Analysis of the distribution of microhardness, mineral, and organic content of human, bovine, and ovine teeth / Análisis de la distribución de microdureza, contenido mineral y orgánico de dientes humanos, bovinos y ovinos

Objetive. Human teeth have been commonly used for in vitro and in situ studies. Cu­rrently, other animals' teeth have been purposed for dental research to overcome human teeth' problematic availability. This study aimed to investigate the enamel and dentin from human, bovine, and ovine teeth concerning the microhardness, organic, and in­ organic contents via micro­Raman spectroscopy. Methods. Human, bovine, and ovine teeth were divided according to their type and age into seven groups: Ovine; Bovine­12 months; Bovine­24 months; Bovine­36 months; Bovine­48 months; Bovine­+60 months; Human (control). The enamel's microhardness (superficial and deep) and den­tin (superficial, middle, and deep) were analyzed. The calcium/phosphate ratio and am­ide contents were determined by micro­Raman spectroscopy. Results. Overall, the mi­crohardness of human enamel was superior to the other species. Dentin's microhardness was similar among groups. Ovine group showed lower values of calcium/phosphate ratio than human. Amide content was similar between bovine and human. The microhardness and calcium/phosphate ratio of enamel and dentin, respectively, decreased as the age of bovine teeth increased. Conclusions. Researchers must be aware and take into consider­ation the differences of ovine and bovine enamel compared to human enamel. Other al­ternatives that are more similar to the microhardness of human enamel should be sought. Bovine teeth of 12 and 24 months are suitable substitutes for dentin of human teeth. Researchers must also be aware of the age of the animals and specify it in the studies.

Objetivo. Los dientes humanos se han utilizado comúnmente para estudios in vitro e in situ. Actualmente, los dientes de otros animales se han destinado a la investiga­ción dental para superar la disponibilidad problemática de los dientes humanos. Este estudio tuvo como objetivo investigar el esmalte y la dentina de los dientes humanos, bovinos y ovinos en relación con la microdureza y los contenidos orgánicos e inor­gánicos a través de la espectroscopia micro­Raman. Métodos. Los dientes humanos, bovinos y ovinos se dividieron según su tipo y edad en siete grupos: Ovinos; Bovino­12 meses; Bovino­24 meses; Bovino­36 meses; Bovino­48 meses; Bovino­+60 meses; Hu­mano (control). Se analizó la microdureza del esmalte (superficial y profunda) y de la dentina (superficial, media y profunda). La relación calcio/fosfato y los contenidos de amida se determinaron mediante espectroscopía micro­Raman. Resultados. En general, la microdureza del esmalte humano fue superior a la de otras especies. La microdureza de la dentina fue similar entre los grupos. El grupo ovino mostró valores más bajos de la relación calcio/fosfato que el humano. El contenido de amida fue similar entre bovinos y humanos. La microdureza y la relación calcio/fosfato del esmalte y la dentina, respectiva­mente, disminuyeron a medida que aumentaba la edad de los dientes bovinos. Conclusiones. El esmalte de los dientes ovinos y bovinos no es un sustituto adecuado del de los dientes humanos. Se deben buscar otras alternativas que sean similares a la microdureza del esmalte humano. Sin embargo, los dientes bovinos de 12 y 24 meses son sustitutos adecuados de la dentina de los dientes humanos. Los investigadores deben conocer la edad de los animales y especificarla en los estudios.

Study of laser fluorescence spectroscopy in livers of rats with hypothermic ischemia

Purpose: After partial hepatectomy (PH), the remaining liver (RL) undergoes regenerative response proportional to the host. Limited literature exists on hepatic viability after tissue injury during hypothermic preservation. Spectroscopy measures cellular fluorescence and is explored for tissue characterization and parameter investigation. This study aimed to assess fluorescence analysis (spectroscopy) in evaluating liver viability and its relationship with hepatic tissue regeneration 24 hours after PH. Additionally, we analyzed liver regeneration in RL after 70% partial hepatectomy under hypothermic conditions with laser irradiation. Methods: Fifty-six Wistar rats were divided into four groups: total non-perfused liver (control), total perfused liver, partial hepatectomy "in situ", and partial hepatectomy "ex situ". Tissue analysis was performed at 0 and 24 hours using spectroscopy with laser devices emitting at 532 (green) and 405 nm (violet). Results: Spectroscopy identified tissue viability based on consistent results with Ki67 staining. The fluorescence spectra and Ki67 analysis displayed similar patterns, linking proliferative activity and absorption intensity. Conclusions: Fluorescence spectroscopy proves to be promising for real-time analysis of cellular activity and viability. Metabolic activity was observed in groups of live animals and hypothermically preserved samples, indicating cellular function even under blood deprivation and hypothermic conditions.

