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The ongoing COVID-19 pandemic has had great societal and health consequences. Despite the availability of vaccines, infection rates remain high due to immune evasive Omicron sublineages. Broad-spectrum antivirals are needed to safeguard against emerging variants and future pandemics. We used messenger RNA (mRNA) display under a reprogrammed genetic code to find a spike-targeting macrocyclic peptide that inhibits SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Wuhan strain infection and pseudoviruses containing spike proteins of SARS-CoV-2 variants or related sarbecoviruses. Structural and bioinformatic analyses reveal a conserved binding pocket between the receptor-binding domain, N-terminal domain, and S2 region, distal to the angiotensin-converting enzyme 2 receptor-interaction site. Our data reveal a hitherto unexplored site of vulnerability in sarbecoviruses that peptides and potentially other drug-like molecules can target.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Pandemias/prevenção & controle , Peptídeos/farmacologiaRESUMO
Duchenne muscular dystrophy (DMD) is a genetic disorder caused by loss of the protein dystrophin. In humans, DMD has early onset, causes developmental delays, muscle necrosis, loss of ambulation, and death. Current animal models have been challenged by their inability to model the early onset and severity of the disease. It remains unresolved whether increased sarcoplasmic calcium observed in dystrophic muscles follows or leads the mechanical insults caused by the muscle's disrupted contractile machinery. This knowledge has important implications for patients, as potential physiotherapeutic treatments may either help or exacerbate symptoms, depending on how dystrophic muscles differ from healthy ones. Recently we showed how burrowing dystrophic (dys-1) C. elegans recapitulate many salient phenotypes of DMD, including loss of mobility and muscle necrosis. Here, we report that dys-1 worms display early pathogenesis, including dysregulated sarcoplasmic calcium and increased lethality. Sarcoplasmic calcium dysregulation in dys-1 worms precedes overt structural phenotypes (e.g., mitochondrial, and contractile machinery damage) and can be mitigated by reducing calmodulin expression. To learn how dystrophic musculature responds to altered physical activity, we cultivated dys-1 animals in environments requiring high intensity or high frequency of muscle exertion during locomotion. We find that several muscular parameters (e.g., size) improve with increased activity. However, longevity in dystrophic animals was negatively associated with muscular exertion, regardless of effort duration. The high degree of phenotypic conservation between dystrophic worms and humans provides a unique opportunity to gain insight into the pathology of the disease as well as the initial assessment of potential treatment strategies.
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Distrofia Muscular Animal/terapia , Distrofia Muscular de Duchenne/terapia , Condicionamento Físico Animal , Esforço Físico/fisiologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos mdx , Contração Muscular/fisiologia , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/fisiopatologia , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/fisiopatologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatologia , Esforço Físico/genéticaRESUMO
The enhanced biological phosphorus removal process makes the phosphorus recovery feasible from the dewatering streams of biological sludge. The physicochemical properties of these sidestreams, as an input to a crystallizer, are different before and after anaerobic digestion. In this study, phosphorus recovery by calcium phosphate is proposed for pre-digestion sidestreams and by struvite precipitation for post-digestion sidestreams. The thermodynamic modeling followed by experimental tests was performed to evaluate the recovery efficiency and product properties of struvite and calcium phosphates. The variations in phosphorus recovery potential, reaction kinetics and particle size distribution emphasize the importance of the adjustment of initial supersaturation and pH of the reaction. The optimum pH, considering the economics and recovery efficiency, for both calcium phosphate and struvite precipitation was found to be pH = 8.5, whereas further increase of pH will not improve the overall efficiency of the process. In the case of calcium phosphate precipitation, it was shown that possible phase transformations should be considered and controlled as they affect both process efficiency and product properties. The economic evaluation indicated that the optimized operational condition should be determined for the phosphorus recovery process and that chemical costs for the production of calcium phosphates is lower than for struvite.
