Fourier-transform infrared spectroscopy

傅里叶变换红外光谱
  • 文章类型: Journal Article
    葡萄酒香气是最常用和探索的质量指标之一。通常,它的评估包括评估葡萄酒的挥发性成分或训练有素的评估员进行感官分析。然而,当前的方法依赖于缓慢的,昂贵且复杂的分析程序。此外,感官评价本质上是主观的。因此,这项工作的目的是验证使用FTIR光谱作为一种快速简便的方法来早期检测葡萄酒中一些最常见的异味的可行性。FTIR光谱与偏最小二乘(PLS)回归相结合,用于同时测量异戊醇,异丁醇,1-己醇,丁酸,异丁酸,癸酸,乙酸乙酯,糠醛和丙酮。开发的校准模型(R2P>0.90,范围误差比>12.1和RPD>3.1)的精密度和准确性证明了所提出的方法定量上述化合物的能力。
    Wine aroma is one of the most frequently used and explored quality indicators. Typically, its assessment involves estimating the volatile composition of wine or highly trained assessors conducting sensory analysis. However, current methodologies rely on slow, expensive and complicated analytical procedures. Additionally, sensory evaluation is inherently subjective in nature. Therefore, the aim of this work is to verify the feasibility of using FTIR spectroscopy as a fast and easy methodology for the early detection of some of the most common off-odors in wines. FTIR spectroscopy was combined with partial least squares (PLS) regression for the simultaneous measurement of isoamyl alcohol, isobutanol, 1-hexanol, butyric acid, isobutyric acid, decanoic acid, ethyl acetate, furfural and acetoin. The precision and accuracy of developed calibration models (R2P > 0.90, range error ratio > 12.1 and RPD > 3.1) proved the ability of the proposed methodology to quantify the aforementioned compounds.
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  • 文章类型: Journal Article
    目的:本研究旨在使用FTIR光谱仪评估次氯酸钠在不同浓度和温度下对神经根牙本质显微硬度及其表面结构变化的综合影响。
    方法:清洁下颌前磨牙并将其成型为F3Protaper黄金旋转文件,之后,他们接受了五个实验条件-I组-中性盐水作为阴性对照,II组-3%NaOCl溶液,III组-5%NaOCl溶液,IV组-3%管内加热的NaOCl溶液,和V组-5%经管内加热的NaOCl溶液。在此之后,进行了距管腔100µm和300µm处的神经根牙本质的显微硬度和傅立叶变换红外(FTIR)光谱分析。
    结果:结果表明,肛门内加热的次氯酸钠组比未加热的对应物降低了300µm处的牙根牙本质显微硬度。在100µm的3%管内加热和室温次氯酸钠组之间没有观察到显微硬度值的差异。无论温度和浓度如何,在用次氯酸钠处理的所有组中都注意到酰胺/磷酸盐比率的降低。
    结论:因此,考虑到有或没有加热的根牙本质的物理和结构变化的变化水平是微不足道的,经肛门内加热的低浓度次氯酸钠溶液可用作高浓度次氯酸钠的替代品。
    结论:经肛门内加热的低浓度次氯酸钠使临床医生能够实现最大程度的消毒,同时保持牙本质的结构和物理性质与室温次氯酸钠相似。
    OBJECTIVE: This study is aimed to evaluate the combined effect of sodium hypochlorite at varied concentrations and temperatures on radicular dentin microhardness along with its surface structural changes using an FTIR spectrometer.
    METHODS: Mandibular premolars were cleaned and shaped up to F3 Protaper gold rotary files, after which they were subjected to five experimental conditions - group I - neutral saline as negative control, group II - 3% NaOCl solution, group III - 5% NaOCl solution, group IV - 3% intracanal-heated NaOCl solution, and group V - 5% intracanal-heated NaOCl solution. Following this, the microhardness of radicular dentin at 100 µm and 300 µm from the canal lumen and Fourier-transform infrared (FTIR) spectroscopic analysis were performed.
    RESULTS: The results showed that intracanal-heated sodium hypochlorite group reduced root dentin microhardness at 300 µm than its nonheated counterpart. No difference in microhardness values was observed between 3% intracanal-heated and room-temperature sodium hypochlorite groups at 100 µm. Reduction in amide/phosphate ratio was noted in all the groups treated with sodium hypochlorite irrespective of temperature and concentration.
    CONCLUSIONS: Thus, considering that the level of alteration in physical and structural changes of root dentin with or without heating is insignificant, intracanal-heated low-concentration sodium hypochlorite solutions could be used as an alternative to high-concentration sodium hypochlorite.