Research and application of Raman spectroscopy in the diagnosis and therapy of brain glioma / 中华核医学与分子影像杂志

Brain glioma invariably relapses since the tumor is difficult to remove completely. Accurate identification of tumor subtypes and tracing of tumor boundaries intraoperatively are the key clinical issues. Raman spectroscopy has a good application prospect in the intraoperative diagnosis of brain glioma due to its advantages of nondestructive, label-free, histology imaging and high specificity. In this article, the research and application of Raman spectroscopy in the in vitro diagnosis and intraoperative navigation-related diagnosis and treatment of brain glioma are reviewed.

Vascular Spectrum of Imaging Findings in COVID-19: Ischemic, Hemorrhagic, and Thromboembolic Complications

Abstract Ischemic strokes secondary to occlusion of large vessels have been described in patients with COVID-19. Also, venous thrombosis and pulmonary thromboembolism have been related to the disease. Vascular occlusion may be associated with a prothrombotic state due to COVID-19-related coagulopathy and endotheliopathy. Intracranial hemorrhagic lesions can additionally be seen in these patients. The causative mechanism of hemorrhage could be associated with anticoagulant therapy or factors such as coagulopathy and endotheliopathy. We report on cases of ischemic, thrombotic, and hemorrhagic complications in six patients diagnosed with SARS-CoV-2 infection. Chest computed tomography (CT) showed typical SARS-CoV-2 pneumonia findings in all the cases, which were all confirmed by either serology or reverse transcription polymerase chain reaction (RT-PCR) tests.

To establish a method of serum detection by Raman spectroscopy for the diagnosis of gastric cancer / 中华检验医学杂志

Objective:To establish a method of serum detection by Raman spectroscopy for the diagnosis of gastric cancer.Methods:Between April and November 2019, 110 patients with gastric cancer [73 males, 37 females, age (57.4±10.3) years] and 74 patients with colorectal cancer [48 males and 26 females, aged (58.3±12.2) years] were collected at the First Affiliated Hospital of Army Military Medical University, along with 100 healthy subjects [59 males and 41 females, aged (55.6±10.61) years] during the same period. Fasting venous blood serum samples were collected from the subjects. A Raman spectrometer XploRA PLUS was used in this experiment, with an excitation light source of 532 nm, a field of view of 100 times, and a spectrum range of 200-2 000 cm -1, etc. The serum samples were detected by nondestructive and non-contact rapid detection, and the Raman spectra of serum samples were collected. Using the Raman spectrum acquisition and processing supporting software LabSpec6 to smooth, baseline, and normalize the obtained Raman spectrum. Multivariate statistical analysis software SIMCA14.1 were applied to import and analyze the obtained Raman spectrum data by principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and other methods for statistical analysis. An operating characteristic curve (ROC) was constructed to evaluate the model analysis effect between serum samples of healthy people and those with gastric cancer. Serum samples from the colorectal cancer group were used to verify the reliability of the model. Results:Six Raman peaks with good repeatability were detected in serum samples in health and gastric cancer group, and peaks were located at 1 001.17, 1 154.63, 1 337.89, 1 446.85, 1 515.33, and 1 658.34 cm -1, respectively. Raman intensities at six Raman peaks were significantly different between healthy and gastric cancer groups. At the displacement of 1 001.17, 1 154.63, and 1 515.33 cm -1, the Raman intensity in the healthy group was higher than that in the gastric cancer group. At 1 337.89, 1 446.85, and 1 658.34 cm -1 displacement, the Raman intensity of the gastric cancer group was higher than that of the healthy group. An OPLS-DA model was constructed to analyze the serum samples of the healthy group and the gastric cancer group. In the model, R 2 is the fitting power, and Q 2 is the predictive ability. The closer the values of R 2 and Q 2 are to 1, the better the performance of the model, and the obtained model's R 2X(cum)=0.809, R 2Y(cum)=0.819, Q 2(cum)=0.758. ROC characteristic curve was drawn based on the OPLS-DA model. The area under the curve (AUC) of the gastric cancer group was 0.998. Six peaks with good repeatability were detected in the serum Raman spectra of gastric cancer stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ, which were located at the displacement of 1 001.85, 1 155.07, 1 338.36, 1 445.75, 1 515.92, and 1 657.68 cm -1, respectively, and at the displacement of 1 155.07 and 1 515.92 cm -1. The Raman intensity of gastric cancer stage Ⅳwas significantly higher than that of gastric cancer stages Ⅰ, Ⅱ, and Ⅲ. Conclusions:According to the model reliability verification, the healthy group, gastric cancer group and colorectal cancer group can also be effectively separated based on OPLS-DA results; it showed a good performance in separating the healthy group from the gastric cancer group. It is possible to detect serum samples from healthy people and gastric cancer patients unlabeled by combining Raman spectroscopy and the OPLS-DA method in multivariate statistics.

