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1.
Cureus ; 16(5): e61336, 2024 May.
Article in English | MEDLINE | ID: mdl-38947581

ABSTRACT

BACKGROUND: Cervical cancer is the fourth most common cause of malignant tumor-related deaths among women in developing nations. Cervical cancer has been estimated to cause 527.600 new cases and 265.700 deaths globally per year. OBJECTIVES: This study aimed to evaluate patients with cervical cancer by ultrastaging all the lymph nodes (LN), sentinel LN (SLN) and non-SLN, to increase the sensitivity of the detection of LN metastases and the diagnostic accuracy in cervical cancer with a five-year follow-up. MATERIALS AND METHODS: This is a retrospective study of 14 cervical cancer cases from 2017 to 2019 at the Municipal Emergency Clinical Hospital of Timisoara, Romania. The cases were selected based on their high risk of LN involvement but negative intraoperative pathologic LN. After re-evaluating all paraffin block biopsy samples from 29 cases, 14 cases were included in the study, which met all criteria for ultrastaging on surgical biopsy samples. RESULTS: Patients' ages included in the study ranged from 43 to 70 years (median: 57.14 years). According to the International Federation of Gynecology and Obstetrics (FIGO) staging, the majority of the patients were in stage IB: seven cases (50%). The study revealed a positive correlation between patient age and FIGO staging, with Pearson's correlation coefficient of 0.707 and a p-value of less than 0.05, indicating that older patients were more likely to be diagnosed with a higher FIGO stage. The mean follow-up was 34.5 months, and the median follow-up was 36 months (range: 6-60 months). We obtained 167 nodes, with a mean of 11.92 nodes/case. Twenty-one LN were found to be positive with the ultrastaging method. We detected 11 LN with macrometastases (MAC) (52.38%), seven with micrometastasis (MIC) (33.3%), and three with tumor cell islets (14.4%). That would be 13% of newly diagnosed ultrastaging cases as positive nodes. This ultrastaging method detected nodal MIC in eight (57.1%) out of the 14 patients, who initially tested negative for LN involvement using the routine Hematoxylin and Eosin (HE) method. The detection of micrometastases in these patients underscored the superior sensitivity of ultrastaging, which was further highlighted by the subsequent relapse of four (28.57%) out of these eight patients. The study also found no correlation between the FIGO standardization and the number of MIC found in these patients. CONCLUSIONS: Predicting cervical LN metastasis (LNM) is crucial for improving survival rates and reducing recurrence. Very few small cohort studies used an ultrastaging method to assess non-SLNs; most of them only assessed SLNs. We showed in our study that the ultrastaging method, both in the case of SLN and non-SLN, is superior compared with H&E analysis, with a 13% rate of new positive nodule diagnosis. Metastatic involvement of non-SLN was found in over 50% of all cases (8/14) according to the ultrastaging method. Additionally, our study confirms that the sensitivity of SLN ultrastaging is high for the presence of both MIC and MAC in SLN pelvic LN. As a result, we feel that ultrastaging is the most effective method for SLN analysis in patients with early-stage cervical cancer, and bilateral detection is preferable, significantly reducing false-negative results. The routine use of SLN along with ultrastaging would lead to more accurate surgical staging and better oncological follow-up of cases.

2.
Medicina (Kaunas) ; 60(6)2024 May 30.
Article in English | MEDLINE | ID: mdl-38929526

ABSTRACT

Background and Objectives: Our aim was to perform a retrospective analysis of the volume of cervical screening tests, the number of patients treated with an excision method, and the incidence of invasive and non-invasive cervical during a pandemic and pre-pandemic period of 24 months. Materials and Methods: The study compared 404 patients who underwent cervical cone biopsy for cervical cancer. The study examined patients' specimens based on histopathological characteristics and categorized cervical lesions based on pap smear. Results: There was a statistically significant age difference between the two study periods. The mean difference was 32 years before the pandemic and 35 years during the pandemic (p-value > 0.05). The biggest patient loss ratio identified by age group was in the 50-59-year group, with a 14.53% loss in the pre-pandemic period and a 9.1% loss in the pandemic period. In the pandemic period, patients from rural areas presented in the clinical trial with a lower rate of 39.52% (83 patients) vs. 60.47% (127 patients) in urban areas. A higher percentage of patients experiencing cervicorrhagia as a clinical manifestation in the pandemic period vs. the pre-pandemic period, with an increase in more severe lesions in the pandemic period, had a statistical significance of 8% more newly diagnosed compared to the pre-pandemic period. Conclusions: The addressability of the patients during the COVID period was not affected in a drastic way in our study. We encountered a decrease in appointments in the age group of 50-59 years and a decrease in patients with rural residence. In our study, we found an increase in cervical bleeding as a reason for consultation in the pandemic period with a higher lesion degree, both on a pap smear and on a cervical biopsy.


