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BACKGROUND: Children and young adults with HIV infection may exhibit vitamin D deficiency, which is harmful to bone health as well as the endocrine and immune systems. OBJECTIVES: This study sought to investigate the effect of vitamin D supplementation on children and young adults with HIV infection. METHODS: The PubMed, Embase, and Cochrane databases were searched. Randomized controlled trials that have evaluated the effects of vitamin D supplementation (ergocalciferol or cholecalciferol) at any dose or for any duration in children and young adults with HIV infection, aged 0-25 y, were included. A random-effects model was used, and the standardized mean difference (SMD) and 95% CI were calculated. RESULTS: Ten trials, with 21 publications and 966 participants (mean age: 17.9 y), were included in the meta-analysis. The supplementation dose and the duration of the studies included ranged from 400 to 7000 IU/d and from 6 to 24 mo, respectively. Vitamin D supplementation was associated with a significantly higher serum 25(OH)D concentration at 12 mo (SMD: 1.14; 95% CI: 0.64, 1.65; P < 0.00001) compared with a placebo. No significant difference was observed in spine BMD (SMD: -0.09; 95% CI: -0.47, 0.3; P = 0.65) at 12 mo between these 2 groups. However, participants who received higher doses (1600-4000 IU/d) had significantly higher total BMD (SMD: 0.23; 95% CI: 0.02, 0.44; P = 0.03) and nonsignificantly higher spine BMD (SMD: 0.3; 95% CI: -0.02, 0.61; P = 0.07) at 12 mo compared with those who received standard doses (400-800 IU/d). CONCLUSIONS: Vitamin D supplementation in children and young adults with HIV infection increases the serum 25(OH)D concentration. A relatively high daily dose of vitamin D (1600-4000 IU) improves total BMD at 12 mo and results in sufficient 25(OH)D concentrations.
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Infecções por HIV , Deficiência de Vitamina D , Humanos , Criança , Adulto Jovem , Adolescente , Infecções por HIV/complicações , Suplementos Nutricionais , Ensaios Clínicos Controlados Aleatórios como Assunto , Vitamina D , Colecalciferol , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/tratamento farmacológicoRESUMO
Tuberculosis (TB) remains a global health crisis, further exacerbated by the slow pace of new treatment options, and the emergence of extreme and total drug resistance to existing drugs. The challenge to developing new antibacterial compounds with activity against Mycobacterium tuberculosis (Mtb), the causative agent of TB, is in part due to unique features of this pathogen, especially the composition and structure of its complex cell envelope. Therefore, targeting enzymes involved in cell envelope synthesis has been of major interest for anti-TB drug discovery. FAAL32 is a fatty acyl-AMP ligase involved in the biosynthesis of the cell wall mycolic acids, and a potential target for drug discovery. To rapidly advance research in this area, we initiated a drug repurposing campaign and screened a collection of 1280 approved human or veterinary drugs (Prestwick Chemical Library) using a biochemical assay that reads out FAAL32 inhibition. These efforts led to the discovery of salicylanilide closantel, and some of its derivatives as inhibitors with potent in vitro activity against M. tuberculosis. These results suggest that salicylanilide represents a potentially promising pharmacophore for the conception of novel anti-tubercular candidates targeting FAAL32 that would open new targeting opportunities. Moreover, this work illustrates the value of drug repurposing campaigns to discover new leads in challenging drug discovery fields.