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Fósforo/análise , Eliminação de Resíduos Líquidos/métodos , Precipitação Química , Compostos de Magnésio , Fosfatos , Esgotos , EstruvitaRESUMO
INTRODUCTION: Body surface area (BSA)-based dosing of 5-fluorouracil (5-FU) results in marked inter-individual variability in drug levels, whereas determination of plasma 5-FU concentration and area under the curve (AUC) is a more precise dosing method but has not been integrated into clinical routine. We conducted a multicenter, prospective study to study 5-FU AUC distributions and assess clinical factors predicting therapeutic dosing in patients receiving BSA-dosed 5-FU. METHODS: Between June 2017 and January 2018, a total of 434 patients receiving continuous, infusional BSA-dosed 5-FU from 37 sites in Germany were included. Plasma 5-FU concentration and AUC were measured in venous blood samples at steady state. The primary objective was to determine 5-FU AUC distributions in relation to the target range, which is defined as 20-30 mg × h/l. The second objective was to explore clinical parameters that correlate with achievement of 5-FU AUC target range. RESULTS: The primary tumor was mainly located in the gastrointestinal tract (96.3%), with colorectal cancer being the most common (71.2%) tumor entity. 5-FU was administered as monotherapy (8.1%) or as part of FOLFOX (33.2%), FOLFIRI (26.3%), or other regimens (12.4%). Treatment setting was adjuvant (31.3%) or metastatic (64.5%). The median AUC was 16 mg × h/l. Only 20.3% of patients received 5-FU treatment within the target range, whereas the majority of patients (60.6%) were underdosed and 19.1% of patients were overdosed. In the univariate logistic regression, treatment setting was the only clinical parameter that significantly correlated with achievement of the target range. Patients treated in the metastatic setting had a 2.1 (95% confidence interval 1.186-3.776, P = 0.011) higher odds to reach the target range compared with patients treated in the adjuvant setting. CONCLUSIONS: The majority of patients received suboptimal doses of 5-FU using BSA dosing. Therapeutic drug monitoring of 5-FU is an option for optimized individualized cancer therapy and should be integrated into the clinical practice.
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Neoplasias Colorretais , Fluoruracila , Humanos , Fluoruracila/uso terapêutico , Fluoruracila/efeitos adversos , Estudos Prospectivos , Monitoramento de Medicamentos/métodos , Neoplasias Colorretais/tratamento farmacológico , Alemanha/epidemiologiaRESUMO
PURPOSE: To determine the intraobserver and interobserver reliability of transvaginal ultrasound measurements of cervical length and quantitative ultrasonic tissue characterization (QUTC). MATERIALS AND METHODS: 20 healthy women in the second and third trimester of pregnancy underwent transvaginal ultrasound examination of the cervix by two sonographers. 3 replicate vaginal measurements of cervical length and QUTC were taken by each observer for each woman. The repeatability coefficient and intraclass correlation coefficient as well as the interclass correlation coefficient and limits of agreement were calculated. RESULTS: The reliability coefficient for transvaginal cervical length measurements was 0.95 for sonographer 1 and 0.99 for sonographer 2. The corresponding intraclass correlation coefficients for cervical length measurements were 0.872 and 0.973. The interclass correlation coefficient for transvaginal cervical length measurements was 0.986, the mean interobserver difference was -2 mm, and the limits of agreement were -5.4 mm to 1.5 mm. The reliability coefficients for QUTC were 0.90 (sonographer 1) and 0.97 (sonographer 2) and the corresponding intraclass correlation coefficients for cervical length measurements were 0.74 and 0.9. The interclass correlation coefficient was 0.56, the mean interobserver difference was 0.14, and the limits of agreement were -22.46 to 22.74. CONCLUSION: Transvaginal cervical length measurements showed a high intraobserver and interobserver reliability, while quantitative ultrasonic tissue characterization had poor interobserver reliability and should currently not be applied in clinical practice.