Subject(s)
COVID-19 , Uterine Cervical Neoplasms , Humans , Female , COVID-19/epidemiology , COVID-19/diagnosis , Retrospective Studies , Middle Aged , Uterine Cervical Neoplasms/epidemiology , Uterine Cervical Neoplasms/diagnosis , Adult , SARS-CoV-2 , Papanicolaou Test/statistics & numerical data , Early Detection of Cancer/methods , Early Detection of Cancer/statistics & numerical data , Aged , Pandemics , Vaginal Smears/statistics & numerical data
3.
Cureus ; 16(4): e59077, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38694662

ABSTRACT

OBJECTIVE: The study investigates morphological variants of tertiary lymphoid structures (TLSs) in relation to cervical cancer development, from intraepithelial neoplastic lesions to invasive carcinomas with locoregional lymph node metastases. MATERIALS AND METHODS: This retrospective analysis comprised 100 cervical cancer cases who had had total hysterectomy with lymphadenectomy in the Obstetrics and Gynecology Clinic of the Municipal Emergency Clinical Hospital of Timisoara, Romania, from 2020 to 2023. Bilateral ilio obturator lymphadenectomy and total hysterectomy were used to acquire biopsy samples. The presence of germinal centers, other stromal structures, TLS density, topography relative to the tumor lesion, and malignant cell islets are used to evaluate and classify TLS. RESULTS: We first globally evaluated the total number of TLSs (TLS.T). We observed topographically two places in the cervical stroma: TLS immediately peritumorally positioned and TLS away from tumor lesions. Invasive carcinomas have bigger superficial TLSs with a well-defined germinal center. As they approached the tumor, TLSs increased in size and density. We also detected a special type of TLS associated with nerve fibers, which we named tertiary lymphoid structures associated with nerves (TLS.N). The total number of TLSs did not correlate with age, but 85.71% of patients presenting TLS.N were aged between 59 and 72 years old. Our findings showed a strong correlation between age (postmenopausal, p = 0.005) and TLS-N presence. Similarly, TLS parameters evolved with tumor differentiation. Only in the TLS.N group did the tumoral grading (G) 3 correlate with TLS (p = 0.041), while TLS.T did not correlate with G. All TLS.N. patients, except one, had lymphovascular invasion and massive histiocytosis. On the first point, TLS.N correlated with lymphovascular invasion (p = 0.032). CONCLUSION: Tertiary lymphoid structures associated with nerves have not been previously reported in cervical cancer, and their effects on prognosis and aggression are unknown. There was a substantial association between TLSs.N presence and age over 60, suggesting it is exclusive to menopausal women. They were also substantially connected with lymphovascular invasion and G3, suggesting they may be a poor cervical cancer prognostic factor.