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Mycobacterium tuberculosis , Tuberculose , Monofosfato de Adenosina/uso terapêutico , Antituberculosos/química , Avaliação Pré-Clínica de Medicamentos , Humanos , Salicilanilidas , Tuberculose/tratamento farmacológico , Tuberculose/microbiologiaRESUMO
OBJECTIVES: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the commonest bacterial causes of sexually transmitted infections in humans with high incidence of co-infection. Treatment with high doses of ceftriaxone (CRO) and cefixime (CFM) is strongly recommended due to the reduced drug susceptibility of NG. However, their safety and efficacy have not been confirmed. We compared the safety and efficacy of a single 1 g intravenous (IV) dose of ceftriaxone (CRO) plus doxycycline (DOX) versus a single 800 mg oral dose of cefixime (CFM) plus DOX for the treatment of NG-CT co-infection. METHODS: An open-label randomized controlled trial was conducted on 125 individuals aged > 18 years with untreated gonorrhea and chlamydia to compare a single 1 g intravenous dose of CRO + DOX and a single 800 mg oral dose of CFM + DOX. The primary outcome was the clearance of NG from all the initially infected sites. Secondary outcomes included symptom resolution, changes in the serum clearance levels, glomerular filtration rate, and antibiotic minimum inhibitory concentrations. RESULTS: Both regimens were highly effective in treating gonorrhea with success rates of 96.7% (95% confidence interval [CI] 88.8-99.1%) for CRO and 95.3% (95% CI 87.1-98.4%) for CFM. However, CRO + DOX was superior to CFM + DOX for the treatment of NG-CT co-infection (odds ratio 4.41, 95% CI 1.11-25.7). The safety profiles of the two regimens were similar. CONCLUSIONS: CRO + DOX was superior to CFM + DOX for the treatment of NG-CT co-infection. CFM + DOX may be indicated in patients with CRO allergy and in settings where CRO is unavailable. Trial registration ClinicalTrials.gov (NCT05216744) on 31/01/22.
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Infecções por Chlamydia , Coinfecção , Gonorreia , Antibacterianos/farmacologia , Cefixima/farmacologia , Cefixima/uso terapêutico , Ceftriaxona/farmacologia , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/tratamento farmacológico , Chlamydia trachomatis , Coinfecção/tratamento farmacológico , Doxiciclina/uso terapêutico , Gonorreia/epidemiologia , Humanos , Neisseria gonorrhoeaeRESUMO
This study aimed to examine the effects of dietary digested soybean protein (DSP) and taurine on bile acid (BA) level, lipase activity, lipid apparent digestibility coefficient (ADC), and growth performance of pompano (Trachinotus blochii). Five diets were formulated with fish meal (FM), defatted soybean meal (SBM), and the DSP as main dietary protein sources. The diets were denoted as follows: FMD (FM-based diet), SBMD (SBM-based diet), SBM+TD (SBM-based diet plus taurine), DSPD (DSP-based diet), and DSP+TD (DSP-based diet plus taurine). Fingerling pompano with an initial body weight (BW) of 21.4 g were stocked in 500-L tanks, with triplicate tanks per dietary treatment. For 8 weeks, the fish were hand-fed the experimental diets to apparent satiation twice daily. The results showed that the DSPD and DSP+TD groups had significantly higher final BW, weight gain, and specific growth rate, but lower feed conversion ratio, than the SBMD and SBM+TD groups, respectively (P < 0.05). There were no significant differences in growth and feed performances between fish fed DSP+TD and FMD. The gallbladder and anterior intestinal BA levels, anterior intestinal lipase activity, and lipid and protein ADCs were markedly increased in fish fed DSPD and DSP+TD compared to those fed SBMD (P < 0.05), and no significant differences were detected between the DSP+TD and FMD groups. The findings of the present study suggested that dietary DSP inclusion with taurine supplementation might effectively improve lipid digestion and this contributed to growth enhancement in pompano fed a soybean protein-based diet.
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Peixes , Proteínas de Soja/farmacologia , Taurina/farmacologia , Ração Animal , Animais , Ácidos e Sais Biliares/metabolismo , Dieta , Proteínas de Peixes/metabolismo , Peixes/crescimento & desenvolvimento , Peixes/metabolismo , Vesícula Biliar/efeitos dos fármacos , Vesícula Biliar/metabolismo , Lipase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismoRESUMO
Background: Biotin has been reported to interfere with several commonly used laboratory assays resulting in misleading values and possible erroneous diagnosis and treatment. This report describes a prospective study of possible biotin interference in thyroid-related laboratory assays, with a comparison of different commonly used assay platforms. Materials and Methods: Thirteen adult subjects (mean age 45 ± 13 years old) were administered biotin 10 mg/day for eight days. Blood specimens were collected at three time points on day 1 and on day 8 (baseline, two, and five hours after biotin ingestion). Thyrotropin (TSH), free triiodothyronine (fT3), free thyroxine (fT4), total triiodothyronine (TT3), total thyroxine (TT4), thyroxine binding globulin (TBG), and thyroglobulin (Tg) levels were analyzed with four different platforms: Abbott Architect, Roche Cobas 6000, Siemens IMMULITE 2000, and liquid chromatography with tandem mass spectrometry (LC-MS/MS). TSH, fT3, fT4, TT3, and TT4 were measured with Abbott Architect and Roche Cobas 6000. fT3, fT4, TT3, and TT4 were also measured by LC-MS/MS. Tg was measured by Siemens IMMULITE 2000. TBG was assessed with Siemens IMMULITE 2000. Results: Significant changes in TSH, fT4, and TT3 measurements were observed after biotin exposure when the Roche Cobas 6000 platform was used. Biotin intake resulted in a falsely lower Tg level when measurements were performed with Siemens IMMULITE 2000. At the time points examined, maximal biotin interference was observed two hours after biotin exposure both on day 1 and day 8. Conclusions: A daily dose of 10 mg was shown to interfere with specific assays for TSH, fT4, TT3, and Tg. Physicians must be aware of the potential risk of erroneous test results in subjects taking biotin supplements. Altered test results for TSH and Tg can be particularly problematic in patients requiring careful titration of levothyroxine therapy such as those with thyroid cancer.
