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1.
Waste Biomass Valorization ; 13(4): 2411-2423, 2022.
Article in English | MEDLINE | ID: mdl-35096210

ABSTRACT

In this study, Artemisia annua stem waste was identified, for the first time, as a potential natural source to produce cellulose microfibers (CMF), as well as cellulose nanocrystals (CNC) with unique functionalities by using various organic acids. The CMF extraction was carried out using alkali and bleaching treatments, while the CNC were isolated under acid hydrolysis by using sulfuric acid (S-CNC), phosphoric acid (P-CNC), and hydrochloric acid / citric acid mixture (C-CNC). The CMF and CNC physicochemical, structural, morphological, dimensional, and thermal properties were characterized. CMF with a yield of 53%, diameter of 5 to 30 µm and crystallinity of 57% were successfully obtained. In contrast, CNC showed a rod-like shape with an aspect ratio of 53, 95, and 64 and a crystallinity index of 84, 79, and 72% for S-CNC, P-CNC, and C-CNC, respectively. Results suggested that the type of acid significantly influenced the structure, morphology, and thermal stability of CNCs. Based on these results, Artemisia annua stem waste is a great candidate source for cellulose derivatives with excellent characteristics.

2.
Nanomaterials (Basel) ; 11(10)2021 Oct 11.
Article in English | MEDLINE | ID: mdl-34685112

ABSTRACT

The present study aims to compare the early stages of graphitization of the same DND source for two annealing atmospheres (primary vacuum, argon at atmospheric pressure) in an identical set-up. DND samples are finely characterized by a combination of complementary techniques (FTIR, Raman, XPS, HR-TEM) to highlight the induced modifications for temperature up to 1100 °C. The annealing atmosphere has a significant impact on the graphitization kinetics with a higher fraction of sp2-C formed under vacuum compared to argon for the same temperature. Whatever the annealing atmosphere, carbon hydrogen bonds are created at the DND surface during annealing according to FTIR. A "nano effect", specific to the <10 nm size of DND, exalts the extreme surface chemistry in XPS analysis. According to HR-TEM images, the graphitization is limited to the first outer shell even for DND annealed at 1100 °C under vacuum.

3.
Nanomaterials (Basel) ; 10(3)2020 Mar 19.
Article in English | MEDLINE | ID: mdl-32204428

ABSTRACT

Nanodiamonds of detonation origin are promising delivery agents of anti-cancer therapeutic compounds in a whole organism like mouse, owing to their versatile surface chemistry and ultra-small 5 nm average primary size compatible with natural elimination routes. However, to date, little is known about tissue distribution, elimination pathways and efficacy of nanodiamonds-based therapy in mice. In this report, we studied the capacity of cationic hydrogenated detonation nanodiamonds to carry active small interfering RNA (siRNA) in a mice model of Ewing sarcoma, a bone cancer of young adults due in the vast majority to the EWS-FLI1 junction oncogene. Replacing hydrogen gas by its radioactive analog tritium gas led to the formation of labeled nanodiamonds and allowed us to investigate their distribution throughout mouse organs and their excretion in urine and feces. We also demonstrated that siRNA directed against EWS-FLI1 inhibited this oncogene expression in tumor xenografted on mice. This work is a significant step to establish cationic hydrogenated detonation nanodiamond as an effective agent for in vivo delivery of active siRNA.

