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排序方式: 共有405条查询结果,搜索用时 31 毫秒
41.
Lopez G Jmenez S Martinez R Pina Mdel S Gallegos B Pérez-Campos E Zenteno E Hernández P 《Preparative biochemistry & biotechnology》2011,41(1):22-29
In humans, at about week 6, sex cords develop within the forming testes. Testes normally descend to the scrotum; cryptorchidism occurs when one or two testes do not descend to scrotum and in some case are accompanied by the appendix testis. The appendix testis is a small sessile or polypoid structure located at the antero superior pole of the testis, adjacent to the head of the epididymis. Glycans can be involved in development of the appendix testis and cryptorchidism. In this work, lectin histochemistry was used to evaluate glycans expression in appendix testis in children with cryptorchidism. Our results showed that lectin from Lens culinaris, Ulex europaeus I., Canavalia ensiformis, Artocarpus integrifolia, Glycine max, and Griffonia simplicifolia recognizes epithelial and estromal cells. Not interaction was observed with lectin from Amaranthus leucocarpus, while lectin from Dolichus biflorus lectin only recognizes epithelial cells. Our results suggest that O-glycans linked in some glycoproteins represent important elements in appendix testis development. 相似文献
42.
43.
Rizzatti-Barbosa CM Ribeiro MC Silva-Concilio LR Di Hipolito O Ambrosano GM 《Gerodontology》2005,22(2):112-115
Background: Elongation and calcification of the stylohyoid ligament complex may be correlated with Eagle's syndrome. The styloid complex pathogenesis is still being debated. Objective: The aim of this study was to investigate the prevalence of stylohyoid ligament complex elongation in panoramic radiographs of 2252 patients in a Brazilian adult, partially edentulous population, of both sexes. Methods: The radiographs, taken in the Semiology Department at the Dental School in Brazil, were randomly selected from January 1997 to December 2000. The stylohyoid ligament complexes were measured from the cranial base up to the osseous tip of each process. Mineralisation of the complex of more than 25 mm in length on the radiograph was considered to be abnormal. The same operator made all the measurements. The lengths of the areas of mineralisation were recorded, and whether the condition was bilateral was noted. Results: This abnormality was present in both sexes. A calcified complex was found in 451 of the 2252 patients. The majority of these calcified complexes (n = 248; 54.9%) were bilateral. Three hundred and fifty‐six (39.5%) of them were longer than 25 mm (and so were abnormal), and the length varied from 26.1 to 65 mm. (average length = 27.8 mm). Forty (4.4%) of the abnormalities were longer than 50 mm, and of these 36 (90%) were in the 40–59 year age group. The mean length of a mineralised stylohyoid ligament complex in patients in the 60–79 year age group was 32.75 mm. Conclusion: The results suggested that an anatomical variant of the stylohyoid ligament complex was more frequently found in the elderly female population, although this abnormality was present in both sexes. There was a greater tendency for the abnormality to be present in patients between 60 and 79 years of age. 相似文献
44.
Paez-Rubio T Viau E Romero-Hernandez S Peccia J 《Applied and environmental microbiology》2005,71(2):804-810
Reuse of partially treated domestic wastewater for agricultural irrigation is a growing practice in arid regions throughout the world. A field sampling campaign to determine bioaerosol concentration, culturability, and identity at various wind speeds was conducted at a flooded wastewater irrigation site in Mexicali, Baja California, Mexico. Direct fluorescent microscopy measurements for total microorganisms, culture-based assays for heterotrophs and gram-negative enteric bacteria, and small-subunit rRNA gene-based cloning were used for microbial characterizations of aerosols and effluent wastewater samples. Bioaerosol results were divided into two wind speed regimens: (i) below 1.9 m/s, average speed 0.5 m/s, and (ii) above 1.9 m/s, average speed 4.5 m/s. Average air-borne concentration of total microorganisms, culturable heterotrophs, and gram-negative enteric bacteria were, respectively, 1.1, 4.2, and 6.2 orders of magnitude greater during the high-wind-speed regimen. Small-subunit rRNA gene clone libraries processed from samples from air and the irrigation effluent wastewater during a high-wind sampling event indicate that the majority of air clone sequences were more than 98% similar to clone sequences retrieved from the effluent wastewater sample. Overall results indicate that wind is a potential aerosolization mechanism of viable wastewater microorganisms at flood irrigation sites. 相似文献
45.
Rafael MS dos Santos-Junior IP Tadei WP Sallum MA Forattini OP 《Genetics and molecular research : GMR》2005,4(4):684-690
Anopheles (Nyssorhynchus) albitarsis sensu lato is an important malaria vector in Brazil, especially in the Brazilian Amazon region. Chromosome preparations of fourth-instar larvae of A. albitarsis from Iranduba and Coari (AM) and Ilha Comprida (SP) were analyzed for karyotype determination and to improve cytogenetic identification of this species. Anopheles albitarsis possesses 2n = 6 chromosomes, with two pairs (submetacentric and metacentric) of autosomes and one pair of sex chromosomes, with X-Y dimorphism. The sex pair is homomorphic and acrocentric in females and heteromorphic in males, with a punctiform Y chromosome. Somatic pairing was detected in the prometaphase and metaphase chromosomes of the three A. albitarsis populations. Apparently, sex chromosome evolution in the Culicidae does not function as does evolution in the Culicidae, since it occurs in the subfamily Anophelinae, which possesses heteromorphic sex chromosomes and is regarded as primitive, based on several criteria. These karyotype data on the albitarsis complex reinforce the hypothesis that sex chromosome evolution in the subfamily Anophelinae is conserved, and the variation revealed in the mean size of chromosomes in three populations indicates that selective pressure in these populations is occurring only at a genetic level. 相似文献
46.