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Biotina/análise , Biotina/farmacologia , Tireoglobulina/análise , Hormônios Tireóideos/análise , Tireotropina/análise , Adulto , Idoso , Cromatografia Líquida de Alta Pressão , Reações Falso-Negativas , Feminino , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Estudos Prospectivos , Testes de Função TireóideaRESUMO
Galgeuntang (GGT), a traditional herbal medicine, is widely co-administered with acetaminophen (AAP) for treatment of the common cold, but this combination has not been the subject of investigation. Therefore, we investigated the herb-drug interaction between GGT and AAP by population pharmacokinetics (PKs) modeling and simulation studies. To quantify PK parameters and identify drug interactions, an open label, three-treatment, three-period, one-sequence (AAP alone, GGT alone, and AAP and GGT in combination) clinical trial involving 12 male healthy volunteers was conducted. Ephedrine (EPD), the only GGT component detected, was identified using a one-compartment model. The PKs of AAP were described well by a one-compartment model and exhibited two-phase absorption (rapid followed by slow) and first-order elimination. The model showed that EPD significantly influenced the PKs of AAP. The simulation results showed that at an AAP dose of 1000 mg × 4 times daily, the area under the concentration versus time curve of AAP increased by 16.4% in the presence of GGT compared to AAP only. In conclusion, the PKs of AAP were affected by co-administration of GGT. Therefore, when AAP is combined with GGT, adverse effects related to overdose of AAP could be induced possibly.
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A 16-wk growth trial was conducted to examine the effects of dietary replacement of fish meal by defatted soybean meal (SBM) and fermented soybean meal (FSBM) with taurine supplementation on growth performance, nutrient apparent digestibility coefficient (ADC) and biological parameters of pompano fish. The FSBM was produced by fermenting SBM with Lactobacillus spp. Seven isonitrogenous and isoenergetic diets were formulated to replace 35% or 50% of fish meal by SBM or FSBM with taurine supplementation. The diets are denoted as follows: FM, SBM35, SBM35T, FSBM35T, SBM50, SBM50T, and FSBM50T. The FM (the basal diet) contained fish meal as a main source of dietary protein. Taurine was supplemented to SBM35T, FSBM35T, SBM50T, and FSBM50T at the level of 15 g/kg diet. Pompano juveniles with an initial body weight (BW) of 80 g reared in floating net cages were fed the experimental diets twice daily for 16 wk. Results showed that the final BW, weight gain, and feed conversion ratio of fish fed SBM35 and SBM50 were significantly lower than those of fish fed FM (P < 0.05), indicating that the replacement of fish meal by SBM at the rate of 35% in the diet is excessive for pompano. Supplementation of taurine to the SBM-included diets significantly increased growth performance and feed utilization (P < 0.05); however, these diets did not restore the performance back to a level equivalent to that of fish offered the basal diet. Meanwhile, fish fed FSBM35T had comparable growth and feed performances to those fed FM. Hematocrit values, total biliary bile acid levels, whole body lipid contents, and tissue taurine concentrations of fish fed SBM35 and SBM50 were the lowest among the treatments, but these parameters were improved by taurine supplementation and FSBM inclusion in the diet. Taurine supplementation increased lipid ADC, and SBM fermentation slightly enhanced both lipid and protein ADCs of the fish. These findings suggest that the combination of FSBM and taurine supplementation is an effective way to improve growth performance, nutrient digestibility, and biological parameters, and that FSBM with taurine supplementation can replace 35% of fish meal in pompano diets without any negative effects on growth and feed performances in a long-term feeding period.