Full spectrum analysis of chemical constituents of Sargassum fusiforme and its in vitro anti-neuroinflammatory activity / 中国药房

OBJECTIVE To study the composition of chemical constituents of Sargassum fusiforme and its in vitro anti- neuroinflammatory activity ，and to provide reference for its development and utilization and the study of pharmacodynamic substances. METHODS UHPLC-QTOF-MS/MS analysis method and GC-MS/MS method were used to analyze the chemical constituents of S. fusiforme . The lipopolysaccharide （1 μg/mL）was adopted to establish the inflammatory model of neuromicroglia BV2. Using paroxetine （5 μg/mL）as positive control ，CCK-8 assay was used to detect the effects of the extracts of S. fusiforme （20，40，60，80，100 μg/mL）on the activity and morphology of neuromicroglia BV 2. The effects of the extracts of S. fusiforme （40，60，80 μg/mL）on the contents of tumor necrosis factor α（TNF-α）and interleukin- 6（IL-6）in cell supernatant were detected by ELISA. RESULTS A total of 103 non-volatile constituents were identified by UHPLC-QTOF-MS/MS ，and 60 volatile constituents were obtained by GC-MS/MS. The extracts of S. fusiforme （40，60，80 μ g/mL） could significantly reduce the abnormally increased activation of neuromicroglia BV 2 and the contents of TNF-α and IL-6 due to lipopolysaccharide （P＜0.05 or P＜0.01）. CONCLUSIONS The study establish the full spectrum of chemical constituents of S. fusiforme ，and it is confirmed that fusiforme has certain in vitro anti-neuroinflammatory activity.

Rapid detection method for identifying and distinguishing Candida auris and its relatives by surface-enhanced Raman spectroscopy / 中华检验医学杂志

Objective:To develop an accurate, specific and rapid and non-destructive technique for the identification of Candida auris and its relatives without destroying the cell wall. Methods:The study was conducted in Beijing Institute of Radiation Medicine in 2021. Surface-enhanced Raman spectroscopy (SERS) substrates were prepared by sodium citrate reduction. Through SERS, the collected SERS fingerprint spectra were analyzed by orthogonal partial least-squares-discrimination analysis (OPLS-DA) using SIMCA 14.1 (Umetrics, Sweden). Four strains of Candida auris, 4 strains of Candida heamulonii, 3 strains of Candida pseudohaemulonii and 4 strains of Candida duobushaemulonii were effectively identified and distinguished. Results:Within the 95% confidence interval, the sample analysis results presented an oval. The four Candida species detected in this study could be well separated. R2X(cum)=0.629, R2Y(cum)=0.947, Q2(cum)=0.915. R2X, R2Y and Q2 all>0.5 and closed to 1, suggesting that the model in this study was well established, and had good prediction ability. The results of the 10-fold-cross validation showed that the accuracy of both the model training data and test data are 100%, indicating that the model established in this research had good classification capabilities. Conclusions:This research has developed a new technique that can identify Candida auris and its relatives in a highly accuracy, specific and rapid way without destroying the cell wall. Being cost-effective and easy to operate, this technique has great potential to be applied in clinical fungal testing.

