Topographic analysis of fiber posts after surface disinfection with different methods

Aims: This study aims to comprehensively examine the surface morphology of fiber posts after undergoing various disinfection methods, utilizing scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Materials and Methods: Twenty-one fiber posts were randomly allocated into seven experimental groups, each consisting of three samples. The disinfection methods employed were as follows: GC - no disinfection treatment; GAL - immersion in 70% alcohol, following the manufacturer's recommended protocol; GHP - soaking in 2.5% sodium hypochlorite for a duration of 10 minutes; GCL - soaking in 2% chlorhexidine gluconate for a period of five minutes; GAC - 30-second etching with 35% phosphoric acid; GPH - soaking in 10% hydrogen peroxide for a duration of 20 minutes; and GSL - autoclave sterilization. Following the disinfection procedures, SEM was employed to scrutinize the surface topography of the posts, while EDX was utilized to identify the chemical elements present on the sample surfaces. Subsequently, a descriptive analysis was conducted on the SEM images and EDX data. Results: SEM analysis revealed that all groups exhibited regions with epoxy resin-coated fibers alongside sections with exposed glass fibers. Analysis of the EDX data indicated that there were no significant differences in the predominant chemical elements across the groups. Carbon (C) and oxygen (O) registered the highest peaks, followed by silicon (Si), zirconium (Zr), sodium (Na), aluminum (Al), and calcium (Ca). Conclusions: The disinfection methods under investigation did not induce substantial alterations in the surface morphology of the fiber posts.

Histological and Ultrastructural Changes in Lungs One Year Post Asymptomatic or Mild SARS-CoV-2 Infection: Evaluating the Potential for Active Virus Presence

SUMMARY: Prior research on post-COVID-19 or long COVID primarily focused on the presence of SARS-CoV-2 mostly in symptomatic patients. This study aimed to investigate the persistence of SARS-CoV-2 after 1 year of asymptomatic or mild COVID-19. SARS-CoV-2 infected and control K18-hACE2 transgenic mice (n=25) were studied. Moderate and severe symptomatic subjects were sacrificed after eight days, while mild or asymptomatic mice were kept in BSL-III for twelve months. Analyses included general condition, histochemistry, immunohistochemistry, transmission electron microscopy, and qRT-PCR. Lungs from the twelve-month group showed thickening of alveolar walls, with some lungs exhibiting the recruitment of inflammatory cells, the presence of SARS- CoV-2 mRNA, immunopositivity for the SARS-CoV-2 spike protein, and TEM showed viruses (60-125 nm) within vesicles, indicating continued replication. Certain lung samples showed persistent SARS-CoV-2 presence in Club cells, endothelial cells, and macrophages. The eight-day group exhibited viral interstitial pneumonitis, SARS-CoV-2 immunopositivity, and mRNA. The eight-day hearts displayed viral mRNA, while the twelve-month hearts tested negative. Some asymptomatic twelve-month subjects presented reduced surfactant, basal membrane thickening, fibrosis, and mild autonomic nerve degeneration. In this study conducted on mice, findings indicate the potential for chronic persistence of SARS-CoV-2 in the lungs one year post initial mild or asymptomatic infection, which could suggest the possibility of recurrent episodes in similar human conditions. The observed thickening of alveolar walls and potential fibrotic areas in these mice may imply an increased risk of post-COVID fibrosis in humans. Furthermore, the presence of SARS-CoV-2-positive inflammatory cells in some asymptomatic murine cases could herald a progression toward ongoing inflammation and chronic lung disease in humans. Therefore, the necessity for further studies in human subjects and vigilant monitoring of high-risk human populations is underscored.

