A probabilistic chemical programmable computer

The exponential growth of the power of modern digital computers is based upon the miniaturisation of vast nanoscale arrays of electronic switches, but this will be eventually constrained by fabrication limits and power dissipation. Chemical processes have the potential to scale beyond these limits performing computations through chemical reactions, yet the lack of well-defined programmability limits their scalability and performance. We present a hybrid digitally programmable chemical array as a probabilistic computational machine that uses chemical oscillators partitioned in interconnected cells as a computational substrate. This hybrid architecture performs efficient computation by distributing between chemical and digital domains together with error correction. The efficiency is gained by combining digital with probabilistic chemical logic based on nearest neighbour interactions and hysteresis effects. We demonstrated the implementation of one- and two- dimensional Chemical Cellular Automata and solutions to combinatorial optimization problems.Comment: 20 page manuscript, 6 figures, 112 page supplementary volum

Kidney transplantation in a patient with absent right common iliac artery and congenital renal abnormalities

AbstractIntroductionCongenital atresia of the common and external iliac arteries is a rare vascular anomaly that may be associated with congenital renal or genitourinary malformations. In ESRD patients, its presence may pose potential problems during renal transplantation.Case presentationWe report a rare case of kidney transplantation in a patient with VACTERL syndrome who was found to have absent right common and external iliac arteries during pre-operative imaging. Vascular supply to the right lower limb is derived from an anomalous branch from the left internal iliac artery which takes on a convoluted course across the pelvis. Kidney transplantation was performed successfully with implantation performed on the left side.DiscussionIsolated cases of congenital iliac artery atresia have been described in association with urological abnormalities but no clear association has yet been established. However, we feel that it may be useful to perform routine angiographic evaluation for ESRD patients with congenital genitourinary abnormalities being planned for kidney transplantation. While most cases of congenital iliac artery anomalies are symptomatic with claudication, some remain asymptomatic with normal physical examination findings. There is some evidence in literature suggesting the usefulness of routine pre-operative CT in a selective group of patients.ConclusionKidney transplantation in such cases is safe and we recommend routine pre-operative imaging of patients known to have congenital genitourniary abnormalities. The kidney should be implanted heterotopically to the contralateral side of the vascular anomaly and care must be taken to preserve vascular supply to the lower limbs

A programmable hybrid digital chemical information processor based on the Belousov-Zhabotinsky reaction

The exponential growth of the power of modern digital computers is based upon the miniaturization of vast nanoscale arrays of electronic switches, but this will be eventually constrained by fabrication limits and power dissipation. Chemical processes have the potential to scale beyond these limits by performing computations through chemical reactions, yet the lack of well-defined programmability limits their scalability and performance. Here, we present a hybrid digitally programmable chemical array as a probabilistic computational machine that uses chemical oscillators using Belousov-Zhabotinsky reaction partitioned in interconnected cells as a computational substrate. This hybrid architecture performs efficient computation by distributing information between chemical and digital domains together with inbuilt error correction logic. The efficiency is gained by combining digital logic with probabilistic chemical logic based on nearest neighbour interactions and hysteresis effects. We demonstrated the computational capabilities of our hybrid processor by implementing one- and two-dimensional Chemical Cellular Automata demonstrating emergent dynamics of life-like entities called Chemits. Additionally, we demonstrate hybrid probabilistic logic as a viable logic for solving combinatorial optimization problems

Publisher Correction: A programmable hybrid digital chemical information processor based on the Belousov-Zhabotinsky reaction

No abstract available

An autonomous electrochemical discovery robot that utilises probabilistic algorithms: probing the redox behaviour of inorganic materials

The discovery of new electroactive materials is slow due to the large combinatorial chemical space of possible experiments. Efficient exploration of redox‐active chemical space requires a machine learning assisted robotic platform with real‐time feedback. Here, we developed a closed‐loop robotic platform which is capable of synthesis and electrochemical characterisation controlled using a probabilistic algorithm. This was used to probe the redox behaviour of different polyoxometalates (POMs) precursors and explore the formation of redox‐active coordination complexes. The system can run accurate analytical electrochemical measurements whilst maintaining the performance and accuracy of both the working and reference electrodes. The platform successfully ran and analysed 336 coordination chemistry reactions by performing ca. 2500 cyclic voltammetry (CV) scans for analysis and electrode cleaning. Overall, the platform carried out over 9900 operations in 350 hours at a rate of 28 operations per hour, and we identified 24 complex solutions which showed significantly different redox activity. Experiments were performed using a universal chemical synthesis language (χDL) with variable inputs. The platform was used autonomously to investigate a range of POM precursor materials demonstrating 45 % increase in capacitance. The experiments ran for 36 hours with more than 6400 operations during which we analysed 200 POM precursor solutions

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

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

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

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

Programmable chemical system for autonomous discovery and computation

Abstract not currently available

Ultrasound-guided percutaneous nephrolithotomy: Advantages and limitations

Purpose: The use of ultrasound in percutaneous nephrolithotomy (PCNL) has not been shown to translate to better clinical and stone outcomes. To compare the operative outcomes, postoperative outcomes and complication rates of ultrasound-guided access PCNL (USGA-PCNL) versus fluoroscopy-guided access PCNL (FGA-PCNL).Materials and Methods: A total of 184 consecutive patients who underwent PCNL from July 2008 to September 2014 were identi-fied from our PCNL database. Seventy-two patients underwent USGA-PCNL and 112 FGA-PCNL.Results: The patients were similar in age, sex, race, American Society of Anesthesiologists physical status classification, mean larg-est stone diameters, side of PCNL, number of stones and the degree of hydronephrosis between both groups. There were higher rates of upper pole (5.6% vs. 3.6%), mid pole (8.3% vs. 2.7%) and multiple pole punctures (4.2% vs. 0%) in USGA-PCNL compared to FGA-PCNL (p=0.027). There was no difference in the stone free rates of both groups in univariate analysis. Those who had FGA-PCNL were 2.26 (95% confidence interval, 1.09–4.75; p=0.029) times more likely to require a second-look procedure compared to USGA-PCNL on univariate analysis but not on multivariate analysis. There were no differences in Clavien-Dindo complications. No patient in the USGA-PCNL group experienced organ injuries during puncture compared to 1 patient in the FGA-PCNL group who had pneumothorax requiring urgent chest tube insertion.Conclusions: The use of ultrasonography to guide access puncture during PCNL eliminates the risk of inadvertent organ injuries. Similar operative and stone outcomes show that the learning curve for USGA is minimal compared to conventional FGA

A catalyst acceleration platform towards realizing the energy transition

The climate emergency has made it necessary to rethink our economy which relies heavily on fossil fuels. Currently, sustainable processes are too costly, but catalysis as a key enabling technology has the potential to reduce process costs to a level that makes them economically viable. In spite of that, the existing catalyst discovery paradigm depends heavily on serendipity and trial and error methods. What is urgently needed to transform the energy transition is a catalyst acceleration platform (CAP) that expedites the development of next-generation sustainable processes. To advance the field, we need to use state-of-the-art robotic and algorithmic tools to look beyond the well-established systems that dominate the current research landscape. Herein, we discuss the requirements for a successful catalyst acceleration concept and the societal impact of breakthrough catalytic materials