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1.
Theriogenology ; 227: 112-119, 2024 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-39053287

RESUMO

Gonadotropin releasing hormone (GnRH) synthesis and secretion regulates seasonal fertility. In the brain, the distribution of GnRH-positive neurons is diffuse, hindering efforts to monitor variations in its cellular and tissue levels. Here, we aim at assessing GnRH immunoreactivity in nuclei responsible for seasonal fertility regulation (SFR) within the posterior, anterior, and preoptic areas of the basal hypothalamus during estrous in ewes. We detected reaction products in the ventromedial basal hypothalamus in neurons, nerve fibers, non-neuronal immunoreactive bodies, and diffuse interstitial areas. Immunoreactivity correlated with the distribution of the main SFR nuclei in the arcuate, retrochiasmatic, periventricular, medial preoptic, supraoptic, and preoptic areas. By independent component analysis density segmentation and by interferential contrast, we identified GnRH non-neuronal positive bodies as microglial cells encapsulated within a dense halo of reaction products. These GnRH-positive microglial cells were distributed in patches and rows throughout the basal ventromedial hypothalamus, suggesting their role in paracrine or juxtacrine signaling. Moreover, as shown by ionized calcium-binding adaptor molecule 1 (IBA1) immunocytochemistry, the distribution of GnRH reaction products overlapped with the microglial dense reactive zones. Therefore, our findings support the assertion that a combined densitometric analysis of GnRH and IBA1 immunocytochemistry enables activity mapping for monitoring seasonal changes following experimental interventions.

2.
Br Poult Sci ; : 1-10, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940321

RESUMO

1. This study investigated the effects of incorporating yellow mealworm (Tenebrio molitor) larval meal as a partial and/or complete substitute for soybean meal on carcass and meat quality in slow-growing chickens.2. A total of 256 one-day-old male broilers were randomly allocated to 1 of 32 experimental units distributed among four treatments (n = 8): the control treatment (C), where soybean (SB) meal was the protein source, and three experimental treatments, in which SB meal was replaced by Tenebrio molitor (TM) larval meal at levels of 50% (T1), 75% (T2) and 100% (T3), respectively. Three different feed phases (1-29; 29-57 and 57-92 d of age) were used for each treatment. All chickens were slaughtered at 92 d of age, with eight animals per treatment randomly selected to assess carcass and meat quality. Near-infrared reflectance spectroscopy (NIR) was used to classify meat quality.3. Carcass traits were not significantly different between treatments, except for head and thigh weight, which were higher in the control group (p < 0.01). In terms of physicochemical characteristics, treatment T2 showed less yellowness (p < 0.05), while water and cooking losses were lower in treatments T1 and T2 (p < 0.01). Meat from both T1 and T2 groups had lower shear forces (p < 0.01), higher moisture content (p < 0.01) and less protein (p < 0.05) compared to treatments C andT3. Birds fed T3 had the highest meat ash content (p < 0.01). Chickens consuming TM had higher monounsaturated fatty acid (MUFA) levels and lower polyunsaturated fatty acid (PUFA) and n-6 acidsPUFA (p < 0.01).4. Substitution of SB with TM is a protein alternative for slow-growing chickens that supports carcass and meat quality comparable to those fed a conventional diet.

3.
J Equine Vet Sci ; 136: 105069, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599258

RESUMO

The aim of this study was to evaluate two cryoprotectants, dimethylformamide (DMF) and methylformamide (MF) in two concentrations (5 and 7 %) in vitro in donkey semen using a rapid freezing technique and the effect on pregnancy rates in mares. Twenty-four ejaculates from 8 jacks (n = 8; r = 3) were divided into 4 extenders: BotuSemen Gold with 5 % or 7 % MF and 5 % or 7 % DMF, all containing 11 % lactose, 20 % egg-yolk and 0.5 % Equex. Post-thaw evaluations included: sperm motility, membrane function and acrosome status. A linear mixed effect model was used to test the effect of different freezing media on semen parameters. No differences were observed between the 4 freezing media used, for any of the seminal parameters (P > 0.05). However, samples with 5 % DMF showed the highest percentages of sperm with acrosomes and functional membranes (DMF: 5 %: 53.67 ± 22.01; 7 %: 33.92 ± 23.4; MF: 5 %: 44.5 ± 20.46; 7 %: 38.75 ± 27.4) (Data: mean ± SD; P > 0.05). Hence, thirty mares were inseminated: 15 with 5 % DMF and 15 with 7 % DMF. The pregnancy rate was 46 % (7/15) and 0 % (0/15) using the extender with 5 % or 7 % DMF, respectively (P = 0.003). To conclude, the use of 5 % or 7 % of MF or DMF did not affect the in vitro parameters. Despite the lack of differences in vitro with the two DMF concentrations, in vivo results only showed pregnancies when using 5 % DMF. Thus, the results of this study demonstrate the importance of accompanying in vitro semen evaluations with studies that evaluate post-insemination pregnancy rates.