4.
Biomedicines ; 12(5)2024 May 16.
Article in English | MEDLINE | ID: mdl-38791070

ABSTRACT

This systematic review evaluates the clinical outcomes and molecular predictors of response to pembrolizumab in patients with advanced and metastatic cervical cancer. We adhered to the PRISMA guidelines for systematic reviews, conducting a database search in PubMed, Scopus, and Embase. The eligibility criteria centered on clinical outcomes, including the overall survival (OS), progression-free survival (PFS), and immune-related biomarkers post-pembrolizumab therapy. We included both prospective and retrospective studies that detailed clinical outcomes and molecular characteristics predictive of therapeutic response. Our search yielded six studies involving 846 patients treated with pembrolizumab from 2017 to 2022. The meta-analysis of these studies showed that pembrolizumab, used as monotherapy or in combination with chemotherapy, extended the OS by a weighted median of 10.35 months and the PFS by 8.50 months. The treatment demonstrated a pooled objective response rate (ORR) of 22.39%, although the I2 test result of 67.49% showed a high heterogeneity among the studies. Notably, patients with high PD-L1 expression (CPS ≥ 10) experienced improved outcomes in terms of the PFS and OS. The most common complications were fatigue, diarrhea, and immune-related adverse events. Pembrolizumab significantly enhances clinical outcomes in metastatic cervical cancer, particularly among patients with high PD-L1 expression. The drug maintains a good safety profile, reinforcing its treatment potential for patients with advanced and metastatic cervical cancer. Future studies should explore long-term effects and strategies to integrate pembrolizumab optimally into current treatment regimens, aiming to maximize patient benefits and effectively manage side effects.

5.
Nanomaterials (Basel) ; 14(2)2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38251157

ABSTRACT

In this work, the effect of thermal annealing on silver nanoparticles@polymer (AgNPs@polymer) nanocomposite coatings was investigated. These photo-generated metallized coatings have a spatial distribution of metal nanoparticles, with a depth-wise decrease in their concentration. During annealing, both structural and morphological variations, as well as a spatial reorganization of AgNPs, were observed, both at the surface and in the core of the AgNPs@polymer coating. Owing to their increased mobility, the polymer chains reorganize spontaneously, and, at the same time, a hopping diffusion process, caused by the minimization of the surface energy, promotes the migration and coalescence of the silver nanoparticles towards the surface. The layer of discrete nanoparticles gradually transforms from a weakly percolative assembly to a denser and more networked structure. Consequently, the surface of the coatings becomes significantly more electrically conductive, hydrophobic, and reflective. The general trend is that the thinner the nanohybrid coating, the more pronounced the effect of thermal annealing on its spatial reorganization and properties. These results open up interesting prospects in the field of metallized coating technology and pave the way for integration into a wide variety of devices, e.g., efficient and inexpensive reflectors for energy-saving applications, electrically conductive microdevices, and printed electronic microcircuits.

6.
Beilstein J Nanotechnol ; 14: 95-109, 2023.
Article in English | MEDLINE | ID: mdl-36761683

ABSTRACT

The control of microbial proliferation is a constant battle, especially in the medical field where surfaces, equipment, and textiles need to be cleaned on a daily basis. Silver nanoparticles (AgNPs) possess well-documented antimicrobial properties and by combining them with a physical matrix, they can be applied to various surfaces to limit microbial contamination. With this in mind, a rapid and easy way to implement a photoinduced approach was investigated for textile functionalization with a silver@polymer self-assembled nanocomposite. By exposing the photosensitive formulation containing a silver precursor, a photoinitiator, and acrylic monomers to a UV source, highly reflective metallic coatings were obtained directly on the textile support. After assessing their optical and mechanical properties, the antimicrobial properties of the functionalized textiles were tested against Escherichia coli (E. coli) and Candida albicans (C. albicans) strains. In addition to being flexible and adherent to the textile substrates, the nanocomposites exhibited remarkable microbial growth inhibitory effects.

7.
Nanomaterials (Basel) ; 12(18)2022 Sep 19.
Article in English | MEDLINE | ID: mdl-36145042

ABSTRACT

An aqueous-phase synthesis of 3-mercaptopropionic acid (3-MPA)-capped core/shell/shell ZnSeS/Cu:ZnS/ZnS QDs was developed. The influence of the Cu-dopant location on the photoluminescence (PL) emission intensity was investigated, and the results show that the introduction of the Cu dopant in the first ZnS shell leads to QDs exhibiting the highest PL quantum yield (25%). The influence of the Cu-loading in the dots on the PL emission was also studied, and a shift from blue-green to green was observed with the increase of the Cu doping from 1.25 to 7.5%. ZnSeS/Cu:ZnS/ZnS QDs exhibit an average diameter of 2.1 ± 0.3 nm and are stable for weeks in aqueous solution. Moreover, the dots were found to be photostable under the continuous illumination of an Hg-Xe lamp and in the presence of oxygen, indicating their high potential for applications such as sensing or bio-imaging.