Neuromonitoreo no invasivo en unidades de cuidados intensivos en Colombia / Non-invasive neuromonitoring in intensive care units in Colombia

Resumen | El monitoreo electroencefalográfico no invasivo continuo es una técnica indispensable en los pacientes neurológicos críticos, ya que muestra de forma directa e indirecta su actividad cerebral y permite relacionar los hallazgos con su estado clínico. Es muy sensible, aunque su especificidad es menor, por lo que puede demostrar la alteración del estado de conciencia sin aclarar su etiología. El uso del registro electroencefalográfico continuo en pacientes con alteraciones del estado de conciencia, convulsiones, o estado epiléptico convulsivo y no convulsivo, se ha incrementado en los últimos años porque permite obtener información en tiempo real de la función cerebral y de los cambios en el tiempo; además, facilita la detección de crisis epilépticas subclínicas y electrográficas, estas últimas de gran importancia, ya que no presentan correlación clínica. Los hallazgos del monitoreo permiten modificar el tratamiento farmacológico y anticonvulsivo, y constituyen una gran ventaja para el médico tratante en la toma de decisiones oportunas que redunden en la mejoría del pronóstico del paciente.

Abstract | Continuous non-invasive electroencephalographic monitoring is an essential technique for critical care patients as it shows directly and indirectly the patient's brain activity and makes it possible to relate it with findings in the clinical status. It is highly sensitive, although its specificity is lower, so they can show alterations of the state of consciousness without clarifying the etiology. Continuous electroencephalographic recording in patients with altered levels of consciousness, seizures, and convulsive and non-convulsive status epilepticus has been increasing in recent years as real-time feedback of the cerebral function shows evolution changes and allows for the identification of electric and subclinical epileptic seizures that are highly important since they do not have clinical correlations. These findings in electroencephalographic monitoring also help to modify pharmacological and antiseizure treatments. For practitioners, they are advantageous when making timely decisions that impact the prognosis of the patient.

Determinación niveles de glucosa por medio de espectroscopía como método no invasivo / Determination of glucose levels by means of spectroscopy as a non-invasive method

Introducción: la diabetes mellitus es uno de los problemas más graves de salud pública que enfrenta México. El factor más preocupante es la falta de control de la misma, lo que incide de manera directa, causando daños severos a la salud y la calidad de vida del paciente y familiares, así como una carga económica al país. Por lo tanto, el desarrollo de un método no invasivo para la medición de la glucemia proporcionaría a los pacientes una forma sencilla e indolora de monitoreo y, en consecuencia, un mejor control de la diabetes. Objetivo: investigar, desarrollar y validar un sensor no invasivo por medio de la espectroscopía para la estimación del nivel de glucosa en sangre. Material y métodos: se realizó un análisis de estudio transversal analítico de correlación realizado en las instalaciones del laboratorio de la UMAE No 1, Bajío. Se incluyeron pacientes adultos voluntarios que acudieron al laboratorio de dicha unidad para la toma de niveles de glucosa sérica y de manera simultánea se realizó la medición a través de método no invasivo por espectroscopía y, posteriormente, se compararon ambos resultados para demostrar la validez del dispositivo. Resultados: mediante el análisis de la diferencia de medias de Bland-Altman, se identificó que solamente un paciente tuvo un valor extremo, y que el método para medir la glucosa de manera no invasiva sobreestima hasta un 10.2% del valor de glucosa central. Conclusión: comparando dichos resultados con las normas para glucómetros digitales se concluye que nuestro dispositivo es capaz de proporcionar niveles de glucosa certeros.

