Development of an Absorption Refrigeration System Powered by Solar Energy to Extract Fresh Water from Humid Air in Saudi Arabia

The purpose of this paper is to investigate the extraction of fresh water from humid air in Saudi Arabia by direct solar absorption system using aqueous ammonia 0 45 mass fractions ammonia water In the system ammonia is boiled out of the water then condensed in an air cooled condenser The refrigerant is then expanded and evaporates in the evaporator exists inside a tunnel where humid air flows and therefore the temperature of humid air is reduced beyond its dew point temperature so a process of water separation from humid air starts To analyze the performance of the system first a comprehensive mathematical model describing the entire processes accomplished within the major components in the cycle is introduced based on heat and mass conservation balancing considering steady flow processes The results of calculations are to find out the actual real sizes of all involved major components within the system based on simulation analyzing The amount of the extracted fresh water from humid air is determined for certain operation conditions in the Kingdome of Saudi Arabia it was found for real atmospheric conditions to be and the efficiency of the system is 1 369 Furthermore analyzing the impact of prevailing atmospheric parameters in order to determine their effects on the performance of the system Thus and furthermore the investigation involved assessing the influence of different operation conditions such initial flow rate of the working fluid Ammonia-water humid air solar radiation and ambient temperature on the system performance characteristics system efficiencies evaporation rate and water productivit

Flexural Behavior of 3D Printed Concrete Beam with Fiber Reinforcement

3D printing with concrete is a promising new method for rapid, low cost construction. The flexural strengths for reinforced/unreinforced and 3D printed/cast concrete Warren trusses were tabulated and the failure mechanisms were reported. The types of reinforcement used were rebar(basalt and steel), and mesh (basalt and aramid). The effect of loading geometry and loading speed  was measured for basalt mesh and aramid mesh composite, respectively. Due to the expected variation in flexure between samples, it cannot be said whether small differences for various tests are significant. Variation stems from a microscopically uneven surface and random inhomogeneities in the bulk of the tested material which act as a microcrack catalyst and propagator. Since the tested beams are short specimens the numerical findings of other studies will vary based on the intended design. This paper is intended to assess the performance of various reinforcements in a qualitative sense by comparing basalt reinforcement with other reinforcements.  It was found that cast beams tolerated deflection better but had a similar flexure strength compared as the printed beams. The steel and basalt rebar reinforced beams had the highest flexure strengths where the traditional steel rebar reinforcement outperformed the basalt in flexure by 36% and the basalt outperformed the steel in deflection by 40%.  The basalt mesh outperformed the cast and printed unreinforced bars by a small margin but had only 25% of steel rebars’ deflection at maximum flexure strength. The aramid mesh tolerated the biggest deflection out of any sample at 2.26 cm

Expression pattern and regulation of genes differ between fibroblasts of adhesion and normal human peritoneum

BACKGROUND: Injury to the peritoneum during surgery is followed by a healing process that frequently results in the attachment of adjacent organs by a fibrous mass, referred commonly as adhesions. Because injuries to the peritoneum during surgery are inevitable, it is imperative that we understand the mechanisms of adhesion formation to prevent its occurrence. This requires thorough understanding of the molecular sequence that results in the attachment of injured peritoneum and the development of fibrous tissue. Recent data show that fibroblasts from the injured peritoneum may play a critical role in the formation of adhesion tissues. Therefore, identifying changes in gene expression pattern in the peritoneal fibroblasts during the process may provide clues to the mechanisms by which adhesion develop. METHODS: In this study, we compared expression patterns of larger number of genes in the fibroblasts isolated from adhesion and normal human peritoneum using gene filters. Contributions of TGF-beta1 and hypoxia in the altered expression of specific genes were also examined using a semiquantitative RT-PCR technique. RESULTS: Results show that several genes are differentially expressed between fibroblasts of normal and adhesion peritoneum and that the peritoneal fibroblast may acquire a different phenotype during adhesion formation. Genes that are differentially expressed between normal and adhesion fibroblasts encode molecules involved in cell adhesion, proliferation, differentiation, migration and factors regulating cytokines, transcription, translation and protein/vesicle trafficking. CONCLUSIONS: Our data substantiate that adhesion formation is a multigenic phenomenon and not all changes in gene expression pattern between normal and adhesion fibroblasts are the function of TGF-beta1 and hypoxia that are known to influence adhesion formation. Analysis of the gene expression data in the perspective of known functions of genes connote to additional targets that may be manipulated to inhibit adhesion development

Literature review regarding the applicability and clinical out-come of basal implant

