25 research outputs found

    Transmission factors, mechanical, and gamma ray attenuation properties of barium-phosphate-tungsten glasses: Incorporation impact of WO3

    Full text link
    The purpose of this study is to conduct a thorough examination of the direct and indirect impacts of increasing the quantity of heavy WO3 on gamma-ray transmission, shielding and mechanical properties for some selected barium-phosphate-tungsten glasses. Accordingly, mechanical properties of barium-phosphate-tungsten oxides with chemical formula (50-x)P2O5-50BaO-xWO3 (x = 0.0(S1), 5.0(S2), 10(S3), and 15(S4)) mol% was evaluated using Makishima-Mackenzie model. Next, newly online Phy-X/PSD software and Monte Carlo code were used to examine the gamma radiation characteristics. Gamma-ray transmission factor (TF) values were calculated for S1, S2, S3 and, S4 glass samples for a range of well-known radioisotope energies such for 67Ga, 57Co-57, 111In-111, 133Ba, 201Tl, 99 mTc, 51Cr, 131I, 58Co, 137Cs, 60Co. The total packing density (Vt) was enhanced from 0.589 for S1 glass sample (free with WO3) to 0.605 for S4 glass sample (with highest WO3 =15 mol%). The total energy dissociation (Gt) of the investigated glasses was increased with increasing the WO3 content: from 51.7 (kJ/cm3) for S1 glasses to 52.45 (kJ/cm3) for S4 glasses. All mechanical moduli were improved with increasing the tungsten trioxide concentration in the studied glasses. Poisson's ratios were increased with increasing the WO3 concentration. The trend of linear (LAC) and mass attenuation (MAC) coefficients were followed as: (LAC, MAC) S1 < (LAC, MAC) S2 < (LAC, MAC) S3 < (LAC, MAC) S4. Half (HVL) and tenth (TVL) value layers have the trend as (HVL, TVL) S1 > (HVL, TVL) S2 > (HVL, TVL) S3 > (HVL, TVL) S4. The effective atomic number (Zeff) and electron density (Neff) have the same trend. The lowest transmission Factor (TF) values for all glass specimens were examined at a thickness of 3 cm. Furthermore, the S4 sample displayed the least transmission tendency across all glass thicknesses evaluated. © 2022 The AuthorsPrincess Nourah bint Abdul Rahman University Researchers Supporting Project Number (PNURSP2022R149)

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Global economic burden of unmet surgical need for appendicitis

    Get PDF
    Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

    Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

    Get PDF
    Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

    Get PDF
    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

    Get PDF
    : The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p &lt; 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)

    Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

    Get PDF
    Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

    Effects of sugarcane (Saccharum officinarum) cultivation on soil quality in the semi-arid tropics of Sudan

    No full text
    This study was carried out to determine the effects of cultivation period of sugarcane on some quality parameters of a vertisols. Samples were collected from the 0-30 and 30-60 cm depths of fields (subjected to burning during harvest of cane) cultivated for 29, 25 and 10 years and also from an adjacent fallow area. The samples were analyzed for pH, electrical conductivity (ECe), saturation percentage (SP), bulk density (BD), organic carbon (OC), total N (TN), particle size distribution, dry aggregate stability (DAS), soil organic matter (SOM) associated with sand size fractions (POM) and mineral N (NH4 +-N and NO3 - -N) accumulation during decomposition of soil organic matter. Results showed that cultivation or cultivation period significantly decreased SP, OC, DAS, clay content and amount of soil organic matter size fractions, while cultivation period showed no significant effect on either amount, or content of C and N of these fractions. During early weeks of mineralization of SOM, mineral N was significantly lower due to cultivation as such or in fields subjected to extended periods of cultivation. It is quite evident that the quality of heavy clay soils (e.g. vertisols) would be recovered more easily if the crop residues during harvest of the cane are incorporated into the soil. This is possibly due to the greater physical protection (due to high clay content) of organic matter against break down, thereby, improving their chances of sequestration. It is also concluded that long-term cultivation enhanced removal of fine clay particles, which might results in the long-term creation of a hard pan.Keywords: Sugarcane, vertisols, soil quality, semi-arid tropics, Suda

    Characteristics of Sustainable Concrete Containing Metakaolin and Magnetized Water

