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1.
Environ Monit Assess ; 195(9): 1114, 2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37648802

RESUMEN

River water quality monitoring is crucial for understanding water dynamics and formulating policies to conserve the water environment. In situ ultraviolet-visible (UV-Vis) spectrometry holds great potential for real-time monitoring of multiple water quality parameters. However, establishing a reliable methodology to link absorption spectra to specific water quality parameters remains challenging, particularly for eutrophic rivers under various flow and water quality conditions. To address this, a framework integrating desktop and in situ UV-Vis spectrometers was developed to establish reliable conversion models. The absorption spectra obtained from a desktop spectrometer were utilized to create models for estimating nitrate-nitrogen (NO3-N), total nitrogen (TN), chemical oxygen demand (COD), total phosphorus (TP), and suspended solids (SS). We validated these models using the absorption spectra obtained from an in situ spectrometer. Partial least squares regression (PLSR) employing selected wavelengths and principal component regression (PCR) employing all wavelengths demonstrated high accuracy in estimating NO3-N and COD, respectively. The artificial neural network (ANN) was proved suitable for predicting TN in stream water with low NH4-N concentration using all wavelengths. Due to the dominance of photo-responsive phosphorus species adsorbed onto suspended solids, PLSR and PCR methods utilizing all wavelengths effectively estimated TP and SS, respectively. The determination coefficients (R2) of all the calibrated models exceeded 0.6, and most of the normalized root mean square errors (NRMSEs) were within 0.4. Our approach shows excellent efficiency and potential in establishing reliable models monitoring nitrogen, phosphorus, COD, and SS simultaneously. This approach eliminates the need for time-consuming and uncertain in situ absorption spectrum measurements during model setup, which may be affected by fluctuating natural and anthropogenic environmental conditions.


Asunto(s)
Monitoreo del Ambiente , Ríos , Análisis de la Demanda Biológica de Oxígeno , Análisis de Regresión , Espectrofotometría Ultravioleta , Redes Neurales de la Computación , Nitrógeno , Fósforo
2.
Oral Dis ; 28(6): 1555-1560, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33835636

RESUMEN

OBJECTIVE: The objective of this study was to evaluate the frequency of upper aerodigestive tract involvement in patients with mucous membrane pemphigoid associated with desquamative gingivitis. SUBJECTS AND METHODS: Data from 25 patients were collected by retrospective chart review. Their upper aerodigestive had been evaluated using a conventional flexible fiberscope. Oral disease activity was quantified on the basis of the Mucous Membrane Pemphigoid Disease Area Index activity score. RESULTS: Lesions of the upper aerodigestive tract were confirmed in nine symptomatic patients (9/25, 36%), of which five (5/25, 20%) had laryngeal involvement. No lesions were seen in the asymptomatic patients on fiberscope examination. There was a statistically significant difference in the symptoms, high oral disease activity score, and linear IgA deposition on direct immunofluorescence between patients with and without upper aerodigestive tract lesions (p = .001, .001, .002, respectively). CONCLUSION: The high frequency of considerable complications highlights the importance of confirming the presence of upper aerodigestive tract involvement in patients with mucous membrane pemphigoid having desquamative gingivitis. Signs including the presence of symptoms, high oral disease activity score, or linear IgA deposition on direct immunofluorescence might indicate a higher risk of upper aerodigestive tract involvement.


Asunto(s)
Gingivitis , Penfigoide Benigno de la Membrana Mucosa , Penfigoide Ampolloso , Gingivitis/complicaciones , Gingivitis/patología , Humanos , Inmunoglobulina A , Membrana Mucosa , Penfigoide Benigno de la Membrana Mucosa/patología , Penfigoide Ampolloso/complicaciones , Estudios Retrospectivos
3.
Clin Calcium ; 26(1): 93-8, 2016 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-26728535

RESUMEN

Current artificial bones made of metals and ceramics may be replaced around a decade after implantation due to its low durability, which is brought on by a large difference from the host bone in mechanical properties, i.e., low mechano-compatibility. On the other hand, tissue engineering could be a solution with regeneration of bone tissues from stem cells in vitro. However, there are still some problems to realize exactly the same mechanical properties as those of real bone. This paper introduces the technical background of bone tissue engineering and discusses possible methods for installation of mechano-compatibility into a regenerative bone. At the end, future directions toward the realization of ideal mechano-compatible regenerative bone are proposed.