Assuntos
Criopreservação , Crioprotetores , Equidae , Preservação do Sêmen , Animais , Equidae/fisiologia , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Crioprotetores/farmacologia , Feminino , Masculino , Criopreservação/métodos , Criopreservação/veterinária , Gravidez , Dimetilformamida/farmacologia , Inseminação Artificial/veterinária , Sêmen/efeitos dos fármacos , Sêmen/química , Motilidade dos Espermatozoides/efeitos dos fármacos , Formamidas
4.
Actas Urol Esp (Engl Ed) ; 44(7): 450-457, 2020 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-32456883

RESUMO

The COVID-19 pandemic caused by the SARS-CoV-2 virus has caused tens of thousands of deaths in Spain and has managed to breakdown the healthcare system hospitals in the Community of Madrid, largely due to its tendency to cause severe pneumonia, requiring ventilatory support. This fact has caused our center to collapse, with 130% of its beds occupied by COVID-19 patients, thus causing the absolute cessation of activity of the urology service, the practical disappearance of resident training programs, and the incorporation of a good part of the urology staff into the group of medical personnel attending these patients. In order to recover from this extraordinary level of suspended activity, we will be obliged to prioritize pathologies based on purely clinical criteria, for which tables including the relevance of each pathology within each area of urology are being proposed. Technology tools such as online training courses or surgical simulators may be convenient for the necessary reestablishment of resident education.


Assuntos
Ocupação de Leitos/estatística & dados numéricos , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Unidade Hospitalar de Urologia/estatística & dados numéricos , Urologia/estatística & dados numéricos , Assistência Ambulatorial/estatística & dados numéricos , Conversão de Leitos/estatística & dados numéricos , COVID-19 , Infecções por Coronavirus/terapia , Humanos , Internato e Residência , Pandemias , Equipe de Assistência ao Paciente/organização & administração , Isolamento de Pacientes , Pneumonia Viral/terapia , SARS-CoV-2 , Espanha/epidemiologia , Procedimentos Cirúrgicos Urológicos/estatística & dados numéricos , Urologistas/provisão & distribuição , Urologia/educação , Urologia/organização & administração , Unidade Hospitalar de Urologia/organização & administração , Ventiladores Mecânicos , Suspensão de Tratamento/estatística & dados numéricos
5.
J Healthc Qual Res ; 35(1): 27-34, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31883955

RESUMO

AIM: Telemedicine has helped to make health care more efficient. However, to date no studies have measured its impact on infertility and fertility healthcare. We assessed the potential care benefits and clinical advantages of an initiative implementing electronic patient portal (EPP) for patients scheduled to undergo assisted reproduction treatment, to reduce waiting times for medical consultation and treatment. METHODS: This was designed as a retrospective cohort study. The experimental group comprised 1972 referral requests received by the assisted reproduction unit of our institution between 2015 and 2016, which were included in the group receiving telemedicine, while the control group was defined by 283 requests received in 2013, all of which were assigned face-to-face care. RESULTS: We found a statistically significant reduction in the experimental group in terms of the days elapsed between the receipt of the assessment request and the first outpatient visit (68 days vs. 180 days, p<.001). Time to initiation of treatment was also significantly lower in this group (169 days vs. 229 days; p<.001). The experimental group contained around 7 times as many patients receiving treatment as the control group. No differences were observed in the pregnancy rate (29.9% vs. 31.1%; p=.77) or in the complication rate (3.2% vs. 0%; p=.16). CONCLUSIONS: Use of telemedicine in electronic portal patient form reduces the total waiting time involved in patient requests for infertility treatment and indirectly increases the number of patients treated, causing no negative impact on treatment outcome.


