Optimization of wear parameters for ECAP-processed ZK30 alloy using response surface and machine learning approaches: a comparative study

The present research applies different statistical analysis and machine learning (ML) approaches to predict and optimize the processing parameters on the wear behavior of ZK30 alloy processed through equal channel angular pressing (ECAP) technique. Firstly, The ECAPed ZK30 billets have been examined at as-annealed (AA), 1-pass, and 4-passes of route Bc (4Bc). Then, the wear output responses in terms of volume loss (VL) and coefficient of friction (COF) have been experimentally investigated by varying load pressure (P) and speed (V) using design of experiments (DOE). In the second step, statistical analysis of variance (ANOVA), 3D response surface plots, and ML have been employed to predict the output responses. Subsequently, genetic algorithm (GA), hybrid DOE-GA, and multi-objective genetic algorithm techniques have been used to optimize the input variables. The experimental results of ECAP process reveal a significant reduction in the average grain size by 92.7% as it processed through 4Bc compared to AA counterpart. Furthermore, 4Bc exhibited a significant improvement in the VL by 99.8% compared to AA counterpart. Both regression and ML prediction models establish a significant correlation between the projected and the actual data, indicating that the experimental and predicted values agreed exceptionally well. The minimal VL at different ECAP passes was obtained at the highest condition of the wear test. Also, the minimal COF for all ECAP passes was obtained at maximum wear load. However, the optimal speed in the wear process decreased with the number of billets passes for minimum COF. The validation of predicted ML models and VL regression under different wear conditions have an accuracy range of 70-99.7%, respectively.

The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Laparoscopic assisted dismembered pyeloplasty versus open pyeloplasty in UPJO with poorly function kidney in pediatrics

BACKGROUND

The management of UPJO with poor function kidney, less than 10%, has been the subject of debate for more than a decade. Some authors have recommended nephrectomy, while others favor renal salvage (pyeloplasty). We report our experience with laparoscopic assisted pyeloplasty in pediatric patients with poorly functioning kidneys in comparison with an open approach.

MATERIALS AND METHODS

A retrospective study was conducted to review 65 patients who were diagnosed with hydronephrosis and had impaired renal function due to UPJO. The study was conducted in the pediatric surgery departments of Al-Azhar University Hospital and Fattouma Bourguiba University Hospital of Monastir over a period of 20 years. Limited to pediatric patients with UPJO with ≥ Grade III hydronephrosis, antero-posterior pelvic diameter ≥ 20 mm, as well as a renal function equal to or less than 10%, was corrected by laparoscopic assisted or open pyeloplasty.

RESULTS

There were 40 cases in group A who underwent laparoscopic assisted pyeloplasty, and 25 cases in group B who underwent open pyeloplasty. There were no complications or difficulties during the operation. The mean operative time in group A was 90 ± 12 min, while in group B, it was 120 ± 11 min. The renal assessment parameters significantly improved in both groups. In group A, the mean split renal function was 7.9 ± 1.3% and increased to 22.2 ± 6.3%. In group B, the mean split renal function was 8.1 ± 1.1% and increased to 24.2 ± 5.1%. However, the differences between both groups in terms of pre-operative and post-operative renal functions were statistically insignificant.

CONCLUSION

Laparoscopic assisted pyeloplasty is an effective treatment for patients with poorly functioning kidneys, especially those with less than 10% function. While this surgical procedure requires shorter operative times, it yields functional outcomes that are comparable to open approach.

Machine-learning approaches in geo-environmental engineering: Exploring smart solid waste management