Asunto(s)
Fenómenos Biomecánicos/fisiología , Regeneración Ósea/fisiología , Huesos/fisiología , Histocompatibilidad/fisiología , Estrés Mecánico , Ingeniería de Tejidos/métodos , Animales , Bovinos , Diferenciación Celular , Fuerza Compresiva , Humanos , Células Madre/citología , Resistencia a la Tracción , Ingeniería de Tejidos/tendencias
4.
J Biomed Mater Res B Appl Biomater ; 112(8): e35457, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39032140

RESUMEN

Calcined bone is an attractive natural material for use as a bone substitute because of its cost-effectiveness and high biocompatibility, which are comparable to that of synthetic hydroxyapatite. However, the calcination process has significantly weakened the mechanical properties. In this study, a composite of calcined bovine bone powder reinforced with silane cross-linked alginate was prepared to assess its biocompatibility, osteoconductivity, and mechanical compatibility as a bone substitute material. Culture studies with osteoblast-like cells (MC3T3-E1) showed no cytotoxicity toward the composite and exhibited general cell proliferative properties in its presence. In contrast, the composite reduced the alkaline phosphatase activity of osteoblasts but led to significant noncellular apatite deposition on the surface. In addition, quasi-static compression tests of the composite revealed mechanical properties comparable to those of human cancellous bone. The mechanical properties remained stable under wet conditions and did not deteriorate significantly even after 2 weeks of immersion in simulated body fluid at 37°C. The results show that this composite, composed of calcined bone powder and silane cross-linked alginate, is a promising bone substitute material with biocompatibility, osteoconductivity, and mechanical compatibility.


Asunto(s)
Alginatos , Sustitutos de Huesos , Ensayo de Materiales , Osteoblastos , Silanos , Alginatos/química , Animales , Sustitutos de Huesos/química , Sustitutos de Huesos/farmacología , Ratones , Bovinos , Osteoblastos/metabolismo , Osteoblastos/citología , Silanos/química , Humanos , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Polvos , Reactivos de Enlaces Cruzados/química , Línea Celular
5.
Ann Biomed Eng ; 52(2): 396-405, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37882922

RESUMEN

Optical bone densitometry (OBD) has been developed for the early detection of osteoporosis. In recent years, machine learning (ML) techniques have been actively implemented for the areas of medical diagnosis and screening with the goal of improving diagnostic accuracy. The purpose of this study was to verify the feasibility of using the combination of OBD and ML techniques as a screening tool for osteoporosis. Dual energy X-ray absorptiometry (DXA) and OBD measurements were performed on 203 Thai subjects. From the OBD measurements and readily available demographic data, machine learning techniques were used to predict the T-score measured by the DXA. The T-score predicted using the Ridge regressor had a correlation of r = 0.512 with respect to the reference value. The predicted T-score also showed an AUC of 0.853 for discriminating individuals with osteoporosis. The results obtained suggest that the developed model is reliable enough to be used for screening for osteoporosis.


Asunto(s)
Densidad Ósea , Osteoporosis , Humanos , Absorciometría de Fotón/métodos
6.
Connect Tissue Res ; 53(2): 180-6, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22148954

RESUMEN

Joint loading is a recently developed loading modality, which can enhance bone formation and accelerate healing of bone fracture. Since mechanical stimulation alters expression of matrix metalloproteinases (MMPs) in chondrocytes, a question addressed herein was, does joint loading alter actions of MMPs in the articular cartilage? We hypothesized that expression and activity of MMPs are regulated in a load-intensity-dependent manner and that moderate load scan downregulates MMPs. To test this hypothesis, a mouse elbow-loading model was employed. In the articular cartilage of an ulna, the mRNA levels of a group of MMPs as well as their degenerative activities were determined. The result revealed that elbow loading altered the expression and activities of MMPs depending on its loading intensity. Collectively, the data in this study indicate that 0.2 and 0.5 N joint loading significantly reduced the expression of multiple MMPs, that is, MMP-1, MMP-3, MMP-8, and MMP-13, and overall activities of collagenases or gelatinases in articular cartilage, while higher loads increased the expression and activity of MMP-1 and MMP-13. Furthermore, moderate loads at 1 N elevated the mRNA level of CBP/p300-interacting transactivator with ED-rich tail 2 (CITED2), but higher loads at 4 N did not induce a detectable amount of CITED2 mRNA. Since CITED2 is known to mediate the downregulation of MMP-1 and MMP-13, the result indicates that joint loading at moderate intensity reduces MMP activities through potential induction of CITED2. MMPs such as MMP-1 and MMP-13 are predominant collagenases in the pathology of osteoarthritis. Therefore, joint loading could offer an interventional regimen for maintenance of joint tissues.