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Alimentos Fermentados , Glycine max , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Suplementos Nutricionais , Digestão , Refeições , Nutrientes , TaurinaRESUMO
Chemical investigation of the cultured polyspore-derived mycobionts of a Pseudopyrenula subnudata lichen led to the isolation of two new compounds, subnudatones A and B (1 and 2), together with four known compounds, 1-(2-hydroxy-1,2,6-trimethyl-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethanone (3), libertalide C (4), aspermytin A (5), and 6,7-dimethoxy-4-hydroxymellin (6). Their chemical structures were elucidated by extensive 1D and 2D NMR analysis and high resolution mass spectroscopy, and comparisons were made with the literature. The absolute configuration of 1 was defined unambiguously using single crystal X-ray crystallography. Compound 1 represents the first dimeric decalin polyketide to be found in nature. The in vitro cytotoxicity of 1 against two cancer cell lines (K562 and MCF-7) was evaluated. Compound 1 showed moderate cytotoxic activity with IC50 values of 23.5 ± 1.0 and 51.9 ± 1.4 µM, respectively.
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Antineoplásicos/isolamento & purificação , Ascomicetos , Policetídeos/isolamento & purificação , Antineoplásicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células K562 , Células MCF-7 , Policetídeos/químicaRESUMO
A simple, easy-to-implement HPLC method was developed and validated for simultaneous determination of two isothiazolinone preservatives, methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI), in hair care shampoo containing plant extracts. In this method, shampoo samples were first dissolved in isopropyl myristate and then MCI and MI were extracted from isopropyl myristate layer by a mixture of methanol and 0.02 M phosphate buffer solution pH 3.0 (30: 70, v/v) and analyzed on an analytical biphenyl column maintained at 25°C with a mixture of methanol and water (10: 90, v/v) in isocratic elution mode as mobile phase. Total flow rate of mobile phase was maintained at 1.0 mL per minute. The UV detection was performed at 274 nm. Injection volume was 50 µl. The method was fully validated in terms of specificity, linearity, precision, accuracy, and robustness according to requirements of AOAC International and was proved as reliable and suitable for the intended application.
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Although hyperbaric oxygen therapy (HBOT) is common as a treatment for injuries, this study aimed to research the ability of HBOT in preconditioning to diminish any potential damage. The hypothesis stated that HBOT preconditioning alleviated the death of cells in primary rat neuronal cells (PRNCs) by transferring mitochondria from astrocytes. In this experiment, PRNCs were given an HBOT treatment before a tumor necrosis factor-alpha or lipopolysaccharide injury which resembled cell death associated with stroke and traumatic brain injury (TBI). After being examined, the study found more cell viability in the PRNCs that had received HBOT precondition and a mitochondrial transfer. The mitochondrial transfer was visualized by a series of images showing the transfer after the HBOT treatment. This study demonstrated the ability of HBOT preconditioning as a treatment for inflammation in stroke and TBI, with the transfer of mitochondria from astrocytes to PRNCs reducing cell death. Along with discussion of the study, this review also focuses on different stroke treatments in comparison with HBOT.