    No full text
    In this study, fourteen sustainable concrete mixes containing metakaolin (MK) as supplementary cement material (SCM) and magnetized water (MW) as concrete mixing water were designed, prepared, tested, analyzed, and compared. The MK was used as a partial replacement of cement weight by 5%, 10%, and 20%, and as an additive to cement by 5%, 10%, and 20% of cement weight. The MW was used to fully replace tap water (TW) in concrete mixes and was prepared using two different magnetic fields of 1.4 tesla (T) and 1.6 T. This experimental research aimed to assess the characteristics of concrete manufactured with MK and MW. The mechanical and durability characteristics of fresh and hardened concrete were measured for the assessment. Microstructural and chemical analyses were carried out on selected materials and concrete mixes. The workability and compressive strength of the materials at 7, 28, and 365 days were measured, in addition to the splitting tensile strength at 28 days and the flexural strength at 28 days. The compressive strength at 365 days was conducted at 18 °C and 100 °C to study the effect of the applied variables on the concrete durability at different elevated temperatures. The microstructural and chemical analyses were conducted using a scanning electron microscope (SEM), energy dispersive X-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The results showed that using 10% MK as a cement additive was the best ratio in this study, which enhanced all the measured mechanical characteristics when the TW or MW was used. Using MW instead of TW in MK concrete increased all the mechanical properties measured at 28 days by about 32–35%. The results of the microstructural and chemical analyses supported the compressive strength increase by showing indications of more C-S-H gel production and less CH when using MW in MK concrete. In addition, fewer micro-cracks and pores, and relatively denser concrete, were detected when using MW with 10% MK as a cement additive

    DNA Binding and Cleavage, Stopped-Flow Kinetic, Mechanistic, and Molecular Docking Studies of Cationic Ruthenium(II) Nitrosyl Complexes Containing “NS<sub>4</sub>” Core

    No full text
    This work aimed to evaluate in vitro DNA binding mechanistically of cationic nitrosyl ruthenium complex [RuNOTSP]+ and its ligand (TSPH2) in detail, correlate the findings with cleavage activity, and draw conclusions about the impact of the metal center. Theoretical studies were performed for [RuNOTSP]+, TSPH2, and its anion TSP−2 using DFT/B3LYP theory to calculate optimized energy, binding energy, and chemical reactivity. Since nearly all medications function by attaching to a particular protein or DNA, the in vitro calf thymus DNA (ctDNA) binding studies of [RuNOTSP]+ and TSPH2 with ctDNA were examined mechanistically using a variety of biophysical techniques. Fluorescence experiments showed that both compounds effectively bind to ctDNA through intercalative/electrostatic interactions via the DNA helix’s phosphate backbone. The intrinsic binding constants (Kb), (2.4 ± 0.2) × 105 M−1 ([RuNOTSP]+) and (1.9 ± 0.3) × 105 M−1 (TSPH2), as well as the enhancement dynamic constants (KD), (3.3 ± 0.3) × 104 M−1 ([RuNOTSP]+) and (2.6 ± 0.2) × 104 M−1 (TSPH2), reveal that [RuNOTSP]+ has a greater binding propensity for DNA compared to TSPH2. Stopped-flow investigations showed that both [RuNOTSP]+ and TSPH2 bind through two reversible steps: a fast second-order binding, followed by a slow first-order isomerization reaction via a static quenching mechanism. For the first and second steps of [RuNOTSP]+ and TSPH2, the detailed binding parameters were established. The total binding constants for [RuNOTSP]+ (Ka = 43.7 M−1, Kd = 2.3 × 10−2 M−1, ΔG0 = −36.6 kJ mol−1) and TSPH2 (Ka = 15.1 M−1, Kd = 66 × 10−2 M, ΔG0 = −19 kJ mol−1) revealed that the relative reactivity is approximately ([RuNOTSP]+)/(TSPH2) = 3/1. The significantly negative ΔG0 values are consistent with a spontaneous binding reaction to both [RuNOTSP]+ and TSPH2, with the former being very favorable. The findings showed that the Ru(II) center had an effect on the reaction rate but not on the mechanism and that the cationic [RuNOTSP]+ was a more highly effective DNA binder than the ligand TSPH2 via strong electrostatic interaction with the phosphate end of DNA. Because of its higher DNA binding affinity, cationic [RuNOTSP]+ demonstrated higher cleavage efficiency towards the minor groove of pBR322 DNA via the hydrolytic pathway than TSPH2, revealing the synergy effect of TSPH2 in the form of the complex. Furthermore, the mode of interaction of both compounds with ctDNA has also been supported by molecular docking
    corecore