Objective: Restoring moderate to severely atrophic jaws with conventional implants often involves extensive surgical procedures. Basal implants, designed for immediate use in atrophied jawbones, offer an alternative by supporting single and multiple-unit restorations in the upper and lower jaws without the need for risky and expensive bone augmentation. However, their success rate diminishes significantly in areas with limited residual bone. This review aims to assess the applicability of basal implants compared to conventional endosseous implants.Methods: A comprehensive literature review was conducted utilizing PubMed, Scopus, the Cochrane Library, EMBASE, and Google Scholar. The analysis focused on manuscripts and overviews published in more than 20 years until September 8, 2022.Results: Studies indicate that basal implants are a reliable option in specific cases, especially when other implants are not feasible, such as in severe alveolar bone atrophy. However, there is insufficient strong evidence to recommend basal implants over conventional ones. The evidence level of the reviewed papers, all belong to evidence level V, which encompasses case reports and studies lacking controls.Conclusions: The advantages of basal implants over conventional implants remain uncertain. The standard of care in dentistry should prioritize evidence-based practices, which commonly include the use of conventional implants. Further research is necessary to establish their efficacy and suitability in various clinical scenarios.<br/

A Threshold Cointegration Analysis of Asymmetric Adjustment of OPEC and non-OPEC Monthly Crude Oil Prices

The purpose of this paper is to analyze the dynamics of crude oil prices of OPEC and non-OPEC countries using threshold cointegration. To capture the long run asymmetric price transmission mechanism, we develop an error correction model within a threshold cointegration and CGARCH errors framework. The empirical contribution of our paper specifies the cointegrating relation between OPEC price and non-OPEC prices and estimates how and to what extent the respective prices adjust to eliminate disequilibrium. The finding exhibits that the conditional volatility of variance has long run memory feature and the shocks on the long run component do not adjust quickly. The OPEC producers could not drive down (up) crude oil prices with equivalent speeds for all participants in the market. The slow adjustment of OPEC process of positive discrepancies to the long run equilibrium indicates that OPEC does not prefer modest oil prices. While, the rapid adjustment of non-OPEC process signifies their preference of modest oil prices after oil price increases. These differences of speeds show evidence for competitive behaviors between OPEC and non-OPEC countries

An Open-Label, Multicenter, Phase I, Dose Escalation Study with Phase II Expansion Cohort to Determine the Safety, Pharmacokinetics, and Preliminary Antitumor Activity of Intravenous TKM-080301 in Subjects with Advanced Hepatocellular Carcinoma.

Lessons learnedTKM-080301 showed a favorable toxicity profile at the studied dose.TKM-080301 targeting PLK1 through small interfering RNA mechanism did not demonstrate improved overall survival in patients with advanced hepatocellular carcinoma compared with historical control. Preliminary antitumor activity as shown in this early-phase study does not support further evaluation as a single agent.BackgroundPolo-like kinase 1 (PLK1) is overexpressed in hepatocellular carcinoma (HCC). Knockdown of PLK1 expression by PLK1 small interfering RNA (siRNA) in an HCC cell line showed reduced expression in RNA-induced silencing complex and a reduction in cell proliferation.MethodsA 3 + 3 dose escalation plus expansion cohort at the maximum tolerated dose (MTD) was implemented. Patients with HCC, Eastern Cooperative Oncology Group (ECOG) performance status ≤2, and Child-Pugh score A received TKM-080301 as an intravenous infusion once every week for 3 consecutive weeks, repeated every 28 days.ResultsThe study enrolled 43 patients. The starting dose of TKM-080301 was 0.3 mg/kg, and MTD was declared at 0.75 mg/kg. Following the development of grade 4 thrombocytopenia in two subjects on the expansion cohort, the MTD was redefined at 0.6 mg/kg. Four patients did not have any evaluable postbaseline scan. Of the other 39 subjects who had received at least 0.3 mg/kg, 18 subjects (46.2%) had stable disease (SD) by independent RECIST 1.1 criteria. By Choi criteria, eight subjects (23.1%) had a partial response (PR). For 37 assessable subjects, with 2 subjects censored, median progression-free survival (PFS) was 2.04 months. Median survival for the whole study population was 7.5 months.ConclusionTKM-080301 was generally well tolerated. In this early-phase study, antitumor effect for TKM 080301 was limited. Further evaluation as a single agent in large randomized trials is not warranted

Impact of chylothorax on the post operative outcome after pediatric cardiovascular surgery

