Results A total of 74 576 EMS missions were screened for the study. Within the first two months after the first COVID-19 cases in the study area, the decline in the number of EMS missions was 5.7% – 13% compared to the control group average. EMS time intervals (emergency call to dispatch, dispatch, en-route, on-scene and hospital handover) prolonged in the COVID-19 period. Dispatches concerning mental health problems increased most in the study period (+1.2%, p < 0.001). Only eleven confirmed COVID-19 infections were encountered by EMS in the study period. Conclusion Our findings suggest that the present COVID-19 pandemic and social restrictions lead to changes in the EMS usage. These preliminary findings emphasize the importance of developing new strategies and protocols in response to the oncoming pandemic waves.

scholarly journals Calcitonin Gene-Related Peptide Influences Bone-Tendon Interface Healing Through Osteogenesis: Investigation in a Rabbit Partial Patellectomy Model

2021 ◽  
Vol 9 (7) ◽  
pp. 232596712110039
Author(s):  
Huabin Chen ◽  
Hongbin Lu ◽  
Jianjun Huang ◽  
Zhanwen Wang ◽  
Yang Chen ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bone Mineral ◽  
Calcitonin Gene Related Peptide ◽  
Control Group ◽  
Mineral Density ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Partial Patellectomy ◽  
Antagonist Group ◽  
Cgrp Antagonist

Background: Calcitonin gene-related peptide (CGRP), which has been shown to play an important role in osteogenesis during fracture repair, is also widely distributed throughout the tendon and ligament. Few studies have focused on the role of CGRP in repair of the bone-tendon interface (BTI). Purpose: To explore the effect of CGRP expression on BTI healing in a rabbit partial patellectomy model. Study Design: Controlled laboratory study. Methods: A total of 60 mature rabbits were subjected to a partial patellectomy and then randomly assigned to CGRP, CGRP-antagonist, and control groups. In the CGRP-antagonist group, the CGRP receptor antagonist BIBN4096BS was administered to block CGRP receptors. The patella–patellar tendon complex was harvested at 8 and 16 weeks postoperatively and subjected to radiographic, microlaser Raman spectroscopy, histologic, and biomechanical evaluation. Results: Radiographic data showed that local CGRP expression improved the growth parameters of newly formed bone, including area and volumetric bone mineral density ( P < .05 for both). Raman spectroscopy revealed that the relative bone mineral composition increased in the CGRP group compared with in the control group and the CGRP-antagonist group ( P < .05 for both). Histologic testing revealed that the CGRP group demonstrated better integration, characterized by well-developed trabecular bone expansion from the residual patella and marrow cavity formation, at the 8- and 16-week time points. Mechanical testing demonstrated that the failure load, ultimate strength, and stiffness in the CGRP group were significantly higher than those in the control group ( P < .05 for all), whereas these parameters in the CGRP-antagonist group were significantly lower compared with those in the control group at 16 weeks after surgery ( P < .05 for all). Conclusion: Increasing the local concentration of CGRP in the early stages of BTI healing enhanced osteogenesis in a rabbit partial patellectomy model and promoted healing of the BTI injury, whereas treatment using a CGRP antagonist had the opposite effect. However, exogenous CGRP expression did not induce novel bone remolding. Clinical Relevance: CGRP may have potential as a new therapy for BTI injuries or may be added to postoperative regimens to facilitate healing.

Quantitative prediction of a functional ingredient in apple using Raman spectroscopy and multivariate calibration analysis

2021 ◽  
Vol 127 (6) ◽  
Author(s):  
Shinsaku Tsuyama ◽  
Akinori Taketani ◽  
Takeharu Murakami ◽  
Michio Sakashita ◽  
Saki Miyajima ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Multivariate Calibration ◽  
Quantitative Prediction ◽  
Functional Ingredient

scholarly journals Influence of Different Conditioning Treatments on The Bond Integrity of Root Dentin to rGO Infiltrated Dentin Adhesive. SEM, EDX, FTIR and MicroRaman Study

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1555
Author(s):  
Firas Alqarawi ◽  
Mazen Alkahtany ◽  
Khalid Almadi ◽  
Afnan Gassem ◽  
Faris Alshahrani ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bond Strength ◽  
Strength Test ◽  
Control Group ◽  
Micro Raman Spectroscopy ◽  
Fiber Posts ◽  
Root Canal Disinfection ◽  
Reduced Graphene ◽  
Root Dentin ◽  
Push Out

