The aim of this study was to compare the degree of conversion and polymerization shrinkage of low and high viscosity bulk-fill giomer-based and resin-based composites. Two bulk-fill giomer (Beautifil Bulk Restorative (BBR), Beautifil Bulk Flowable (BBF)), two bulk-fill (Tetric N-Ceram Bulk-fill (TBF), SureFil SDR flow (SDR)) and two conventional resin composites (Tetric N-Ceram (TN), Tetric N-flow (TF)) were selected for this study. The degree of conversion was measured by using Fourier transform infrared spectroscopy. Polymerization shrinkage was measured with the linometer. For all depth, BBR had the lowest degree of conversion and SDR had the highest. At 4 mm, the degree of conversion of low and high viscosity bulk-fill giomer resin composites was lower than that of bulk-fill resin composites (p < 0.05). At the depth between 2 mm and 4 mm, there were significant difference with TBF, TN and TF (p < 0.05), while no significant difference in the degree of conversion was measured for BBR, BBF and SDR. Polymerization shrinkage of six resin composites decreased in the following order: TF > SDR > BBF > TBF > TN and BBR (p < 0.05). Polymerization shrinkage of bulk-fill giomer resin composites was lower than that of bulk-fill resin composites (p < 0.05). From this study, it is found that the bulk-fill giomer resin composites and TBF were not sufficiently cured in 4 mm depth. The degree of conversion of low and high viscosity bulk-fill giomer resin composites was significantly lower than bulk-fill resin composites in both 2 mm and 4 mm depths. Therefore, such features of bulk-fill giomer resin composites should be carefully considered in clinical application.
Polymerization ; Polymers ; Spectroscopy, Fourier Transform Infrared ; Viscosity

Breast cancer is the most common cancer in women. Later diagnosis of the disease is the leading cause of poor prognosis. Fourier-transform infrared (FTIR) spectroscopy is a novel approach to provide information about the molecular components and metabolic conditions of human tissue; therefore it can detect the early changes caused by cancer cells prior to histological manifestation. FTIR-based diagnosis is rapid, simple and label free, which meets the requirements of an automated and patient-friendly technique. The current article gives an overview of the experimental techniques, data analysis methods and spectral signatures of breast cancer in FTIR-based diagnosis, summarizes the present challenges by focusing on the history of FTIR spectroscopy in breast cancer since 1990s, and highlights some investigations that give a perspective of FTIR-based diagnosis.
Breast Neoplasms ; diagnosis ; Female ; Humans ; Spectroscopy, Fourier Transform Infrared

Common and variation peak rates were calculated as dual-index for drug samples based on the infrared spectrogram of Angelicae Pubescentis Radix samples from different places. The results indicated that the common peak rates of 4 samples from Sichuan province, 2 samples from Gansu province, and 2 samples from Hubei province were higher than 73% , 79. 5% and 76. 3%, respectively. Also, the variation peak rates of 2 samples from Gansu province were lower than 12. 9%. Therefore, there is similar germplasm resources and similar chemical composition in the samples originated from the same place. However, for the samples originated from different places, their germplasm resources and chemical composition maybe have been changed. Fourier transform infrared spectrometry could be used to evaluate the rule of the fingerprint and overview of Angelicae Pubescentis Radix originated from different places by its changes of germplasm resources and chemical composition.
Apiaceae ; chemistry ; Medicine, Chinese Traditional ; Spectroscopy, Fourier Transform Infrared ; methods

Carbon Monoxide ; analysis ; Spectroscopy, Fourier Transform Infrared ; methods

Objective To infer postmortem interval （PMI） based on spectral changes of the dorsal skin of rats within 15 days postmortem using Fourier transform infrared （FTIR） spectroscopy. Methods The rats were sacrificed by cervical dislocation after anesthesia, and then placed at 25 ℃ and relative humidity of 50%. The FTIR spectral data collected from the dorsal skin at PMI points were modeled with machine learning technique. Results There was no significant difference of absorption peak location among all the PMI groups but their peak intensities changed as a function of PMIs. The model for PMI estimation was constructed using partial least squares （PLS） regression, reaching a R² of 0.92 and a root mean square error （RMSE） of 1.30 d. As shown in variable importance for projection （VIP）, four spectral bands including 1 760-1 700 cm^-1, 1 660-1 640 cm^-1, 1 580-1 540 cm^-1 and 1 460-1 420 cm^-1 were determined as important contributions to model prediction. Conclusion Application of the FTIR technique to detect postmortem spectral changes of the rat skin provides a novel proposal for PMI estimation.
Animals ; Autopsy ; Postmortem Changes ; Rats ; Spectroscopy, Fourier Transform Infrared