Assuntos
Saúde Pública , Técnicas de Reprodução Assistida , Telemedicina , Adulto , Estudos de Coortes , Humanos , Estudos Retrospectivos
6.
Actas Urol Esp ; 44(7): 450-457, 2020 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-38620218

RESUMO

The COVID-19 pandemic caused by the SARS-CoV-2 virus has caused tens of thousands of deaths in Spain and has managed to breakdown the healthcare system hospitals in the Community of Madrid, largely due to its tendency to cause severe pneumonia, requiring ventilatory support. This fact has caused our center to collapse, with 130% of its beds occupied by COVID-19 patients, thus causing the absolute cessation of activity of the urology service, the practical disappearance of resident training programs, and the incorporation of a good part of the urology staff into the group of medical personnel attending these patients. In order to recover from this extraordinary level of suspended activity, we will be obliged to prioritize pathologies based on purely clinical criteria, for which tables including the relevance of each pathology within each area of urology are being proposed. Technology tools such as online training courses or surgical simulators may be convenient for the necessary reestablishment of resident education.

7.
Front Plant Sci ; 9: 1320, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30298075

RESUMO

Germplasm collections are basic tools for conservation, characterization, and efficient use of olive genetic resources. The identification of the olive cultivars maintained in the collections is an important ongoing task which has been performed by both, morphological and molecular markers. In the present study, based on the sequencing results of previous genomic projects, a new set of 1,043 EST-SNP markers has been identified. In order to evaluate its discrimination capacity and utility in diversity studies, this set of markers was used in a representative number of accessions from 20 different olive growing countries and maintained at the World Olive Germplasm Collection of IFAPA Centre 'Alameda del Obispo' (Córdoba, Spain), one of the world's largest olive germplasm bank. Thus, the cultivated material included: cultivars belonging to previously defined core collections by means of SSR markers and agronomical traits, well known homonymy cases, possible redundancies previously identified in the collection, and recently introduced accessions. Marker stability was tested in repeated analyses of a selected number of accessions, as well as in different trees and accessions belonging to the same cultivar. In addition, 15 genotypes from a cross 'Picual' × 'Arbequina' cultivars from the IFAPA olive breeding program and a set of 89 wild genotypes were also included in the study. Our results indicate that, despite their relatively wide variability, the new set of EST-SNPs displayed lower levels of genetic diversity than SSRs in the set of olive core collections tested. However, the EST-SNP markers displayed consistent and reliable results from different plant material sources and plant propagation events. The EST-SNPs revealed a clear cut off between inter- and intra-cultivar variation in olive. Besides, they were able to reliably discriminate among different accessions, to detect possible homonymy cases as well as efficiently ascertain the presence of redundant germplasm in the collection. Additionally, these markers were highly transferable to the wild genotypes. These results, together with the low genotyping error rates and the easy and fully automated procedure used to get the genotyping data, validate the new set of EST-SNPs as possible markers of choice for olive cultivar identification.

8.
Oncologist ; 23(9): 1092-1102, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29700210

RESUMO

BACKGROUND: HER2-positive gastric cancer (GC) affects 7%-34% of patients with GC. Trastuzumab-based first-line treatment has become the standard of care for HER2-positive advanced gastric cancer (AGC). However, there are no clinically validated biomarkers for resistance to HER2-targeted therapies. Upregulation of PI3K pathway and tyrosine kinase receptor (TKR) alterations have been noted as molecular mechanisms of resistance in breast cancer. Our study aimed to perform a molecular characterization of HER2-positive AGC and investigate the role of PI3K/Akt/mTOR signaling pathway activation and TKR gene copy number (GCN) gains as predictive biomarkers in HER2-positive AGC treated with trastuzumab. PATIENTS AND METHODS: Forty-two HER2-positive GC samples from patients treated with trastuzumab-based first-line chemotherapy were selected. DNA samples were sequenced. PTEN and MET immunohistochemistry were also performed. RESULTS: Concurrent genetic alterations were detected in 97.1% of HER2-positive AGC. We found activation of PI3K/Akt/mTOR pathway in 52.4% of patients and TKR GCN gains in 38.1%. TKR GCN gains did not correlate with overall survival (OS) or progression-free survival (PFS). Multivariate Cox models showed that PI3K/Akt/mTOR activation negatively affects the effectiveness of trastuzumab-based chemotherapy in terms of OS and PFS. CONCLUSION: Our results provide for the first time a detailed molecular profile of concurrent genetic alterations in HER2-positive AGC. PI3K pathway activation could be used as a predictive marker of worse outcome in this patient population. In addition, gains in copy number of other TKR genes in this subgroup may also influence the survival benefit obtained with trastuzumab. IMPLICATIONS FOR PRACTICE: This article reports, for the first time, a detailed molecular profile of genomic alterations in patients with HER2-positive advanced gastric cancer (AGC). PI3K/Akt/mTOR signaling pathway activation seems to have a differentially negative effect on overall survival and progression-free survival in AGC treated with trastuzumab-based chemotherapy. Combining different targeted agents could be a successful therapeutic strategy to improve the prognosis of HER2-positive AGC.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Genômica/métodos , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Neoplasias Gástricas/tratamento farmacológico , Serina-Treonina Quinases TOR/genética , Trastuzumab/uso terapêutico , Adulto , Idoso , Antineoplásicos Imunológicos/farmacologia , Humanos , Pessoa de Meia-Idade , Neoplasias Gástricas/patologia , Trastuzumab/farmacologia , Resultado do Tratamento , Adulto Jovem
9.
Clin Transl Oncol ; 19(11): 1303-1311, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28646282