Investigaciones anteriores sobre COVID-19 o COVID prolongado se centraron principalmente en la presencia de SARS-CoV-2 principalmente en pacientes sintomáticos. Este estudio tuvo como objetivo investigar la persistencia del SARS-CoV-2 después de 1 año de COVID-19 asintomático o leve. Se estudiaron ratones transgénicos K18-hACE2 infectados con SARS-CoV-2 y de control (n=25). Los animales con síntomas moderados y graves se sacrificaron después de ocho días, mientras que los ratones con síntomas leves o asintomáticos se mantuvieron en BSL-III durante doce meses. Los análisis incluyeron estado general, histoquímica, inmunohistoquímica, microscopía electrónica de transmisión y qRT- PCR. Los pulmones del grupo de doce meses mostraron engrosamiento de las paredes alveolares, y algunos pulmones exhibieron reclutamiento de células inflamatorias, presencia de ARNm del SARS-CoV-2, inmunopositividad para la proteína de la espícula del SARS-CoV-2 y TEM mostró virus (60 -125 nm) dentro de las vesículas, lo que indica una replicación continua. Ciertas muestras de pulmón mostraron una presencia persistente de SARS- CoV-2 en exocrinocitos bronquiolares, células endoteliales y macrófagos. El grupo de ocho días presentó neumonitis intersticial viral, inmunopositividad al SARS-CoV-2 y ARNm. Los corazones de ocho días mostraron ARNm viral, mientras que los corazones de doce meses dieron negativo. Algunos animales asintomáticos de doce meses presentaron disminución del surfactante, engrosamiento de la membrana basal, fibrosis y degeneración leve del nervio autónomo. En este estudio realizado en ratones, los hallazgos indican la posibilidad de persistencia crónica del SARS-CoV-2 en los pulmones un año después de la infección inicial leve o asintomática, lo que podría sugerir la posibilidad de episodios recurrentes en condiciones humanas similares. El engrosamiento observado de las paredes alveolares y las posibles áreas fibróticas en estos ratones puede implicar un mayor riesgo de fibrosis post-COVID en humanos. Además, la presencia de células inflamatorias positivas para SARS- CoV-2 en algunos casos murinos asintomáticos podría presagiar una progresión hacia una inflamación continua y una enfermedad pulmonar crónica en humanos. Por lo tanto, se subraya la necesidad de realizar más estudios en seres humanos y realizar un seguimiento atento de las poblaciones humanas de alto riesgo.

Alpaca (Vicugna pacos) Skin Analyzed Under Architecture and Structure / Piel de Alpaca (Vicugna pacos) Analizada Bajo Arquitectura y Estructura

SUMMARY: This study evaluated the morphology of alpacas skin. Biopsies were collected and samples were fixed in 10 % neutral buffered formalin for histological procedures. The sections were stained with hematoxylin and eosin, picrosirius red and Masson's trichrome. Types I, III and IV collagen were analyzed by immunohistochemistry. The derma presented sebaceous and sweat glands, as well as follicular groups with medullated fibers. Type I and type IV collagen were observed at epidermis and dermis as well as in glandular structures and hair follicles. The collagen III, was observed only in dermis.

Este estudio evaluó la morfología de la piel de alpacas. Se recogieron biopsias y las muestras se fijaron en formalina tamponada neutra al 10 % para procedimientos histológicos. Las secciones se tiñeron con hematoxilina y eosina, rojo picrosirius y tricrómico de Masson. El colágeno tipo I, III y IV se analizó mediante inmunohistoquímica. La dermis presentó glándulas sebáceas y sudoríparas, así como grupos foliculares con fibras medulares. Se observó colágeno tipo I y tipo IV en la epidermis y la dermis, así como en estructuras glandulares y folículos pilosos. El colágeno III, se observó únicamente en la dermis.

Bisphenol A released and ultrastructural changes in dental composite resins

Dental composite resins may release bisphenol-A or similar molecules affecting patient health and the environment. This study measured bisphenol-A release from three commonly used in patients composite resins (Filtek™ Z350 XT, Filtek™ P60, Filtek™ Bulk Fill) immersed in three liquid mediums (artificial saliva, 0.001 M lactic acid and 15% ethanol) and assessed the changes in the surface micromorphology.The released BPA was measured by HPLC at basal time (t=0), 1 h, 1 d, 7 d and 30 d. Topographic analysis of specimens was performed by scanning electron microscopy (SEM). The data were analyzed using one-way ANOVA and Tukey post-hoc test (P < 0.05). BPA in solution increased significantly in the three DCRs immersed in 0.001 M lactic acid at all times. SEM micrographs of the specimen in 0.001 M lactic acid disclosed more structural defects than others. The surface of the three composite resins was morphologically affected by their immersion in all solutions. SEM evidenced that the dental materials underwent erosion and cracks with filler particles protruding from the surface. The morphological changes in tested dental materials produced by exposure to these solutions are potentially dangerous to patients by causing caries, infections, and partial loss of dental material.