PURPOSE: The aim of this Fourier transform infrared (FTIR) spectroscopic study was to measure the degree of conversion (DC) of dual-cured resin cements light-irradiated through zirconia ceramic disks with different thicknesses using various light-curing methods. MATERIALS AND METHODS: Zirconia ceramic disks (KT12) with three different thicknesses (1.0, 2.0, and 4.0 mm) were prepared. The light transmittance of the disks was measured using ultraviolet visible near-infrared spectroscopy. Four different light-curing protocols were used by combining two curing light modes (Elipar TriLight (standard mode) and bluephase G2 (high power mode)) with light-exposure times of 40 and 120 seconds. The DCs of the two dual-cured resin cements (Duo-Link and Panavia F2.0) light-irradiated through the disks was analyzed at three time intervals (3, 7, and 10 minutes) by FTIR spectroscopy. The data was analyzed using repeated measures ANOVA (alpha=.05).Two-way ANOVA and Tukey post hoc test were used to analyze the 10 minute DC results. RESULTS: The 1.0 mm thick disk exhibited low light transmittance (<25%), and the transmittance decreased considerably with increasing disk thickness. All groups exhibited significantly higher 10 minute DC values than the 3 or 7 minute values (P<.05), but some exceptions were observed in Duo-Link. Two-way ANOVA revealed that the influence of the zirconia disk thickness on the 10 minute DC was dependent on the light-curing methods (P<.001). This finding was still valid even at 4.0 mm thickness, where substantial light attenuation took place. CONCLUSION: The curing of the dual-cured resin cements was affected significantly by the light-curing technique, even though the additional chemical polymerization mechanism worked effectively.
Ceramics* ; Fourier Analysis ; Methods ; Polymerization ; Polymers ; Resin Cements* ; Spectroscopy, Fourier Transform Infrared ; Spectroscopy, Near-Infrared ; Spectrum Analysis ; Zirconium

OBJECTIVE: To observe the chemical groups changing in rat kidney with regard to fatal hyperthermia by Fourier transform infrared microspectroscopy (FTIR-MSP) and to provide a new method to diagnose fatal hyperthermia. METHODS: Rats were sacrificed by hyperthermia, brainstem injury, massive hemorrhage and asphyxiation and divided into groups. The renal samples were dissected immediately after death. The data of infrared spectroscopy in glomerulus were measured by FTIR-MSP. RESULTS: The absorbances of 3290, 3070, 2850, 1540 and 1396 cm(-1) significantly increased (P < 0.05), and the ratios of Al650/A3290 and A1650/A1540 significantly decreased (P < 0.05) in group of hyperthermia. CONCLUSION FTIR-MSP can analyze the changes of chemical groups of kidney as an auxiliary diagnosis for discriminating hyperthermia with other causes of death.
Animals ; Fever/mortality* ; Fourier Analysis ; Kidney/metabolism* ; Microspectrophotometry ; Rats ; Spectroscopy, Fourier Transform Infrared/methods*

In order to research the infrared radiation characteristics of the skin covering Traditional Chinese acupuncture points, which are NeiGuan in the forearm and LaoGong in the center of the palm, we detected continuously the infrared radiation spectra of the human body surface by using Fourier Transform Infrared Spectroscopy. The experimental results showed that firstly, the differences of the infrared radiation spectra of the human body surface were obvious between individuals. Secondly, the infrared radiation intensity of the human body surface changed with time changing. The infrared radiation intensity in two special wavelength ranges (wavelengths from 6. 79 microm to 6. 85 microm and from 13. 6 microm to 14. 0 microm) changed much more than that in other ranges obviously. Thirdly, the proportions of the infrared radiation spectra changed, which were calculated from the spectra of two different aupuncture points, were same in these two special wavelength ranges, but their magnitude changes were different. These results suggested that the infrared radiation of acupuncture points have the same biological basis, and the mechanism of the infrared radiation in these two special wavelength ranges is different from other tissue heat radiation.
Acupuncture Points ; Adult ; Female ; Humans ; Infrared Rays ; Male ; Skin ; radiation effects ; Spectroscopy, Fourier Transform Infrared