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Medida do Comprimento Cervical/métodos , Colo do Útero/diagnóstico por imagem , Endossonografia/métodos , Interpretação de Imagem Assistida por Computador , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Ultrassonografia Pré-Natal , Algoritmos , Feminino , Humanos , Variações Dependentes do Observador , Trabalho de Parto Prematuro/diagnóstico por imagem , Gravidez , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Risco , Software , Estatística como Assunto , Vagina/diagnóstico por imagemRESUMO
INTRODUCTION: The aim of this clinical study was to define foetal cardiac volumetry utilising 3D ultrasound. METHOD: 3D volumetry was performed in 131 cases. Cardiac output and stroke volume were calculated. Cardiac output and stroke volume of the right and left ventricles were defined in relation to foetal weight and gestational age in weeks. RESULTS: The mean value for foetal cardiac output was 393.68 mL/min. A progredient rise was detected with increasing gestational age. The mean values were 215.12 mL/min in the 28th week, 315.99 mL/min in the 32nd week, 464.14 mL/min in the 36th week and 681.77 mL/min at term. In relation to body weight (kg), the cardiac output was higher at 28 weeks (252.24 mL/min/kg) as compared with later in gestation, namely 208.91 mL/min/kg at term. CONCLUSION: It is technically feasible to calculate foetal cardiac volumes by means of 3D ultrasound. While the overall cardiac output of the foetus is high, it decreases in relation to body weight at the end of gestation.
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Débito Cardíaco , Ecocardiografia Tridimensional/métodos , Ultrassonografia Pré-Natal/métodos , Feminino , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Volume SistólicoRESUMO
Prophylactic anti-D is a very safe and effective therapy for the suppression of anti-D immunization and thus prevention of haemolytic disease of the foetus and newborn. However, migration from countries with low health standards and substantial cuts in public health expenses have increased the incidence of anti-D immunization in many "developed" countries. Therefore, this forum focuses on prenatal monitoring standards and treatment strategies in pregnancies with anti-D alloimmunization. The following questions were addressed, and a response was obtained from 12 centres, mainly from Europe.
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Antígenos de Grupos Sanguíneos/imunologia , Isoanticorpos/administração & dosagem , Complicações Hematológicas na Gravidez/terapia , Isoimunização Rh/terapia , Sistema do Grupo Sanguíneo Rh-Hr/imunologia , Feminino , Sangue Fetal/imunologia , Hemoglobina Fetal/análise , Humanos , Isoanticorpos/sangue , Isoanticorpos/imunologia , Gravidez , Complicações Hematológicas na Gravidez/sangue , Complicações Hematológicas na Gravidez/imunologia , Complicações Hematológicas na Gravidez/prevenção & controle , Isoimunização Rh/imunologia , Isoimunização Rh/prevenção & controle , Imunoglobulina rho(D)RESUMO
OBJECTIVE: The aim of the study was to determine the sensitivity, specificity and accuracy of noninvasive tests for the fetal rhesus CcEc (RHCE) alleles C, c and E in early pregnancy. DESIGN: A prospective clinical trial was carried out to evaluate diagnostic accuracy. SETTING: Women were recruited at four centres specialising in prenatal diagnosis. Peripheral blood and amniotic fluid samples were obtained and sent to a single laboratory for analysis. SAMPLE: A total of 233 tests (46 for C, 87 for c and 100 for E) were performed on 181 specimens obtained from pregnant women at weeks 12 to 28 (median week 16) of gestation. METHODS: Following automated extraction of fetal DNA from maternal plasma, two different real-time polymerase chain reaction (PCR) protocols were used for the detection of the C, c and E alleles of RHCE. The results of the PCR were compared with genotyping results for the amniotic fluid. MAIN OUTCOME MEASURES: Failure rate, sensitivity, specificity and accuracy were the main outcome measures. RESULTS: Unequivocal results were obtained for all specimens. With the first PCR protocol, the sensitivity was 100% for C, 38% for c and 59% for E. In contrast, with the second protocol, the sensitivity for C, c and E was 100%. The specificity for all assays was found to be between 99% and 100%. CONCLUSIONS: A highly accurate protocol has been identified for the detection of fetal RHCE alleles in maternal plasma in early pregnancy. This noninvasive approach can be considered as a useful test in the management of pregnancies with anti-c, anti-E or anti-C alloimmunisation.