4.
JFMS Open Rep ; 5(1): 2055116919839857, 2019.
Article in English | MEDLINE | ID: mdl-30984411

ABSTRACT

CASE SUMMARY: An 8-year-old spayed female domestic shorthair cat was referred for trismus of progressive onset, which had started at least 1 month previously. The patient presented with weakness, anorexia, chronic bilateral purulent nasal discharge and concurrent reduced nasal airflow. Upon physical examination, painful mouth opening, bilateral swelling of the temporal areas, with an inability to open and close the mouth completely, were apparent. A vertical mandibular range of motion (vmROM) of 22 mm was noted. Complete blood count, biochemistry, electrolytes and various serology tests were unremarkable. CT revealed multiple mineralised lesions within the masticatory muscles. Histopathological features were consistent with those seen in the human disease fibrodysplasia ossificans progressiva (FOP). Supportive treatment did not improve the vmROM, eventually resulting in a 13 mm open bite, and total inability to close and open the mouth. Cardiac arrest occurred at the induction of an anaesthesia procedure aiming to perform tracheostomy and nasal lavage. Despite emergency tracheotomy and cardiac resuscitation, humane euthanasia was elected by the owners. Post-mortem molecular investigations highlighted a heterozygous deletion, compatible with a splicing site mutation in ACVR1, which is also associated with FOP in humans. RELEVANCE AND NOVEL INFORMATION: This is the first report in the veterinary literature of FOP-like disease selectively affecting the masticatory muscles. This condition is associated with a poor prognosis, as no medical or surgical treatment has currently proven to be of any prophylactic or curative benefit. Although rare, FOP-like disease should be included in the differential diagnosis of trismus in the cat. Any further muscle injury should be avoided.

5.
Nanoscale ; 11(16): 8027-8036, 2019 Apr 23.
Article in English | MEDLINE | ID: mdl-30964938

ABSTRACT

We report here on a robust and easy-to-implement method for the labelling of detonation nanodiamonds (DND) with hydrogen isotopes (deuterium and tritium), using thermal annealing performed in a closed system. With this method, we have synthesized and fully characterized (FTIR, Raman, DLS, 3H/2H/1H and 13C MAS NMR) deuterium-treated and tritium-treated DND and demonstrated the usefulness of isotope incorporation in investigating the surface chemistry of such nanomaterials. For instance, surface treatment with deuterium coupled to FTIR spectroscopy allowed us to discriminate the origin of C-H terminations at the DND surface after the hydrogenation process. As a complementary, tritium appeared very useful for quantification purposes, while 1,2,3H NMR confirmed the nature of the C-1,2,3H bonds created. This isotopic study provides new insights into the characteristics of hydrogen-treated DND.

7.
BMJ Open ; 7(1): e013348, 2017 01 30.
Article in English | MEDLINE | ID: mdl-28137928

ABSTRACT

INTRODUCTION: Stroke frequently results in balance disorders, leading to lower levels of activity and a diminution in autonomy. Current physical therapies (PT) aiming to reduce postural imbalance have shown a large variety of effects with low levels of evidence. The objectives are to determine the efficiency of PT in recovering from postural imbalance in patients after a stroke and to assess which PT is more effective. METHODS AND ANALYSIS: We will search several databases from inception to October 2015. Only randomised controlled trials assessing PT to recover from poststroke postural imbalance in adults will be considered.Outcome measures will be the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke (PASS), the 'weight-bearing asymmetry' (WBA), the 'centre of pressure' (COP) and the 'limit of stability' (LOS). WBA, COP and LOS are measured by a (sitting or standing) static evaluation on force plate or another device.Two independent reviewers will screen titles, abstracts and full-text articles, evaluate the risk of bias and will perform data extraction. In addition to the outcomes, measures of independence will be analysed. This study will aim at determining the effects of PT on the function (WBA, COP, LOS), the activity (BBS, PASS) and the independence of patients. Subgroup analyses will be planned according to the location of brain lesion (hemispheric, brainstem or cerebellum), the time since stroke (early, late, chronic), the PT (type, main aim (direct effect or generalisation), overall duration), the type of approaches (top-down or bottom-up) and the methodological quality of studies. ETHICS AND DISSEMINATION: No ethical statement will be required. The results will be published in a peer-reviewed journal. This meta-analysis aims at managing the rehabilitation after postural imbalance by PT after a stroke. TRIAL REGISTRATION NUMBER: Prospero CRD42016037966;Pre-results.