RESUMO

Surgical resection is the only potentially curative option in the treatment of pancreatic ductal adenocarcinoma. Preoperative radiological imaging allows to rule out the presence of metastases. Three resectability categories are established based on the radiological findings depending on the degree of contact between the tumor and the blood vessels. Histological confirmation of malignancy is only required in cases of borderline or non-resectable tumors, prior to neoadjuvant treatment initiation. Diagnostic laparoscopy is recommended in the presence of large tumors of the body or tail and in borderline tumors to explore the possibility of resection and to apply treatment with curative intent, as well as in those cases with high level of biomarkers to rule out peritoneal involvement. Prior to surgery preoperative nutritional measures as well as endoscopic biliary drainage can be applied to optimize patient's conditions. Cephalic pancreaticoduodenectomy is the recommended surgical technique in tumors located in the head of the pancreas. The benefits from pyloric preservation, type or reconstruction (one vs. two loops), type of anastomosis (pancreaticojejunostomy vs. pancreaticogastrostomy), intraoperative biopsy of the pancreatic resection margin or the use of intraperitoneal drainages are inconclusive. Total pancreatectomy and/or portal resection should only be performed in particular cases; however, arterial resections have shown no benefits. Radical antegrade modular pancreaticosplenectomy, that can be performed laparoscopically, is the technique used for those tumors located in the pancreatic body-tail.


Assuntos
Adenocarcinoma/cirurgia , Carcinoma Ductal Pancreático/cirurgia , Neoplasias Pancreáticas/cirurgia , Qualidade de Vida , Humanos
10.
Clin Transl Oncol ; 19(6): 667-681, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27995549

RESUMO

The management of patients with pancreatic cancer has advanced over the last few years. We convey a multidisciplinary group of experts in an attempt to stablish practical guidelines for the diagnoses, staging and management of these patients. This paper summarizes the main conclusions of the working group. Patients with suspected pancreatic ductal adenocarcinoma should be rapidly evaluated and referred to high-volume centers. Multidisciplinary supervision is critical for proper diagnoses, staging and to frame a treatment plan. Surgical resection together with chemotherapy offers the highest chance for cure in early stage disease. Patients with advanced disease should be classified in treatment groups to guide systemic treatment. New chemotherapeutic regimens have resulted in improved survival. Symptomatic management is critical in this disease. Enrollment in a clinical trial is, in general, recommended.


Assuntos
Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/terapia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia , Seguimentos , Humanos , Guias de Prática Clínica como Assunto , Espanha
11.
Clin Exp Allergy ; 45(10): 1590-600, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25823713