Asunto(s)
Cartílago Articular/enzimología , Articulación del Codo/fisiología , Metaloproteinasas de la Matriz/metabolismo , Cúbito/fisiología , Animales , Remodelación Ósea/fisiología , Femenino , Expresión Génica , Metaloproteinasas de la Matriz/genética , Ratones , Ratones Endogámicos C57BL , Osteocalcina/genética , Osteocalcina/metabolismo , ARN Mensajero/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Estrés Mecánico , Inhibidores Tisulares de Metaloproteinasas/genética , Inhibidores Tisulares de Metaloproteinasas/metabolismo , Transactivadores/genética , Transactivadores/metabolismo , Soporte de Peso
7.
Ann Diagn Pathol ; 16(2): 141-4, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21419679

RESUMEN

Sublingual gland tumors, especially mesenchymal tumors, are extremely rare. We describe the first reported case of schwannoma arising from the sublingual gland with details of the histopathologic and immunohistochemical features. A 70-year-old woman developed a painless swelling on the floor of the mouth. The excised material was sublingual gland tissue with an ovoid, grayish-yellow solid tumorous mass at the cut surface. The tumor was composed of proliferated spindle-shaped tumor cells exhibiting palisading patterns. In the center of the tumor, a small salivary gland component was recognized. Immunohistochemically, the tumor cells were strongly positive for S-100 protein but negative for neurofilament protein. The Ki-67 labeling index was 4.58. The clear presence of a remnant sublingual gland lobule in the present tumor provided convincing evidence that it was a schwannoma arising from the sublingual gland and thus the first of its type to be reported.


Asunto(s)
Neurilemoma/patología , Neoplasias de la Glándula Sublingual/patología , Anciano , Femenino , Humanos , Inmunohistoquímica , Neurilemoma/metabolismo , Neoplasias de la Glándula Sublingual/metabolismo
8.
J Biomed Opt ; 27(5)2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35585663

RESUMEN

SIGNIFICANCE: To achieve early detection of osteoporosis, a simple bone densitometry method using optics was proposed. However, individual differences in soft tissue structure and optical properties can cause errors in quantitative bone densitometry. Therefore, developing optical bone densitometry that is robust to soft tissue variations is important for the early detection of osteoporosis. AIM: The purpose of this study was to develop an optical bone densitometer that is insensitive to soft tissue, using Monte Carlo simulation and machine learning techniques, and to verify its feasibility. APPROACH: We propose a method to measure spatially resolved diffuse light from three directions of the biological tissue model and used machine learning techniques to predict bone density from these data. The three directions are backward, forward, and lateral to the direction of ballistic light irradiation. The method was validated using Monte Carlo simulations using synthetic biological tissue models with 1211 different random structural and optical properties. RESULTS: The results were computed after a 10-fold cross-validation. From the simulated optical data, the machine learning model predicted bone density with a coefficient of determination of 0.760. CONCLUSIONS: The optical bone densitometry method proposed in this study was found to be robust against individual differences in soft tissue.