Background: Diabetes mellitus is one of the most serious public health problems in Mexico. The most worrying factor is the lack of control of it, which has a direct impact, causing severe damage to the health and quality of life of the patient and its family, as well as an economic burden to the health system. Therefore, the development of a non-invasive method for measuring blood glucose would provide to patients a simple and painless way of monitoring and consequently better control of diabetes. Objective: Research, development and validation of a non-invasive sensor by means of spectroscopy for the estimation of the blood glucose level. Material and methods: An analysis of a cross-sectional analytical correlation study was carried out in the facilities of the laboratory at the UMAE No. 1, Bajío. Voluntary adult patients who attended the laboratory of the UMAE to take serum glucose levels were included, and simultaneously the measurement was carried out through a non-invasive method by spectroscopy and, later, both results were compared to demonstrate the validity of the device. Results: By the Bland-Altman mean difference analysis, it was identified that only one patient had an extreme value, and that the method to measure glucose non-invasively overestimates up to 10.2% of the central glucose value. Conclusion: Comparing these results with the standards for digital glucometers, it is concluded that our device is capable of providing accurate glucose levels.

Assessment of changes in the electrical activity of the brain during general anesthesia using portable electroencephalography / Evaluación de los cambios de la actividad eléctrica cerebral durante anestesia general usando electroencefalografía portable

Abstract Introduction The analysis of the electrical activity of the brain using scalp electrodes with electroencephalography (EEG) could reveal the depth of anesthesia of a patient during surgery. However, conventional EEG equipment, due to its price and size, are not a practical option for the operating room and the commercial units used in surgery do not provide access to the electrical activity. The availability of low-cost portable technologies could provide for further research on the brain activity under general anesthesia and facilitate our quest for new markers of depth of anesthesia. Objective To assess the capabilities of a portable EEG technology to capture brain rhythms associated with the state of consciousness and the general anesthesia status of surgical patients anesthetized with propofol. Methods Observational, cross-sectional study that reviewed 10 EEG recordings captured using OpenBCI portable low-cost technology, in female patients undergoing general anesthesia with propofol. The signal from the frontal electrodes was analyzed with spectral analysis and the results were compared against the reports in the literature. Results The signal captured with frontal electrodes, particularly α rhythm, enabled the distinction between resting with eyes closed and with eyes opened in a conscious state, and sustained anesthesia during surgery. Conclusions It is possible to differentiate a resting state from sustained anesthesia, replicating previous findings with conventional technologies. These results pave the way to the use of portable technologies such as the OpenBCI tool, to explore the brain dynamics during anesthesia.

Resumen Introducción El análisis de la actividad eléctrica cerebral mediante electrodos ubicados sobre el cuero cabelludo con electroencefalografía (EEG) podría permitir conocer la profundidad anestésica de un paciente durante cirugía. Sin embargo, los equipos de EEG convencionales, por su precio y tamaño, no son una alternativa práctica en quirófanos y los equipos comerciales usados en cirugía no permiten acceder a la actividad eléctrica. Disponer de tecnologías portables y de bajo costo aumentaría el número de investigaciones sobre la actividad cerebral bajo anestesia general y facilitaría la búsqueda de nuevos marcadores para la profundidad anestésica. Objetivo Evaluar la capacidad de una tecnología EEG portable de adquirir ritmos cerebrales relacionados con el estado consciente y el estado de anestesia general de pacientes en cirugía anestesiados con propofol. Métodos Estudio observacional de corte transversal en el que se analizaron datos de 10 registros EEG obtenidos mediante tecnología portable y de bajo costo OpenBCI, de pacientes de sexo femenino que fueron sometidas a anestesia general con propofol. La señal obtenida de los electrodos frontales se analizó mediante análisis espectral y se contrastaron los resultados con lo descrito en la literatura. Resultados La señal obtenida con electrodos frontales, especialmente el ritmo α, permitió diferenciar el reposo con ojos cerrados y ojos abiertos en estado consciente, del estado de mantenimiento de la anestesia durante cirugía. Conclusiones Se logra la diferenciación de estado de reposo y de mantenimiento de la anestesia replicando hallazgos previos de tecnologías convencionales. Estos resultados abren la posibilidad de utilizar las tecnologías portables como el OpenBCI para investigar la dinámica cerebral durante la anestesia.