8.
Healthcare (Basel) ; 10(8)2022 Jul 28.
Article in English | MEDLINE | ID: mdl-36011067

ABSTRACT

We report the case of a 29-year-old patient with low-grade squamous intraepithelial lesion (L-SIL), negative human papilloma virus (HPV), positive p16/Ki-67 dual-staining and colposcopy suggestive for severe dysplastic lesion. The patient underwent a loop electrosurgical excision procedure (LEEP), the pathology report revealing mesonephric hyperplasia and adenocarcinoma. The patient also opted for non-standard fertility-sparing treatment. The trachelectomy pathology report described a zone of hyperplasia at the limit of resection towards the uterine isthmus. Two supplementary interpretations of the slides and immunohistochemistry (IHC) were performed. The results supported the diagnosis of mesonephric adenocarcinoma, although with difficulty in differentiating it from mesonephric hyperplasia. Given the discordant pathology results that were inconclusive in establishing a precise diagnosis of the lesion and the state of the limits of resection, the patient was referred to a specialist abroad. Furthermore, the additional interpretation of the slides and IHC were performed, the results suggesting a clear cell carcinoma. The positive p16/Ki-67 dual-staining prior to LEEP, the non-specific IHC and the difficulties in establishing a diagnosis made the case interesting. Given the limitations of cytology and the fact that these variants are independent of HPV infection, dual staining p16/Ki-67 could potentially become useful in the diagnosis of rare adenocarcinoma variants of the cervix, however further documentation is required.

9.
ACS Omega ; 6(48): 33100-33110, 2021 Dec 07.
Article in English | MEDLINE | ID: mdl-34901661

ABSTRACT

Doping of transition metals within a semiconductor quantum dot (QD) has a high impact on the optical and magnetic properties of the QD. In this study, we report the synthesis of Mn2+-doped Ag-In-Ga-Zn-S (Mn:AIGZS) QDs via thermolysis of a dithiocarbamate complex of Ag+, In3+, Ga3+, and Zn2+ and of Mn(stearate)2 in oleylamine. The influence of the Mn2+ loading on the photoluminescence (PL) and magnetic properties of the dots are investigated. Mn:AIGZS QDs exhibit a diameter of ca. 2 nm, a high PL quantum yield (up to 41.3% for a 2.5% doping in Mn2+), and robust photo- and colloidal stabilities. The optical properties of Mn:AIGZS QDs are preserved upon transfer into water using the glutathione tetramethylammonium ligand. At the same time, Mn:AIGZS QDs exhibit high relaxivity (r 1 = 0.15 mM-1 s-1 and r 2 = 0.57 mM-1 s-1 at 298 K and 2.34 T), which shows their potential applicability for bimodal PL/magnetic resonance imaging (MRI) probes.

10.
Exp Ther Med ; 22(4): 1066, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34434280

ABSTRACT

Despite the significant evolution in recent years in the medical field, many fetal conditions that can be detected in the early stages, remain a social and economic burden due to a lack of diagnostic and treatment programs. The main objective of the present study was to realize a screening program related to the early detection of Down syndrome, by analyzing biochemical and imaging markers, in women from the rural areas of Southwest Romania. Accordingly, data from 269 pregnant women were taken into evaluation for maternal age, maternal weight, smoking and diabetic statuses, along with ultrasound measurements that were performed to establish fetal nuchal translucency (FNT) and biochemical analysis of free ß-human chorionic gonadotropin (ß-hCG) and pregnancy-associated plasma protein (PAPP-A). Patients at high risk for trisomy 21 (≥1:250) were counseled and the optimal protocol was established for each case. Of the 269 patients studied, 5.6% were included in the risk group based on ß-hCG-associated MoM (multiple median approaches) analysis, sonographic measurements and maternal age correlation. Specifically, 60% of patients at risk presented a ß-hCG MoM value >1.5 and 20% of patients at risk presented a value ≤0.5 for PAPP-A MoM, and the average maternal age was 33. Measurement of FNT and serum markers, together with associated MoM intervals, was not sufficient to establish the diagnosis of trisomy 21 and to make a risk group inclusion. In summary, the association between sonographic measurements and serum marker values, together with maternal age, are predetermined and indispensable conditions for the most accurate classification in a high-risk group.