RESUMO

BACKGROUND: Prostaglandin E2 (PGE2 ) has been proposed to exert antiasthmatic effects in patients, to prevent antigen-induced airway pathology in murine models, and to inhibit mast cells (MC) activity in vitro. OBJECTIVE: To assess in a murine model whether the protective effect of PGE2 may be a consequence of its ability to activate the E-prostanoid (EP)2 receptor on airway MC. METHODS: Either BALB/c or C57BL/6 mice were exposed intranasally (i.n.) to house dust mite (HDM) aeroallergens. Both strains were given PGE2 locally (0.3 mg/kg), but only BALB/c mice were administered butaprost (EP2 agonist: 0.3 mg/kg), or AH6809 (EP2 antagonist; 2.5 mg/kg) combined with the MC stabilizer sodium cromoglycate (SCG: 25 mg/kg). Airway hyperresponsiveness (AHR) and inflammation, along with lung MC activity, were evaluated. In addition, butaprost's effect was assessed in MC-mediated passive cutaneous anaphylaxis (PCA) in mice challenged with 2,4-dinitrophenol (DNP). RESULTS: Selective EP2 agonism attenuated aeroallergen-caused AHR and inflammation in HDM-exposed BALB/c mice, and this correlated with a reduced lung MC activity. Accordingly, the blockade of endogenous PGE2 by means of AH6809 worsened airway responsiveness in sensitive BALB/c mice, and such worsening was reversed by SCG. The relevance of MC to PGE2 -EP2 driven protection was further highlighted in MC-dependent PCA, where butaprost fully prevented MC-induced ear swelling. Unlike in BALB/c mice, PGE2 did not protect the airways of HDM-sensitized C57BL/6 animals, a strain in which we showed MC to be irrelevant to aeroallergen-driven AHR and inflammation. CONCLUSIONS & CLINICAL RELEVANCE: The beneficial effect of both exogenous and endogenous PGE2 in aeroallergen-sensitized mice may be attributable to the activation of the EP2 receptor, which in turn acts as a restrainer of airway MC activity. This opens a path towards the identification of therapeutic targets against asthma along the 'EP2 -MC-airway' axis.


Assuntos
Asma/imunologia , Dinoprostona/imunologia , Mastócitos/imunologia , Pyroglyphidae , Receptores de Prostaglandina E Subtipo EP2/imunologia , Animais , Asma/patologia , Modelos Animais de Doenças , Feminino , Inflamação/imunologia , Inflamação/patologia , Mastócitos/patologia , Camundongos , Camundongos Endogâmicos BALB C
12.
Lab Chip ; 15(6): 1508-14, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25609565

RESUMO

The adhesion of small silicon chips to cells has many potential applications as direct interconnection of the cells to the external world can be accomplished. Hence, although some typical applications of silicon nanowires integrated into microsystems are focused on achieving a cell-on-a-chip strategy, we are interested in obtaining chip-on-a-cell systems. This paper reports the design, technological development and characterization of polysilicon barcodes featuring silicon nanowires as nanoscale attachment to identify and track living mouse embryos during their in vitro development. The chips are attached to the outer surface of the Zona Pellucida, the cover that surrounds oocytes and embryos, to avoid the direct contact between the chip and the embryo cell membrane. Two attachment methodologies, rolling and pushpin, which allow two entirely different levels of applied forces to attach the chips to living embryos, are evaluated. The former consists of rolling the mouse embryos over one barcode with the silicon nanowires facing upwards, while in the latter, the barcode is pushed against the embryo with a micropipette. The effect on in vitro embryo development and the retention rate related to the calculated applied forces are stated. Field emission scanning electron microscopy inspection, which allowed high-resolution imaging, also confirms the physical attachment of the nanowires with some of them piercing or wrapped by the Zona Pellucida and revealed extraordinary bent silicon nanowires.


Assuntos
Embrião de Mamíferos/citologia , Nanotecnologia/instrumentação , Nanofios , Silício/química , Coloração e Rotulagem/métodos , Animais , Adesão Celular , Cinética , Camundongos , Microscopia Eletrônica de Varredura , Volatilização , Zona Pelúcida/metabolismo
13.
Nanoscale ; 6(16): 9494-530, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-25030381

RESUMO

The current status of the use of nanoparticles for photothermal treatments is reviewed in detail. The different families of heating nanoparticles are described paying special attention to the physical mechanisms at the root of the light-to-heat conversion processes. The heating efficiencies and spectral working ranges are listed and compared. The most important results obtained in both in vivo and in vitro nanoparticle assisted photothermal treatments are summarized. The advantages and disadvantages of the different heating nanoparticles are discussed.