    CONCLUSIONS: Intracanal-heated low-concentration sodium hypochlorite enables the clinicians to achieve maximum disinfection while keeping the structural and physical properties of the dentin similar to room-temperature sodium hypochlorite.
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  • 文章类型: Journal Article
    Microplastics (MPs) are an emerging pollutant of concern in all known aquatic ecosystems. However, studies at a regional scale on MP pollution in freshwater systems and the necessary risk assessments are limited. Therefore, in this study, we examined microplastic concentrations, size distributions, and polymer types in surface waters and sediments in the geographic region Flanders (Belgium), as a case study for a densely populated region and one of the most developed parts of Europe. Samples have been taken on nine different locations, of which five were repeated in a different weather condition. In total 43 aqueous and nine sediment samples have been collected. The quantity and identity of the microplastics in the samples were determined with μFTIR spectroscopy in the range of 25-1000 μm. The MPs\' abundances in surface waters and sediments ranged from 0 to 4.8 MP L-1 (average = 0.48 MP L-1) and from 0 to 9558 MP kg-1 dry weight (average = 2774.57 ± 2317.93 MP kg-1 DW), respectively. Polystyrene and polypropylene were the most common polymer compositions found. No correlations were observed between microplastic concentrations in the sediment/the surface water samples and the measured environmental variables rainfall, conductivity, pH, dissolved oxygen content, waterway flow rate and width, and surrounding land use. Risk assessment results for the measured surface water concentrations through the risk quotient (RQ) method and the probabilistic risk assessment framework suggest that most of the sampled sites in Flanders posed negligible risks to freshwater biota, while this was not the case for some of the sediment concentrations. Our results illustrate the need to urgently develop analytical methods that can routinely measure the full size range of MP in environmental samples to adequately assess risks for the environment.
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  • 文章类型: Journal Article
    为了评价绿豆分离蛋白(MPI)稳定乳状液的冻融稳定性及其与蛋白质结构的关系,对8个绿豆品种的蛋白质进行了比较。结果表明,从所有八个品种制备的MPIs主要由五个亚基带组成,白蛋白和球蛋白含量范围为188.4-310.3和301.1-492.7mg/g总蛋白,分别。蛋白质结构分析表明,无规卷曲结构(32.34-33.51%)占MPI二级结构的30%以上。同时,蛋白质性质分析显示乳化活性指数(EAI),乳化稳定性指数(ESI)和柔韧性值范围为6.735-8.598m2/g,分别为20.13-34.25%和0.125-0.182。对MPI乳液的冻融稳定性的测量表明,乳液暴露于多个冻融循环会导致乳液乳化指数显着不同。涂油,各种乳液的粒度和ζ电位值。此外,所有八种蛋白质乳液的稳定性随着每个冻融循环而降低,用光学显微照片证明。采用相关分析方法研究了原始结构之间的相关性,蛋白质的乳化特性和MPI乳液的冻融稳定性。相关分析结果显示白蛋白含量之间存在显著关系,分子量为26.9kDa的亚基条带和乳化性能与MPI乳液的冻融稳定性显着相关。因此,通过确定这些指标值,我们可以预测MPI稳定乳液的冻融稳定性。
    In order to evaluate the freeze-thaw stability of mung bean protein isolate (MPI)-stabilized emulsions and its relationship with protein structure, proteins of eight mung bean varieties were compared. The results revealed that MPIs prepared from all eight varieties were mainly composed of five subunit bands, with albumin and globulin content ranges of 188.4-310.3 and 301.1-492.7 mg/g total protein, respectively. Protein structural analysis revealed that random coil structure (32.34-33.51%) accounted for greater than 30% of MPI secondary structure. Meanwhile, analysis of protein properties revealed emulsifying activity index (EAI), emulsifying stability index (ESI) and flexibility value ranges of 6.735-8.598 m2/g, 20.13-34.25% and 0.125-0.182, respectively. Measurements of freeze-thaw stability of MPI emulsions demonstrated that exposures of emulsions to multiple freeze-thaw cycles resulted in significantly different emulsion creaming index, oiling-off, particle size and zeta potential values for the various emulsions. Moreover, the stabilities of all eight protein emulsions decreased with each freeze-thaw cycle, as demonstrated using optical micrographs. The correlation analysis method was used to study the correlation between the original structures, emulsifying properties of proteins and the freeze-thaw stability of MPI emulsions. Correlation analysis results revealed significant relationships between albumin content, subunit bands with a molecular weight of 26.9 kDa and emulsifying properties were significantly related to the freeze-thaw stability of MPI emulsion. Thus, by determining these indicator values, we can predict the freeze-thaw stability of MPI-stabilized emulsions.