11.
Nanotechnology ; 31(46): 465704, 2020 Nov 13.
Article in English | MEDLINE | ID: mdl-32853176

ABSTRACT

In this work, novel heterostructured photocatalysts associating graphitic carbon nitride (g-CN) and SmFeO3 were prepared via a mixing-ultrasonication process. Structural, optical and morphological characterizations demonstrate that the interfacial junction between g-CN and SmFeO3 is well established for all g-CN/SmFeO3 composites prepared with g-CN:SmFeO3 weight ratio of 20:80, 50:50 and 80:20. The g-CN/SmFeO3 (80:20) composite exhibits the highest photocatalytic activity for the degradation of pollutants like the Orange II dye and the tetracycline hydrochloride antibiotic under visible light irradiation. This high photocatalytic activity originates from the enhanced light absorption over the whole visible region compared to pure g-CN and from the improved separation and transfer of photogenerated electron/hole pairs as demonstrated by photoluminescence and photocurrent measurements. A Z-scheme charge carrier transfer mechanism was demonstrated for the photocatalytic reactions. The g-CN/SmFeO3 (80:20) catalyst was also demonstrated to be stable and can be reused up to six times without significant alteration of the activity.

12.
Nanomaterials (Basel) ; 10(7)2020 Jul 16.
Article in English | MEDLINE | ID: mdl-32708780

ABSTRACT

Photocatalysts composed of graphitic carbon nitride (g-CN) and TiO2 were efficiently prepared by thermolysis of the MIL-125(Ti) metal organic framework deposited on g-CN. The heterojunction between the 12 nm-sized TiO2 nanoparticles and g-CN was well established and the highest photocatalytic activity was observed for the g-CN/TiO2 (3:1) material. The g-CN/TiO2 (3:1) composite exhibits high visible light performances both for the degradation of pollutants like the Orange II dye or tetracycline but also for the production of hydrogen (hydrogen evolution rate (HER) up to 1330 µmolh-1g-1 and apparent quantum yield of 0.22% using NiS as a cocatalyst). The improved visible light performances originate from the high specific surface area of the photocatalyst (86 m2g-1) and from the efficient charge carriers separation as demonstrated by photoluminescence, photocurrent measurements, and electrochemical impedance spectroscopy. The synthetic process developed in this work is based on the thermal decomposition of metal organic framework deposited on a graphitic material and holds huge promise for the preparation of porous heterostructured photocatalysts.

13.
J Hazard Mater ; 396: 122616, 2020 09 05.
Article in English | MEDLINE | ID: mdl-32289641

ABSTRACT

Metal oxide nanoparticles (NPs), and among them metal oxides Quantum Dots (QDs), exhibit a multifactorial toxicity combining metal leaching, oxidative stress and possibly direct deleterious interactions, the relative contribution of each varying according to the NP composition and surface chemistry. Their wide use in public and industrial domains requires a good understanding and even a good control of their toxicity. To address this question, we engineered ZnO QDs with different surface chemistries, expecting that they would exhibit different photo-induced reactivities and possibly different levels of interaction with biological materials. No photo-induced toxicity could be detected on whole bacterial cell toxicity assays, indicating that ROS-dependent damages, albeit real, are hidden behind a stronger source of toxicity, which was comforted by the fact that the different ZnO QDs displayed the same level of cell toxicity. However, using in vitro DNA damage assays based on quantitative PCR, significant photo-induced reactivity could be measured precisely, showing that different NPs exhibiting similar inhibitory effects on whole bacteria could differ dramatically in terms of ROS-generated damages on biomolecules. We propose that direct interactions between NPs and bacterial cell surfaces prime over any kind of intracellular damages to explain the ZnO QDs toxicity on whole bacterial cells.