Asunto(s)
Aprendizaje Automático , Osteoporosis , Simulación por Computador , Densitometría , Humanos , Método de Montecarlo
9.
Biomed Tech (Berl) ; 67(6): 503-512, 2022 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-36102674

RESUMEN

Skin thickness, including the adipose layer, which varies from individual to individual, affects the bone density measurement using light. In this study, we proposed a method to measure skin thickness using light and to correct the bias caused by differences in skin thickness and verified the proposed method by experiments using a phantom. We measured simulated skin of different thicknesses and bovine trabecular bone of different bone mineral densities (BMDs) using an optical system consisting of lasers of 850 and 515 nm wavelengths, lenses, and slits. Although the slope of the light intensity distribution formed on the surface of the material when irradiated by the 850 nm laser is affected by the thickness of the skin phantom. The difference of the intensity distribution peaks (δy) between the 850 and 515 nm lasers was strongly correlated with the thickness of the skin phantom. The coefficient of determination between the measurements and the BMD was improved by correcting the 850 nm laser measurements with δy. This result suggests that the method is applicable to optical bone densitometry, which is insensitive to differences in skin thickness.


Asunto(s)
Densidad Ósea , Piel , Bovinos , Animales , Fantasmas de Imagen , Luz , Densitometría/métodos
10.
Front Vet Sci ; 9: 931088, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35990280

RESUMEN

Background: Perineal hernia (PH) in dogs is caused by the separation of the anal septal muscles and the displacement of pelvic/abdominal organs under the perineal skin. Reconstruction of the pelvic septum by surgical repositioning is the only curative treatment. Objectives: To describe the procedure and outcomes of surgical repair using the pedunculated tunica vaginalis communis (TVC) for PH in dogs. Methods: Intact male dogs diagnosed with PH were included in this study. For surgery, each dog was positioned in the Trendelenburg position. Castration was performed with the open technique, followed by colopexy and cystopexy via laparotomy. The remaining bilateral TVCs transposed to the opening of PH were used for the perineal herniorrhaphy. Intraoperative findings, complications, and outcomes were evaluated and recorded. Results: Eight dogs [median age 10.5 years (range, 9-13 years); median body weight 4.9 kg (range, 1.6-12.3 kg)] were treated using the TVC surgical technique. Perineal herniorrhaphy with the TVC was feasible in all dogs. The median operation time was 105.5 min (range, 46-149 min) in unilateral PH, and 92 and 122 min in two dogs with bilateral PH. Short-term postoperative complications during hospitalization did not occur in six dogs, whereas the residual two dogs had a temporary local infection as a minor complication. Postoperative recurrence occurred in one dog (13%) on postoperative day 136. Conclusions: Our study suggests that the herniorrhaphy technique using the pedunculated TVC is an alternative option for the repair of PH in dogs.

11.
J Vet Med Sci ; 73(5): 693-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21187679

RESUMEN

A 13-year-old neutered female Shih Tzu was referred for investigation of a cranial abdominal mass. Investigations including conventional radiography, abdominal ultrasonography and computed tomography confirmed the mass in the caudate lobe of the liver. As a collateral vein originating from the caudal vena cava (CVC) communicated with the azygos vein, the CVC was ligated and transected cranial to the right renal vein and cranial to the mass under temporary occlusion of the thoracic descending aorta and posthepatic CVC. The mass combined with the CVC was excised. The mass was confirmed as hepatocellular carcinoma (HCC). This report describes the first case with successful en bloc resection of a large HCC involving the CVC in a dog.


Asunto(s)
Carcinoma Hepatocelular/veterinaria , Enfermedades de los Perros/cirugía , Neoplasias Hepáticas/veterinaria , Vena Cava Inferior/patología , Animales , Carcinoma Hepatocelular/cirugía , Perros , Femenino , Neoplasias Hepáticas/cirugía
12.
Materials (Basel) ; 14(2)2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33419103

RESUMEN

17-4PH stainless steel specimens were fabricated by fused deposition of metals (FDMet) technology, which combines 17-4PH particles with an organic binder. FDMet promises a low-cost additive manufacturing process. The present research aims to clarify the influence of layer directions in the 3D printing process on the mechanical and shrinkage properties of as-sintered and as-aged specimens. All specimens (the as-sintered and as-aged specimens printed in three layer directions) exhibited high relative density (97.5-98%). The highest ultimate strengths (880 and 1140 MPa in the as-sintered and as-aged specimens, respectively) were obtained when the layer direction was perpendicular to the tensile direction. Conversely, the specimens printed with their layer direction parallel to the tensile direction presented a low ultimate strength and low strain at breakage. The fact that the specimens with their layer direction parallel to the tensile direction presented a low ultimate strength and low strain at breakage is a usual behavior of parts obtained by means of FDM. The SEM images revealed oriented binder domains in the printed parts and oriented voids in the sintered parts. It was assumed that large binder domains in the filament were oriented perpendicular to the layer directions during the fused deposition modeling printing, and remained as oriented voids after sintering. Stress concentration in the oriented void defects was likely responsible for the poor tensile properties of these specimens.

