Global economic burden of unmet surgical need for appendicitis

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 $92 492 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 $95 004 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

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

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 Effect of Rise Angle of V-Hull Non Ballast Ship on Seakeeping Performance

In this paper a new concept in ship design was used to be alternative of ballast water system, to emerge that remedy the introduction of invasive marine species and the disadvantages of ballast water treatment systems. Thus, the hydrodynamic influences due to hull line variation of this kind of ships were studied, using the invariant cross-section area curve under the design draft to change the rise angle at bottom. Then numerical calculation was used to get the seakeeping at each angle. Two 3D models were constructed for 59000 DWT oil tankers and 35000 DWT bulk carriers, where the result of the bulk carrier was exposed

The Effect of Rise Angle of V-Hull Non Ballast Ship on Seakeeping Performance

In this paper a new concept in ship design was used to be alternative of ballast water system, to emerge that remedy the introduction of invasive marine species and the disadvantages of ballast water treatment systems. Thus, the hydrodynamic influences due to hull line variation of this kind of ships were studied, using the invariant cross-section area curve under the design draft to change the rise angle at bottom. Then numerical calculation was used to get the seakeeping at each angle. Two 3D models were constructed for 59000 DWT oil tankers and 35000 DWT bulk carriers, where the result of the bulk carrier was exposed

Modification of optical and electrical properties of nanocrystalline VO2·0.5 H2O/ZrV2O7: influence of Cs, Cr and Ga doping

A facile and economical route has been demonstrated for large-scale synthesis of nano VO2·0.5 H2O/ZrV2O7 and it is doping with Cs, Cr and Ga using combined precipitation-hydrothermal that followed by a gentle heating at low temperature. The growth mechanism of doping is discussed and investigated by XRD, SEM, TEM, Raman, TGA, DSC, and UV–vis spectroscopy. The band gap is enhanced with doping. The results show that the all composites have a negative thermal coefficient in the range 25–100 °C while it has a positive thermal coefficient in the range 100–300 °C. Also, Cs doped has increase in conductivity as compared to Cr doped which may be due to the enhancement of oxygen vacancies as resulted from addition of low valence cations. Doping with Cr or Cs show the contribution of grain and grain boundary properties, respectively, while the doping with Ga shows the insulating behavior. Keywords: VO2·0.5 H2O/ZrV2O7, Doping, Band gap, Grain and grain boundary, Ionic conductivity, Electrical conductivit

Multiband circularly polarised CubeSat antenna operating in S, C, X, Ku, K, and Ka bands

Abstract A novel design of a high‐frequency multiband with a circular polarisation antenna based on a four‐patch antenna system consolidated with an Archimedean spiral antenna for CubeSat applications. The geometry and size are compatible with the CubeSat standard structure dimensions of 10 × 10 cm2. The antenna consists of a spiral antenna in the middle of four patch antennas surrounding it; the first antenna structure consists of two sets of two orthogonal identical patch antennas with a 90° phase shift to cover the band from 1.55 to 1.94 GHz at L‐band, 2, 2.1, and 2.3 GHz at S‐band, the second antenna is an Archimedean spiral antenna to cover all C‐bands, all X‐bands, all Ku‐bands, all K‐bands, and from 26 to 29 GHz at Ka‐band. The measured results show that the reflection coefficients (S11) and (S22) achieve < −10 dB and the axial ratio achieves <3 dB, with a reference impedance of 50 Ω. The simulated and the measured results give a better agreement

Influence of encapsulation materials on the thermal performance of concentrator photovoltaic cells

The Ethylene-Vinyl Acetate (EVA) layer in the polycrystalline solar cells suffers from lower thermal conductivity. Therefore, this work presents a numerical study for a possible way to enhance the thermal conductivity of the lower encapsulant layer. A comprehensive three-dimensional (3D) model is proposed to evaluate the conventional and modified solar cell performance. The ongoing research study can be achieved by doping three different nanoparticles of Boron Nitride (BN), Zinc Oxide (ZnO), and Silicon Carbide (SiC) with loading ratios of 10%, 20%, and 30% to the lower EVA matrix layer. The present numerical work was conducted under 20 suns concentration ratio and variable coolant flowrates. The findings reveal that a significant reduction in local and average solar cell temperature is achieved for all studied cases, especially at a 30% loading ratio of n-SiC. Moreover, it is observed that the net gained electrical power was enhanced by 7.16% at the same SiC loading ratio. However, ZnO and BN fillers reported a slight percentage increase of 6.77% and 5.95%, respectively. The thermal and electrical efficiency has been improved with the new EVA-nanoparticle layer due to lower average cell temperature. Therefore, at 1200 ml/h, the thermal and electrical efficiency achieved the highest value in SiC than BN and ZnO; the maximum value was reported 70.02% for thermal efficiency and 16.94% for electrical one