Subject(s)
Metal Nanoparticles , Quantum Dots , Zinc Oxide , Oxidation-Reduction , Oxidative Stress , Quantum Dots/toxicity , Reactive Oxygen Species , Zinc , Zinc Oxide/toxicity
14.
Nanomaterials (Basel) ; 10(1)2020 Jan 04.
Article in English | MEDLINE | ID: mdl-31947956

ABSTRACT

2,2'-(Ethylenedioxy)bis(ethylamine)-functionalized graphene quantum dots (GQDs) were prepared under mild conditions from graphene oxide (GO) via oxidative fragmentation. The as-prepared GQDs have an average diameter of ca. 4 nm, possess good colloidal stability, and emit strong green-yellow light with a photoluminescence (PL) quantum yield of 22% upon excitation at 375 nm. We also demonstrated that the GQDs exhibit high photostability and the PL intensity is poorly affected while tuning the pH from 1 to 8. Finally, GQDs can be used to chelate Fe(II) and Cu(II) cations, scavenge radicals, and reduce Fe(III) into Fe(II). These chelating and reducing properties that associate to the low cytotoxicity of GQDs show that these nanoparticles are of high interest as antioxidants for health applications.

15.
Rom J Morphol Embryol ; 61(3): 879-887, 2020.
Article in English | MEDLINE | ID: mdl-33817729

ABSTRACT

Females require at a certain period of life the administration or supplementation of specific hormones (estrogen, progesterone), for various needs, such as: prevention of unwanted pregnancies, decreased menstrual bleeding, dysmenorrhea and pelvic pain in endometriosis, alleviation of symptoms associated with menopause, regulation of certain skin processes related to acne or aging and others. Also, hormones could act as oncogenes being known eloquent examples of estrogens labeled both as promoters of cell specific alteration or as mutagenic agents. The use of hormones and exposure to solar radiation is expected to cause a number of adverse changes to the body, especially due to their association with malignant processes. The current study was purported as a basis for understanding certain processes that occur with the administration of hormones and exposure to ultraviolet B (UVB) radiation. The animal model was made on healthy adult female BALB∕c mice, which were separated into groups and treated with Ethinylestradiol (EES), Levonorgestrel (LNG) and their combination in the presence of UVB radiation. Changes in skin physiological parameters were analyzed by non-invasive methods, biochemical parameters related to changes in blood circulating system were evaluated by standard methods and histopathological analysis was conducted to point out the changes at the level of the internal body. Measurement of skin parameters such as erythema, melanin, skin hydration, has highlighted some changes in hormone-treated and exposed to UVB radiation groups which were significant only in the case of erythema. Biochemical parameters showed variations in terms of liver enzymes in groups treated with active substances. Histologically, aspects of internal organs revealed significant changes in the group treated with EES and LNG and exposed to UVB radiation.


Subject(s)
Skin Physiological Phenomena , Ultraviolet Rays , Animals , Estrogens , Female , Mice , Mice, Inbred BALB C , Skin , Ultraviolet Rays/adverse effects
16.
Nanomaterials (Basel) ; 9(5)2019 May 03.
Article in English | MEDLINE | ID: mdl-31058852

ABSTRACT

This work describes the preparation of molecularly imprinted polymer (MIP)-modified core/shell CdTe0.5S0.5/ZnS quantum dots (QDs). The QDs@MIP particles were used for the selective and sensitive detection of dopamine (DA). Acrylamide, which is able to form hydrogen bonds with DA, and ethylene glycol dimethylacrylate (EGDMA) as cross-linker were used for the preparation of the MIP. Highly cross-linked polymer particles with sizes up to 1 µm containing the dots were obtained after the polymerization. After the removal of the DA template, MIP-modified QDs (QDs@MIP) exhibit a high photoluminescence (PL) with an intensity similar to that of QDs embedded in the nonimprinted polymer (NIP). A linear PL decrease was observed upon addition of DA to QDs@MIP and the PL response was in the linear ranges from 2.63 µM to 26.30 µM with a limit of detection of 6.6 nM. The PL intensity of QDs@MIP was quenched selectively by DA. The QDs@MIP particles developed in this work are easily prepared and of low cost and are therefore of high interest for the sensitive and selective detection of DA in biological samples.

17.
Materials (Basel) ; 11(11)2018 Nov 01.
Article in English | MEDLINE | ID: mdl-30388867

ABSTRACT

ZnO nanorods (NRs) with an average length and diameter of 186 and 20 nm, respectively, were prepared through a mild solvothermal route and used as photocatalysts either as dispersed powder or immobilized on glass slides. The ZnO NRs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Dispersed ZnO NRs and, to a lesser extent, immobilized ZnO NRs were demonstrated to exhibit high photocatalytic activity under simulated sunlight of low intensity (5.5 mW/cm²) both for the degradation of the Orange II dye and for Escherichia coli bacterial decontamination (2.5-fold survival decrease after 180 min irradiation for immobilized NRs). SEM, atomic force microscopy (AFM), fluorescence spectroscopy, and epifluorescence microscopy demonstrate that cell surface damages are responsible of bacterial inactivation. The immobilized ZnO NRs could be reused up to five times for bacterial decontamination at comparable efficiency and therefore have great potential for real environmental applications.