BackgroundChylothorax is the accumulation of chyle in the pleural cavity, usually develops after disruption of the thoracic duct along its intra-thoracic route. In the majority of cases this rupture is secondary to trauma (including cardio thoracic surgeries). Chylothorax is a potentially serious complication after cardiovascular surgeries that require early diagnosis and adequate management.MethodsA retrospective study of all cases complicated with chylothorax after pediatric cardiac surgery in King Abdulaziz Cardiac Center between January 2007 and December 2009 was conducted. The study aim to determine the risk factors, and the impact on the post operative course.ResultsWe have 1135 cases operated during the study period, 57 cases (5%) were complicated with chylothorax in the post operative period. The most common surgeries complicated with chylothorax were the single ventricle repair surgeries (Glenn-Fontan) 15 cases (27%), followed by the arch repair cases 10 cases (18%), the ventricular septal defect cases 10 cases (18%), the Atrioventricular septal defect cases 7 cases (12%), the arterial switch cases 6 cases (11%), and others 8 cases (14%). The ICU stay, the length of hospital stay and the bypass time were significantly longer in the chylothorax group, also the ventilation time, the inotropes duration and number were higher in the chylothorax group.ConclusionChylothorax after pediatric open heart surgery is not an uncommon complication, it occurs more commonly with single ventricle repair and aortic arch repair surgeries, it has a significant impact on the post operative course and post operative morbidity

An MR-compatible antenna and application in a murine superficial hyperthermia applicator

In this work, a novel magnetic resonance (MR)-compatible microwave antenna was designed and validated in a small animal superficial hyperthermia applicator. The antenna operates at 2.45 GHz and matching is made robust against production and setup inaccuracies. To validate our theoretical concept, a prototype of the applicator was manufactured and tested for its properties concerning input reflection, sensitivity for setup inaccuracies, environment temperature stability and MR-compatibility. The experiments show that the applicator indeed fulfils the requirements for MR-guided hyperthermia investigation in small animals: it creates a small heating focus (<1 cm3), has a stable and reliable performance (S11< −15 dB) for all working conditions and is MR-compatible

Molecular characterization, toxin detection and resistance testing of human clinical Clostridium difficile isolates from Lebanon

Clostridium (Clostridioides) difficile is the main cause for nosocomial diarrhoea in industrialised nations. Epidemiologic data on the pathogen’s occurrence in other world regions are still scarce. In this context we characterized with phenotypic and molecular genetic methods C. difficile isolates stemming from hospitalised patients with diarrhoea in Lebanon. From 129 stool samples of symptomatic patients at a tertiary care University hospital in Lebanon, a total of 107 C. difficile strains were cultivated and underwent ribotyping, toxin gene detection and antibiotic resistance testing. Ribotype 014 (RT014, 16.8%) predominated, followed by RT002 (9.3%), RT106 (8.4%) and RT070 (6.5%). Binary toxin gene-positive isolates (RT023, RT078 and RT126) were rarely detected and RT027 was absent. Interestingly, within one isolate only the toxin A gene (tcdA) was detected. Multiple-locus variable-number tandem repeat analysis (MLVA) revealed strong strain diversity in most RTs. The isolates were sensitive to metronidazole and vancomycin, and only a small proportion of strains displayed resistance against moxifloxacin, rifampicin, and clarithromycin (5.6%, 1.9%, and 2.8%), respectively. The data indicate that the genetic strain composition of Lebanese strains differs markedly from the situation seen in Europe and North America. Especially the epidemic RTs seen in the latter regions were almost absent in Lebanon. Interestingly, most strains showed almost no resistance to commonly used antibiotics that are suspected to play a major role in the development of C. difficile infection, despite frequent use of these antibiotics in Lebanon. Thus, the role of antimicrobial resistance as a major driving force for infection development remains uncertain in this area

Left ventricular rotational mechanics in Tanzanian children with sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is a common inherited hemoglobinopathy. Adults with SCD manifest both systolic and diastolic cardiac dysfunction, though the age of onset of dysfunction has not been defined. Left ventricular (LV) rotational mechanics have not been studied in children with SCD. The aim of this study was to investigate whether cardiac rotational mechanics differed between children with SCD and age-matched controls. METHODS: Basal and apical LV short-axis images were acquired prospectively in 213 patients with SCD (mean age, 14.1 ± 2.6 years) and 49 controls (mean age, 13.3 ± 2.8 years) from the Muhimbili Sickle Cohort in Dar es Salaam, Tanzania. The magnitude of basal and apical rotation, net twist angle, torsion, and untwist rate were obtained by two-dimensional speckle-tracking. The timing of events was normalized to aortic valve closure. RESULTS: Mean basal rotation was significantly lower in patients with SCD compared with controls (P = .012), although no difference was observed in apical rotation (P = .37). No statistically significant differences in torsion or net twist angle were detected. Rotation rate at the apex (P = .001) and base (P = .0004) were significantly slower in subjects with SCD compared with controls. Mean peak untwisting rate was also significantly slower in patients with SCD (P = .006). No associations were found between hemoglobin concentration and apical rotation, basal rotation, net twist, and torsion. CONCLUSION: This study demonstrates alterations in LV rotational mechanics in children with SCD, including lower basal rotation, peak differential twist, and untwist rate. These abnormalities denote subclinical changes in LV systolic and diastolic performance in children with SCD. Future work may reveal an association between rotational metrics and long-term patient outcomes