Assuntos
Nanopartículas , Nanotecnologia , Fototerapia , Animais , Linhagem Celular , Humanos , Camundongos , Nanopartículas/química , Nanopartículas/uso terapêutico
15.
Parasitology ; 141(1): 8-16, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23611102

RESUMO

Many Neglected Tropical Diseases (NTDs) have recently been subject of increased focus, particularly with relation to high-throughput screening (HTS) initiatives. These vital endeavours largely rely of two approaches, in vitro target-directed screening using biochemical assays or cell-based screening which takes no account of the target or targets being hit. Despite their successes both of these approaches have limitations; for example, the production of soluble protein and a lack of cellular context or the problems and expense of parasite cell culture. In addition, both can be challenging to miniaturize for ultra (u)HTS and expensive to utilize. Yeast-based systems offer a cost-effective approach to study and screen protein targets in a direct-directed manner within a eukaryotic cellular context. In this review, we examine the utility and limitations of yeast cell-based, target-directed screening. In particular we focus on the currently under-explored possibility of using such formats in uHTS screening campaigns for NTDs.


Assuntos
Bioensaio/estatística & dados numéricos , Avaliação Pré-Clínica de Medicamentos , Ensaios de Triagem em Larga Escala/estatística & dados numéricos , Saccharomyces cerevisiae/genética , Bioensaio/economia , Doenças Transmissíveis/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Descoberta de Drogas , Drogas em Investigação/farmacologia , Expressão Gênica , Engenharia Genética , Ensaios de Triagem em Larga Escala/economia , Humanos , Doenças Negligenciadas/tratamento farmacológico , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Medicina Tropical
16.
Phys Rev Lett ; 109(2): 025503, 2012 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-23030178

RESUMO

We report on the nonlinear coupling between the mechanical modes of a nanotube resonator. The coupling is revealed in a pump-probe experiment where a mode driven by a pump force is shown to modify the motion of a second mode measured with a probe force. In a second series of experiments, we actuate the resonator with only one oscillating force. Mechanical resonances feature exotic line shapes with reproducible dips, peaks, and jumps when the measured mode is commensurate with another mode with a frequency ratio of either 2 or 3. Conventional line shapes are recovered by detuning the frequency ratio using the voltage on a nearby gate electrode. The exotic line shapes are attributed to strong coupling between the mechanical modes. The possibility to control the strength of the coupling with the gate voltage holds promise for various experiments, such as quantum manipulation, mechanical signal processing, and the study of the quantum-to-classical transition.

17.
Nanotechnology ; 22(50): 505301, 2011 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-22107927

RESUMO

We report on a new approach for magnetic imaging, highly sensitive even in the presence of external, strong magnetic fields. Based on FIB-assisted fabricated high-aspect-ratio rare-earth nanomagnets, we produce groundbreaking magnetic force tips with hard magnetic character where we combine a high aspect ratio (shape anisotropy) together with strong crystalline anisotropy (rare-earth-based alloys). Rare-earth hard nanomagnets are then FIB-integrated to silicon microcantilevers as highly sharpened tips for high-field magnetic imaging applications. Force resolution and domain reversing and recovery capabilities are at least one order of magnitude better than for conventional magnetic tips. This work opens new, pioneering research fields on the surface magnetization process of nanostructures based either on relatively hard magnetic materials-used in magnetic storage media-or on materials like superparamagnetic particles, ferro/antiferromagnetic structures or paramagnetic materials.


Assuntos
Campos Eletromagnéticos , Imãs/química , Microscopia/métodos , Nanoestruturas/química , Anisotropia , Compostos Férricos/química
18.
Langmuir ; 27(13): 8302-8, 2011 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21661741

RESUMO

In this work, two types of polycrystalline silicon (polysilicon) microparticles were modified with specific ligands in order to be selectively attached to chemical residues located at the plasma membrane and thus to be applied to study individual cells in culture. Two different functionalization approaches based on adsorption and covalent attachment were assayed. A comparative study of the efficiency of the ligand immobilization and stability of the modified particle in the culture medium was carried out using the selected ligands labeled with a fluorophore. Cylindrical microparticles (nonencoded microparticles) and shape-encoded microparticles (bar codes) were used with the aim of demonstrating the nondependence of the particle size and shape on the efficiency of the immobilization protocol. Fluorescence imaging and statistical analysis of the recorded fluorescence intensity showed that the covalent attachment of the ligand to the surface of the microparticle, previously modified with an aldehyde-terminated silane, gave the best results. As a proof of concept, Vero cells in culture were labeled with the covalently modified bar codes and successfully tracked for up to 1 week without observing any alteration in the viability of the cells. Bar code numbers could be easily read by eye using a bright-field optical microscope. It is anticipated that such modified microparticles could be feasible platforms for the introduction of other analytical functions of interest in single-cell monitoring and cell sorting in automatic analysis systems.