Over the past few decades, increased attention has been paid to domestic waste (DW) generation. DW comprises a large percentage of municipal solid waste (MSW), and its handling and processing involves serious technical issues while also consuming a major portion of municipal budgets. The accurate estimation, prediction, and characterization of DW is an ongoing challenge for many cities, municipalities, and local governments as they strive to implement sustainable strategies for MSW. The main objective of the present study is to estimate and correctly predict DW quantities using machine-learning (ML) algorithms. Several different ML algorithms are used in the research, including linear regression, regression trees, Gaussian process regression, support vector machine, and autoregressive integrated moving average methods for time series analysis. Two case studies are presented in this paper. In the first, domestic waste data covering the period from 2010 to 2021 were collected from the Saudi and Bahrain authorities, and in the second, the domestic waste-generating behavior of a family of eleven members was followed for one month. The results show that the biodegradable and non-biodegradable wastes generated by the family were in the range of 1.7-7.9 kg and 0.0-2.0 kg, respectively, and promising outcomes were obtained using an appropriate selection of input predictors in conjunction with time series analysis. The trained models are validated and tested using several types of evaluation metrics, including calculated residuals, mean square error, root mean square error, and coefficient determination (R²-Score). The latter values are in the range of 0.67-0.85 for the training and testing datasets for many of the predicted waste quantities. The results obtained from the study show that these algorithms can be used to reduce the environmental, economic, and societal impacts of waste by designing a smart waste management engineering system.

Investigation of the Effect of ECAP Parameters on Hardness, Tensile Properties, Impact Toughness, and Electrical Conductivity of Pure Cu through Machine Learning Predictive Models

Copper and its related alloys are frequently adopted in contemporary industry due to their outstanding properties, which include mechanical, electrical, and electronic applications. Equal channel angular pressing (ECAP) is a novel method for producing ultrafine-grained or nanomaterials. Modeling material design processes provides exceptionally efficient techniques for minimizing the efforts and time spent on experimental work to manufacture Cu or its associated alloys through the ECAP process. Although there have been various physical-based models, they are frequently coupled with several restrictions and still require significant time and effort to calibrate and enhance their accuracies. Machine learning (ML) techniques that rely primarily on data-driven models are a viable alternative modeling approach that has recently achieved breakthrough achievements. Several ML algorithms were used in the modeling training and testing phases of this work to imitate the influence of ECAP processing parameters on the mechanical and electrical characteristics of pure Cu, including the number of passes (N), ECAP die angle (φ), processing temperature, and route type. Several experiments were conducted on pure commercial Cu while altering the ECAP processing parameters settings. Linear regression, regression trees, ensembles of regression trees, the Gaussian process, support vector regression, and artificial neural networks are the ML algorithms used in this study. Model predictive performance was assessed using metrics such as root-mean-squared errors and R² scores. The methodologies presented here demonstrated that they could be effectively used to reduce experimental effort and time by reducing the number of experiments runs required to optimize the material attributes aimed at modeling the ECAP conditions for the following performance characteristics: impact toughness (I_T), electrical conductivity (E_C), hardness, and tensile characteristics of yield strength (σ_y), ultimate tensile strength (σ_u), and ductility (D_u).

Use of artificial intelligence in diagnosis of head and neck precancerous and cancerous lesions: A systematic review

This systematic review analyses and describes the application and diagnostic accuracy of Artificial Intelligence (AI) methods used for detection and grading of potentially malignant (pre-cancerous) and cancerous head and neck lesions using whole slide images (WSI) of human tissue slides. Electronic databases MEDLINE via OVID, Scopus and Web of Science were searched between October 2009 - April 2020. Tailored search-strings were developed using database-specific terms. Studies were selected using a strict inclusion criterion following PRISMA Guidelines. Risk of bias assessment was conducted using a tailored QUADAS-2 tool. Out of 315 records, 11 fulfilled the inclusion criteria. AI-based methods were employed for analysis of specific histological features for oral epithelial dysplasia (n = 1), oral submucous fibrosis (n = 5), oral squamous cell carcinoma (n = 4) and oropharyngeal squamous cell carcinoma (n = 1). A combination of heuristics, supervised and unsupervised learning methods were employed, including more than 10 different classification and segmentation techniques. Most studies used uni-centric datasets (range 40-270 images) comprising small sub-images within WSI with accuracy between 79 and 100%. This review provides early evidence to support the potential application of supervised machine learning methods as a diagnostic aid for some oral potentially malignant and malignant lesions; however, there is a paucity of evidence using AI for diagnosis of other head and neck pathologies. Overall, the quality of evidence is low, with most studies showing a high risk of bias which is likely to have overestimated accuracy rates. This review highlights the need for development of state-of-the-art deep learning techniques in future head and neck research.