Reflectance confocal microscopy - Consensus terminology glossary in Brazilian Portuguese for normal skin, melanocytic and non-melanocytic lesions

Abstract Background: Currently, there is no uniform and official terminology in Portuguese for reflectance confocal microscopy analysis, despite the increasing number of Brazilian dermatologists using this new tool. Objective: To present the terminology in Brazilian Portuguese for the description of reflectance confocal microscopy and establish the first Brazilian consensus on terms related to normal skin and cutaneous tumors. Methods: 10 Brazilian specialists from different institutions and states of Brazil were selected to evaluate the best corresponding terms in Portuguese for normal skin, melanocytic and non-melanocytic tumors. The terms used were translated from international consensuses in the English language. The modified Delphi method was used to create the consensus in 3 steps. Results: The terms considered the most appropriate in the Portuguese language to describe the findings of normal skin, melanocytic and non-melanocytic lesions in the reflectance confocal microscopy analysis were presented. Study limitations: The limitations of the present study include the number of participants and limited regional representation (only two of the five Brazilian regions were represented). Conclusion: This Brazilian consensus represents an opportunity for dermatologists and physicians specializing in cutaneous oncology to become familiar with reflectance confocal microscopy, propagating the technique in clinical and research environments to stimulate national and international publications on this subject.

Quality Evaluation of Atractylodis Macrocephalae Rhizoma in Different Production Methods Based on Traditional Traits / 中国实验方剂学杂志

ObjectiveBased on the experience of traditional quality evaluation， the quality of Atractylodis Macrocephalae Rhizoma（AMR） with different production methods such as direct seeding， transplanting after seedling raising， topping and non-topping， and difference in growth years was compared. MethodVernier caliper was used to measure the trait data of AMR in different production methods. Paraffin sections of AMR with different production methods were made by saffron solid green staining， and the microstructure was observed. The contents of water-soluble and alcohol-soluble extracts in AMR with different production methods were determined according to the 2020 edition of Chinese Pharmacopoeia. The content of water-soluble total polysaccharides in AMR with different production methods was detected by sulfuric acid-anthrone method. Fiber analyzer was used to detect the content of fiber components in AMR with different production methods. The contents of monosaccharides， oligosaccharides and some secondary metabolites in AMR with different production methods were detected by ultra performance liquid chromatography（UPLC）， and the differences of chemical components were compared by multivariate statistical analysis methods such as principal component analysis（PCA） and partial least squares-discriminant analysis（PLS-DA）. ResultIn terms of traits， the 3-year-old AMR with direct seeding and without topping was close to the high-quality AMR with "phoenix-head and crane-neck， strong sweetness and clear aroma" recorded in ancient materia medica， followed by the 3-year-old AMR with topping after transplanting， while the 2-year-old AMR with topping after transplanting with high market circulation rate was generally fat and strong with mild odor. In the microscopic aspect， the arrangement of xylem vessels and fiber bundles in the 3-year-old samples formed two obvious rings. Compared with the 2-year-old samples cultivated in Bozhou and Zhejiang， the 3-year-old samples without topping after transplanting had more wood fibers. In terms of chemical composition， the contents of 70% ethanol extract， fructose， glucose， sucrose， 1-kestose， atractylenolide Ⅰ， chlorogenic acid， neochlorogenic acid， cryptochlorogenic acid and other components in 3-year-old AMR with direct seeding and without topping were significantly higher than those in the other three samples（P<0.05）. The contents of cellulose， 70% ethanol extract， sucrose， atractylenolide Ⅰ， atractylone and other components in 3-year-old AMR with topping after transplanting were significantly higher than those in the 2-year-old AMR with high market circulation rate（P<0.05）， while the contents of water-soluble extract and water-soluble total polysaccharides in 2-year-old samples with topping after transplanting were significantly higher than those in the 3-year-old AMR with topping after transplanting， direct seeding and without topping（P<0.05）. ConclusionUnder the current mainstream production mode， too much manual intervention makes AMR heavily enriched in polysaccharides and increased the yield， but the accumulation of sweet substances， fragrant substances and fiber substances is insufficient， which affects its quality. The current quality standard of AMR has some shortcomings in guiding the high quality production of it， it is suggested to revise the quality standard of AMR， supplement the quantitative analysis of secondary metabolites， and strengthen the production of imitation wild AMR.

Retinal microstructure and developmental characteristics in Zebrafish / 解剖学报

Objective To study the microscopic structure and morphological characteristics of Zebrafish eyeball and retina at different developmental stages, and to lay a foundation for visual research model. Methods Select eight groups of zebrafish at different ages, with six fish in each group, 48 fish in total. Optical microscopy and transmission electron microscopy were used to observe the eyeball structure of Zebrafish at different developmental stages, and the thickness of retinal each layer was measured to analyze the temporal and spatial development pattern. The morphological characteristics of various cells in the retina and the way of nerve connection were observed from the microscopic and ultrastructural aspects, especially the structural differences between rod cells and cone cells. Results The retina of Zebrafish can be divided into ten layers including retinal pigment epithelial layer, rod cells and cone cells layer, outer limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, nerve fiber layer, inner limiting membrane. Rod cells had a smaller nucleus and a higher electron density than cone cells. Photoreceptor terminals were neatly arranged in the outer plexiform layer, forming neural connections with horizontal cells and bipolar cells, and several synaptic ribbons are clearly visible within them. In Zebrafish retina, ganglion cell layer and inner plexiform layer are the earliest developed. With the growth and development of Zebrafish, the thickness of rod cells and cone cells layer and retinal pigment epithelial layer gradually increases, and the retinal structure was basically developed in about 10 weeks. Conclusion The retinal structure of Zebrafish is typical, with obvious stratification and highly differentiated nerve cells. There are abundant neural connections in the outer plexiform layer. The ocular development characteristics of Zebrafish are similar to those of most mammals.