Subject(s)
Physical Therapy Modalities , Postural Balance , Research Design , Stroke Rehabilitation , Stroke/physiopathology , Cerebellum , Cerebrum , Humans , Meta-Analysis as Topic , Systematic Reviews as Topic
8.
Chem Commun (Camb) ; 53(7): 1237-1240, 2017 Jan 19.
Article in English | MEDLINE | ID: mdl-28058432

ABSTRACT

For the first time, overproduction of hydroxyl radicals (HO˙) induced by plasma hydrogenated detonation nanodiamonds (H-NDs) under X-ray irradiation is reported. Using coumarin (COU) as a fluorescent probe, we reveal a significant increase of 40% of the HO˙ production in the presence of H-NDs (6-100 µg ml-1) compared with water alone. This effect is related to the negative electron affinity of the hydrogenated nanodiamonds and illustrates the ability of H-NDs to produce reactive oxygen species probably via electron emission in water under X-ray irradiation.

9.
Nano Lett ; 16(6): 3514-8, 2016 06 08.
Article in English | MEDLINE | ID: mdl-27124492

ABSTRACT

Engineered nanoparticles such as graphenes, nanodiamonds, and carbon nanotubes correspond to different allotropes of carbon and are among the best candidates for applications in fast-growing nanotechnology. It is thus likely that they may get into the environment at each step of their life cycle: production, use, and disposal. The aquatic compartment concentrates pollutants and is expected to be especially impacted. The toxicity of a compound is conventionally evaluated using mass concentration as a quantitative measure of exposure. However, several studies have highlighted that such a metric is not the best descriptor at the nanoscale. Here we compare the inhibition of Xenopus laevis larvae growth after in vivo exposure to different carbon nanoparticles for 12 days using different dose metrics and clearly show that surface area is the most relevant descriptor of toxicity for different types of carbon allotropes.


Subject(s)
Nanoparticles/toxicity , Animals , Carbon/chemistry , Dose-Response Relationship, Radiation , Ecotoxicology , Humans , Larva/drug effects , Larva/growth & development , Nanoparticles/chemistry , Nanotechnology , Nanotubes, Carbon/chemistry , Nanotubes, Carbon/toxicity , Particle Size , Radiation Dosage , Surface Properties , Xenopus laevis/growth & development
10.
ACS Appl Mater Interfaces ; 7(29): 15752-64, 2015 Jul 29.
Article in English | MEDLINE | ID: mdl-26151414

ABSTRACT

Small size and enhanced properties of nanoparticles (NP) are great advantages toward device miniaturization. However, adhesion is essential for the reliability of such NP layer-based devices. In this work, we present some quick tests to investigate the adhesion behavior of the whole NP layer by mimicking several applicative environments: biological buffers and cells, corrosion, and microfabrication processes. This statistic approach evaluates both adhesion and mobility respectively through particle density and layer homogeneity. We chose nanodiamonds (ND) as reference particles because they are spherical and inert and exhibit either positive or negative zeta potential for the same diameter while surfactant-free. Several deposition methods were used to prepare a wide range of ND layers with various densities and size distribution. We found some unexpected results confirming that the deposition method has to be carefully selected according to the targeted application. A selection of the suitable method(s) to prepare ND layers which are resilient in their applicative environment can be done based on these results. However, ND adhesion still remains critical in some conditions and thus requires further improvement. Most important, this study points out that NP adhesion behavior is more complex than simple particle detachment-or not-from the surface. The particles could also reorganize themselves in clusters. We evidenced, in particular, a surprising mobility driven by air/water interfaces during evaporation of water microdroplets. Further comparison with other materials would indicate if the highlighted phenomena could be extended to any nanoparticles layer.


Subject(s)
Materials Testing/methods , Membranes, Artificial , Nanodiamonds/chemistry , Nanodiamonds/ultrastructure , Printing, Three-Dimensional , Adhesiveness , Adsorption , Diffusion , Motion
11.
Biomaterials ; 45: 93-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25662499

