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High-magnification observation of seminiferous tubules through the tunica albuginea by two-photon laser scanning microscopy

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Asian Journal of Andrology 2011年第5期13卷 774-776页

作者： vincent Achard Pascal Weber Georges Mercier Marie-Pierre Blanchard Laboratoire d＇Histologie-Cytologie Faculte de Medecine secteur Timone Universite de la Mediterranee Marseille 13385 France Centre d＇Assistance Medicale a la Procreation AP-HM Conception Marseille 13385 France CNRS - IBDML - UMR6216 Service Imagerie - Case 907 Faculte des Sciences de Luminy Marseille 13288 France and Centre de Microscopie et Imagerie IFR Jean Roche Universite de la Mediterranee Marseille 13916 France

Testicular sperm extraction is widely used in the treatment of male infertility in cases of non-obstructive azoospermia. Identifying spermatogenetic foci within the testes is critical for testicular sperm extraction. Two-photon laser scanning microscopy （TPLSM） is an autofluorescence-based microscopy technique that allows observation at a cellular level in the depth of fresh living tissues and does not require any histological processing （fixation or staining）. The wavelengths previously used have shown no phototoxicity on sperm. We used TPLSM to detect spermatogenetic foci in fresh mouse testicular parenchyma without disrupting the tunica albuginea. Fresh surgically retrieved testes were observed using TPLSM within 1 h after extraction. Contralateral testes for each animal were observed using standard histology. Using TPLSM we were able to observe and measure the diameter of seminiferous tubules through the tunica albuginea, similar to the histological control. Structures within epithelial tubules were also observed, although their nature has yet to be identified. TPLSM is a real-time microscopy technique that could detect spermatogenetic foci.

关键词： seminiferous epithelium spermatogenesis

Derivation of FFT numerical bounds of the effective properties ofcomposites and polycristals

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Theoretical & Applied Mechanics Letters 2021年第2期11卷 94-101页

作者： Minh-Tan Nguyen Quy-Dong To vincent Monchiet Univ Gustave Eiffel Univ Paris Est CreteilCNRSMSME UMR 8208F-77454 Marne-la-VallÃl’eFrance

In this paper,we provide exact fast Fourier transform(FFT)-based numerical bounds for the elastic prop-erties of composites having arbitrary *** bounds,an upper and a lower,are derivedby considering usual variational principles based on the strain and the stress *** bounds arecomputed by solving the Lippmann-Schwinger equation together with the shape coefficients which al-low an exact description of the microstructure of the *** coefficients are the exact Fouriertransform of the characteristic functions of the *** this study,the geometry of the microstructureis approximated by polygonals(two-dimensional,2D objects)and by polyhedrons(three-dimensional,3Dobjects)for which exact expressions of the shape coefficients are *** applications are pre-sented in the paper showing the relevance of the *** the first benchmark example,we considerthe case of a composite with *** effective elastic coefficients ares derived and compared,consider-ing the exact shape coefficient of the circular inclusion and its approximation with a ***,thehomogenized elastic coefficients are derived for a composite reinforced by 2D flower-shaped inclusionsand with 3D toroidal-shaped ***,the method is applied to polycristals considering Voronoitessellations for which the description with polygonals and polyhedrons becomes *** comparisonwith the original FFT method of Moulinec and Suquet is provided in order to show the relevance of thesenumerical bounds.

关键词： Composites Homogenization Fast Fourier transform Numerical bounds

State of machine and deep learning in histopathological applications in digestive diseases

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World Journal of Gastroenterology 2021年第20期27卷 2545-2575页

作者： Soma Kobayashi Joel H Saltz vincent W Yang Department of Biomedical Informatics Renaissance School of MedicineStony Brook UniversityStony BrookNY 11794United States Department of Medicine Renaissance School of MedicineStony Brook UniversityStony BrookNY 11794United States Department of Physiology and Biophysics Renaissance School of MedicineStony Brook UniversityStony BrookNY 11794United States

Machine learning(ML)-and deep learning(DL)-based imaging modalities have exhibited the capacity to handle extremely high dimensional data for a number of computer vision *** these approaches have been applied to numerous data types,this capacity can be especially leveraged by application on histopathological images,which capture cellular and structural features with their highresolution,microscopic ***,these methodologies have demonstrated promising performance in a variety of applications like disease classification,cancer grading,structure and cellular localizations,and prognostic predictions.A wide range of pathologies requiring histopathological evaluation exist in gastroenterology and hepatology,indicating these as disciplines highly targetable for integration of these *** have also already been primed to consider the impact of these algorithms,as development of real-time endoscopic video analysis software has been an active and popular field of *** heightened clinical awareness will likely be important for future integration of these methods and to drive interdisciplinary collaborations on emerging *** provide an overview on the application of these methodologies for gastrointestinal and hepatological histopathological slides,this review will discuss general ML and DL concepts,introduce recent and emerging literature using these methods,and cover challenges moving forward to further advance the field.