13.
BMC Plant Biol ; 10: 261, 2010 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-21106055

RESUMEN

BACKGROUND: Thellungiella halophila (also known as T. salsuginea) is a model halophyte with a small size, short life cycle, and small genome. Thellungiella genes exhibit a high degree of sequence identity with Arabidopsis genes (90% at the cDNA level). We previously generated a full-length enriched cDNA library of T. halophila from various tissues and from whole plants treated with salinity, chilling, freezing stress, or ABA. We determined the DNA sequences of 20 000 cDNAs at both the 5'- and 3' ends, and identified 9569 distinct genes. RESULTS: Here, we completely sequenced 1047 Thellungiella full-length cDNAs representing abiotic-stress-related genes, transcription factor genes, and protein phosphatase 2C genes. The predicted coding sequences, 5'-UTRs, and 3'-UTRs were compared with those of orthologous genes from Arabidopsis for length, sequence similarity, and structure. The 5'-UTR sequences of Thellungiella and Arabidopsis orthologs shared a significant level of similarity, although the motifs were rearranged. While examining the stress-related Thellungiella coding sequences, we found a short splicing variant of T. halophila salt overly sensitive 1 (ThSOS1), designated ThSOS1S. ThSOS1S contains the transmembrane domain of ThSOS1 but lacks the C-terminal hydrophilic region. The expression level of ThSOS1S under normal growth conditions was higher than that of ThSOS1. We also compared the expression levels of Na+-transport-system genes between Thellungiella and Arabidopsis by using full-length cDNAs from each species as probes. Several genes that play essential roles in Na+ excretion, compartmentation, and diffusion (SOS1, SOS2, NHX1, and HKT1) were expressed at higher levels in Thellungiella than in Arabidopsis. CONCLUSIONS: The full-length cDNA sequences obtained in this study will be essential for the ongoing annotation of the Thellungiella genome, especially for further improvement of gene prediction. Moreover, they will enable us to find splicing variants such as ThSOS1S (AB562331).


Asunto(s)
Brassicaceae/genética , Genoma de Planta/genética , Genómica/métodos , Plantas Tolerantes a la Sal/genética , Regiones no Traducidas 3'/genética , Regiones no Traducidas 5'/genética , Secuencia de Aminoácidos , Arabidopsis/genética , Secuencia de Bases , Northern Blotting , ADN Complementario/química , ADN Complementario/genética , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , Proteínas de Plantas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico
14.
J Exp Bot ; 61(4): 1125-38, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20080827

RESUMEN

Many accessions (ecotypes) of Arabidopsis have been collected. Although few differences exist among their nucleotide sequences, these subtle differences induce large genetic variation in phenotypic traits such as stress tolerance and flowering time. To understand the natural variability in salt tolerance, large-scale soil pot experiments were performed to evaluate salt tolerance among 350 Arabidopsis thaliana accessions. The evaluation revealed a wide variation in the salt tolerance among accessions. Several accessions, including Bu-5, Bur-0, Ll-1, Wl-0, and Zu-0, exhibited marked stress tolerance compared with a salt-sensitive experimental accession, Col-0. The salt-tolerant accessions were also evaluated by agar plate assays. The data obtained by the large-scale assay correlated well with the results of a salt acclimation (SA) assay, in which plants were transferred to high-salinity medium following placement on moderate-salinity medium for 7 d. Genetic analyses indicated that the salt tolerance without SA is a quantitative trait under polygenic control, whereas salt tolerance with SA is regulated by a single gene located on chromosome 5 that is common among the markedly salt-tolerant accessions. These results provide important information for understanding the mechanisms underlying natural variation of salt tolerance in Arabidopsis.