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BACKGROUND: Brainstem encephalitis is a serious complication of hand foot and mouth disease (HFMD) in children. Autonomic nervous system (ANS) dysregulation and hypertension may occur, sometimes progressing to cardiopulmonary failure and death. Vietnamese national guidelines recommend use of milrinone if ANS dysregulation with Stage 2 hypertension develops. We wished to investigate whether magnesium sulfate (MgSO4) improved outcomes in children with HFMD if used earlier in the evolution of the ANS dysregulation (Stage 1 hypertension). METHODS: During a regional epidemic we conducted a randomized, double-blind, placebo-controlled trial of MgSO4 in children with HFMD, ANS dysregulation and Stage 1 hypertension, at the Hospital for Tropical Diseases in Ho Chi Minh city. Study participants received an infusion of MgSO4 or matched placebo for 72 h. We also reviewed data from non-trial HFMD patients in whom milrinone failed to control hypertension, some of whom received MgSO4 as second line therapy. The primary outcome for both analyses was a composite of disease progression within 72 h - addition of milrinone (trial participants only), need for ventilation, shock, or death. RESULTS: Between June 2014 and September 2016, 14 and 12 participants received MgSO4 or placebo respectively, before the trial was stopped due to futility. Among 45 non-trial cases with poorly controlled hypertension despite high-dose milrinone, 33 received MgSO4 while 12 did not. There were no statistically significant differences in the composite outcome between the MgSO4 and the placebo/control groups in either study (adjusted relative risk (95%CI) of [6/14 (43%) vs. 6/12 (50%)], 0.84 (0.37, 1.92), p = 0.682 in the trial and [1/33 (3%) vs. 2/12 (17%)], 0.16 (0.01, 1.79), p = 0.132 in the observational cohort). The incidence of adverse events was similar between the groups. Potentially toxic magnesium levels occurred very rarely with the infusion regime used. CONCLUSION: Although we could not demonstrate efficacy in these studies, there were no safety signals associated with use of 30-50 mg/kg/hr. MgSO4 in severe HFMD. Intermittent outbreaks of HFMD are likely to continue across the region, and an adequately powered trial is still needed to evaluate use of MgSO4 in controlling hypertension in severe HFMD, potentially involving a higher dose regimen. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01940250 (Registered 22 AUG 2013). Trial sponsor: University of Oxford.
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Doenças do Sistema Nervoso Autônomo/tratamento farmacológico , Doença de Mão, Pé e Boca/tratamento farmacológico , Sulfato de Magnésio/uso terapêutico , Animais , Sistema Nervoso Autônomo/efeitos dos fármacos , Sistema Nervoso Autônomo/fisiologia , Doenças do Sistema Nervoso Autônomo/etiologia , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Método Duplo-Cego , Feminino , Doença de Mão, Pé e Boca/complicações , Doença de Mão, Pé e Boca/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Humanos , Lactente , Sulfato de Magnésio/efeitos adversos , Masculino , PlacebosRESUMO
Two new triterpenes, the seco-friedelane type secofriedelanophyllemblicine and the ursane-derived saponin ursophyllemblicoside were isolated from the roots of the edible fruit-producing Phyllanthus emblica. Their structures were unambiguously elucidated using extensive 1D and 2D NMR analyses, high resolution mass spectrometry and single-crystal X-ray crystallographic analyses along with comparison with literature data. Secofriedelanophyllemblicine represents the first 3,4-secofriedelane bearing a carboxylic acid group substituent at C-20. Ursophyllemblicoside, incorporating the rare 21α hydroxyursolic acid as a sapogenol represents the first example of saponin comprising this aglycone. Secofriedelanophyllemblicine displayed a moderate cytotoxicity against K562 and HepG2 cancer cell lines.
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Antineoplásicos Fitogênicos/farmacologia , Phyllanthus emblica/química , Saponinas/farmacologia , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Células Hep G2 , Humanos , Células K562 , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Raízes de Plantas/química , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação , VietnãRESUMO
Two new clerodane diterpenoids (1 and 2) and the known compound caseanigrescen D (3) were isolated from the leaves of Casearia grewiifolia by bioassay-guided fractionation. Their structures were determined by analyses of MS and 2D NMR data. The absolute configurations of 1 and 3 were established by analysis of X-ray diffraction data. Compounds 1-3 were evaluated for their cytotoxicity against four cancer cell lines, KB (mouth epidermal carcinoma cells), HepG-2 (human liver hepatocellular carcinoma cells), LU-1 (human lung adenocarcinoma cells), and MCF-7 (human breast cancer cells). Caseagrewifolin B (2) had inhibitory activity against KB and HepG-2 cell lines with IC50 values of 6.2 to 7.0 µM, respectively. When tested against the normal cells (NIH/3T3), caseagrewifolin B (2) exhibited a significant selective inhibition against cancer cells in comparison with the normal cells. Caseanigrescen D (3) was cytotoxic against four cancer cell lines; however it had no selective inhibition compared with normal cells.