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Reação em Cadeia da Polimerase/métodos , Diagnóstico Pré-Natal/métodos , Isoimunização Rh/diagnóstico , Sistema do Grupo Sanguíneo Rh-Hr/genética , Adolescente , Adulto , Feminino , Marcadores Genéticos/genética , Genótipo , Humanos , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase/normas , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Diagnóstico Pré-Natal/normas , Isoimunização Rh/embriologia , Sensibilidade e Especificidade , Adulto JovemRESUMO
BACKGROUND: Historically, adults with ultra short bowel syndrome (USBS) have been considered candidates for lifetime parenteral nutrition (PN) or are referred for visceral transplantation. We examined the surgical and nutritional outcomes of adult patients with USBS managed at a single intestinal rehabilitation center. METHODS: We retrospectively reviewed data on 588 adult patients referred to our center between January 2013 and December 2018. USBS was defined as residual small bowel (SB) length ≤ 50 cm. RESULTS: Forty-five patients (7.6%) with a mean age of 46.7 years (range 17-78) were identified. Indications for enterectomy included mesenteric ischemia (n=17) and internal hernias (n=6), followed by large intraabdominal fibroids, trauma, and allograft enterectomies, with five cases each. Median SB length was 18.0 cm; 20 patients (44.4%) had their entire SB resected. Thirteen patients had an intact colon, of which nine had preservation of the ileocecal valve. Patients who underwent autologous reconstruction of their gastrointestinal (GI) tract required a lower total PN volume (29.0 ± 7.6 vs. 40.8 ± 13.2 ml/Kg/day, p=0.002) and presented better short- and long- term survival (p=0.005). Patients with no gut had higher mortality (p=0.036). Hormonal therapy with the glucagon-like peptide-2 analog teduglutide was used in nine patients (20%) five of whom were weaned off TPN. Excluding patients with no gut (n=20), discontinuation of total PN rate for patients with an end ostomy or tube decompression (n= 6), jejunocolostomy (n= 10), and jejunoileostomy (n=9) were 0%, 40%, and 77.7%, respectively. Eleven patients (44%) with some residual small intestine achieved nutritional autonomy in an average of 20 months after GI reconstruction. Fifteen patients were listed for transplantation (33.3%). Seven patients underwent isolated SB transplantation and achieved nutritional autonomy in an average of three months after transplantation. One-year patient and graft survival were 100%. After a 37-month median follow-up period, 36 of 42 patients followed by our center were still alive (85.7%). CONCLUSION: Nutritional autonomy can be achieved in a significant number of patients with USBS in specialized centers with surgical and/or hormonal therapy. The presence of an intact colon and ileocecal valve can significantly increase the adaptation rate. Moreover, restoration of GI tract continuity has a positive impact on medical management and survival.
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Procedimentos Cirúrgicos do Sistema Digestório , Síndrome do Intestino Curto/cirurgia , Adolescente , Adulto , Idoso , Algoritmos , Feminino , Fármacos Gastrointestinais/uso terapêutico , Humanos , Intestino Delgado/transplante , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Nutrição Parenteral Total , Peptídeos/uso terapêutico , Estudos Retrospectivos , Transplantados/estatística & dados numéricos , Adulto JovemRESUMO
Link travel speeds in road networks are essential data for a variety of research problems in logistics, transportation, and traffic management. Real-world link travel speeds are stochastic, and highly dependent on speeds in previous time periods and neighboring road links. To understand how link travel speeds vary over space and time, we uncover their distributions, their space- and/or time-dependent correlations, as well as partial correlations, based on link travel speed datasets from an urban road network and a freeway network. We find that more than 90% (57%) of travel speeds are normally distributed in the urban road (freeway) network, and that correlations generally decrease with increased distance in time and space. We also investigate if and how different types of road links affect marginal distributions and correlations. The results show that different road link types produce quite similar marginal distributions and correlations. Finally, we study marginal distributions and correlations in a freeway network. Except that the marginal distribution and time correlation are different from the urban road network, others are similar.