Asunto(s)
Arabidopsis/fisiología , Tolerancia a la Sal , Selección Genética , Aclimatación , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular
15.
J Vet Med Sci ; 72(7): 917-20, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20179386

RESUMEN

Survivin overexpression has been reported in relation to tumor malignancy, suggesting that it is an unfavorable prognostic marker, and antibody responses to this protein have been confirmed in human cancer patients. In this study, we investigated antibody responses to survivin in canine cancer cases, and examined the prevalence of such responses by enzyme-linked immunosorbent assay (ELISA) using recombinant canine survivin protein as the antigen. The cut-off value for positivity in the anti-survivin ELISA was 0.35, as determined using the mean absorbance +2 S.D. of samples from healthy dogs. Sera from 16 of 59 (27.1%) cancer and 3 of 25 (12%) non-cancer disease dogs were positive on ELISA. The highest positivity rates (>50%) among the cancer cases were seen in dogs with mammary tumor, squamous cell carcinoma and melanoma.


Asunto(s)
Autoanticuerpos/sangre , Enfermedades de los Perros/inmunología , Neoplasias/veterinaria , Animales , Cartilla de ADN , Enfermedades de los Perros/sangre , Perros , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Escherichia coli/inmunología , Amplificación de Genes , Humanos , Proteínas Asociadas a Microtúbulos/sangre , Proteínas Asociadas a Microtúbulos/inmunología , Neoplasias/sangre , Neoplasias/inmunología
16.
J Vet Med Sci ; 72(10): 1345-9, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20460835

RESUMEN

The objective of this paper was to evaluate the sequence of feline prepro-adrenomedullin (AM) and its tissue distribution and to investigate whether expression of feline AM mRNA increases in association with spontaneous cardiomyopathy. The feline prepro-AM cDNA sequence and deduced amino acids were 564 base pairs and 188 residues, respectively. The cDNA sequences of feline prepro-AM including AM and proadrenomedullin N-terminal 20 peptide showed high homology with those of other mammalian species. The mRNA expression of AM was detectable in various normal tissues. The mRNA levels of AM were elevated in hearts with cardiomyopathy compared with normal hearts. This study suggests that AM has an important role as a neurohumoral factor in cats with spontaneous heart diseases.


Asunto(s)
Cardiomiopatías/veterinaria , Enfermedades de los Gatos/genética , Precursores de Proteínas/genética , ARN Mensajero/genética , Secuencia de Aminoácidos , Animales , Emparejamiento Base , Secuencia de Bases , Cardiomiopatías/genética , Gatos , Clonación Molecular , Cartilla de ADN , Humanos , Mamíferos/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
17.
Materials (Basel) ; 13(11)2020 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-32486111

RESUMEN

Metal specimens were fabricated via the fused deposition of metals (FDMet) technique with a filament composed of the 316L stainless steel particles and an organic binder. This process was adopted due to its potential as a low-cost additive manufacturing process. The objective of this study is to investigate the influence of the processing conditions-layer directions and layer thicknesses-on the mechanical and shrinkage properties of the metal components. The specimens were printed in three different layer directions. The highest ultimate strength of 453 MPa and strain at break of 48% were obtained in the specimen printed with the layer direction perpendicular to the tensile direction. On the other hand, the specimen printed in the layer direction parallel to the tensile direction exhibited poor mechanical properties. The reason for the anisotropy of the properties was investigated through systematic SEM observations. The observations revealed the presence of segregated binder domains in the filaments. It was deduced that the binder domain was oriented in the direction perpendicular to that of the layer and remained as oriented voids even after sintering. The voids oriented perpendicular to the tensile direction act as defects that could cause stress concentration, thus resulting in poor mechanical properties.

18.
Plant Mol Biol ; 70(3): 327-40, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19266168

RESUMEN

We employed a comparative genomic approach to understand protein phosphatase 2C (PP2C)-mediated abscisic acid (ABA) signaling in the moss Physcomitrella patens. Ectopic expression of Arabidopsis (Arabidopsis thaliana) abi1-1, a dominant mutant allele of ABI1 encoding a PP2C involved in the negative regulation of ABA signaling, caused ABA insensitivity of P. patens both in gene expression of late embryogenesis abundant (LEA) genes and in ABA-induced protonemal growth inhibition. The transgenic abi1-1 plants showed decreased ABA-induced freezing tolerance, and decreased tolerance to osmotic stress. Analyses of the P. patens genome revealed that only two (PpABI1A and PpABI1B) PP2C genes were related to ABI1. In the ppabi1a null mutants, ABA-induced expression of LEA genes was elevated, and protonemal growth was inhibited with lower ABA concentration compared to the wild type. Moreover, ABA-induced freezing tolerance of the ppabi1a mutants was markedly enhanced. We provide the genetic evidence that PP2C-mediated ABA signaling is evolutionarily conserved between Arabidopsis and P. patens.