ABSTRACT

The expression of a defective gene can lead to major cell dysfunctions among which cell proliferation and tumor formation. One promising therapeutic strategy consists in silencing the defective gene using small interfering RNA (siRNA). In previous publications we showed that diamond nanocrystals (ND) of primary size 35 nm, rendered cationic by polyethyleneimine-coating, can efficiently deliver siRNA into cell, which further block the expression of EWS/FLI-1 oncogene in a Ewing sarcoma disease model. However, a therapeutic application of such nanodiamonds requires their elimination by the organism, particularly in urine, which is impossible for 35 nm particles. Here, we report that hydrogenated cationic nanodiamonds of primary size 7 nm (ND-H) have also a high affinity for siRNA and are capable of delivering them in cells. With siRNA/ND-H complexes, we measured a high inhibition efficacy of EWS/FLI-1 gene expression in Ewing sarcoma cell line. Electron microscopy investigations showed ND-H in endocytosis compartments, and especially in macropinosomes from which they can escape before siRNA degradation occurred. In addition, the association of EWS/FLI-1 silencing by the siRNA/ND-H complex with a vincristine treatment yielded a potentiation of the toxic effect of this chemotherapeutic drug. Therefore ND-H appears as a promising delivery agent in anti-tumoral gene therapy.


Subject(s)
Gene Transfer Techniques , Nanodiamonds/chemistry , Oncogene Proteins, Fusion/genetics , Plasma Gases/chemistry , Proto-Oncogene Protein c-fli-1/genetics , RNA, Small Interfering/metabolism , RNA-Binding Protein EWS/genetics , Sarcoma, Ewing/metabolism , Cations , Cell Death/drug effects , Cell Line, Tumor , Endocytosis/drug effects , Fluorescence , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hydrogenation , Nanodiamonds/ultrastructure , Oncogene Proteins, Fusion/metabolism , Proto-Oncogene Protein c-fli-1/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Protein EWS/metabolism , Sarcoma, Ewing/genetics , Sarcoma, Ewing/ultrastructure , Subcellular Fractions/drug effects , Subcellular Fractions/metabolism , Vincristine/pharmacology
12.
Chem Commun (Camb) ; 50(22): 2916-8, 2014 Mar 18.
Article in English | MEDLINE | ID: mdl-24492594

ABSTRACT

For the first time, the radioactive labeling of detonation nanodiamonds was efficiently achieved using a tritium microwave plasma. According to our measurements, the total radioactivity reaches 9120 ± 120 µCi mg(-1), with 93% of (3)H atoms tightly bonded to the surface and up to 7% embedded into the diamond core. Such (3)H doping will ensure highly stable radiolabeled nanodiamonds, on which surface functionalization is still allowed. This breakthrough opens the way to biodistribution and pharmacokinetics studies of nanodiamonds, while this approach can be scalable to easily treat bulk quantities of nanodiamonds at low cost.


Subject(s)
Nanodiamonds/chemistry , Tritium/chemistry , Isotope Labeling , Microwaves , Spectroscopy, Fourier Transform Infrared
13.
Nanoscale ; 5(19): 8958-62, 2013 Oct 07.
Article in English | MEDLINE | ID: mdl-23965659

ABSTRACT

Although undoped diamond is insulating, hydrogenated bulk diamond surfaces exhibit surface conductivity under air and are electrochemically active in aqueous solutions. Due to their large surface/volume ratio, similar surface effects may exhibit a dramatic impact on the properties of nanodiamonds. Here we show that plasma-hydrogenated detonation nanodiamonds (NDs-H) display a positive zeta potential in water due to charge transfer with a redox couple involving oxygen in water. The transfer doping of NDs-H in water can be modulated by pH. Surprisingly, after acid addition, strong Coulomb coupling between NDs-H and adsorbed counterions induces the self-assembly of NDs-H into organized macro-structures reaching millimeter scale.

14.
Langmuir ; 29(5): 1634-41, 2013 Feb 05.
Article in English | MEDLINE | ID: mdl-23305296

ABSTRACT

Electrical potential of nanoparticles under relevant environment is substantial for their applications in electronics as well as sensors and biology. Here, we use Kelvin force microscopy to characterize electrical properties of semiconducting diamond nanoparticles (DNPs) of 5-10 nm nominal size and metallic gold nanoparticles (20 and 40 nm) on Si and Au substrates under ambient conditions. The DNPs are deposited on Si and Au substrates from dispersions with well-defined zeta-potential. We show that the nanoparticle potential depends on its size and that the only reliable potential characteristic is a linear fit of this dependence within a 5-50 nm range. Systematically different potentials of hydrogenated, oxidized, and graphitized DNPs are resolved using this methodology. The differences are within 50 mV, that is much lower than on monocrystalline diamond. Furthermore, all of the nanoparticles assume their potential within -60 mV according to the Au and Si substrate, thus gaining up to 0.4 V difference. This effect is attributed to DNP charging by charge transfer and/or polarization. This is confirmed by secondary electron emission. Such effects are general with broad implications for nanoparticles applications.


