Integrated Experimental, Atomistic, and Microstructurally Based Finite Element Investigation of the Dynamic Compressive Behavior of 2139 Aluminum

The objective of this study was to identify the microstructural mechanisms related to the high strength and ductile behavior of 2139-Al, and how dynamic conditions would affect the overall behavior of this alloy. Three interrelated approaches, which span a spectrum of spatial and temporal scales, were used: (i) The mechanical response was obtained using the split Hopkinson pressure bar, for strain-rates ranging from 1.0×10^(−3) s to 1.0×10^4 s^(−1). (ii) First principles density functional theory calculations were undertaken to characterize the structure of the interface and to better understand the role played by Ag in promoting the formation of the Ω phase for several Ω-Al interface structures. (iii) A specialized microstructurally based finite element analysis and a dislocation-density based multiple-slip formulation that accounts for an explicit crystallographic and morphological representation of Ω and Θ' precipitates and their rational orientation relations were conducted. The predictions from the microstructural finite element model indicated that the precipitates continue to harden and also act as physical barriers that impede the matrix from forming large connected zones of intense plastic strain. As the microstructural FE predictions indicated, and consistent with the experimental observations, the combined effects of Θ' and Ω, acting on different crystallographic orientations, enhance the strength and ductility, and reduce the susceptibility of 2139-Al to shear strain localization due to dynamic compressive loads

Nano Sized Moringa oleifera an Effective Strategy for Pb(II) ions Removal from Aqueous Solution

Nano-sized  Moringa oleifera is considered an effective   biosorbent  with  high surface area from agricultural waste, low coast and environment-friendly which can be used for removal of  Pb2+ from waste water. Thus our study stem to investigate the ability of natural nano-sized biosorbents for removing  very toxic Pb2+ ions from aqueous solution. The investigated biosorbent (Moringa oleifera) was characterized by FTIR, SEM, TEM, XRD and EDX techniques. Moreover, the influence of pH, temperature, adsorbent dosage, contact time and initial metal ion concentration on adsorption process were investigated. The maximum biosorption capacities (qm) of Pb2+ ions by Moringa oleifera was 37.9 mg/g. The lowest biosorption was observed (61.4%) for Pb2+ ions at pH 2.0 while the highest one (94.36%) at pH 5. The optimum contact time for the adsorption process was found to be at 60 minutes. The amount of Pb2+ ions adsorbed increases with increasing in initial metal ion concentration. Moreover, biosorption capacity (qe) and removal efficiency of Pb2+ ions solutions increase as temperature increases. FT-IR data indicated that the adsorption of metal ions occurs on the surface of Moringa oleifera powder as the main functional groups that are responsible for metal ions binding are involved in the process. Furthermore, Thermodynamic studies confirmed that the biosorption process was endothermic and the positive value of ΔG° is quite common when an ion-exchan­­ge mechanism applies in the biosorption. The Positive value of ΔS◦ suggested an increase in randomness during the biosorption. The kinetics study of sorption indicates that the pseudo second-order model provides better correlation of the sorption data (R2=0.99) than the pseudo first-order model (R2 = 0.91), confirming the chemisorption of metal ions solutions on Moringa oleifera. The Freundlich isotherm has agood fit with the experimental data (R2 close to 1) compared to Langmuir isotherm (R2=0.99). This study shows that Moringa oleifera are available, low cost, effective and environment friendlly biosorbent for the removal of Pb2+ ions from aqueous environment. Keywords: Lead, biosorption, Thermodynamics, kinetics, removal efficiency, Moringa oleifera, isother

Comparative Toxicity of Neem and Peppermint Oils Nano Formulations against Agrotis ipsilon (Hufn.) Larvae (Lepidoptera: Noctuidae)

Applications of nanotechnology in agriculture will result in the development of efficient and potential approaches towards the management of insect pests. The toxicity effects of four essential oils peppermint, thyme, camphor and sage oils were tested against the fourth instar larvae of Agrotis ipsilon to select the most effective essential oil to be converted to the nano form. According to the results obtained, peppermint oil was the most toxic compound, which has been used in the present investigation  compared  with neem oil. The toxicity of  bulk and nano- formulations of neem  and pepper mint oils were tested  against  2nd and 4th instar  larvae of A. ipsilon under laboratory conditions of 25±2 °C& 65 -70 % R.H.relative humidity The results show that the LC50 value (the concentration used which kill 50% of the tested individuals)of loaded neem or pepper mint were lower (0.62 and 36.47 ppm) compared with neem or pepper mint oil nano-emulsion and bulk neem for the second larval instar. The different formulations of neem are more potent than in case of peppermint oil, as LC50 and LC90 values were significantly lower.The same trend was found concerning the 4th larval instar. Age of treated larvae had a detrimental effect on the response to the compounds tested. It was noticed that the younger larvae were much more sensitive to the prepared compounds compared to the older ones. The least LC50 value for loaded neem nano-emulsion was 6.68 ppm compared with the highest value for  bulk neem oil (16.68 ppm ). Also,  LC90  values followed the same trend as in  case ofLC50.  Again, the toxicity of loaded peppermint oil had the most insecticidal activity as expressed by the lowest LC50 value (51.9 ppm) with more insecticidal effect than the bulk(125.43 ppm)  or nano-emulsion (85.43 ppm).  The present results indicated that these novel systems could be used in integrated pest management program for A. ipsilon control

Comparative Toxicity of Neem and Peppermint Oils Nano Formulations against Agrotis ipsilon (Hufn.) Larvae (Lepidoptera: Noctuidae)

