86 research outputs found
Obstetrical complications among adolescent girls at the maternity ward of Ignace Deen National Hospital
Background: The objective of this study was to highlight obstetrical complications that occurred among adolescent girls who delivered at the ward and to identify factors associated with the occurrence of such complications.Methods: This was a prospective study of descriptive and analytical type extending over a period of one year from September 1, 2016 to August 31, 2017 carried out at the maternity ward of Ignace Deen National Hospital at Conakry Teaching Hospital (CHU). It covered a continuous series of 1034 deliveries among adolescent girls.Results: The frequency of childbirth among adolescent girls was 16.7%. The main complications identified were dystocia, severe preeclampsia, eclampsia, retroplacental hematoma, placenta previa, uterine rupture, severe anemia, postpartum hemorrhage and puerperal endometritis. These complications occurred among adolescent girls aged 18 to 19, christian, skin and pelvic bones secondary school or university students. Factors associated with such complications were the marital status (p=0.010), the gestational age (p=0.012), the number of prenatal consultations (p=0.001), the place of prenatal consultation (p=0.001), the reason for admission (p=0.000) and the mode of admission (p=0.000).Conclusions: Childbirth among adolescent girls is frequent in this context; complications are numerous but they are preventable in the vast majority of cases
Surgical intervention on uterine fibromyoma in a country with limited resources: case of the gynaecology-obstetrics department of the Communal Medical Centre of Ratoma Conakry - Guinea
Background: In developing countries, treatment of uterine fibromyoma is confronted with numerous problems, namely: financial inaccessibility to the proposed treatments, fear of surgery and the weakness of the technical platform. The objectives of the study were to calculate the frequency of uterine fibromyomas, describe the socio-demographic characteristics of patients, identify the main clinical data and to describe the modalities of surgical management.Methods: It was a mixed descriptive study, cumulative over a period of 5 years (60 months) with data collection in two phases: a 4-year retrospective study from January 1, 2015 to December 31, 2018 and a 1-year prospective study from January 1, 2019 to December 31, 2019.Results: Authors collected 135 cases of uterine fibromyomas operated on out of a total of 260 cases of gynaecological pathologies, i.e. a frequency of 51.92%. Nulliparous women were the most concerned (45.18%), and women who attended school (60%) and those who did not attend school (40%). Women at home and housewives accounted for 42.20% and 54.07% respectively. Clinically, the circumstances of discovery were dominated by menometrorrhagia and menorrhagia respectively 77.77% and 68.14%. The large uterus was the most frequent physical sign found in 96.29% of cases. Uterine fibromyomas were recorded in 86.6% of cases in women with genital activity. The operative indications were dominated by the large polymyomatous uterus (64.44%), followed by hemorrhagic fibroma (18.52%) The surgical treatment was conservative in 92.60%. The total hysterectomy was performed in 7.40. Lethality was 1.4%.Conclusions: The surgical management of fibroids contrasts conservative treatment (myomectomy) with radical treatment (hysterectomy) with multiple possible approaches (hysteroscopy, vaginal surgery, laparoscopy or laparotomy). In this context, only laparotomy was possible due to lack of equipment. Laparoscopy and hysteroscopy equipment are necessary for less invasive surgery
IoT Notary: Sensor Data Attestation in Smart Environment
Contemporary IoT environments, such as smart buildings, require end-users to
trust data-capturing rules published by the systems. There are several reasons
why such a trust is misplaced --- IoT systems may violate the rules
deliberately or IoT devices may transfer user data to a malicious third-party
due to cyberattacks, leading to the loss of individuals' privacy or service
integrity. To address such concerns, we propose IoT Notary, a framework to
ensure trust in IoT systems and applications. IoT Notary provides secure log
sealing on live sensor data to produce a verifiable `proof-of-integrity,' based
on which a verifier can attest that captured sensor data adheres to the
published data-capturing rules. IoT Notary is an integral part of TIPPERS, a
smart space system that has been deployed at UCI to provide various real-time
location-based services in the campus. IoT Notary imposes nominal overheads for
verification, thereby users can verify their data of one day in less than two
seconds.Comment: Accepted in IEEE International Symposium on Network Computing and
Applications (NCA), 201
Dendritic Chelating Agents. 2. U(VI) Binding to Poly(amidoamine) and Poly(propyleneimine) Dendrimers in Aqueous Solutions