Assuntos
Polímeros/química , Silício/química , Animais , Membrana Celular/química , Células Cultivadas , Chlorocebus aethiops , Ligantes , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície , Células Vero
19.
Eur J Pain ; 15(1): 29-35, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20538494

RESUMO

Transcutaneous electrical nerve stimulation (TENS) is a noninvasive alternative to traditional pain treatments. TENS has been studied in the past as a pain reduction modality in colonoscopy with limited success. Reviews and meta-analysis have shown that the inconclusive results of TENS may be due to the lack of randomized controlled trials and the difficulty in defining precise output parameters. The objective of this double-blind randomized placebo-controlled trial was to investigate the pain-relieving effect of a new application of TENS in unsedated screening colonoscopy. Ninety patients undergoing unsedated screening colonoscopy were randomly allocated to one of three groups: a control group (n=30), a group to receive active TENS (n=30), or a group to receive placebo TENS (n=30). A visual analogue scale (VAS) and a five-point Likert scale were used to assess pain 5 min into the procedure and at the end of the procedure. The patient's bloating sensation during colonoscopy and the effect on the duration of the procedure were also evaluated. Throughout the procedure, the active TENS group experienced a VAS pain score reduction ≥50% compared to the placebo TENS group (P<0.001) and the control group (P<0.001). On the five-point Likert scale, there was also a significant reduction in pain score in the active TENS group compared to the placebo TENS and control groups (P=0.009). No significant differences were found between the study groups as to the bloating sensation and the duration of the procedure. We conclude that TENS can be used as a pain relief therapy in unsedated screening colonoscopy.


Assuntos
Colonoscopia/métodos , Manejo da Dor , Estimulação Elétrica Nervosa Transcutânea , Colonoscopia/efeitos adversos , Sedação Consciente , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Medição da Dor/métodos , Satisfação do Paciente , Placebos , Estimulação Elétrica Nervosa Transcutânea/métodos , Resultado do Tratamento
20.
Cytometry B Clin Cytom ; 80(1): 38-42, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20632413

RESUMO

BACKGROUND: Fetal erythrocytes cross the placenta during gestation, but invasive prenatal procedures might develop into fetomaternal hemorrhage (FMH). We examine whether flow cytometry immunophenotyping might be useful for measuring the volume of FMH after such procedures. METHODS: Fetal erythrocytes (%) were determined in 153 pregnant women after amniocentesis (129) and chorionic villous sampling (24) using a monoclonal antibody against fetal hemoglobin. Fetal erythrocytes were identified for their high expression of fetal hemoglobin (HbF(++) ). Blood samples from two control groups, 53 healthy males and 21 pregnant women not submitted to invasive tests, were used to establish normal values of circulating HbF(++) erythrocytes in adults. RESULTS: The highest percentage of HbF(++) erythrocytes in the control groups was 0.015%. The rate of HbF(++) erythrocytes in samples after invasive tests ranged between <0.01% and 0.15%. Seventy-three women (47%) had ≤0.015% HbF(++) erythrocytes, and this rate was higher in 80. Nine women presented >1 ml of FMH (volume of packed cells corresponding to 0.054-0.15% HbF(++) erythrocytes), but only two had sonographic evidence of bleeding. CONCLUSIONS: Most women in our series had a very low volume of FMH after the invasive tests. Acute bleeding should be thoroughly investigated in women with either more than 1 ml of packed cells or more than 0.05% of HbF(++) erythrocytes. Intermediate values between >0.015% and <0.05%, should be carefully considered depending on the week of gestation. Data obtained before 15 weeks might reflect previous cell trafficking between fetus and mother instead of acute hemorrhage.


Assuntos
Amniocentese/efeitos adversos , Amostra da Vilosidade Coriônica/efeitos adversos , Transfusão Feto-Materna/sangue , Adolescente , Adulto , Estudos de Casos e Controles , Eritrócitos/química , Feminino , Hemoglobina Fetal/análise , Transfusão Feto-Materna/diagnóstico , Transfusão Feto-Materna/etiologia , Citometria de Fluxo , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Gravidez , Medição de Risco , Adulto Jovem
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