18.
Sci Rep ; 7(1): 12410, 2017 09 29.
Article in English | MEDLINE | ID: mdl-28963491

ABSTRACT

The development of metalized surfaces exhibiting mirror properties and/or electric conductivity without heavy equipments and with low metal charge is a big challenge in view of many industrial applications. We report herein on the photo-assembling of silver nanoparticles (AgNPs) in a polymer matrix, carried out within minutes from an acrylate monomer and silver nitrate at room temperature, under air and without any solvents. The top surface of the material gets converted into a continuous silver thin film and a depthwise concentration gradient of AgNPs is created in the polymer, which images the absorption profile of the actinic UV light in the reactive formulation. This specific assembling of the silver@polymer coating induces excellent reflective and conductive properties. The conductance was observed to strongly increase with increasing the exposure from 3 to 30 min due to the formation of a more and more compact metal film. This coating strategy works with a variety of substrates (textile, paper, glass, wood, plastic and stainless steel). Moreover, on flexible surfaces such as textile, the flexibility was preserved. The possibility to use this kind of nanomaterial as a printing ink, with a much lower metal concentration (3 to 5 wt.%) than concurrent inks, was also demonstrated.

19.
Beilstein J Nanotechnol ; 8: 1080-1093, 2017.
Article in English | MEDLINE | ID: mdl-28685109

ABSTRACT

Alloyed CuInZn x S2+x (ZCIS) quantum dots (QDs) were successfully associated to ZnO nanoparticles by a thermal treatment at 400 °C for 15 min. The ZnO/ZCIS composite was characterized by TEM, SEM, XRD, XPS and UV-vis absorption spectroscopy. ZCIS QDs, with an average diameter of ≈4.5 nm, were found to be homogeneously distributed at the surface of ZnO nanoparticles. ZCIS-sensitized ZnO nanoparticles exhibit a high photocatalytic activity under simulated solar light irradiation for the degradation of Orange II dye (>95% degradation after 180 min of irradiation at an intensity of 5 mW/cm2). The heterojunction built between the ZnO nanoparticle and ZCIS QDs not only extends the light adsorption range by the photocatalyst but also acts to decrease electron/hole recombination. Interestingly, the ZnO/ZCIS composite was found to produce increased amounts of H2O2 and singlet oxygen 1O2 compared to ZnO, suggesting that these reactive oxygen species play a key role in the photodegradation mechanism. The activity of the ZnO/ZCIS composite is retained at over 90% of its original value after ten successive photocatalytic runs, indicating its high stability and its potential for practical photocatalytic applications.

20.
Nanotechnology ; 28(10): 105603, 2017 Mar 10.
Article in English | MEDLINE | ID: mdl-28155842

ABSTRACT

This paper reports on a simple and environmentally friendly photochemical process capable of generating nano-layers (8-22 nm) of silver nanostructures directly onto glass surfaces. This approach opens the way to large-scale functionalized surfaces with plasmonic properties through a single light-induced processing. Thus, Ag nanostructures top-coated were obtained through photo-reduction, at room temperature, of a photosensitive formulation containing a metal precursor, free from extra toxic stabilizers or reducing agents. The reactive formulation was confined between two glass slides and exposed to a continuous near-UV source. In this way, stable silver nano-layers can be generated directly on the substrate with a very good control of the morphology of as-synthesized nanostructures that allows tailoring the optical properties of the coated layers. The position and width of the corresponding surface plasmon resonance bands can be adjusted over a broad spectral window. By extension, this low-cost and easy-to-apply process can also be used to coat ultra thin layers of metal nanostructures on a variety of substrates. The possibility of controlling of nanostructures shape should achieve valuable developments in many fields, as diverse as plasmonics, surface enhanced Raman scattering, nano-electronic circuitry, or medical devices.

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