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Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Casearia/química , Diterpenos Clerodânicos/isolamento & purificação , Diterpenos Clerodânicos/farmacologia , Plantas Medicinais/química , Antineoplásicos Fitogênicos/química , Diterpenos Clerodânicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Células Hep G2 , Humanos , Células KB , Estrutura Molecular , Folhas de Planta/química , VietnãRESUMO
This paper considers our developed control system which aims to regulate the exercising subjects' heart rate (HR) to a predefined profile. The controller would be an adaptive integral sliding mode controller. Here it is assumed that the controller commands are interpreted as biofeedback auditory commands. These commands can be heard and implemented by the exercising subject as a part of the control-loop. However, transmitting a feedback signal while the pedals are not in the appropriate position to efficiently exert force may lead to a cognitive disengagement of the user from the feedback controller. To address this problem this paper will employ a different form of control system regarding as "actuator-based event-driven control system". This paper will claim that the developed event-driven controller makes it possible to effectively regulate HR to a predetermined HR profile.
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Ergometria/métodos , Exercício Físico , Frequência Cardíaca/fisiologia , Biorretroalimentação Psicológica , Ergometria/instrumentação , Humanos , Modelos TeóricosRESUMO
BACKGROUND: Although Vietnam is a region with a plant-based diet that has a high zinc deficiency, epidemiological data showing how this affects pregnant women are limited. This study explores the prevalence of zinc deficiency and possible correlates in pregnant Vietnamese women in Ho Chi Minh City. METHODS: This was a cross-sectional study conducted at a general hospital in Ho Chi Minh City, Vietnam. All pregnant women who came to their first antenatal care visit from November 2011 to June 2012 were recruited. Those taking a vitamin and/or mineral supplement were excluded. Serum zinc concentrations, determined by a standard colorimetric method, of 10.7 µmol/L-17.5 µmol/L (70.0 g/dL-114 g/dL) were classified as normal and under 10.7 µmol/L (70.0 g/dL) as zinc deficient. RESULTS: In total, 254 pregnant women were invited and 107 (42%) participated. The mean age of participants was 29 years, and mean gestational age was 10 weeks. Median zinc concentration in serum was 13.6 µmol/L, and the prevalence of zinc deficiency was 29% (95% CI=21%-39%). The daily intake of a milk product supplement was the only significant correlate of zinc deficiency of the items investigated (adjusted OR=0.40, 95% CI=0.16-0.99, p=0.049). DISCUSSION: This is the first study reporting that more than 25% of pregnant Vietnamese women in Ho Chi Minh City are zinc deficient. Further academic and clinical input is needed to confirm the scale of this neglected issue and to investigate the potential of milk product supplementation in this population.
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Complicações na Gravidez/epidemiologia , Zinco/deficiência , Adulto , Estudos Transversais , Laticínios , Dieta , Dieta Vegetariana , Suplementos Nutricionais , Escolaridade , Feminino , Idade Gestacional , Humanos , Gravidez , Vietnã , Zinco/administração & dosagem , Zinco/sangueRESUMO
This paper presents a three-class mental task classification for an electroencephalography based brain computer interface. Experiments were conducted with patients with tetraplegia and able bodied controls. In addition, comparisons with different time-windows of data were examined to find the time window with the highest classification accuracy. The three mental tasks used were letter composing, arithmetic and imagery of a Rubik's cube rolling forward; these tasks were associated with three wheelchair commands: left, right and forward, respectively. An eyes closed task was also recorded for the algorithms testing and used as an additional on/off command. The features extraction method was based on the spectrum from a Hilbert-Huang transform and the classification algorithm was based on an artificial neural network with a fuzzy particle swarm optimization with cross-mutated operation. The results show a strong eyes closed detection for both groups with average accuracy at above 90%. The overall result for the combined groups shows an improved average accuracy of 70.6% at 1s, 74.8% at 2s, 77.8% at 3s, 79.6% at 4s and 81.4% at 5s. The accuracy for individual groups were lower for patients with tetraplegia compared to the able-bodied group, however, does improve with increased duration of the time-window.