Ultrasound evaluation of acute compartment syndrome: Based on healthy volunteers / 中华急诊医学杂志

Objective:To explore the application value of ultrasound in the early noninvasive monitoring of acute compartment syndrome model, and to provide reference for further clinical applications.Methods:This was a prospective self-controlled study. A model of healthy volunteers with acute compartment syndrome was established by cuff compression. The random method was used to determine the experimental side and the control side. The experimental side cuff was given 0, 20, 30, 40, 50, 60, 70, and 80 mmHg pressure in sequence, while the control side cuff was kept uncompressed at all times. Each pressure on the experimental side lasted for 5 min, during which the ultrasound was used to measure the blood flow waveform and vascular structure of the bilateral popliteal artery, popliteal vein and dorsal plantar artery. Statistical analysis was performed using repeated measures analysis of variance and multivariate analysis of variance.Results:The study included 25 healthy volunteers. There was no statistically significant difference in calf circumference and anterior tibial compartment thickness ( P = 0.314 and 0.678). During compression, the volunteers' heart rate and blood pressure were stable ( P = 0.235 and 0.358). On the experimental side, the maximum blood flow velocity of the popliteal artery during systole increased with the increase of pressure ( P<0.001), and the minimum blood flow velocity of the popliteal artery increased with the increase of pressure ( P<0.001). When pressurized by 30 mmHg, the maximum blood flow velocity of the popliteal artery on the experimental side was significantly higher than that on the control side [(73 ± 19) cm/s vs (59 ± 14) cm/s, P=0.023)]. When pressurized by 20 mmHg, the minimum blood flow velocity of the popliteal artery on the experimental side was significantly higher than that on the control side [(-28 ± 8) cm/s vs (-22 ± 6) cm/s, P=0.012)]. With the increase of pressure, the diastolic retrograde arterial flow ratio of the experimental side gradually increased ( P <0.001), and when the pressure was increased by 20 mmHg, the diastolic retrograde arterial flow ratio of the experimental side of the popliteal artery increased significantly [(0.42 ± 0.14) cm/s vs (0.30 ± 0.12) cm/s, P=0.009)]. The systolic prograde arterial flow ratio of the dorsal artery in the experimental side decreased with the increase of pressure ( P = 0.024). Conclusions:Increased limb compartment pressure can significantly change the arterial flow waveform of the proximal and distal arteries, and ultrasound can be used as an early monitoring tool for acute compartment syndrome.

An electroencephalogram-based study of resting-state spectrogram and attention in tinnitus patients / 生物医学工程学杂志

The incidence of tinnitus is very high, which can affect the patient's attention, emotion and sleep, and even cause serious psychological distress and suicidal tendency. Currently, there is no uniform and objective method for tinnitus detection and therapy, and the mechanism of tinnitus is still unclear. In this study, we first collected the resting state electroencephalogram (EEG) data of tinnitus patients and healthy subjects. Then the power spectrum topology diagrams were compared of in the band of δ (0.5-3 Hz), θ (4-7 Hz), α (8-13 Hz), β (14-30 Hz) and γ (31-50 Hz) to explore the central mechanism of tinnitus. A total of 16 tinnitus patients and 16 healthy subjects were recruited to participate in the experiment. The results of resting state EEG experiments found that the spectrum power value of tinnitus patients was higher than that of healthy subjects in all concerned frequency bands. The

Analysis of the vibration reduction effect of three common protective gloves / 中国职业医学