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The recycling of nutrients from wastewater and their recovery in the form of valuable products is an effective strategy to accelerate the circular economy concept. Phosphorus recovery from wastewater by struvite crystallization (MgNH4PO4·6H2O) is one of the most applied techniques to compensate for the increasing demand and to slow down the depletion rate of phosphate rocks. Using low-cost magnesium sources, such as seawater, improves the financial sustainability of struvite production. In this study, the potential of seawater for struvite crystallization versus the commonly used magnesium source, MgCl2, was tested by crystal growth and kinetic experiments. The impact of ammonium concentration, magnesium concentration and pH on the growth kinetics of struvite in synthetic and real reject water were studied. The results showed that simultaneous precipitation of calcium phosphate was insignificant when using seawater, while presence of struvite seeds diminished it further. Among the supersaturation regulators, pH had the most significant effect on the struvite growth with both MgCl2 and seawater, while high N:P molar ratios further improved the struvite crystal growth by seawater. The N:P molar ratios higher than 6 and Mg:P molar ratios higher than 0.2 are recommended to improve the crystal growth kinetics. It was concluded that seawater is a promising alternative magnesium source and the control of supersaturation regulators (i.e., Mg:P, N:P and pH) is an effective strategy to control the reaction kinetics and product properties.
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Modelos Químicos , Água do Mar/química , Estruvita/química , Fosfatos de Cálcio , Cristalização , Cinética , Magnésio/química , Cloreto de Magnésio/química , Compostos de Magnésio/química , Minerais , Fosfatos/química , Fósforo/química , Reciclagem , Águas Residuárias/químicaRESUMO
Despite the advantage of model-based design, anaerobic digesters are seldom designed using biokinetic models due to lack of reliable kinetic coefficients and/or systematic approaches for incorporating kinetic models into digester design. This study presents a systematic framework, which couples practical identifiability, uncertainty quantification and attainable region (AR) concepts for defining process performance targets, especially when reliable kinetic coefficients are unavailable. Within the framework, we introduce the concept of self-optimizing ARs, which define performance targets that results in near optimal operation in spite of variations in kinetic coefficients. Using the case of modified Hill model, only 3 out of the 6 model parameters (unidentifiable set) are responsible for the model prediction uncertainty. The uncertainty bands (mean, 10th percentile and 90th percentile) on the model states has been computed using the Monte Carlo Simulation procedure and attainable regions for the different levels of uncertainty has been constructed and the boundaries interpreted into digester structures. The self-optimizing attainable regions have been defined as the intersection region of the attainable regions corresponding to the mean, 10th percentile and 90th percentile. Incorporating uncertainty significantly reduces performance targets of the process but increases self-optimality in defining performance targets. Unlike the attainable region, which represents the limits of achievability for defined kinetics, the self-optimizing attainable region represents the set of all possible states attainable by the system even in cases of kinetic uncertainty. In summary, the concept of self-optimizing ARs provides a systematic way of defining process performance targets and making economic decisions under conditions of uncertainty.