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Interfaces Cérebro-Computador , Quadriplegia/fisiopatologia , Cadeiras de Rodas , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Eletroencefalografia , Humanos , Pessoa de Meia-Idade , Redes Neurais de Computação , Análise e Desempenho de Tarefas , Fatores de TempoRESUMO
This paper presents a non-motor imagery tasks classification electroencephalography (EEG) based brain computer interface (BCI) for wheelchair control. It uses only two EEG channels and a better feature extractor to improve the portability and accuracy in the practical system. In addition, two different features extraction methods, power spectral density (PSD) and Hilbert Huang Transform (HHT) energy are compared to find a better method with improved classification accuracy using a Genetic Algorithm (GA) based neural network classifier. The results from five subjects show that using the original eight channels with three tasks, accuracy between 76% and 85% is achieved. With only two channels in combination with the best chosen task using a PSD feature extractor, the accuracy is reduced to between 65% and 79%. However, the HHT based method provides an improved accuracy between 70% and 84% for the classification of three discriminative tasks using two EEG channels.
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Cognição , Eletroencefalografia/métodos , Cadeiras de Rodas , Adulto , Algoritmos , Interfaces Cérebro-Computador , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The presence and importance of microenvironments in the subsurface at contaminated sites were suggested by previous geochemical studies. However, no direct quantitative characterization of the geochemical microenvironments had been reported. We quantitatively characterized microscale geochemical gradients (dissolved oxygen (DO), H(2), pH, and redox potential) in Hanford 300A subsurface sediment biofilms. Our results revealed significant differences in geochemical parameters across the sediment biofilm/water interface in the presence and absence of U(VI) under oxic and anoxic conditions. While the pH was relatively constant within the sediment biofilm, the redox potential and the DO and H(2) concentrations were heterogeneous at the microscale (<500-1000 µm). We found microenvironments with high DO levels (DO hotspots) when the sediment biofilm was exposed to U(VI). On the other hand, we found hotspots (high concentrations) of H(2) under anoxic conditions both in the presence and in the absence of U(VI). The presence of anoxic microenvironments inside the sediment biofilms suggests that U(VI) reduction proceeds under bulk oxic conditions. To test this, we operated our biofilm reactor under air-saturated conditions in the presence of U(VI) and characterized U speciation in the sediment biofilm. U L(III)-edge X-ray absorption spectroscopy (XANES and EXAFS) showed that 80-85% of the U was in the U(IV) valence state.
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Biofilmes , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Urânio/química , Anaerobiose , Reatores Biológicos/microbiologia , Água Subterrânea/química , Hidrogênio/análise , Concentração de Íons de Hidrogênio , Oxirredução , Oxigênio/análise , Solubilidade , Urânio/isolamento & purificação , Washington , Espectroscopia por Absorção de Raios XRESUMO
This paper presents the results of cardiovascular changes that occur during a novel rehabilitation strategy called activity based therapy (ABT). Blood volume pulse (BVP) signals were measured during functional electrical stimulation (FES)-induced cycling in adults with spinal cord injury (SCI) persons and results were compared to a passive cycling task and able-bodied controls performing normal cycling. BVP signals were compared during three conditions, a baseline pre-exercise condition, 5 minutes after exercise and after 30-minutes rest following exercise. Exercise recovery was evaluated using normalized inner products values in BVP signals. The results showed that FES-induced cycling in SCI participants resulted in a significantly greater peripheral resistance level and longer time to recover from exercise compared with passive cycling and normal cycling in able-bodied controls.
Assuntos
Pressão Sanguínea , Volume Sanguíneo , Terapia por Estimulação Elétrica/métodos , Terapia por Exercício/métodos , Tolerância ao Exercício , Atividade Motora , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação , Adulto , Humanos , Resultado do TratamentoRESUMO
The paper proposes a robust online adaptive neural network control scheme for an automated treadmill system. The proposed control scheme is based on Feedback-Error Learning Approach (FELA), by using which the plant Jacobian calculation problem is avoided. Modification of the learning algorithm is proposed to solve the overtraining issue, guaranteeing to system stability and system convergence. As an adaptive neural network controller can adapt itself to deal with system uncertainties and external disturbances, this scheme is very suitable for treadmill exercise regulation when the model of the exerciser is unknown or inaccurate. In this study, exercise intensity (measured by heart rate) is regulated by simultaneously manipulating both treadmill speed and gradient in order to achieve fast tracking for which a single input multi output (SIMO) adaptive neural network controller has been designed. Real-time experiment result confirms that robust performance for nonlinear multivariable system under model uncertainties and unknown external disturbances can indeed be achieved.