关键词： Artificial intelligence Machine learning Deep learning Gastroenterology Hepatology Histopathology

Improved “cure on demand” of aromatic bismaleimide with thiol triggered by retro-Diels-Alder reaction

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Frontiers of Chemical Science and Engineering 2021年第2期15卷 330-339页

作者： vincent Froidevaux Melanie Decostanzi Abdelatif Manseri Sylvain Caillol Bernard Boutevin Remi Auvergne Institut Charles Gerhardt Montpellier UMR 5253-CNRSUniversitede MontpellierENSCM34296 Montpellier Cedex 5France

This study focuses on the synthesis of new liquid aromatic bismaleimide monomers in order to improve self-curing on demand(SCOD)systems previously based on aliphatic *** SCOD systems are based on Diels-Alder(DA)/retro-DA *** syntheses of new different aromatic bismaleimides with ester and amide bonds are *** maleimides have been protected using DA reaction and characterized by 1H NMR analysis to determine protection rate and diastereomer *** retro-DA reactions of both aromatic and aliphatic DA adducts in presence of thiol molecules were *** analysis was monitored by 1H NMR and compared to model ***,both aromatic and aliphatic bismaleimides-based polymers were synthesized with 2-mercaptoethyl ether and thermal properties of polymers were *** glass transition temperature values ranged from–20°C to 14°C and very good thermal stabilities were observed(up to 300°C).

关键词： thiol-ene polymerization self-curing on demand thia-michael addition Diels-Alder maleimide

Role of cytokines and chemokines in non-alcoholic fatty liver disease

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World Journal of Gastroenterology 2012年第8期18卷 727-735页

作者： vincent Braunersreuther Giorgio Luciano Viviani Franois Mach Fabrizio Montecucco Division of Cardiology Foundation for Medical Researches Faculty of Medicine Geneva University Hospital Department of Internal Medicine Adult Diabetes Centre University of Genoa

Non-alcoholic fatty liver disease (NAFLD) includes a variety of histological conditions (ranging from liver steatosis and steatohepatitis, to fibrosis and hepatocarcinoma) that are characterized by an increased fat content within the liver. The accumulation/deposition of fat within the liver is essential for diagnosis of NAFLD and might be associated with alterations in the hepatic and systemic inflammatory state. Although it is still unclear if each histological entity represents a different disease or rather steps of the same disease, inflammatory processes in NAFLD might influence its pathophysiology and prognosis. In particular, non-alcoholic steatohepatitis (the most inflamed condition in NAFLDs, which more frequently evolves towards chronic and serious liver diseases) is characterized by a marked activation of inflammatory cells and the upregulation of several soluble inflammatory mediators. Among several mediators, cytokines and chemokines might play a pivotal active role in NAFLD and are considered as potential therapeutic targets. In this review, we will update evidence from both basic research and clinical studies on the potential role of cytokines and chemokines in the pathophysiology of NAFLD.

关键词： Inflammation Non-alcoholic fatty liver disease Cytokine Chemokine

Antiviral activities of extracts from Hong Kong seaweeds

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第12期9卷 969-976页

作者： Hui WANG Engchoon vincent OOI Put O. ANG Jr Medical College Jinan University Guangzhou 510632 China Department of Biology the Chinese University of Hong Kong Shatin N. T. Hong Kong China

We extracted six Hong Kong brown seaweed species with hot water for their antiviral properties. The cytotoxicity and antiviral activity of these extracts were tested by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenlytetrezolium bromide] method, cytopathic effect reduction assay, and plaque reduction assay. The antiviral effect was further determined by flow cytometric analysis. The results showed that most of these extracts inhibited the propagation of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) standard strains with very low cytotoxicity to the host cells. The extracts of Hydroclathrus clathratus and Lobophora variegata showed more potential anti-HSV activities than the extracts of the other four seaweeds. They also had moderate anti- respiratory syncytial virus (RSV) activities but could not inhibit influenza A virus. Hydroclathrus clathratus was further extracted by diluted acid and alkali and the antiviral effects of the extracts were also detected. The result showed that the hot water extract contained the main carbohydrate components that exhibited the antiviral activities against various strains of HSV, including the acyclovir-resistant strain. HI-3, a compound fractionated from this hot water extract, showed a dose-dependent anti-HSV activity in flow cytometric analysis and plaque reduction assay.