Applications of nanotechnology in agriculture will result in the development of efficient and potential approaches towards the management of insect pests. The toxicity effects of four essential oils peppermint, thyme, camphor and sage oils were tested against the fourth instar larvae of Agrotis ipsilon to select the most effective essential oil to be converted to the nano form. According to the results obtained, peppermint oil was the most toxic compound, which has been used in the present investigation  compared  with neem oil. The toxicity of  bulk and nano- formulations of neem  and pepper mint oils were tested  against  2nd and 4th instar  larvae of A. ipsilon under laboratory conditions of 25±2 °C& 65 -70 % R.H.relative humidity The results show that the LC50 value (the concentration used which kill 50% of the tested individuals)of loaded neem or pepper mint were lower (0.62 and 36.47 ppm) compared with neem or pepper mint oil nano-emulsion and bulk neem for the second larval instar. The different formulations of neem are more potent than in case of peppermint oil, as LC50 and LC90 values were significantly lower.The same trend was found concerning the 4th larval instar. Age of treated larvae had a detrimental effect on the response to the compounds tested. It was noticed that the younger larvae were much more sensitive to the prepared compounds compared to the older ones. The least LC50 value for loaded neem nano-emulsion was 6.68 ppm compared with the highest value for  bulk neem oil (16.68 ppm ). Also,  LC90  values followed the same trend as in  case ofLC50.  Again, the toxicity of loaded peppermint oil had the most insecticidal activity as expressed by the lowest LC50 value (51.9 ppm) with more insecticidal effect than the bulk(125.43 ppm)  or nano-emulsion (85.43 ppm).  The present results indicated that these novel systems could be used in integrated pest management program for A. ipsilon control

Humoral Immune Response and Safety of SARS-CoV-2 Vaccination in Pediatric Inflammatory Bowel Disease

INTRODUCTION:Children with inflammatory bowel disease (IBD) may respond differently to COVID-19 immunization as compared with healthy children or adults with IBD. Those younger than 12 years receive a lower vaccine dose than adults. We sought to describe the safety and humoral immune response to COVID-19 vaccine in children with IBD.METHODS:We recruited children with IBD, ages 5-17 years, who received ≥ 2 doses of the BNT162b2 vaccine by a direct-to-patient outreach and at select sites. Patient demographics, IBD characteristics, medication use, and vaccine adverse events were collected. A subset of participants had quantitative measurement of anti-receptor binding domain IgG antibodies after 2-part immunization.RESULTS:Our study population included 280 participants. Only 1 participant required an ED visit or hospitalization because of an adverse event. Of 99 participants who underwent anti-receptor binding domain IgG antibody measurement, 98 had a detectable antibody, with a mean antibody level of 43.0 g/mL (SD 67) and a median of 22 g/mL (interquartile range 12-38). In adjusted analyses, older age (P = 0.028) and antitumor necrosis factor monotherapy compared with immunomodulators alone (P = 0.005) were associated with a decreased antibody level. Antibody response in patients treated with antitumor necrosis factor combination vs monotherapy was numerically lower but not significant.DISCUSSION:Humoral immune response to COVID-19 immunization in children with IBD was robust, despite a high proportion of this pediatric cohort being treated with immunosuppressive agents. Severe vaccine-related AEs were rare. Overall, these findings provide a high level of reassurance that pediatric patients with IBD respond well and safely to SARS-CoV-2 vaccination

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

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

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

Mortality of emergency abdominal surgery in high-, middle- and low-income countries

Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI). Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression. Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1⋅6 per cent at 24 h (high 1⋅1 per cent, middle 1⋅9 per cent, low 3⋅4 per cent; P < 0⋅001), increasing to 5⋅4 per cent by 30 days (high 4⋅5 per cent, middle 6⋅0 per cent, low 8⋅6 per cent; P < 0⋅001). Of the 578 patients who died, 404 (69⋅9 per cent) did so between 24 h and 30 days following surgery (high 74⋅2 per cent, middle 68⋅8 per cent, low 60⋅5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2⋅78, 95 per cent c.i. 1⋅84 to 4⋅20) and low-income (OR 2⋅97, 1⋅84 to 4⋅81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days. Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)

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

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

The capacity of the International Monetary Fund to influence policymaking in a LDC: A case study of Egypt

This dissertation analyzes the policy making process in a developing country, Egypt, that followed the path of state led development and later attempted to liberalize the economy. Despite the promulgation of liberal legislation and the leverage applied by external actors, particularly the IMF, the economic system has not been transformed. It is argued that a highly autonomous state during the early 1950s and 1960s was able to institutionalize changes but, as its autonomy progressively diminished, largely as a result of the policies earlier implemented and the socio-economic structure that emerged, its capacity to develop a liberal political economy was markedly reduced. Societal forces did not have sufficient strength to bring about systemic changes and a capitalist force, with interests to fully liberalize the system did not develop. The first part of this study discusses developments in the international political economy which provided the mandate for IMF intervention in deficit countries, particularly LDCs. The second part, the case study, starts with an analysis of the development of the Egyptian political economy during 1930-1967 and discusses the socio-economic development paths and policy decisions taken by the state, its relationship with international financial actors and its position in the international system, which constrained future state action. Subsequently, an analysis of specific decisions taken by the state towards liberalization, starting with 1967, is presented. This is followed by an identification of the position of the Fund and other international actors vis-a-vis such decisions, as well as, the interests and actions of particular social forces. On an empirical level, the contribution of this study lies in the presentation of coherent statistical data and the specifics of IMF programs that have not been publicized thus providing an alternate interpretation of political events. Furthermore, the study provides policy-applicable knowledge for less developing countries that are attempting to liberalize their economies, particularly the emerging newly-industrializing countries. On a theoretical level, the analytical approach utilized attempts to override the deficiencies of the existing literature and offers a unifying conceptual framework that incorporates the notion of a state and its interaction with internal and external forces