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  • 文章类型: Journal Article
    TrinakantamaniPishti(TMP)是一种强心剂(Hridya),厌食症(RaktaStambhaka),经常用于各种出血性疾病如腹泻(Raktatisaara)的收敛(Kashaya)制剂,Raktarsha(出血桩),和月经过多的疾病(Atyartava)。尽管如此,没有关于其表征的公开数据。
    使用复杂的仪器技术为原始和加工的TMP生成指纹,以评估TMP的抗微生物活性。
    使用标准参考方法制备TMP的三个样品。通过傅里叶变换红外光谱(FTIR)对TMP进行表征,能量色散X射线分析(EDEX)与扫描电子显微镜,粉末X射线衍射(XRD)。通过孔扩散法进行抗菌活性。
    通过扫描电子显微镜分析显示,原始样品和TMP中的最大粒径<5μm和<3μm,分别。TMP中的最小粒度为1至2μm和701nm。EDEX分析显示碳和氧是主要成分,而Na,Mg,Ca,Si,Fe,S存在于痕迹中。XRD图表明药物的无定形性质,而FTIR分析显示存在官能团如O-H,CO2,C=O,C-N,N-H.重金属,微生物总数,和微生物限度测试被发现在允许的限度内。抗微生物研究对测试病原体金黄色葡萄球菌,大肠杆菌,铜绿假单胞菌和鼠伤寒沙门氏菌未显示TMP的任何作用。
    EDEX研究的结果表明,Pishti样品具有较小的粒径,即比原始的701nm,即,1-2μm,这可能会使药物吸收到体内。样品中的所有重金属均在允许范围内。碳,氢和氧是药物的主要元素,这证实了与琥珀的相似性,由于目前的工作是首次发表的关于TMP的表征和抗微生物研究的文献,结果可以被认为是使用上述参考方法制备的药物的指纹。
    UNASSIGNED: Trinakantamani Pishti (TMP) is a cardio-tonic (Hridya), styptic (Rakta Stambhaka), astringent (Kashaya) formulation frequently used in varieties of bleeding disorders such as bloody diarrhea (Raktatisaara), Raktarsha (bleeding piles), and disorders of excessive menstruation (Atyartava). Still, no published data is available regarding its characterization.
    UNASSIGNED: To generate a fingerprint for raw and processed TMP using sophisticated instrumental techniques to assess antimicrobial activity of TMP.
    UNASSIGNED: Three samples of TMP were prepared using the standard reference method. Characterization of TMP was carried out by Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDEX) with scanning electron microscopy, powder X-ray diffraction (XRD). Antibacterial activity was carried out by the well-diffusion method.
    UNASSIGNED: Analysis by scanning electron microscope revealed maximum particle size <5 μm and <3 μm in the raw sample and TMP, respectively. Minimum particle size in TMP ranges from 1 to 2 μm and 701 nm. EDEX analysis shows carbon and oxygen as major constituents while Na, Mg, Ca, Si, Fe, and S were present in traces. XRD pattern indicates the amorphous nature of the drug, while FTIR analysis reveals the presence of functional groups such as O-H, CO2, C = O, C-N, N-H. Heavy metals, total microbial count, and microbial limit test were found to be under permissible limits. Anti-microbial study against tested pathogens Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium did not show any effect of TMP.
    UNASSIGNED: The results of EDEX study showed that Pishti samples have the small particle size i.e., 701nm than the raw i.e., 1-2 μm, which may facillitate absobtion of drug into the body. All heavy metals in the samples were within the permissible limit. Carbon, hydrogen and oxygen are the chief elements of drug which confirms similarity to the Amber, Since the present work is the first published literature on characterization and anti-microbial study on TMP, the outcome can be considered as fingerprint for the drug prepared using the mentioned reference method.