Chelating agents are widely employed in many separation processes used to recover uranyl [U(VI)] from contaminated aqueous solutions. This article describes an experimental investigation of the binding of U(VI) to poly(amidoamine) [PAMAM] and poly(propyleneimine) [PPI] dendrimers in aqueous solutions. We combine fluorescence spectroscopy with bench scale ultrafiltration experiments to measure the extent of binding and fractional binding of U(VI) in aqueous solutions of these dendrimers as a function of (i) metal−ion dendrimer loading, (ii) dendrimer generation, (iii) dendrimer core and terminal group chemistry, and (iv) solution pH and competing ligands (NO_3^−, PO_4^(3−), CO_3^(2−), and Cl^−). The overall results of this study suggest that uranyl binding to PAMAM and PPI dendrimers in aqueous solutions involves the coordination of the UO22+ ions with the dendrimer amine, amide, and carboxylic groups. We find significant binding of U(VI) to PAMAM dendrimers in (i) acidic solutions containing up to 1.0 M HNO_3 and H_3PO_4 and (ii) in basic solutions containing up to 0.5 M Na_2CO_3. However, no binding of U(VI) by PAMAM dendrimers is observed in aqueous solutions containing 1.0 M NaCl at pH 3.0. These results strongly suggest that PAMAM and PPI dendrimers can serve as high capacity and selective chelating ligands for U(VI) in aqueous solutions
3-D Structural Modeling of Humic Acids through Experimental Characterization, Computer Assisted Structure Elucidation and Atomistic Simulations. 1. Chelsea Soil Humic Acid
This paper describes an integrated experimental and computational framework for developing 3-D structural models for humic acids (HAs). This approach combines experimental characterization, computer assisted structure elucidation (CASE), and atomistic simulations to generate all 3-D structural models or a representative sample of these models consistent with the analytical data and bulk thermodynamic/structural properties of HAs. To illustrate this methodology, structural data derived from elemental analysis, diffuse reflectance FT-IR spectroscopy, 1-D/2-D ^1H and ^(13)C solution NMR spectroscopy, and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI QqTOF MS) are employed as input to the CASE program SIGNATURE to generate all 3-D structural models for Chelsea soil humic acid (HA). These models are subsequently used as starting 3-D structures to carry out constant temperature-constant pressure molecular dynamics simulations to estimate their bulk densities and Hildebrand solubility parameters. Surprisingly, only a few model isomers are found to exhibit molecular compositions and bulk thermodynamic properties consistent with the experimental data. The simulated ^(13)C NMR spectrum of an equimolar mixture of these model isomers compares favorably with the measured spectrum of Chelsea soil HA
Dendritic Anion Hosts: Perchlorate Uptake by G5-NH_2 Poly(propyleneimine) Dendrimer in Water and Model Electrolyte Solutions
Perchlorate (ClO_4^-) has emerged as a major groundwater and surface water contaminant in the United States. Ion exchange (IX) is the most widely used technology for treating water containing lower concentrations of perchlorate (<100 ppb). However, a major drawback of IX is the need for frequent regeneration or disposal of the perchlorate-laden resins. As a first step toward the development of high-capacity, selective and recyclable dendritic ligands for the recovery of perchlorate from aqueous solutions by dendrimer filtration, we tested the hypothesis that dendrimers with hydrophobic cavities and positively charged internal groups should selectively bind ClO_4^- over more hydrophilic anions such as Cl^-, NO_3^-, SO_4^(2-), and HCO_3^-. We measured the uptake of ClO_4^- by the fifth generation (G5-NH_2) poly(propyleneimine) (PPI) dendrimer with a diaminobutane core and terminal NH_2 groups in deonized water and model electrolyte solutions as a function of (i) anion−dendrimer loading, (ii) solution pH, (iii) background electrolyte concentration, and (iv) reaction time. The ClO_4^- binding capacity of this dendrimer is comparable to those of perchlorate-selective IX resins. However, its ClO_4^- binding kinetics is faster and reaches equilibrium in ∼1 h. Note also that only a high pH (∼9.0) aqueous solution is needed to release more than 90% of the bound ClO_4^- anions by deprotonation of the dendrimer tertiary amine groups. The overall results of this study suggest that dendritic macromolecules such as the G5-PPI NH_2 dendrimer provide ideal building blocks for the development of high-capacity, selective and recyclable ligands for the recovery of anions such as perchlorate from aqueous solutions by dendrimer enhanced filtration
Dendrimer Enhanced Ultrafiltration. 1. Recovery of Cu(II) from Aqueous Solutions Using PAMAM Dendrimers with Ethylene Diamine Core and Terminal NH_2 Groups