Developing Egyptian water quality index for drainage water reuse in agriculture

In Egypt, water quality (WQ) is an ordinary activity. However, the calculation of a tailor-made Egyptian WQ index is not. Therefore, this research attempts to develop an index for the agricultural drainage water (EG-DWQI) that can be reused for irrigation based on collected WQ data measured monthly from August 2000 to July 2015. The development of the EG-DWQI was carried out in four main steps, namely, parameters selection, parameter transformation to a common scale, assignment of parameters weights, and aggregation of subindices to produce a final index score. In its final form, the index can be easily estimated using a set of rating curves and their corresponding equations that were statistically tested and proved to be verified. The developed index was successfully employed to delineate the drainage WQ status that can be reused for irrigation in the Nile Delta of Egypt as benchmarking for future comparisons. The EG-DWQI is proved to be easy, fast, and does not entail complex mathematics and can be easily managed by means of a spreadsheet. PRACTITIONER POINTS: This research develops a tailor made water quality index for assessing agricultural drainage water that can be re-used for irrigation. Then, the developed index was successfully employed to delineate the water quality in the main drains located in the Nile Delta of Egypt as benchmarking for future comparisons. The application of the index is proved to be easy, fast and does not entail complicated mathematics especially with the new computer facilities.

Erectile function and gonadal hormones levels in men with end-stage renal disease: It's relevance to duration of haemodialysis

In this study, we evaluated the relationship between haemodialysis (HD) duration and erectile function status and gonadal hormones serum levels in adult men with end-stage renal disease (ESRD). A total of 118 men with ESRD on chronic HD were eligible for analysis. The erectile dysfunction (ED) was defined and graded according to the international index of erectile function (IIEF-5) score. The serum levels of follicle stimulating hormones (FSH), luteinising hormone (LH), testosterone (TST), prolactin (PRL) and estradiol (E2) were measured using the standard laboratory technique. The mean age was 48.97 ± 14.68 years and mean duration of HD was 4.58 ± 3.03 years. The overall prevalence of ED was 78.8%; from them 31.2% had severe grade. The prevalence of ED was comparable in HD duration categories [≤5 years (79.7%), 5-10 years (76.5%), >10 years (80.0%); p > 0.05]. The percentage of abnormal serum levels of FSH, LH, TST, PRL, E2 were 5.1%, 1.6%, 18.6%, 90.7% and 0.0% respectively. No significant relationships were observed between HD duration and IIEF-5 score or gonadal hormones serum levels (p < 0.05). We concluded that HD duration has no effect on erectile function status and gonadal hormones serum levels. Other factors may be relevant to these conditions in this particular group of patients.

Decline in transmission of schistosomiasis mansoni in Oman

BACKGROUND

Intestinal schistosomiasis due to Schistosoma mansoni was first reported in Oman in 1979. We describe the trend in parasitological and serological prevalence of human infection with S. mansoni in the endemic area over the period 1982-2014, and the compliance of data generated by the national monitoring and evaluation system with schistosomiasis elimination criteria set by the Ministry of Health of Oman.

METHODS

Parasitological and serological assessments were carried out on population (mainly children) living in the area at risk for schistosomiasis in Dhofar, the country's only endemic Governorate, for a period of over 30 years. Kato-Katz thick smear and Indirect Haemagglutination Assay were the techniques employed.

RESULTS

Data indicate a progressive decline in prevalence of S. mansoni throughout the 1980s and the 1990s, a recrudescence in the early 2000s, and a more marked decrease following the implementation of six rounds of mass treatment with praziquantel from 2007 to 2013. Latest parasitological prevalence (2011) was 0%, while latest serological prevalence (2014) was 0.11%.

CONCLUSION

Transmission of schistosomiasis has reached very low levels in Oman. Elimination criteria established by the Ministry of Health of Oman (parasitological prevalence ≤ 1% and serological prevalence ≤ 5%) have been met since 2008. Further investigations are required to assess whether interruption of transmission has been achieved in some or all foci, in view of the establishment of a formal verification process under the auspices of WHO.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Exon skipping restores dystrophin expression, but fails to prevent disease progression in later stage dystrophic dko mice