Observation of corneal cell in diabetic patients using in vivo confocal microscopy / 国际眼科杂志(Guoji Yanke Zazhi)

In vivo confocal microscopy of the cornea is a non-invasive, rapid, and comprehensive technique for real-time, dynamic observation of all layers of the cornea. Confocal microscopy allows the examination of the morphology and cell density in the different layers of the cornea through direct visualization. With the increasing prevalence of diabetes, ocular complications have become common and have garnered more interest and in-depth research from clinical and scientific communities. This paper provides a comprehensive review of research progress made using in vivo confocal microscopy to observe various layers of cornea tissue in diabetic patients.

Constructing a model of anterior cruciate ligament reconstruction with autologous Achilles tendon in southern Yunnan small-ear pigs / 中国组织工程研究

BACKGROUND:As a dominant breed pig in southwest China,the southern Yunnan small-ear pig has been widely used as an experimental animal in the basic research of other disciplines,but there are still no reports on its application in anterior cruciate ligament reconstruction. OBJECTIVE:To establish a large animal model of the southern Yunnan small-ear pig with anterior cruciate ligament with autologous Achilles tendon was established. METHODS:Twenty adult female Yunnan small-ear pigs were equally randomized into two groups.In the autologous Achilles tendon group,the right knee anterior cruciate ligament was reconstructed with autologous Achilles tendon as a graft,while in the sham-operated group,a similar operation was performed on the right knee without any treatment of the anterior cruciate ligament.General conditions of each pig were observed and recorded before and 12 months after surgery.Ligaments and grafts were taken for gross observation and MAS scoring.Hematoxylin-eosin staining was performed to observe morphological characteristics of ligaments.The staining and arrangement of type I and type Ⅲ collagen were evaluated by immunohistochemistry.Transmission electron microscopy was used to observe the type,size,diameter,ratio,and distribution of collagen fibers in ligaments. RESULTS AND CONCLUSION:All animals had normal diet and activity,good wound healing,no obvious inflammatory reaction,no local purulent infection,and no significant changes in mental and urinary conditions compared with those before surgery.The reconstructed cruciate ligament of the knee was intact,with no stiffness and normal range of motion.Both the anterior drawer and Lachman tests were negative.Gross observation of the graft:12 months after surgery,the grafts was in good position,with good integrity,obvious tension,ligament color close to the original anterior cruciate ligament,and complete surface synovial coverage.Most of the intraarticular ligaments in the autologous Achilles tendon group were defined as MAS I type and a few were defined as MAS Ⅱ type.In the sham-operated group,the intraarticular ligament was defined as MAS I type.Hematoxylin-eosin staining indicated that,12 months after surgery,collagen fibers in the autologous Achilles tendon group began to appear bundled,isotropic,and uniformly arranged,with more obvious isotropic corrugations,and the nuclei were mainly linear or spindle-shaped,which were similar to those in normal anterior cruciate ligament tissue of the sham-operated group.Immunohistochemistry results indicated that,12 months after surgery,there was a higher expression of type I collagen and significantly less expression of type Ⅲ collagen in the reconstructed anterior cruciate ligament in the autologous Achilles tendon group.The degree of type I and type Ⅲ staining was similar in the two groups.Under the transmission electron microscope,the diameter,arrangement and density of collagen fibers in the reconstructed anterior cruciate ligament of the autologous Achilles tendon group were similar to those of the original anterior cruciate ligament at 12 months after surgery,indicating that the ligament remodeling process had been basically completed in the autologous Achilles tendon group at 12 months after surgery.Through a comprehensive evaluation of animal general conditions,ligament general view,MAS score,hematoxylin-eosin staining,immunohistochemistry,and transmission electron microscopy observation,we successfully established a large animal model of anterior cruciate ligament reconstruction using autogenous Achilles tendon in southern Yunnan small-ear pigs,with good morphological,histological and ultrastructural results.