Subject(s)
Electric Stimulation , Gold/chemistry , Metal Nanoparticles/chemistry , Particle Size , Semiconductors , Surface Properties
15.
Nanoscale ; 4(21): 6792-9, 2012 Nov 07.
Article in English | MEDLINE | ID: mdl-23000973

ABSTRACT

Surface-graphitized nanodiamonds (NDs) are promising hybrid nanomaterials which appear to combine core properties of diamond with surface properties of graphene-based materials. Here we demonstrate that NDs covered by graphene islands, so-called Fullerene-Like Reconstructions (FLRs), are sensitive to hole doping by molecular oxygen in water. NDs covered by FLRs (NDs-FLRs) are prepared by annealing under vacuum of detonation NDs at 750 °C. We propose that oxygen hole doping is promoted on FLRs due to a unique electronic interaction between the diamond core and the outer graphene layer. As a consequence, NDs-FLRs exhibit positive zeta potential in water, unlike NDs surrounded by several graphitic layers. Surface hole-doped NDs may be promising nanomaterials for new electronic and biomedical applications.

16.
Tanzan J Health Res ; 12(1): 73-9, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20737832

ABSTRACT

Côte d'Ivoire is an endemic area for Plasmodium falciparum malaria, with perennial transmission in the southern forest and seasonal transmission in the northern savannah. Change of first-line treatment of uncomplicated malaria to artemisinin-combination therapy (ACT) is widespread in the country as elsewhere in Africa. The present study was conducted to assess the in vitro response of Plasmodium falciparum to antimalarial drugs currently used in the country (chloroquine, artemisinin and dihydroartemisinin) and new drugs that could be used in the near future (pyronaridine) and to analyse the pattern of cross-resistance between these drugs. The standard in vitro drug sensitivity microtechnique recommended by the World Health Organization was used to assess the sensitivity of Plasmodium falciparum isolates collected in Abidjan (Côte d'Ivoire) between April and December 2006. Of 128 in vitro tests performed, 112 (87.5%) were successful. Among them, 32, 27, 25, and 28 P. falciparum isolates grew satisfactorily and yield interpretable results for chloroquine, pyronaridine, artemisinin, and dihydroartemisinin respectively. The proportions of resistant isolates were 56.2% for chloroquine, 48% for pyronaridine, 36% for artemisinin and 3.6% for dihydroartemisinin. The most potent drug was dihydroartemisinin with a geometric mean IC50 of 2.72 nM ranged from 1.45 to 3.99 nM. No multi-resistant isolates (showing resistance to more than three drugs) were found. A positive correlation was found between the IC50 values for the following drugs: chloroquine and pyronaridine (r=0.45), pyronaridine and dihydroartemisinin (r=0.40), chloroquine and artemisinin (r=0.68), artemisinin and dihydroartemisinin (r=0.62). Data suggested cross-resistance between these drugs and warrant an improved surveillance programme for drug resistance to malaria in Côte d'Ivoire.


Subject(s)
Anti-Infective Agents/pharmacology , Antimalarials/pharmacology , Malaria, Falciparum/drug therapy , Plasmodium falciparum/drug effects , Cote d'Ivoire , Drug Resistance, Microbial , Inhibitory Concentration 50 , Malaria, Falciparum/parasitology , Microbial Sensitivity Tests , Plasmodium falciparum/isolation & purification
17.
ACS Appl Mater Interfaces ; 1(12): 2738-46, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20356151