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  • 文章类型: Journal Article
    过度出血可使外科手术复杂化;这可以使用提供即时和早期出血控制的有效止血剂来管理。明胶海绵和金盏花已被证明具有良好的止血性能。本体外研究分析了明胶海绵和金盏花的细胞毒性和止血性能。通过MTT(3-[4,5-二甲基噻唑-2-基]-2,5二苯基四唑溴化物)测定法确定金盏花的细胞毒性浓度/有效浓度。使用垂直Franz扩散池装置确定药物释放;使用傅里叶变换红外光谱(FTIR)和差示扫描量热计(DSC)评估固态表征。MTT分析显示7%金盏花是细胞相容性的,细胞增殖增加。当将7%的金盏花装入海绵中时,它是兼容的,药物含量为56.28±13.84%。使用Lee-White方法测量血凝块形成所花费的时间。明胶海绵凝块形成时间为161.70±3.11s,金盏花负载明胶海绵的凝块形成时间为158.75±4.60s。因此,可以得出结论,当金盏花被掺入明胶海绵中时,它显示了材料相容性和细胞相容性,减少凝块形成的时间,并且可以用作其他止血剂的替代品。
    Excessive bleeding can complicate surgical intervention; this could be managed using an effective hemostatic agent that provides immediate and early bleeding control. Gelatin sponge and Calendula officinalis have been proven to have good hemostatic properties. The present In-vitro study analyzed the cytotoxicity and hemostatic properties of gelatin sponge and Calendula officinalis. The cytotoxic concentration/effective concentration of Calendula officinalis was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The drug release was determined using a vertical Franz diffusion cell apparatus; solid-state characterization was assessed using Fourier-transform infrared spectroscopy (FTIR) and a differential scanning calorimeter (DSC). The MTT assay showed 7% Calendula officinalis to be cytocompatible, and there was an increase in cell proliferation. When the 7% Calendula officinalis was loaded into the sponge, it was compatible, and the drug content was found to be 56.28 ± 13.84%. The time taken for the blood clot formation was measured using the Lee-White method. The gelatin sponge\'s time for clot formation was 161.70 ± 3.11 s, and the Calendula officinalis loaded gelatin sponge\'s time for clot formation was 158.75 ± 4.60 s. Hence, it could be concluded that when Calendula officinalis is incorporated into a gelatin sponge, it shows material compatibility and cytocompatibility, reduces the time for clot formation, and could be used as an alternative to other hemostatic agents.
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  • 文章类型: Journal Article
    UNASSIGNED: Lower degree of conversion (DC%) of monomer to polymer in a resin composite restoration could be a health hazard for the patient as well as it could affect the longevity of the restoration.
    UNASSIGNED: This study is aimed to compare and evaluate the DC% of four different composites polymerized using ultrafast photopolymerization.
    UNASSIGNED: In-vitro study.
    UNASSIGNED: A total of 40 disc-shaped composite samples were used in the study. Twenty samples were prepared for each group using 2 mm height and 6 mm diameter Tygon tube as a matrix. All of the composites were cured using the Woodpecker i Led light-curing unit with an intensity of 2300-2500 mW/cm2 (TURBO mode). Samples in Group 1 were cured for 1 s and samples in Group 2 were cured for 3 s. Each group had 4 subgroups of five samples of the 4 resin composites tested. After photo-activation, the specimens were stored under dark dry conditions at room temperature for 24 h before testing. The DC% was measured using Fourier-transform infrared spectroscopy.
    UNASSIGNED: The DC% were analyzed using ANOVA, and Tukey HSD post hoc test using IBM SPSS 21 software.
    UNASSIGNED: Among the experimental groups, Group 2 showed a higher DC% which ranges from 93.7% to 95.4% than Group 1 which ranges from 58.5% to 65.5%. There was a statistically significant difference in the DC% among the materials tested (P < 0.05).
    UNASSIGNED: Within the limitations of the study, it was concluded that composites cured for 3 s showed a higher DC% which ranges from 93.7% to 95.4% than those cured for 1 s. The DC% also varied among the four different composites tested.
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  • 文章类型: Journal Article
    The development of crop varieties that are resistant to lodging is a top priority for breeding programmes. Herein, we characterize the rye mutant ´Stabilstroh\' (\'stable straw\') possessing an exceptional combination of high lodging resistance, tall posture and high biomass production. Nuclear magnetic resonance imaging displayed the 3-dimensional assembly of vascular bundles in stem. A higher number of vascular bundles and a higher degree of their incline were the features of lodging-resistant versus lodging-prone lines. Histology and electron microscopy revealed that stems are fortified by a higher proportion of sclerenchyma and thickened cell walls, as well as some epidermal invaginations. Biochemical analysis using Fourier-transform infrared spectroscopy and inductively coupled plasma-optical emission spectrometry further identified elevated levels of lignin, xylan, zinc and silicon as features associated with high lodging resistance. Combined effects of above features caused superior culm stability. A simplistic mathematical model showed how mechanical forces distribute within the stem under stress. Main traits of the lodging-resistant parental line were heritable and could be traced back to the genetic structure of the mutant. Evaluation of lodging-resistant wheat \'Babax\' (\'Baviacora\') versus contrasting, lodging-prone, genotype ´Pastor´ agreed with above findings on rye. Our findings on mechanical stability and extraordinary culm properties may be important for breeders for the improvement of lodging resistance of tall posture cereal crops.