Antisense therapy with both chemistries of phosphorodiamidate morpholino oligomers (PMOs) and 2'-O-methyl phosphorothioate has demonstrated the capability to induce dystrophin expression in Duchenne muscular dystrophy (DMD) patients in phase II-III clinical trials with benefit in muscle functions. However, potential of the therapy for DMD at different stages of the disease progression is not understood. In this study, we examined the effect of peptide-conjugated PMO (PPMO)-mediated exon skipping on disease progression of utrophin-dystrophin-deficient mice (dko) of four age groups (21-29, 30-39, 40-49 and 50+ days), representing diseases from early stage to advanced stage with severe kyphosis. Biweekly intravenous (i.v.) administration of the PPMO restored the dystrophin expression in nearly 100% skeletal muscle fibers in all age groups. This was associated with the restoration of dystrophin-associated proteins including functional glycosylated dystroglycan and neuronal nitric synthase. However, therapeutic outcomes clearly depended on severity of the disease at the time the treatment started. The PPMO treatment alleviated the disease pathology and significantly prolonged the life span of the mice receiving treatment at younger age with mild phenotype. However, restoration of high levels of dystrophin expression failed to prevent disease progression to the mice receiving treatment when disease was already at advanced stage. The results could be critical for design of clinical trials with antisense therapy to DMD.

Detection and mapping of water pollution variation in the Nile Delta using multivariate clustering and GIS techniques

The limited water resources of Egypt lead to widespread water-stress. Consequently, the use of marginal water sources, such as agricultural drainage waters, provides one of the national feasible solutions to the problem. However, the marginal quality of the drainage waters may restrict their use. The objective of this research is to develop a tool for planning and managing the reuse of agricultural drainage water for irrigation in the Nile Delta. This is achieved by classifying the pollution levels of drainage water into several categories using a statistical clustering approach that may ensure simple but accurate information about the pollution levels and water characteristics at any point within the drainage system. The derived clusters are then visualized by using a Geographical Information System (GIS) to draw thematic maps based on the entire Nile Delta, thus making GIS as a decision support system. The obtained maps may assist the decision makers in managing and controlling pollution in the Nile Delta regions. The clustering process also provides an effective overview of those spots in the Nile Delta where intensified monitoring activities are required. Consequently, the obtained results make a major contribution to the assessment and redesign of the Egyptian national water quality monitoring network.

Influence of pattern of exposure, parasite genetic diversity and sex on the degree of protection against reinfection with Schistosoma mansoni

This paper analyzed, experimentally, the influences of pattern of exposure, parasite genetic diversity, and parasite sex on the degree of protection against reinfection with Schistosoma mansoni in the mouse. The results show that, (1) in infections with one male parasite genotype, successive infections induced a significant decrease in the infectivity of the parasite and significant increases in the spleen and liver weights compared to mass infections, (2) successive infections with one male genotype induced a significant decrease in the infectivity of the parasite compared to successive infections with five male genotypes, and (3) genotype infectivities were determined by the order at which they were used in the successive infections. These results are discussed in terms of protective effect and concomitant immunity and provide an ecological explanation of the natural sex-biased dispersal toward the male schistosomes.

Emergence of infections with Schistosoma mansoni in the Dhofar Governorate, Oman

Infections with Schistosoma mansoni were identified in an area of Dhofar (Oman), where this parasite had been virtually absent during recent years and was reported only very sporadically before 1992. In the present survey, performed late in 2001, between 1 and 13% of children (n=519) were found to excrete eggs (one Kato-Katz-smear) in four schools, from four different villages, but no infections were detected in additional five schools (n=281). Infections were light (<72 eggs/g of faeces) in 19 of the 36 children found infected. Serologic examination of sera (n=511) was done by ELISA (based on soluble worm antigen) and immunofluorescence tests (IFT, based on cryostat sections of adult S. mansoni). The prevalence according to serological tests was between 3 and 43% in the four schools with infected children. Positive test results were taken to reflect active infections, since false positive reactions could largely be excluded. According to ultrasound (US) examinations performed on 96 individuals (children and adults) from the four villages, livers were normal in all except three cases of mild pathology, which could be assigned to schistosomiasis mansoni (pattern C, ages 32-40 years). All data suggest that transmission of S. mansoni has been re-introduced only recently in Dhofar and that this emergence of schistosomiasis is limited to at most a few foci.

