353 research outputs found
Performance and bacterial community shifts during phosphogypsum biotransformation
Phosphogypsum (PG) is an industrial waste composed mainly by sulfate, turning it a suitable sulfate source for sulfate-reducing bacteria (SRB). In the present work, the capability of two SRB communities, one enriched from Portuguese PG (culture PG) and the other from sludge from a wastewater treatment plant (culture WWT-1), to use sulfate from PG was compared. In addition, the impact of this sulfate-rich waste in the microbial community was assessed. The highest efficiency in terms of sulfate reduction was observed with culture WWT-1. The bacterial composition of this culture was not significantly affected when sodium sulfate from the nutrient medium was replaced by PG as a sulfate source. Next generation sequencing (NGS) showed that this community was phylogenetically diverse, composed by bacteria affiliated to Clostridium, Arcobacter, and Sulfurospirillum genera and by SRB belonging to Desulfovibrio, Desulfomicrobium, and Desulfobulbus genera. In contrast, the bacterial structure of the community enriched from PG was modified when sodium sulfate was replaced by PG as the sulfate source. This culture, which showed the poorest performance in the use of sulfate from PG, was mainly composed by SRB related to Desulfosporosinus genus. The present work provides new information regarding the phylogenetic characterization of anaerobic bacterial communities with the ability to use PG as sulfate donor, thus, contributing to improve the knowledge of microorganisms suitable to be used in PG bioremediation. Additionally, this paper demonstrates that an alternative to lactate and low-cost carbon source (wine wastes) can be used efficiently for that purpose
Bacterial cellulose production by Gluconacetobacter xylinus by employing alternative culture media
Bacterial cellulose (BC) is used in different fields as a biological material due to its unique properties. Despite there being many BC applications, there still remain many problems associated with bioprocess technology, such as increasing productivity and decreasing production cost. New technologies that use waste from the food industry as raw materials for culture media promote economic advantages because they reduce environmental pollution and stimulate new research for science sustainability. For this reason, BC production requires optimized conditions to increase its application. The main objective of this study was to evaluate BC production by Gluconacetobacter xylinus using industry waste, namely, rotten fruits and milk whey, as culture media. Furthermore, the structure of BC produced at different conditions was also determined. The culture media employed in this study were composed of rotten fruit collected from the disposal of free markets, milk whey from a local industrial disposal, and their combination, and Hestrin and Schramm media was used as standard culture media. Although all culture media studied produced BC, the highest BC yield60 mg/mLwas achieved with the rotten fruit culture. Thus, the results showed that rotten fruit can be used for BC production. This culture media can be considered as a profitable alternative to generate high-value products. In addition, it combines environmental concern with sustainable processes that can promote also the reduction of production cost.The authors would like to acknowledge the Brazil National Council of Technological and Scientific Development (CNPq, FAPESP, and CAPES), the financial support from FAPESP 2009/14897-7, and Fundacao para a Ciencia e a Tecnologia (FCT)/Portugal through the project PTDC/EBB-EBI/112170/2009 for the financial support and scholarship. Special thanks to Talita Almeida Vicentin for technical support
Retroviral transfer of the p16INK4a cDNA inhibits C6 glioma formation in Wistar rats
BACKGROUND: The p16(INK4A) gene product halts cell proliferation by preventing phosphorylation of the Rb protein. The p16INK4a gene is often deleted in human glioblastoma multiforme, contributing to unchecked Rb phosphorylation and rapid cell division. We show here that transduction of the human p16INK4a cDNA using the pCL retroviral system is an efficient means of stopping the proliferation of the rat-derrived glioma cell line, C6, both in tissue culture and in an animal model. C6 cells were transduced with pCL retrovirus encoding the p16INK4a, p53, or Rb genes. These cells were analyzed by a colony formation assay. Expression of p16INK4a was confirmed by immunohistochemistry and Western blot analysis. The altered morphology of the p16-expressing cells was further characterized by the senescence-associated β-galactosidase assay. C6 cells infected ex vivo were implanted by stereotaxic injection in order to assess tumor formation. RESULTS: The p16INK4a gene arrested C6 cells more efficiently than either p53 or Rb. Continued studies with the p16INK4a gene revealed that a large portion of infected cells expressed the p16INK4a protein and the morphology of these cells was altered. The enlarged, flat, and bi-polar shape indicated a senescence-like state, confirmed by the senescence-associated β-galactosidase assay. The animal model revealed that cells infected with the pCLp16 virus did not form tumors. CONCLUSION: Our results show that retrovirus mediated transfer of p16INK4a halts glioma formation in a rat model. These results corroborate the idea that retrovirus-mediated transfer of the p16INK4a gene may be an effective means to arrest human glioma and glioblastoma
Numerical analysis of different heating systems for warm sheet metal forming
The main goal of this study is to present an analysis
of different heating methods frequently used in laboratory
scale and in the industrial practice to heat blanks at warm
temperatures. In this context, the blank can be heated inside
the forming tools (internal method) or using a heating system
(external method). In order to perform this analysis, a finite
element model is firstly validated with the simulation of the
direct resistance system used in a Gleeble testing machine.
The predicted temperature was compared with the temperature
distribution recorded experimentally and a good agreement
was found. Afterwards, a finite element model is used to
predict the temperature distribution in the blank during the
heating process, when using different heating methods. The
analysis also includes the evaluation of a cooling phase associated
to the transport phase for the external heating methods.