This article discusses the feasibility of using dendrimer enhanced ultrafiltration (DEUF) to recover Cu(II) from aqueous solutions. Building upon the results of fundamental investigations of Cu(II) binding to PAMAM dendrimers with ethylenediamine (EDA) core and terminal NH_2 groups, we combine (i) dead-end ultrafiltration (UF) experiments with (ii) atomic force microscopy (AFM) characterization of membrane fouling to assess the feasibility of using DEUF to recover Cu(II) from aqueous solutions. On a mass basis, the Cu(II) binding capacities of the EDA core PAMAM dendrimers are much larger and more sensitive to solution pH than those of linear polymers with amine groups. The dendrimer−Cu(II) complexes can be efficiently separated from aqueous solutions by ultrafiltration. The metal ion laden dendrimers can be regenerated by decreasing the solution pH to 4.0; thus enabling the recovery of the bound Cu(II) ions and recycling of the dendrimers. The UF measurements and AFM characterization studies show that EDA core PAMAM dendrimers with terminal NH_2 groups have very low tendency to foul the commercially available regenerated cellulose (RC) membranes evaluated in this study. The overall results of these experiments suggest that DEUF is a promising process for recovering metal ions such as Cu(II) from aqueous solutions
Dendritic Chelating Agents. 1. Cu(II) Binding to Ethylene Diamine Core Poly(amidoamine) Dendrimers in Aqueous Solutions
Dendritic Chelating Agents. 1. Cu(II) Binding to Ethylene Diamine Core Poly(amidoamine) Dendrimers in Aqueous Solutions
This paper describes an investigation of the uptake of Cu(II) by poly(amidoamine) (PAMAM) dendrimers with an ethylenediamine (EDA) core in aqueous solutions. We use bench scale measurements of proton and metal ion binding to assess the effects of (i) metal ion−dendrimer loading, (ii) dendrimer generation/terminal group chemistry, and (iii) solution pH on the extent of binding of Cu(II) in aqueous solutions of EDA core PAMAM dendrimers with primary amine, succinamic acid, glycidol, and acetamide terminal groups. We employ extended X-ray absorption fine structure (EXAFS) spectroscopy to probe the structures of Cu(II) complexes with Gx-NH_2 EDA core PAMAM dendrimers in aqueous solutions at pH 7.0. The overall results of the proton and metal ion binding measurements suggest that the uptake of Cu(II) by EDA core PAMAM dendrimers involves both the dendrimer tertiary amine and terminal groups. However, the extents of protonation of these groups control the ability of the dendrimers to bind Cu(II). Analysis of the EXAFS spectra suggests that Cu(II) forms octahedral complexes involving the tertiary amine groups of Gx-NH_2 EDA core PAMAM dendrimers at pH 7.0. The central Cu(II) metal ion of each of these complexes appears to be coordinated to 2−4 dendrimer tertiary amine groups located in the equatorial plane and 2 axial water molecules. Finally, we combine the results of our experiments with literature data to formulate and evaluate a phenomenological model of Cu(II) uptake by Gx-NH_2 PAMAM dendrimers in aqueous solutions. At low metal ion−dendrimer loadings, the model provides a good fit of the measured extent of binding of Cu(II) in aqueous solutions of G4-NH_2 and G5-NH_2 PAMAM dendrimers at pH 7.0
Quantifying the value of viral genomics when inferring who infected whom in the 2014–16 Ebola virus outbreak in Guinea
Transmission trees can be established through detailed contact histories, statistical or phylogenetic inference, or a combination of methods. Each approach has its limitations, and the extent to which they succeed in revealing a 'true' transmission history remains unclear. In this study, we compared the transmission trees obtained through contact tracing investigations and various inference methods to identify the contribution and value of each approach. We studied eighty-six sequenced cases reported in Guinea between March and November 2015. Contact tracing investigations classified these cases into eight independent transmission chains. We inferred the transmission history from the genetic sequences of the cases (phylogenetic approach), their onset date (epidemiological approach), and a combination of both (combined approach). The inferred transmission trees were then compared to those from the contact tracing investigations. Inference methods using individual data sources (i.e. the phylogenetic analysis and the epidemiological approach) were insufficiently informative to accurately reconstruct the transmission trees and the direction of transmission. The combined approach was able to identify a reduced pool of infectors for each case and highlight likely connections among chains classified as independent by the contact tracing investigations. Overall, the transmissions identified by the contact tracing investigations agreed with the evolutionary history of the viral genomes, even though some cases appeared to be misclassified. Therefore, collecting genetic sequences during outbreak is key to supplement the information contained in contact tracing investigations. Although none of the methods we used could identify one unique infector per case, the combined approach highlighted the added value of mixing epidemiological and genetic information to reconstruct who infected whom
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