Construction and application of a deep learning-based assistant system for corneal in vivo confocal microscopy images recognition / 中华实验眼科杂志

Objective:To construct an artificial intelligence (AI)-assisted system based on deep learning for corneal in vivo confocal microscopy (IVCM) image recognition and to evaluate its value in clinical applications. Methods:A diagnostic study was conducted.A total of 18 860 corneal images were collected from 331 subjects who underwent IVCM examination at Renmin Hospital of Wuhan University and Zhongnan Hospital of Wuhan University from May 2021 to September 2022.The collected images were used for model training and testing after being reviewed and classified by corneal experts.The model design included a low-quality image filtering model, a corneal image diagnosis model, and a 4-layer identification model for corneal epithelium, Bowman membrane, stroma, and endothelium, to initially determine normal and abnormal corneal images and corresponding corneal layers.A human-machine competition was conducted with another 360 database-independent IVCM images to compare the accuracy and time spent on image recognition by three senior ophthalmologists and the AI system.In addition, 8 trainees without IVCM training and with less than three years of clinical experience were selected to recognize the same 360 images without and with model assistance to analyze the effectiveness of model assistance.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2021-K148).Results:The accuracy of this diagnostic model in screening high-quality images was 0.954.Its overall accuracy in identifying normal/abnormal corneal images was 0.916 and 0.896 in the internal and external test sets, respectively.Its accuracy reached 0.983, 0.925 in the internal test sets and 0.988, 0.929 in the external test sets in identifying corneal layers of normal and abnormal images, respectively.In the human-machine competition, the overall recognition accuracy of the model was 0.878, which was similar to the average accuracy of the three senior physicians and was approximately 300 times faster than the experts in recognition speed.Trainees assisted by the system achieved an accuracy of 0.816±0.043 in identifying corneal layers of normal and abnormal images, which was significantly higher than 0.669±0.061 without model assistance ( t=6.304, P<0.001). Conclusions:A deep learning-based assistant system for corneal IVCM image recognition is successfully constructed.This system can discriminate normal/abnormal corneal images and diagnose the corresponding corneal layer of the images, which can improve the efficiency of clinical diagnosis and assist doctors in training and learning.

Risk factors for recurrence of benign vocal cord lesions after microsurgery / 中国基层医药

Objective:To investigate the risk factors for recurrence of benign vocal cord lesions after microsurgery.Methods:The clinical data of 2 214 patients with benign vocal cord lesions who underwent laryngeal microsurgery at the Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital of Yangzhou University from April 2013 to April 2022 were collected. The data, including sex, age, drinking history, smoking history, unilateral and bilateral lesions, and diagnosis, were recorded. These patients were divided into six groups according to admission diagnosis: polyps, Reinke's edema, leukoplakia, granulomas, cysts, and other benign lesions. All patients were followed up for 0-115 months, with a median follow-up time of 55 months. The Kaplan-Meier curve was used to determine whether there was any difference in the recurrence rate of benign vocal cord lesions among groups after surgical treatment. The Cox regression model was used to analyze the risk factors for the recurrence of benign vocal cord lesions after surgical treatment.Results:Out of the 2 214 patients, there were 1 953 cases of polyps (88.21%), 41 cases of granulomas (1.85%), 67 cases of cysts (3.03%), 87 cases of leukoplakia (3.93%), 34 cases of Reinke's edema (1.54%), and 32 cases of other benign lesions (1.45%). The recurrence rate for benign vocal cord lesions was 4.86% (95/1 953) in the polyp group, 31.70% (13/41) in the granuloma group, 14.94% (13/87) in the leukoplakia group, 2.98% (2/67) in the cysts group, 8.82% (3/34) in the Reinke's edema group, and 9.37% (3/32) in the other benign lesions group. Univariate analysis showed that bilateral lesions (95% CI 6.899-17.289, P < 0.001), smoking history (95% CI 1.282-2.564, P = 0.001), and alcohol consumption (95% CI 1.173-2.346, P = 0.001) were significantly associated with the recurrence of benign vocal cord lesions. The recurrence rate for benign vocal cord lesions in the leukoplakia group (95% CI 1.375-27.011, P = 0.017) and granuloma group (95% CI 3.053-60.980, P = 0.001) was significantly higher than that in the cysts group. Multivariate analysis of the risk factors for postoperative recurrence of benign vocal cord lesions showed that patients who had bilateral lesions (95% CI 6.680-16.900, P < 0.001) and a history of smoking (95% CI 1.572-16.157, P = 0.007) had a higher risk of recurrence of benign vocal cord lesions compared with those without bilateral lesions and a history of smoking. Granulomas were found to be significantly associated with postoperative recurrence of benign vocal cord lesions (95% CI 4.691-97.667, P < 0.05). Conclusion:Bilateral lesions and smoking are independent risk factors for the recurrence of benign vocal cord lesions after microsurgery. Granuloma is strongly associated with the postoperative recurrence of benign vocal cord lesions.