The results of this analysis show that neglecting the heating
phase and a transport phase could lead to inaccuracies in the
simulation of the forming phase.The authors gratefully acknowledge the financial
support of the Portuguese Foundation for Science and Technology (FCT)
under project PTDC/EMS-TEC/1805/2012 and by FEDER funds
through the program COMPETE—Programa Operacional Factores de
Competitividade, under the project CENTRO-07-0224-FEDER-002001
(MT4MOBI). The authors would like to thank Prof. A. Andrade-Campos
for helpful contributions on the development of the finite element code
presented in this work.info:eu-repo/semantics/publishedVersio
Temporal relationship between rainfall, temperature and occurrence of dengue cases in São Luís, Maranhão, Brazil
Human immunodeficiency virus and AIDS and other important predictors of maternal mortality in Mulago Hospital Complex Kampala Uganda
BACKGROUND: Women with severe maternal morbidity are at high risk of dying. Quality and prompt management and sometimes luck have been suggested to reduce on the risk of dying. The objective of the study was to identify the direct and indirect causes of severe maternal morbidity, predictors of progression from severe maternal morbidity to maternal mortality in Mulago hospital, Kampala, Uganda. METHODS: This was a longitudinal follow up study at the Mulago hospital's Department of Obstetrics and Gynaecology. Participants were 499 with severe maternal morbidity admitted in Mulago hospital between 15th November 2001 and 30th November 2002 were identified, recruited and followed up until discharge or death. Potential prognostic factors were HIV status and CD4 cell counts, socio demographic characteristics, medical and gynaecological history, past and present obstetric history and intra- partum and postnatal care. RESULTS: Severe pre eclampsia/eclampsia, obstructed labour and ruptured uterus, severe post partum haemorrhage, severe abruptio and placenta praevia, puerperal sepsis, post abortal sepsis and severe anaemia were the causes for the hospitalization of 499 mothers. The mortality incidence rate was 8% (n = 39), maternal mortality ratio of 7815/100,000 live births and the ratio of severe maternal morbidity to mortality was 12.8:1.The independent predictors of maternal mortality were HIV/AIDS (OR 5.1 95% CI 2-12.8), non attendance of antenatal care (OR 4.0, 95% CI 1.3-9.2), non use of oxytocics (OR 4.0, 95% CI 1.7-9.7), lack of essential drugs (OR 3.6, 95% CI 1.1-11.3) and non availability of blood for transfusion (OR 53.7, 95% CI (15.7-183.9) and delivery of amale baby (OR 4.0, 95% CI 1.6-10.1). CONCLUSION: The predictors of progression from severe maternal morbidity to mortality were: residing far from hospital, low socio economic status, non attendance of antenatal care, poor intrapartum care, and HIV/AIDS.There is need to improve on the referral system, economic empowerment of women and to offer comprehensive emergency obstetric care so as to reduce the maternal morbidity and mortality in our community
Reduced responsiveness is an essential feature of chronic fatigue syndrome: A fMRI study
BACKGROUND: Although the neural mechanism of chronic fatigue syndrome has been investigated by a number of researchers, it remains poorly understood. METHODS: Using functional magnetic resonance imaging, we studied brain responsiveness in 6 male chronic fatigue syndrome patients and in 7 age-matched male healthy volunteers. Responsiveness of auditory cortices to transient, short-lived, noise reduction was measured while subjects performed a fatigue-inducing continual visual search task. RESULTS: Responsiveness of the task-dependent brain regions was decreased after the fatigue-inducing task in the normal and chronic fatigue syndrome subjects and the decrement of the responsiveness was equivalent between the 2 groups. In contrast, during the fatigue-inducing period, although responsiveness of auditory cortices remained constant in the normal subjects, it was attenuated in the chronic fatigue syndrome patients. In addition, the rate of this attenuation was positively correlated with the subjective sensation of fatigue as measured using a fatigue visual analogue scale, immediately before the magnetic resonance imaging session. CONCLUSION: Chronic fatigue syndrome may be characterised by attenuation of the responsiveness to stimuli not directly related to the fatigue-inducing task
INTERFERON BETA-1A TREATMENT IN HTLV-1-ASSOCIATED MYELOPATHY/TROPICAL SPASTIC PARAPARESIS: A CASE REPORT
Here a young patient (< 21 years of age) with a history of infective dermatitis is described. The patient was diagnosed with myelopathy associated with HTLV-1/tropical spastic paraparesis and treated with interferon beta-1a. The disease was clinically established as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and laboratory tests confirmed the presence of antibodies to HTLV-1 in the cerebrospinal fluid (CSF). Mumps, cytomegalovirus, Epstein-Barr virus, schistosomiasis, herpes virus 1 and 2, rubella, measles, varicella-zoster toxoplasmosis, hepatitis, HIV, and syphilis were excluded by serology. The patient was diagnosed with neurogenic bladder and presented with nocturia, urinary urgency, paresthesia of the lower left limb, a marked reduction of muscle strength in the lower limbs, and a slight reduction in upper limb strength. During the fourth week of treatment with interferon beta-1a, urinary urgency and paresthesia disappeared and clinical motor skills improved
Trabecular bone area and bone healing in spontaneously hypertensive rats: a histometric study
Microabrasion in tooth enamel discoloration defects: three cases with long-term follow-ups
Superficial irregularities and certain intrinsic stains on the dental enamel surfaces can be resolved by enamel microabrasion, however, treatment for such defects need to be confined to the outermost regions of the enamel surface. Dental bleaching and resin-based composite repair are also often useful for certain situations for tooth color corrections. This article presented and discussed the indications and limitations of enamel microabrasion treatment. Three case reports treated by enamel microabrasion were also presented after 11, 20 and 23 years of follow-ups
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