The present study aimed to synthesize and equate the mechanical properties and dentin interaction of two adhesives; experimental adhesive (EA) and 5 wt.% reduced graphene oxide rGO) containing adhesive. Scanning electron microscopy (SEM)-Energy-dispersive X-ray spectroscopy (EDX), Micro-Raman spectroscopy, push-out bond strength test, and Fourier Transform Infrared (FTIR) spectroscopy were employed to study nano-bond strength, degree of conversion (DC), and adhesive-dentin interaction. The EA was prepared, and rGO particles were added to produce two adhesive groups, EA-rGO-0% (control) and rGO-5%. The canals of sixty roots were shaped and prepared, and fiber posts were cemented. The specimens were further alienated into groups based on the root canal disinfection technique, including 2.5% sodium hypochlorite (NaOCl), Photodynamic therapy (PDT), and ER-CR-YSGG laser (ECYL). The rGO nanoparticles were flake-shaped, and EDX confirmed the presence of carbon (C). Micro-Raman spectroscopy revealed distinct peaks for graphene. Push-out bond strength test demonstrated highest values for the EA-rGO-0% group after NaOCl and PDT conditioning whereas, rGO-5% showed higher values after ECYL conditioning. EA-rGO-0% presented greater DC than rGO-5% adhesive. The rGO-5% adhesive demonstrated comparable push-out bond strength and rheological properties to the controls. The rGO-5% demonstrated acceptable DC (although lower than control group), appropriate dentin interaction, and resin tag establishment.

A prospective randomized study to assess the efficacy of post-operative nasal medication after endonasal surgery

1995 ◽  
Vol 109 (7) ◽  
pp. 618-621 ◽  
Author(s):  
Paul D. R. Spraggs ◽  
Marcelle Macnamara ◽  
Theo Joseph
Keyword(s):  
Randomized Study ◽  
Correlation Coefficients ◽  
Control Group ◽  
Time Intervals ◽  
Treatment Groups ◽  
Ephedrine Hydrochloride ◽  
Patent Airway ◽  
Significant Difference ◽  
Blood Clots ◽  
Betamethasone Sodium Phosphate

AbstractPost-operative nasal medications are commonly used following routine septal or turbinate surgery but their efficacy in removing blood clots, improving the sensation of a patent airway and promoting healing are unknown. This prospective randomized trial of patients undergoing septal and/or turbinate surgery assessed the efficacy of three commonly used nasal medicines, 0.5 per cent ephedrine hydrochloride nasal drops, betamethasone sodium phosphate (Betnosol®) nose drops and alkaline nasal douches, in producing the sensation of a patent airway in the 14 days following surgery. Ninety-seven patients were randomized into the three treatment groups and a control group who received no nasal medication. Patients assessed their nasal patency by means of a visual analogue scale (VAS) and any complications of treatment were recorded. Statistical analysis of the 76 complete sets of results using the Mann-Whitney U-test showed that there was a significant difference in the distribution of all of the treatments for each of the time intervals (p<0.05). Glass rank biserial correlation coefficients were all small (rg<0.085) but the most significant differences were between ephedrine and the control group at two hours, two, seven and 10 days (0.02, 0.054, 0.057, 0.085 respectively), alkaline nasal douches being most significant at four and 14 days (0.06 and 0.0722 respectively).

scholarly journals Association Between Osteoarticular Scores and Acute Phase Reactant Levels in Rheumatoid Arthritis

2009 ◽  
Vol 28 (2) ◽  
pp. 116-121 ◽  
Author(s):  
Irena Kafeđiska ◽  
Dejan Spasovski ◽  
Todor Gruev ◽  
Mane Grličkov ◽  
Kočo Cakalaroski ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Acute Phase ◽  
Acute Phase Reactant ◽  
Control Group ◽  
Time Intervals ◽  
Acute Phase Reactants ◽  
Mean Values ◽  
Cell Counts ◽  
Phase Reactant ◽  
The Mean

Association Between Osteoarticular Scores and Acute Phase Reactant Levels in Rheumatoid Arthritis The aim of this prospective control study was a quantitative evaluation of the activity of rheumatoid arthritis (RA) in certain time intervals, using articular indexes (set of 28 sensitive and 28 swollen joints), laboratory parameters (Hb, Hct, Er, Le and Plt) and acute phase reactants (ESR, RF, CRP); to determine which of the acute phase reactants is the most useful biochemical marker for the evaluation of disease activity in RA; to quantify the therapeutical and laboratory differences in certain time intervals in the group with and without immunomodulatory therapy with Methotrexate. Sixty patients with RA were included, 27 of who were treated with non-steroid antiinflammatory drugs (NSAIDs) and Methotrexate (MTX). The control group consisted of 33 patients treated only with NSAIDs because of irregular controls. In the first group of patients the disease activity was estimated at four time intervals, and in the control group of patients at three time intervals following the scores of the articular indexes, blood cell counts, ESR and CRP in every patient. In the first group of patients decreased activity of RA was found upon every following control with a consecutive decrease in mean values of the scores of articular indexes with statistically significant differences at the four time intervals. Considering laboratory parameters, there were statistically significant differences in the mean values of Hb, Er, Plt, ESR, (p=0.0462, p=0.0076, p= 0.0058, p= 0.0003). Mean values of CRP did not show statistically significant differences, but the number of patients who were CRP negative increased (there were great standard deviations). In the group of patients treated only with NSAIDs, there were statistically significant differences in the mean values of the scores of articular indexes with an increse at every following control (in favour of progression of the disease). There were no statistically significant differences considering blood cell counts, ESR and CRP (in favour of permanently active disease). In conclusion, CRP is the most useful marker for the prospective follow-up of patients with RA.

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