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Anaerobiose , Método de Monte Carlo , Cinética , IncertezaRESUMO
Seawater, as an alternative magnesium source, has the potential to improve the overall economics and environmental footprint of struvite production compared to the use of pure magnesium salts. However, the dilution effect and the presence of other ions in seawater can reduce the phosphorus recovery potential and the simultaneous precipitation of other compounds may reduce the quality of the produced struvite. This work presents a comparative study of seawater and MgCl2 by performing a series of thermodynamic equilibrium modeling and crystallization experiments. The results revealed that acceptable phosphorus recovery (80-90%) is achievable by using seawater as the magnesium source for struvite precipitation. Further, the simultaneous precipitation of calcium phosphates was successfully controlled and minimized by optimum selection of reaction pH and seawater volume (i.e. Mg:P and Mg:Ca molar ratios). The increase of temperature from 20 °C to 30 °C reduced the phosphorus recovery by 15-20% while it increased the particle size by 30-35%. The presence of suspended solids in reject water did not have significant effects on phosphorus recovery but it made the struvite separation difficult as the obtained struvite was mixed with suspended solids. The experimental results and economic evaluation showed that the use of seawater can reduce the chemical costs (30-50%) and the CO2-footprint (8-40%) of struvite production. It was concluded that seawater is a potential alternative to pure magnesium sources in struvite production, while studies in larger scale and continuous mode are needed for further verification before full-scale applications.
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Compostos de Magnésio , Fósforo , Precipitação Química , Cristalização , Fosfatos , Água do Mar , Estruvita , Eliminação de Resíduos LíquidosRESUMO
The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space. This instrument may be the key to our understanding of cosmic birth-the formation of planets, stars, galaxies, active galactic nuclei, and quasars. Compared with IRAS and existing telescopes, SIRTF's power derives from a thousandfold gain in sensitivity over five octaves of the spectrum.
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PURPOSE: We report a rare case of Pallister-Killian syndrome diagnosed prenatally with increased nuchal translucency during screening for trisomy 21. MATERIALS AND METHODS: Echografic and postmortem examination of the fetus, G-banded chromosome and FISH analysis on short- and long-term chorion villous sampling (CVS) culture. RESULTS AND DISCUSSION: Cytogenetic analysis revealed a supernumerary isochromosome 12p after long-term culture whereas a normal cell line was detected in short-term culture only. Sonografic examination in 17-weeks' gestation showed further increase of the NT and the additional presence of brachymelia, diaphragmatic hernia and a marked dextroposition of the heart. Termination of the pregnancy was performed. The cases of PKS karyotypically confirmed on CVS are reviewed, and cytogenetic and sonographic aspects of the prenatal diagnosis of PKS are discussed.
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Anormalidades Múltiplas/embriologia , Aberrações Cromossômicas/embriologia , Cromossomos Humanos Par 12/genética , Isocromossomos/genética , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/genética , Feto Abortado , Adulto , Evolução Fatal , Feminino , Humanos , Cariotipagem , Medição da Translucência Nucal , Gravidez , Ultrassonografia Pré-NatalRESUMO
BACKGROUND: Although foetal macrosomia is a known risk factor for shoulder dystocia, foetal weight estimation by ultrasound is imprecise. METHODS: We analysed in a retrospective, single-centre study whether the combination of foetal sonographic parameters and maternal parameters could improve the prediction of foetal macrosomia and whether on the basis of this findings the prediction of shoulder dystocia in foetal macrosomia could be enhanced. Likelihood ratios for sonographic parameters have been assessed and have been used to calculate post-test-probabilities for fetal macrosomia. All vaginal singleton deliveries with cephalic presentation >or=37+0 week of gestation in the period 1994-2005 (n=8 576) have been analysed. Shoulder dystocia has been observed in 136 cases (1.6%). RESULTS: In multivariate analysis the strongest predictor for shoulder dystocia was foetal macrosomia (>or= 4000 g), odds ratio=4.04 (95% confidence interval 2.71-6.05), next to diabetes 2.43 (1.14-5.17), obesity (BMI >or=30 kg/m (2)) 1.55 (1.02-2.46), and foetal head circumference (>35 cm) 1.51 (1.02-2.24). Foetal sonographic parameters showed likelihood ratios up to 6.93. The accuracy of shoulder dystocia predictions in cases of birth weight >or=4,500 g improved only slightly from 0.2-3.3%. DISCUSSION: The accuracy of the estimation of foetal macrosomia has been improved by combining ultrasonography with prepartal maternal risk factors.