Cellular Temperature Imaging Technology Based on Single-molecule Quantum Coherent Modulation / 生物化学与生物物理进展

ObjectiveCellular temperature imaging can assist scientists in studying and comprehending the temperature distribution within cells, revealing critical information about cellular metabolism and biochemical processes. Currently, cell temperature imaging techniques based on fluorescent temperature probes suffer from limitations such as low temperature resolution and a limited measurement range. This paper aims to develop a single-cell temperature imaging and real-time monitoring technique by leveraging the temperature-dependent properties of single-molecule quantum coherence processes. MethodsUsing femtosecond pulse lasers, we prepare delayed and phase-adjustable pairs of femtosecond pulses. These modulated pulse pairs excite fluorescent single molecules labeled within cells through a microscopic system, followed by the collection and recording of the arrival time of each fluorescent photon. By defining the quantum coherence visibility (V) of single molecules in relation to the surrounding environmental temperature, a correspondence between V and environmental temperature is established. By modulating and demodulating the arrival times of fluorescent photons, we obtain the local temperature of single molecules. Combined with scanning imaging, we finally achieve temperature imaging and real-time detection of cells. ResultsThis method achieves high precision (temperature resolution<0.1°C) and a wide temperature range (10-50°C) for temperature imaging and measurement, and it enables the observation of temperature changes related to individual cell metabolism. ConclusionThis research contributes to a deeper understanding of cellular metabolism, protein function, and disease mechanisms, providing a valuable tool for biomedical research.

Deep Learning Image Recognition-assisted Atomic Force Microscopy for Precise and Efficient Detection of Single-cell Mechanical Properties / 生物化学与生物物理进展

ObjectiveThe advent of atomic force microscope (AFM) provides a powerful tool for the studies of life sciences. Particularly, AFM-based indentation assay has become an important method for the detection of cellular mechanics, yielding numerous novel insights into the physiological and pathological activities from the single-cell level and considerably complementing traditional biochemical ensemble-averaged assays. However, current AFM indentation technology is mainly dependent on manual operation with low efficiency, seriously restricting its practical applications in the field of life sciences. Here, a method based on the combination of deep learning image recognition and AFM is developed for precisely and efficiently detecting the mechanical properties of single isolated cells and clustered cells. MethodsThe YOLO deep learning algorithm was used to recognize the central region of the cell in the optical image, the dual UNet neural network with an embedded vision transformer (ViT) module was used to recognize the peripheral regions of cell, and the template matching algorithm was used to recognize the tip of spherical probe. Based on the automatic determination of the positional relationships between the microsphere tip and the different parts of cell, the AFM tip was accurately moved to the central and peripheral regions of the target cell for rapid measurements of cell mechanical properties. Two types of cells, including HEK 293 cell (human embryonic kidney cell) and HGC-27 cell (human undifferentiated gastric cancer cell), were used for the experiments. The Hertz model was applied to analyze the force curves obtained on cells to obtain cellular Young’s modulus. ResultsAFM probe can be precisely moved to the different parts (central areas and peripheral areas) of cells to perform mechanical measurements under the guidance of deep learning-based optical image automatic recognition. The experimental results show that the proposed method is not only suitable for single isolated cells, but also suitable for clustered cells. ConclusionThe research demonstrates the great potential of deep learning image recognition to aid AFM in the precise and efficient detection of cellular mechanical properties mechanics, and combining deep learning-based image recognition with AFM will benefit the development of high-throughput AFM-based methodology to measure the mechanical properties of cells.

Research on Automatic Microalgae Detection System Based on Deep Learning / 生物化学与生物物理进展

ObjectiveThe scale of microalgae farming industry is huge. During farming, it is easy for microalgae to be affected by miscellaneous bacteria and other contaminants. Because of that, periodic test is necessary to ensure the growth of microalgae. Present microscopy imaging and spectral analysis methods have higher requirements for experiment personnel, equipment and sites, for which it is unable to achieve real-time portable detection. For the purpose of real-time portable microalgae detection, a real-time microalgae detection system of low detection requirement and fast detection speed is needed. MethodsThis study has developed a microalgae detection system based on deep learning. A microscopy imaging device based on bright field was constructed. With imaged captured from the device, a neural network based on YOLOv3 was trained and deployed on microcomputer, thus realizing real-time portable microalgae detection. This study has also improved the feature extraction network by introducing cross-region residual connection and attention mechanism and replacing optimizer with Adam optimizer using multistage and multimethod strategy. ResultsWith cross-region residual connection, the mAP value reached 0.92. Compared with manual result, the detection error was 2.47%. ConclusionThe system could achieve real-time portable microalgae detection and provide relatively accurate detection result, so it can be applied to periodic test in microalgae farming.