OBJECTIVE: To test and analyze the vibration transmissivity of three common kinds of protective gloves, and to determine their actual protecting effect. METHODS: Three kinds of protective gloves were selected as test materials, and five healthy volunteers were selected as subjects using typical sampling methods. According to the ISO 10819:2013 Mechanical Vibration and Shock--Hand-arm Vibration--Measurement and Evaluation of the Vibration Transmissibility of Gloves at the Palm of the Hand(hereinafter referred to as ISO 10819:2013), investigation and measurement of basic parameters of protective gloves. The gloved vibration transmission(GVT) test system was used to test the vibration transmission of different protective gloves worn by the subjects, and the spectrum analysis of vibration reduction characteristics was carried out. RESULTS: The thickness of damping material of all the three kinds of protective gloves met the standard requirements. The mean value for the corrected frequency-weighted glove vibration transmissibility values at 25.0-200.0 Hz were 0.91, 0.75 and 0.94, and 1.05, 0.85 and 1.10 at 200.0-1 250.0 Hz, for the protective gloves A, B and C, respectively. The results of anti-vibration characteristic spectrum analysis show that there has no vibration reduction effect at the frequency of 25.0-200.0 Hz when wearing these three kinds of gloves. Wearing gloves A and B on part of the 200.0-1 250.0 Hz frequency vibration has an amplifying effect. Wearing glove C has a partial vibration reduction effect at the 200.0-1 250.0 Hz frequency, and the vibration reduction efficiency is the highest at the frequency of 1 250.0 Hz.CONCLUSION: According to the ISO 10819:2013 standard, the mean value of GVT measured when wearing the three kinds of protective gloves does not meet the relevant requirements, and the anti-vibration effect is poor. These gloves cannot be defined as anti-vibration gloves.

Synthesis, characterization, and incorporation of upconverting nanoparticles into a dental adhesive

Abstract: The purpose of this study was to describe the synthesis, characterization, and functionalization of b-NaYF4:30%Yb/0.5%Tm upconverting nanocrystals for use as nanofillers in a dental adhesive and microscopically evaluate the interface between the particles and a commercial adhesive. The upconverting nanoparticles were synthesized and purified by thermal decomposition, and their chemical composition determined by energy dispersive X-Ray spectroscopy. The crystalline structure was characterized using X-Ray diffraction and morphology and size were observed with scanning and transmission electron microscopy. Upconverting emission was evaluated by spectrophotometry irradiating the particles with a 975 nm diode laser. Particles were functionalized with polyacrylic acid and the success was confirmed by measurement of Zeta Potential and transmission electron microscopy. The results of X-ray diffraction found a pure hexagonal phase crystalline pattern. Scanning electron microscopy showed uniform dispersion of hexagonal-shaped particles of approximately 150 nm. Upconversion emission was observed in 344 nm, 361 nm, 450 nm, 474nm, 646 nm, 803 nm. Functionalization success was confirmed by formation of a stable aqueous colloid with a Zeta potential of −29.5mV and the absence of voids in the particle-adhesive interface on the transmission electron microscopy images. The reported synthesis and functionalization process produced upconverting nanoparticles emitting photons within the blue spectral region (450 nm and 474 nm).

EEG Signal Analysis Methods and Their Applications / 中国医疗器械杂志

EEG is a weak physiological electrical signal, which has important value in clinical and laboratory research. This paper mainly introduces several common methods of EEG signal processing, including power spectrum analysis, time-frequency analysis, bispectral analysis, etc, it mainly introduces their principles and applications in EEG signal processing, and provides methods and approaches for studying EEG.

Nuevo detector de enfermedades vestibulares basado en el análisis espectro temporal de nistagmogramas

Introducción: La exploración del sistema vestibular exige una evaluación precisa, sistemática y completa de la respuesta vestíbulo-ocular. Actualmente los sistemas solo analizan secciones definidas subjetivamente por especialistas clínicos en los registros del nistagmo, y se calculan parámetros en el dominio del tiempo, que a menudo se ven afectados por las interferencias y el ruido en el sistema de exploración durante las pruebas vestibulares. Objetivo: Presentar un nuevo sistema para la exploración y caracterización del nistagmo obtenido mediante electronistagmografía. Métodos: Los registros fueron adquiridos a partir de pruebas rotatorias en una muestra de 49 sujetos, se introdujo el análisis espectro temporal del nistagmo inducido, que permitió definir la zona de mayor interés clínico para el análisis durante las pruebas. Resultados: Se obtuvo un nuevo indicador espectro temporal, detector de enfermedades vestibulares, basado en la comparación del comportamiento del análisis espectral del nistagmo en la sección central de fases de velocidad constante y desaceleración de los registros clínicos. Se obtuvo una buena sensibilidad (90,32 %) y una buena especificidad (88,89 %) del nuevo indicador, relacionado con la determinación de personas enfermas en uno o ambos laberintos. Conclusiones: El método y el nuevo indicador definido, presentaron mayor capacidad diagnóstica, que el habitual análisis cuantitativo de las señales; mostraron una sensibilidad y especificidad superiores. Permiten llegar a conclusiones en la práctica clínica diaria, con mucha más rapidez que la valoración de los parámetros temporales habitualmente utilizados en los análisis, que presentan como debilidad, el amplio intervalo de valores normales.