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Traumatismos do Nascimento/diagnóstico , Traumatismos do Nascimento/etiologia , Distocia/diagnóstico , Distocia/epidemiologia , Peso Fetal , Lesões do Ombro , Ultrassonografia Pré-Natal/estatística & dados numéricos , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Gravidez , Prognóstico , Reprodutibilidade dos Testes , Medição de Risco/métodos , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
Unlike high-rate anaerobic digesters that employ some mechanism to retain microbial sludge mass, low-rate systems use sufficiently long hydraulic retention times to ensure process stability, which becomes economically unattractive for treating large quantities of waste. This study presents the use of attainable region to develop a new strategy to enhance the stability of low-rate digesters. By considering three digestion cases, diary manure only (batch 1) or diary manure with granular (batch 2) or lagoon (batch) sludge as innoculum, the following findings were obtained. (1) For a given concentration of volatile acids in an anaerobic digester, higher concentrations of methanogenic archae can be attained using a digester structure (combination of different digesters) as opposed to single digester. (2) For a given digested substrate, a change in the source of inoculum results in a change in the limits of achievability by the system (attainable limits for batches 1, 2 and 3 were 46.486(g/L)2, 5.562(g/L)2 and 0.551(g/L)2, which resulted in performance improvements of 118.604%,175.627% and 200.436% respectively), and hence optimal digester structure. The evidence from this study suggests that the technique can be used to simultaneously improve process stability, define performance targets and propose digester structures required to achieve a given target.
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Reatores Biológicos , Euryarchaeota , Anaerobiose , Esterco , Metano , EsgotosRESUMO
Ultrasonography has been shown to improve obstetric management in sub-Saharan Africa. This study demonstrates that basic ultrasonography can be performed by midwives and that a two-level ultrasonographic service in the maternity care unit of a rural sub-Saharan district hospital is feasible.
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Hospitais de Distrito , Hospitais Rurais , Serviços de Saúde Materna/métodos , Tocologia/educação , Complicações na Gravidez/diagnóstico por imagem , Ultrassonografia/estatística & dados numéricos , Atenção à Saúde , Feminino , Humanos , Gravidez , Cuidado Pré-Natal , Saúde da População Rural , TanzâniaRESUMO
BACKGROUND: The population-based Caesarean rate in sub-Saharan Africa is very low. The lack of necessary Caesarean sections is an important cause of the high maternal mortality and morbidity in sub-Saharan Africa. The Nyakahanga District Hospital in Western Tanzania showed a persistent and massive increase in the Caesarean rate which was induced by the Rwandan refugee crisis of 1994-1996. We thus examined the question: Is the doubling of the hospital-based Caesarean rate in a rural district hospital in sub-Saharan Africa associated with a change of maternal mortality and morbidity? MATERIAL AND METHODS: All deliveries at the Nyakahanga District Hospital from 1985 to 1999 were included. The study period was divided into the period before and that after the refugee crisis. Caesarean rate, overall uterine rupture, uterine rupture after Caesarean section, maternal death, and stillbirth of both periods were compared. RESULTS: The mean Caesarean rate increased from 9.4 % in the pre-refugee period to 20.3 % in the post-refugee period. The doubling of the Caesarean rate has been associated with an increase of the rate of uterine rupture from 4.4 to 13.5 per 1 000 deliveries [odds ratio 3.08 (95 % CI 1.97-4.81)]. Uterine rupture associated with previous Caesarean section increased even more [OR 6.3 (1.77-22.42)]. Maternal mortality [OR 1.17 (0.83-1.66)] and stillbirth [OR 0.96 (0.77-1.19)] rates did not change. DISCUSSION: The increasing Caesarean rates in rural sub-Saharan Africa might impose an additional hazard of increasing rates of uterine rupture without reducing the rates of maternal mortality and stillbirths.