Adenosine receptor-mediated inhibition of neurite outgrowth from cultured sensory neurons is via an A1 receptor and is reduced by nerve growth factor

Adult dorsal root ganglion (DRG) cells are capable of neurite outgrowth in vitro as well as in vivo. We have investigated the influence of adenosine and analogs on the potential of cultured adult mouse DRG neurons to produce neurites in the presence and absence of nerve growth factor (NGF) which is a well-established trophic factor of sympathetic and sensory neurons during development. It is also believed to be essential for the maintenance or regulation of differentiated phenotypes of mature peripheral neurons. The results demonstrate that DRG neurons are modulated by purines in the absence of exogenous NGF. The addition of 100 microM adenosine to neurite-bearing DRG neurons inhibited neurite growth by 47% after 2-day exposures in vitro and by 50% after 5 days whereas in the presence of NGF this inhibition was reduced to 28% and 32%, respectively. 100 microM CHA (N(6)-cyclohexyl adenosine) alone reduced neurite total length by 47% after 2 days and by 48% after 5 days. 100 microM CGS21680 (2-p-(2-carboxyethyl) phenethylamino-5'-N-ethylcarboxamido adenosine hydrochloride) alone also reduced neurite total length by 46% after 2 days and by 58% after 5 days which was reduced to 21% and 37%, respectively, in the presence of 100 ng/ml NGF. The antagonist studies revealed that activation of A1 adenosine receptors is primarily responsible for the effect on neuritogenesis since the inclusion of 1 or 10 microM CPX (8-cyclopentyl-1,3-dipropyl xanthine) fully prevented the inhibitory activity of adenosine or CHA whereas DMPX (3,7-dimethyl-1-propargyl xanthine) did not prevent inhibition by CHA. The converse experiment yielded the consistent result that inhibition by the A2 receptor agonist CGS21680 could be prevented by CPX, but not DMPX.

Purine suppression of proliferation of Sertoli-like TM4 cells in culture

The effect of adenosine and related compounds on the proliferation of cultured TM4 cells, a Sertoli-like cell line, has been examined. Adenosine, as well as A1 and A2 adenosine receptor agonists (cyclohexyladenosine and N6-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)ethyl]adenosine) inhibited cell proliferation. These effects were prevented by 8-cyclopentyl theophylline, 1,3-dimethyl-propargylxanthine and caffeine, antagonists at the A1, A2 and both receptors, respectively. The xanthines had no effect by themselves and, consistent with this, the bathing medium was found not to contain detectable levels of adenosine. It is concluded that TM4 cell proliferation can be regulated by receptors for adenosine.

Haemostatic abnormalities in multidrug-resistant enteric fever

Twenty-five consecutive patients with multidrug-resistant enteric fever were evaluated and followed for haemostatic abnormalities. Twenty-one (84%) of the patients had evidence of disseminated intravascular coagulation (DIC) and 12 (48%) also had evidence of associated fibrinolysis. Clinical bleeding was observed in 3 (12%) cases, and did not bear any correlation with clotting abnormalities. Protein C activity was found to be decreased in 11 of the 15 cases with DIC, and a block in its activation, as previously postulated, could not be substantiated. DIC was reversed in most cases within 8 days of the institution of specific antibiotic therapy.

Comparative study of white cell count and differential leukocyte count in school children at Dead Sea level and at Amman

White cell and differential counts were studied in school children living at Amman (group A), Dead Sea natives (group B), and residents of the Dead Sea area who originated from different areas (group C). A total of 159 subjects from group A, 146 from group B, and 38 from group C, were studied. Significant leukopenia was observed in group B, as compared with groups A and C (p less than 0.005). This was due to selective neutropenia in group B (p less than 0.005). Careful analysis revealed that this difference was genetic and not environmental. Living at 390 m below sea level does not affect the white cell or the differential count.

Synthesis of some 2-styrylquinazoline derivatives structurally related to certain chemotherapeutic agents

The synthesis of certain 2-styryl-4-arylaminoquinazolines having the general formula 1 is described. 4-Chloro-2-styrylquinazolines were prepared by chlorination of 2-styryl-4-quinazolones in benzene solution using phosphorus oxychloride and an excess of dimethylaniline. Reacting the chlorostyrylquinazolines with certain arylamines afforded 1.