Possible biphasic sweating response during short-term heat acclimation protocol for tropical natives
Magalhães Fde C Machado-Moreira CA Vimieiro-Gomes AC Silami-Garcia E Lima NR Rodrigues LO 《Journal of physiological anthropology》2006,25(3):215-219
The aim of the present study was to evaluate the sweat loss response during short-term heat acclimation in tropical natives. Six healthy young male subjects, inhabitants of a tropical region, were heat acclimated by means of nine days of one-hour heat-exercise treatments (40+/-0 degrees C and 32+/-1% relative humidity; 50% (.)VO(2peak) on a cycle ergometer). On days 1 to 9 of heat acclimation whole-body sweat loss was calculated by body weight variation corrected for body surface area. On days 1 and 9 rectal temperature (T(re)) and heart rate (HR) were measured continuously, and rating of perceived exertion (RPE) every 4 minutes. Heat acclimation was confirmed by reduced HR (day 1 rest: 77+/-5 b.min(-1); day 9 rest: 68+/-3 b.min(-1); day 1 final exercise: 161+/-15 b.min(-1); day 9 final exercise: 145+/-11 b.min(-1), p<0.05), RPE (13 vs. 11, p<0.05) and T(re) (day 1 rest: 37.2+/-0.2 degrees C; day 9 rest: 37.0+/-0.2 degrees C; day 1 final exercise: 38.2+/-0.2 degrees C; day 9 final exercise: 37.9+/-0.1 degrees C, p<0.05). The main finding was that whole-body sweat loss increased in days 5 and 7 (9.49+/-1.84 and 9.56+/-1.86 g.m(-2).min(-1), respectively) compared to day 1 (8.31+/-1.31 g.m(-2).min(-1), p<0.05) and was not different in day 9 (8.48+/-1.02 g.m(-2).min(-1)) compared to day 1 (p>0.05) of the protocol. These findings are consistent with the heat acclimation induced adaptations and suggest a biphasic sweat response (an increase in the sweat rate in the middle of the protocol followed by return to initial values by the end of it) during short-term heat acclimation in tropical natives. 相似文献
47.
Carlos Roberto Maximiano da Silva Leandro Bento da Silva Célia Guadalupe Tardelli de Jesus Andrade Rafael Trevisan María Socorro González-Elizondo André Luís Laforga Vanzela 《Plant Systematics and Evolution》2012,298(2):391-398
Micromorphology of the achene surface of 26 Brazilian species of Eleocharis was studied by scanning electron microscopy in order to evaluate its usefulness in the taxonomy of the genus. The results
point out two patterns of cell organization according to silica structures of achenes. The first corresponds to a group of
species (group A) that have small to medium cells arranged vertically. The second is found in those species (group B) with
medium to large cells arranged horizontally. These data were useful in separating species of Eleocharis subgenus Scirpidium and E. subgenus Limnochloa (group B) from E. subgenus Eleocharis (group A). However, group A shows considerable variation in silica wall arrangement. Eleocharis
squamigera, previously considered as part of E. subgenus Eleocharis, shows features rather similar to those of Scirpidium, confirming recent phylogenies. The subgenus Limnochloa was clearly distinguished from others by achenes with large cells (over 55 μm width), presence of crenate or repand anticlinal
walls, and some orifices near the wall in some species. The silica wall ornamentation seems to be a useful morphological tool
for studying relationships between subgenera and distinguishes Limnochloa from the other subgenera. 相似文献
48.
de-Oliveira-Pinto LM Gandini M Freitas LP Siqueira MM Marinho CF Setúbal S Kubelka CF Cruz OG Oliveira SA 《Memórias do Instituto Oswaldo Cruz》2012,107(1):48-56
Dengue virus (DENV) and parvovirus B19 (B19V) infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL)-1 receptor antagonist (Ra), CXCL10/inducible protein-10 (IP-10), CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1) were determined by multiplex immunoassay in serum samples obtained from B19V (37) and DENV-infected (36) patients and from healthy individuals (7). Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients. 相似文献
49.
Viñas-Bravo O Martinez-Pascual R Vega-Baez JL Gómez-Calvario V Sandoval-Ramírez J Montiel-Smith S Meza-Reyes S López-De Rosas A Martínez-Montiel M Reyes M Ruiz JA 《Steroids》2012,77(1-2):59-66
We report a facile protocol to obtain 22-substituted furostans and pseudosapogenins in high yields from (25R)- and (25S)-sapogenins. This method involves the treatment of the sapogenin with acetic-trifluoroacetic mixed anhydride and BF(3)·OEt(2) at room temperature, followed by the addition of a nucleophile (H(2)O, MeOH or KSeCN). In the case of 22-hydroxyfurostans, they can be transformed to pseudosapogenins by treatment with p-toluensulfonic acid. 相似文献
50.
Rare earth (RE) metals are essentials for the manufacturing of high-technology products. The separation of RE is complex and expensive; biosorption is an alternative to conventional processes. This work focuses on the biosorption of monocomponent and bicomponent solutions of lanthanum(III) and neodymium(III) in fixed-bed columns using Sargassum sp. biomass. The desorption of metals with HCl 0.10 mol L(-1) from loaded biomass is also carried out with the objective of increasing the efficiency of metal separation. Simple models have been successfully used to model breakthrough curves (i.e., Thomas, Bohart-Adams, and Yoon-Nelson equations) for the biosorption of monocomponent solutions. From biosorption and desorption experiments in both monocomponent and bicomponent solutions, a slight selectivity of the biomass for Nd(III) over La(III) is observed. The experiments did not find an effective separation of the RE studied, but their results indicate a possible partition between the metals, which is the fundamental condition for separation perspectives. 相似文献