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  • 文章类型: Journal Article
    Myotonic dystrophy type 1 (DM1) is a hereditary disease characterized by progressive distal muscle weakness and myotonia. Patients with DM1 have abnormal lipid metabolism and a high propensity to develop a metabolic syndrome in comparison to the general population. It follows that metabolome evaluation in these patients is crucial and may contribute to a better characterization and discrimination between DM1 disease phenotypes and severities. Several experimental approaches are possible to carry out such an analysis; among them is Fourier-transform infrared spectroscopy (FTIR) which evaluates metabolic profiles by categorizing samples through their biochemical composition. In this study, FTIR spectra were acquired and analyzed using multivariate analysis (Principal Component Analysis) using skin DM1 patient-derived fibroblasts and controls. The results obtained showed a clear discrimination between both DM1-derived fibroblasts with different CTG repeat length and with the age of disease onset; this was evident given the distinct metabolic profiles obtained for the two groups. Discrimination could be attributed mainly to the altered lipid metabolism and proteins in the 1800-1500 cm-1 region. These results suggest that FTIR spectroscopy is a valuable tool to discriminate both DM1-derived fibroblasts with different CTG length and age of onset and to study the metabolomic profile of patients with DM1.
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  • 文章类型: Journal Article
    结构之间的比较,形态学,来自谷物即小麦(WS)的淀粉的功能和消化率研究,玉米(CS),低直链淀粉玉米(LACS)和水稻(RS),块茎,即马铃薯(PS)和甘薯(SP),和豆类,即菜豆(KB)进行了研究。颗粒的形状根据来源从卵形到椭圆形或球形。异淀粉酶脱支材料的分布表明,支链淀粉的长链和短侧链分数分别为12.6%至33.1%和40.5%至52.5%。KB淀粉显示出最高的直链淀粉含量(49.50%),而RS显示出最低的直链淀粉含量(8.51%)。颗粒尺寸较大的淀粉(PS,SP和KB)显示出较高比例的支链淀粉(AP)的长侧链(Fr。II)比AP的短侧链(Fr。III).峰值粘度(PV),分解粘度(BV)和最终粘度(FV)与Fr呈显著正相关。Ⅱ和阴性与表观直链淀粉含量(AAC)和Fr。III.块茎淀粉显示出更大的糊状粘度,其次是豆类淀粉。块茎和豆类淀粉具有较高的表观直链淀粉含量和Fr。II显示更大的结晶度。凝胶硬度和糊化温度与RS淀粉具有较高比例的较小颗粒(0-10µm)成反比。直链淀粉含量较高的KB显示出最大的可快速消化淀粉(RDS)含量,而SP显示出最高的抗性淀粉。以上观察结果将用于修饰天然淀粉的性质,并有助于改善质地,淀粉及其制品的保湿能力和凝胶硬度。
    A comparison between structural, morphological, functional and digestibility studies of starches from cereals i.e. wheat (WS), corn (CS), low amylose corn (LACS) and rice (RS), tubers i.e. potato (PS) and sweet potato (SP), and legumes i.e. kidney bean (KB) were investigated. The shape of granules varied from oval to elliptical or spherical according to the source. Distribution of iso- amylase debranched materials revealed that long and short side chains fractions of amylopectin ranged from 12.6 to 33.1% and 40.5 to 52.5% respectively. KB starch showed the highest amylose content (49.50%) while RS showed the lowest (8.51%). Starches with greater granule size (PS, SP and KB) showed higher proportion of long side chains of amylopectin (AP) (Fr.II) than short side chains of AP (Fr.III). Peak viscosity (PV), breakdown viscosity (BV) and final viscosity (FV) showed significant positive relationship with Fr. II and negative with apparent amylose content (AAC) and Fr.III. Tuber starches showed greater paste viscosities followed by legume starches. Tuber and legume starches with higher apparent amylose content and Fr. II showed greater crystallinity. Gel hardness and gelatinization temperatures showed inverse relationship with RS starch having higher proportion of smaller granules (0-10 µm). KB with higher amylose content showed maximum rapidly digestible starch (RDS) content while SP showed the highest resistant starch. Above observations would be utilized in modifying properties of native starches and help in improving texture, moisture retention capacity and gel firmness of starch and its products.
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