In Situ Labeling of Erythrocyte Membrane Anion Channel Proteins with Gold Nanoparticles Observed by Cryo-Scanning Electron Microscopy / 分析化学

Band 3 protein is an important channel protein in the erythrocyte membrane which mediates the anion transport process inside and outside the cell membrane,as well as contributes to the maintenance of erythrocyte morphology,and has important physiological functions.However,the distribution state of this protein in the primary cell membrane is not known.Cryo-scanning electron microscopy enables imaging of the surface morphology of biological samples in a near-physiological state.In order to investigate the distribution of band 3 protein on erythrocyte membranes under physiological conditions,the present study utilized 5-nm gold nanoparticles modified with the antibodies to specifically bind to the band 3 protein on human blood erythrocyte membranes and imaged them by cryo-scanning electron microscopy,to obtain distribution of band 3 protein on human blood erythrocyte membranes.The results showed that the membrane proteins on the erythrocyte membranes tended to be clustered and distributed to form ″protein islands″,and band 3 proteins were mainly distributed in these protein islands,which were tightly connected with each other to form several functional microregions to play their respective roles.

Effect of N-acetyl cysteine, rifampicin, and ozone on biofilm formation in pan-resistant Klebsiella pneumoniae: an experimental study

ABSTRACT BACKGROUND: To the best of our knowledge, this is the first study to evaluate the effectiveness of specific concentrations of antibiofilm agents, such as N-acetyl cysteine (NAC), rifampicin, and ozone, for the treatment of pan-resistant Klebsiella pneumoniae (PRKp). OBJECTIVES: We evaluated the effectiveness of antibiofilm agents, such as NAC, rifampicin, and ozone, on biofilm formation in PRKp at 2, 6, 24, and 72 h. DESIGN AND SETTING: This single-center experimental study was conducted on June 15, 2017, and July 15, 2018, at Istanbul Faculty of Medicine, Istanbul University, Turkey. METHODS: Biofilm formation and the efficacy of these agents on the biofilm layer were demonstrated using colony counting and laser-screened confocal microscopy. RESULTS: NAC at a final concentration of 2 μg/mL was administered to bacteria that formed biofilms (24 h), and no significant decrease was detected in the bacterial counts of all isolates (all P > 0.05). Rifampicin with a final concentration of 0.1 μg/mL was administered to bacteria that formed biofilm (24 h), and no significant decrease was detected in bacterial count (all P > 0.05). Notably, ozonated water of even 4.78 mg/L concentration for 72 h decreased the bacterial count by ≥ 2 log10. CONCLUSION: Different approaches are needed for treating PRKp isolates. We demonstrate that PRKp isolates can be successfully treated with higher concentrations of ozone.

A novel agent for myeloma causing toxic keratopathy, belantamab mafodotin: a case report and literature review / Belantamabe-mafodotina, um novo agente para mieloma, causando ceratopatia tóxica: relato de caso e revisão da literatura

ABSTRACT A 60-year-old-male with refractory relapsed multiple myeloma presented with redness, pain, foreign body sensation, and blurred vision in both eyes that gradually increased after his third belantamab mafotodin infusion. Biomicroscopy revealed bilateral microcyst-like epithelial changes and epithelial crystal-like deposits, whereas in vivo confocal microscopy revealed intraepithelial and subepithelial hyperreflective deposits in corneal epithelium. Belantamab mafodotin therapy was discontinued for seven weeks due to corneal toxicity, which cleared progressively. We aim to demonstrate belantamab mafodotin-related corneal toxicity that may be detected using slit lamp and in vivo confocal biomicroscopy.

RESUMO Um homem de 60 anos, diagnosticado com mieloma múltiplo recidivante refratário, apresentou vermelhidão, dor, sensação de corpo estranho e visão turva em ambos os olhos, aumentando gradualmente após sua terceira infusão de belantamabe mafodotina. À biomicroscopia, foram observadas alterações epiteliais bilaterais semelhantes a microcistos e depósitos epiteliais semelhantes a cristais. A microscopia confocal in vivo revelou depósitos hiper-refletivos intraepiteliais e subepiteliais na córnea. Devido à toxicidade corneana, a terapia com belantamabe mafodotina foi interrompida por sete semanas e a toxicidade foi gradualmente resolvida. Nosso objetivo é demonstrar os achados à biomicroscopia confocal in vivo e à lâmpada de fenda da toxicidade corneana relacionada ao belantamabe mafodotina.