Introduction: The exploration of the vestibular system requires an accurate, systematic and complete evaluation of the vestibule-ocular response. Currently, systems only analyze sections subjectively defined by clinical specialists in nystagmus records, and time domain parameters are calculated, which are often affected by interference and noise in the scanning system during vestibular tests. Objective: To present a new system for the exploration and characterization of nystagmus obtained by electronistagmography. Methods: The records were acquired from rotary tests in a sample of 49 subjects, the temporal spectrum analysis of the induced nystagmus was introduced, which allowed defining the area of ​​greatest clinical interest for the analysis during the tests. Results: A new temporal spectrum indicator was obtained, detector of vestibular diseases, based on the comparison of the behavior of the spectral analysis of nystagmus in the central section of constant velocity phases and deceleration of clinical records. A good sensitivity (90.32%) and a good specificity (88.89%) of the new indicator were obtained, related to the determination of sick people in one or both labyrinths. Conclusions: The method and the new defined indicator, presented greater diagnostic capacity, than the usual quantitative analysis of the signals; they showed superior sensitivity and specificity. They allow conclusions to be reached in daily clinical practice, much faster than the assessment of the temporal parameters usually used in the analyzes, which present as a weakness, the wide range of normal values.

Surface-enhanced Raman nanoparticles for cancer theranostics / 中华核医学与分子影像杂志

Raman spectroscopy is amplified by surface-enhanced Raman scattering nanoparticles(SERS-NPs),and Raman signal can be enhanced by SERS-NPs,which can achieve high-resolution imaging of tumors.Meanwhile,SERS-NPs have high molecular specificity and sensitivity,showing a good prospect of tumor diagnosis and treatment.The advantages of SERS-NPs and its application in tumor diagnosis and treatment,and related experimental studies are reviewed in this article.

Preparation of silymarin-SBE-β-CD inclusion complex / 中草药

Objective: The inclusion compound of silymarin-SBE-β-CD was prepared. Methods: Phase solubility method was used to screen the inclusion materials of cyclodextrin and determine the type of inclusion. The technological conditions of silymarin inclusion complex were optimized by orthogonal design. The solubility of inclusion was determined and its structure was characterized by means of microscope, infrared spectrum analysis and X-ray diffraction analysis. Results: Due to its higher solubilization effect on silymarin, SBE-β-CD was determined as inclusion material. The ratio of drug to cyclodextrin was coated in the mode of 1:n. The process optimized by orthogonal design was as follow: molar ratio of silymarin to SBE-β-CD of 1:8, inclusion temperature of 60 ℃, and inclusion time of 3 h. Microscope, infrared spectrum analysis and X-ray diffraction analysis showed that the inclusion compound was formed and the drug existed in the inclusion compound as amorphous. Conclusion: The inclusion compound of silymarin-SBE-β-CD has been successfully prepared, which can significantly improve the solubility of the drug, and provide experimental basis for its clinical application.

The application of Raman spectroscopy in male reproduction diagnosis / 中华检验医学杂志

The limited method demands for new technology in the management of male infertility. Raman spectroscopy is a rapid and sensitive non-invasive diagnosing technology. Raman spectroscopy was able to obtain Raman spectra from individual human sperm cells and allows for the comparison of their biochemical components, DNA and mitochondrial structure as well as epigenetic changes. This review provided an overview of the principle of each major types and discussed the progress in clinical application , indicating the potential of Raman spectroscopy as an valuable addition in assessing the quality of sperm cells for in vitro fertilization.

Mineral content analysis of root canal dentin using laser-induced breakdown spectroscopy

OBJECTIVES: This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. MATERIALS AND METHODS: Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. RESULTS: In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001). CONCLUSIONS: Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.