关键词： Hong Kong seaweed Hydroclathrus clathratus Antiviral activity Herpes simplex virus (HSV) Flow cytometry

Virtual colonoscopy-induced perforation in a patient with Crohn's disease

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World Journal of Gastroenterology 2007年第6期13卷 978-979页

作者： Sunny H Wong vincent WS Wong Joseph JY Sung Institute of Digestive Disease and Department of Medicine and Therapeutics The Chinese University of Hong Kong Hong Kong China

We report a case of sigmoid colon perforation in a patient with Crohn's disease undergoing computed-tomographic (CT) colonography. A 70-year-old patient with Crohn's disease with terminal ileitis and sigmoid stricture underwent CT colonography after incomplete conventional colonoscopy. During the procedure, the colon was inflated by air insufflation and the patient developed abdominal pain with radiological evidence of retroperitoneal and intraperitoneal free gas. Hartmann's operation was performed. This case highlights that CT colonography is not risk-free. The risk of perforation may be higher in patients with inflammatory bowel disease.

关键词： Perforation Colonography Crohn's disease Stricture Hartmann's Inflammatory bowel disease

Measuring Mental Workload Using ERPs Based on FIR,ICA,and MARA

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Computer Systems Science & Engineering 2022年第5期41卷 781-794页

作者： Yu Sun Yi Ding Junyi Jiang vincent G.Duffy Business School Shenyang UniversityShenyang110044China School of Economics and Management Anhui Polytechnic UniversityWuhu241000China Center for Science Communication and Achievement Transformation National Natural Science Foundation of ChinaBeijing100085China School of Industrial Engineering Purdue UniversityWest LafayetteIN 47906USA

Mental workload is considered to be strongly linked to human performance,and the ability to measure it accurately is key for balancing human health and *** this study,brain signals were elicited by mental arithmetic tasks of varying difficulty to stimulate different levels of mental *** addition,a finite impulse response(FIR)filter,independent component analysis(ICA),and multiple artifact rejection algorithms(MARAs)were used to filter event-related potentials(ERPs).Then,the data consisting of ERPs,subjective ratings of mental workload,and task performance,were analyzed through the use of variance and Spearman’s correlation during a simulated computer *** found that participants responded faster and performed better in the easy task condition,followed by the medium and high-difficulty conditions,which verifies the validity of the ERP ***,larger P2 and P3 waveforms were evoked as the task difficulty increased,and a higher task difficulty elicited a more enhanced *** analysis revealed a negative relationship between the amplitude of P3 and the subjective ratings,and a positive relationship between the P3 amplitude and *** results presented in this paper demonstrate that a combination of FIR,ICA,and MARA methods can filter ERPs in the non-invasive real-time measurement of ***,frontocentral P2,N3,and parietal P3 components showed differences between *** proposed measurement of mental workload can be useful for real-time identification of mental states and can be applied to human-computer interaction in the future.

关键词： Mental workload event-related potentials finite impulse response filter independent component analysis multiple artifact rejection algorithms

Silk fibroin-based inks for in situ 3D printing using a double crosslinking process

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Bioactive Materials 2024年第5期35卷 122-134页

作者： Francesca Agostinacchio vincent Fitzpatrick Sandra Dire David LKaplan Antonella Motta National Interuniversity Consortium of Material Science and Technology FlorenceItaly BIOtech Research Center and European Institute of Excellence on Tissue Engineering and Regenerative Medicine Department of Industrial EngineeringUniversity of TrentoTrentoItaly Materials Chemistry Group&“Klaus Müller”Magnetic Resonance Laboratory Department of Industrial EngineeringUniversity of TrentoTrentoItaly Department of Biomedical Engineering Tufts UniversityMedfordMA02155USA

The shortage of tissues and organs for transplantation is an urgent clinical *** situ 3D printing is an advanced 3D printing technique aimed at printing the new tissue or organ directly in the *** ink for this process is central to the outcomes,and must meet specific requirements such as rapid gelation,shape integrity,stability over time,and adhesion to surrounding healthy *** natural materials,silk fibroin exhibits fascinating properties that have made it widely studied in tissue engineering and regenerative ***,further improvements in silk fibroin inks are needed to match the requirements for in situ 3D *** the present study,silk fibroin-based inks were developed for in situ applications by exploiting covalent crosslinking process consisting of a pre-photo-crosslinking prior to printing and in situ enzymatic *** different silk fibroin molecular weights were characterized and the synergistic effect of the covalent bonds with shear forces enhanced the shift in silk secondary structure towardβ-sheets,thus,rapid *** hydrogels exhibited good mechanical properties,stability over time,and resistance to enzymatic degradation over 14 days,with no significant changes over time in their secondary structure and swelling ***,adhesion to tissues in vitro was demonstrated.

关键词： Silk fibroin inks In situ 3D printing Covalent crosslinking Regenerative medicine Rapid gelation