Asunto(s)
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Bryopsida/enzimología , Fosfoproteínas Fosfatasas/metabolismo , Transducción de Señal , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Secuencia de Bases , Bryopsida/genética , Clonación Molecular , Evolución Molecular , Regulación de la Expresión Génica de las Plantas , Genoma de Planta , Datos de Secuencia Molecular , Mutación , Fosfoproteínas Fosfatasas/genética , Filogenia , Plantas Modificadas Genéticamente/enzimología , Plantas Modificadas Genéticamente/genética , Proteína Fosfatasa 2C , ARN de Planta/genética , Estrés Fisiológico
19.
Mycoses ; 52(1): 80-3, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18444972

RESUMEN

The first case of feline true mycetoma because of a dermatophyte has been reported in this manuscript, although pseudomycetoma has been described in dogs and cats. The patient was a 9-year-old castrated male Persian cat weighing 4.2 kg with subcutaneous nodules on the dorsal trunk. Physical examination revealed two subcutaneous nodules (2.5 x 5.0 cm and 3.5 x 5.0 cm in size) that drained purulent exudates with cement-like substances containing yellowish granules. The impression smear of the yellowish granules demonstrated by PAS staining that they were masses of fungal septated hyphae (3-4 mum of width). From the nodular inflammation with fibrosis, fistulae draining from deep tissue and many grains containing abundant hyphal filaments, the case was diagnosed as mycetoma, complying with the definitive criteria of mycetoma. The etiologic fungus was molecularly as well as morphologically identified as Microsporum canis.


Asunto(s)
Enfermedades de los Gatos/microbiología , Microsporum/aislamiento & purificación , Micetoma/veterinaria , Animales , Antifúngicos/uso terapéutico , Enfermedades de los Gatos/tratamiento farmacológico , Gatos , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Itraconazol/uso terapéutico , Masculino , Micetoma/tratamiento farmacológico , Micetoma/microbiología , ARN Ribosómico 28S/genética , Análisis de Secuencia de ADN , Piel/microbiología , Piel/patología
20.
J Vet Med Sci ; 71(10): 1285-9, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19887732

RESUMEN

Twelve healthy Beagles were divided into 3 groups of 4 dogs each. To compare 2 methods of total hepatic vascular exclusion (THVE), we investigated the hemodynamic changes during THVE and assessed the influences on hepatic, renal and pancreatic biochemistry and the complications after THVE. In Group A, the thoracic aorta, hepatic pedicle and prehepatic and posthepatic caudal vena cava were occluded for 20 min, while in Group B, the celiac and cranial mesenteric arteries, hepatic pedicle and prehepatic and posthepatic caudal vena cava were occluded for 20 min. In Group C, a sham operation was performed. The arterial, venous and portal venous pressures and serum biochemistry parameters were measured before and during THVE and for 30 min after reperfusion. The carotid arterial pressure did not change in Group A during THVE, but decreased in Group B. The femoral and portal venous pressures in Group B increased significantly during THVE compared with those in Group C. With the exception of alanine aminotransferase, the serum biochemical profiles remained unchanged after the operation. For 7 days after the operation, no complications were observed in any of the dogs. In conclusion, occlusion of thoracic aorta, hepatic pedicle and prehepatic and posthepatic caudal vena cava is a feasible and safe method of hepatic vascular occlusion. This technique appears to be effective for canine hepatic surgery, such as removal of a large right-divisional hepatic tumor and attenuation of intrahepatic portosystemic shunt.


Asunto(s)
Perros , Hígado/irrigación sanguínea , Animales , Presión Sanguínea , Femenino , Frecuencia Cardíaca
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