Effect of upper eyelid blepharoplasty on the ocular surface, tear film, and corneal microstructure

ABSTRACT Purpose: This study aimed to investigate the effect of upper eyelid blepharoplasty with the removal of the skin and a strip of orbicularis oculi muscle on the ocular surface, tear film, and dry eye-related symptoms. Methods: Twenty-two eyes of 22 consecutive patients operated by a single surgeon (21 females; mean age, 61 years; age range, 41-75 years) were included. All subjects completed the Ocular Surface Disease Index questionnaire, underwent in vivo confocal microscopy, tear film breakup time measurements, the Schirmer test with anesthesia, and fluorescein and lissamine green staining measurements before, 1 month, and 6 months after upper blepharoplasty alone with preseptal orbicularis excision. Results: A significant increase in Ocular Surface Disease Index, and corneal fluorescein and lissamine green staining and a significant decrease in tear film breakup time were observed after 1 month (p=0.003, p=0.004, p=0.029, and p=0.024 respectively) and 6 months (p=0.001 for all findings). No significant difference in the Schirmer test score was observed during the follow-up. None of the in vivo confocal microscopy parameters showed significant changes during the study. Conclusions: An increase in dry eye symptoms and a decrease in tear film stability along with ocular surface staining were observed in patients undergoing upper eyelid blepharoplasty.

Comparative analysis of SARS-CoV-2 variants Alpha (B.1.1.7), Gamma (P.1), Zeta (P.2) and Delta (B.1.617.2) in Vero-E6 cells: ultrastructural characterization of cytopathology and replication kinetics

Abstract This study compares the effects of virus-cell interactions among SARS-CoV-2 variants of concern (VOCs) isolated in Brazil in 2021, hypothesizing a correlation between cellular alterations and mortality and between viral load and transmissibility. For this purpose, reference isolates of Alpha, Gamma, Zeta, and Delta variants were inoculated into monolayers of Vero-E6 cells. Viral RNA was quantified in cell supernatants by RT‒PCR, and infected cells were analyzed by Transmission Electron Microscopy (TEM) for qualitative and quantitative evaluation of cellular changes 24, 48, and 72 hours postinfection (hpi). Ultrastructural analyses showed that all variants of SARS-CoV-2 altered the structure and function of mitochondria, nucleus, and rough endoplasmic reticulum of cells. Monolayers infected with the Delta variant showed the highest number of modified cells and the greatest statistically significant differences compared to those of other variants. Viral particles were observed in the cytosol and the cell membrane in 100 % of the cells at 48 hpi. Alpha showed the highest mean particle diameter (79 nm), and Gamma and Delta were the smallest (75 nm). Alpha and Gamma had the highest particle frequency per field at 48 hpi, while the same was observed for Zeta and Delta at 72 hpi and 24 hpi, respectively. The cycle threshold of viral RNA varied among the target protein, VOC, and time of infection. The findings presented here demonstrate that all four VOCs evaluated caused ultrastructural changes in Vero-E6 cells, which were more prominent when infection occured with the Delta variant.

Corneal ectasia following photorefractive keratectomy: a confocal microscopic case report and literature review / Ectasia corneana após ceratectomia fotorrefrativa: relato de caso de microscopia confocal e revisão da literatura

ABSTRACT The occurrence of corneal ectasia after photorefractive keratectomy is a rare but serious complication of refractive surgery. Possible risk factors are not well assessed, but a probable reason is the failure to detect keratoconus preoperatively. In this report, we describe a case of corneal ectasia after photorefractive keratectomy in a patient who presented a suspicious tomography pattern preoperatively but had no degenerative alterations associated with pathologic keratoconus, as revealed by in vivo corneal confocal microscopy. We also review eligible case reports of post-photorefractive keratectomy ectasia to find similar characteristics.

RESUMO A ocorrência de ectasia corneana após ceratectomia fotorrefrativa é uma complicação rara, porém grave, em cirurgia refrativa. Os possíveis fatores de risco não são bem avaliados, mas a opinião atual é que a falha na detecção de ceratocone pré-operatório possa ser o principal motivo. Neste relato, descrevemos um caso de ectasia corneana após ceratectomia fotorrefrativa em paciente apresentando padrão tomográfico suspeito no pré-operatório, mas sem alterações degenerativas associadas a ceratocone patológico, conforme revelado por microscopia confocal in vivo da córnea. Além disso, revisamos, na literatura, relatos de casos elegíveis de ectasia pós-ceratectomia fotorrefrativa para encontrar características semelhantes.