ABSTRACT

Nanodiamond (ND) seeding is a well-established route toward the CVD (chemical vapor deposition) synthesis of diamond ultrathin films. This method is based on the deposition onto a substrate of diamond nanoparticles which act as pre-existing sp(3) seeds. Here, we report on a straightforward method to disperse diamond nanoparticles on a substrate by taking advantage of the electrostatic interactions between the nanodiamonds and the substrate surface coated with a cationic polymer. This layer-by-layer deposition technique leads to reproducible and homogeneous large-scale nanoparticle deposits independent of the substrate's nature and shape. No specific functionalization of the nanoparticles is required, and low concentrated solutions can be used. The density of NDs on the substrate can be controlled, as shown by in situ ATR-FTIR (attenuated total reflection Fourier transform infrared) analysis and QCM (quartz crystal microbalance) measurements. Highly dense and compact ND deposits can be obtained, allowing CVD growth of nanocrystalline diamond ultrathin films (70 nm) on various substrates. The synthesis of 3D structured and patterned diamond thin films has also been demonstrated with this method.

18.
Vet Radiol Ultrasound ; 48(5): 439-47, 2007.
Article in English | MEDLINE | ID: mdl-17899979

ABSTRACT

The goals of our study were to review the ultrasonographic features of spontaneous extrahepatic biliary obstruction in cats and to determine whether these features can assist in differentiating tumor, inflammation, and choleliths as the cause of obstruction. Thirty cats with a presurgical ultrasound examination an dconfirmed extrahepatic biliary obstruction were studied. A common bile duct diameter over 5 mm was present in 97% of the cats with extrahepatic biliary obstruction. Gallbladder dilation was seen in < 50% of the cats. Ultrasound identified all obstructive choleliths (calculus or plugs) in the common bile duct. However, neither common bile duct diameter nor appearance or any other ultrasonographic feature allowed differentiation between tumor and inflammation as the cause of obstruction. A short duration of clinical signs (10 days or less) seemed to be associated with obstructive cholelithiasis.


Subject(s)
Cat Diseases/diagnostic imaging , Cholestasis, Extrahepatic/veterinary , Animals , Bile Ducts, Extrahepatic/diagnostic imaging , Cats , Cholestasis, Extrahepatic/diagnostic imaging , Female , Male , Medical Records , Retrospective Studies , Ultrasonography/veterinary
19.
Rev Int Hist Psychanal ; 6: 429-82, 1993.
Article in French | MEDLINE | ID: mdl-11640441

ABSTRACT

A series of letters that Freud wrote to Joan Riviere in the period from 12-8-1921 to 22-1-1939 has been transcribed, translated into French and published here for the first time in the original text. They were given by Joan Riviere to the Sigmund Freud Archives and deposited at the Library of Congress in Washington where access to them had been restricted. Through the efforts of Dr. Harold Blum, the present Executive Director of the Freud Archives, the restriction was lifted. The letters concern arrangements that Freud made for his analysis of Joan Riviere; his (and her) relationship to Ernest Jones; the translation into English and the publication of his works in England. They also concern Freud's reaction to the reception in England of Anna Freud's book on The Technique of Child Analysis (1927) and his view of Melanie Klein's approach to the theory and practice of child analysis.


Subject(s)
Psychoanalysis/history , Austria , History, 20th Century , Humans , United Kingdom
20.
Sem Hop ; 56(25-28): 1183-7, 1980.
Article in French | MEDLINE | ID: mdl-6256868

ABSTRACT

The same radiosurgical treatment was given to 108 cases of stages T1 and T2 uterine cancers, and consisted of curietherapy followed by an extended colpohysterectomy with lymph node resection (Meigs operation) Intravenous urography was performed during operation in all patients, and at least one postoperative intravenous urography was also carried out. Stricture of the pelvic ureter was discovered postoperatively in 50.9% of cases, with or without subjacent stasis: this type of image is transient and disappears within eight months. A lymphocele can cause images showing signs of bladder pressure. Ureteral and vesical complications of a true and definitive nature are extremely rare.


Subject(s)
Urologic Diseases/complications , Uterine Neoplasms/surgery , Female , Humans , Neoplasm Staging , Urography , Uterine Neoplasms/complications , Uterine Neoplasms/radiotherapy
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