The near infrared (NIR) spectroscopy technique has been applied in many fields because of its advantages of simple preparation, fast response, and non-destructiveness. We investigated the potential of NIR spectroscopy in diffuse reflectance mode for determining the soluble solid content (SSC) and acidity (pH) of intact loquats. Two cultivars of loquats (Dahongpao and Jiajiaozhong) harvested from two orchards (Tangxi and Chun'an, Zhejiang, China) were used for the measurement of NIR spectra between 800 and 2500 nm. A total of 400 loquats (100 samples of each cultivar from each orchard) were used in this study. Relationships between NIR spectra and SSC and acidity of loquats were evaluated using partial least square (PLS) method. Spectra preprocessing options included the first and second derivatives, multiple scatter correction (MSC), and the standard normal variate (SNV). Three separate spectral windows identified as full NIR (800approximately2500 nm), short NIR (800approximately1100 nm), and long NIR (1100approximately2500 nm) were studied in factorial combination with the preprocessing options. The models gave relatively good predictions of the SSC of loquats, with root mean square error of prediction (RMSEP) values of 1.21, 1.00, 0.965, and 1.16 degrees Brix for Tangxi-Dahongpao, Tangxi-Jiajiaozhong, Chun'an-Dahongpao, and Chun'an-Jiajiaozhong, respectively. The acidity prediction was not satisfactory, with the RMSEP of 0.382, 0.194, 0.388, and 0.361 for the above four loquats, respectively. The results indicate that NIR diffuse reflectance spectroscopy can be used to predict the SSC and acidity of loquat fruit.
Eriobotrya ; chemistry ; Hydrogen-Ion Concentration ; Least-Squares Analysis ; Spectroscopy, Fourier Transform Infrared ; methods ; Spectroscopy, Near-Infrared ; methods

OBJECTIVES: This study was performed to investigate the effects of different intracanal medicaments on chemical structure and microhardness of dentin. MATERIALS AND METHODS: Fifty human dentin discs were obtained from intact third molars and randomly assigned into two control groups and three treatment groups. The first control group received no treatment. The second control group (no medicament group) was irrigated with sodium hypochlorite (NaOCl), stored in humid environment for four weeks and then irrigated with ethylenediaminetetraacetic acid (EDTA). The three treatment groups were irrigated with NaOCl, treated for four weeks with either 1 g/mL triple antibiotic paste (TAP), 1 mg/mL methylcellulose-based triple antibiotic paste (DTAP), or calcium hydroxide [Ca(OH)2] and finally irrigated with EDTA. After treatment, one half of each dentin disc was subjected to Vickers microhardness (n = 10 per group) and the other half was used to evaluate the chemical structure (phosphate/amide I ratio) of treated dentin utilizing attenuated total reflection Fourier transform infrared spectroscopy (n = 5 per group). One-way ANOVA followed by Fisher's least significant difference were used for statistical analyses. RESULTS: Dentin discs treated with different intracanal medicaments and those treated with NaOCl + EDTA showed significant reduction in microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.05) compared to no treatment control dentin. Furthermore, dentin discs treated with TAP had significantly lower microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.0001) compared to all other groups. CONCLUSIONS: The use of DTAP or Ca(OH)2 medicaments during endodontic regeneration may cause significantly less microhardness reduction and superficial demineralization of dentin compared to the use of TAP.
Calcium Hydroxide ; Dentin* ; Edetic Acid ; Humans ; Molar, Third ; Regeneration* ; Sodium Hypochlorite ; Spectroscopy, Fourier Transform Infrared