Investigation on Concrete Properties for Nano Silica Concrete by using Different Plasticizers

This paper presents results of the optimal dosage levels of polycarboxylate-based (PSP) (0.4 and 0.8%) and naphthalene-based (NSP) (0.8 and 1.6%) super plasticizers and different water to binder (w/b) ratios (0.4 and 0.45 ) that produce an adequate balance between strength and workability for concrete containing nano-SiO2 (NS) of 1%, 2%, and 3% as cement replacement. These results indicate that For two types super plasticizers mixes. Increasing the w/c ratio from 0.40 to 0.45 increased the slump of all mixes. Either those containing polycarboxylate or naphthalene sulphonate super plasticizer or the control mixes. For polycarboxylate super plasticizer mixes. Decreasing the w/c ratio from 0.45 to 0.40 increased the compressive strength of all mixes. Either those containing polycarboxylate super plasticizer. For naphthalene sulphonate super plasticizer mixes. Increasing the w/c ratio from 0.40 to 0.45 increased the compressive strength of all mixes. Either those containing 0.8 % naphthalene super plasticizer or the control mixes. While decreasing the w/c ratio from 0.45 to 0.40 increased the compressive strength of all mixes. Either those containing 1.6 % naphthalene sulphonate super plasticizer. the use of (1.6 %) sulphonated naphthalene super plasticizer (NSP) with 0.4 w/c ratio reached a gain in strength equivalent to the  use of  (0.8 %) polycarboxylic super plasticizer (PSP) for mix containing 3 % nano silica . the use of (1.6 %)  naphthalene super plasticizer (NSP) with 0.45 w/c ratio reached a gain in strength equivalent to the  use of  (0.8 %) polycarboxylic super plasticizer (PSP) for mix containing 2 % nano silica. Keywords: Nano silica, concrete, plasticizers, workability, strength

Flexural Behavior of Unbounded Pre-stressed Beams Modified With Carbon Nanotubes under Elevated Temperature

Since fire is one of the common reasons for rehabilitation and reconstructions during the service life of a building, it is necessary to assess the elements structural and technical conditions. The objective of the present paper is to investigate the flexural behavior in bending for unbounded full pre-stressed beams with and without the incorporation of carbon nanotubes (CNTs) under the exposure to elevated temperature in comparison with non-pre-stressed beams. The test Method was divided into two major stages where the principal stage’s goal was considering the flexural behavior of fully and non-prestressed concrete beams containing CNT of 0 and 0.04% as cement replacement at ambient temperature. In the second stage, a typical group of beams was prepared and the flexural behavior was explored under the exposure to temperature of 400ºC, for 120 minutes. The major findings upon monitoring the failure mechanisms, ultimate load capacity, and deflection at critical sections, was that the CNT had shown a significant impact on the behavior and extreme resistance of fully and non-prestressed normal concrete. With CNT beams also exhibited higher imperviousness to high-temperature than that of the normal beams. Finally the significant Improvement was that the ultimate load of the non-pre-stressed beam with the presence of the CNT at the lower 50mm in the tension zone showed a gain of 13%, while the ultimate load of the fully pre-stressed beam with the presence of the CNT at the lower 50mm in the tension zone showed a gain of 21% as compared to the same beam without CNT, respectively. For the non-pre-stressed beams, the load capacity of the beam with CNT after exposure had a similar load capacity as the beam without CNT before exposure to high temperature

Upregulation of Twist2 in Non-Muscle Invasive Urothelial Carcinoma of the Bladder Correlate with Response to Treatment and Progression

BACKGROUND: Twist2 is a transcription factor and an epithelial-to-mesenchymal transition that plays an important role in cell polarity, cell adhesion, and has a role in tumour invasion and metastases.AIM: In this study, we examined the expression of Twist2 in non-muscle invasive bladder carcinoma (NMIBC) and correlated the expression with response to treatment and tumour progression.METHODS: Data of 305 patients with NMIBC of Ta, T1 were retrieved from hospitals archives. Twist2 expression was examined in tissue samples by immunohistochemistry at initial diagnosis and final follow-up, normal control was 10 normal urothelium, 10 patients with muscle-invasive bladder cancer (MIBC) were a positive control. Treatment of NMIBC was implemented according to the European Association of Urology guidelines on NMIBC. The descriptive statistical analysis included means, standard deviation, p-value; Univariate and multivariate Cox regression analyses.RESULTS: Twist2 expression score was identified as negative, low (1-15%); medium (15-40%); and high (40-100%). Patients who had low or low medium scores at the initial diagnosis had a good response and a favourable prognosis. Expression of a high score of Twist2 in patients having high-grade T1 tumours showed non-responsiveness to repeated courses of intravesical bacillus Calmette Guerin (BCG) therapy and was upstaged to MIBC.CONCLUSION: Twist2 expression in tissue samples of NMIBC would indicate the tumour response to therapy, upgrading and upstaging in the follow up after intravesical BCG therapy

Endophytic Aspergillus hiratsukae mediated biosynthesis of silver nanoparticles and their antimicrobial and photocatalytic activities

In the current study, endophytic Aspergillus hiratsukae was used for the biosynthesis of silver nanoparticles (Ag-NPs) for the first time. The characterizations were performed using X ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), and UV–Vis spectroscopy. The obtained results demonstrated the successful formation of crystalline, spherical Ag-NPs with particle diameters ranging from 16 to 31 nm. The FT-IR studied and displayed the various functional groups involved, which played a role in capping and reducing agents for Ag-NPs production. The SEM–EDX revealed that the main constituent of the AS-formed sample was primarily Ag, with a weight percentage of 64.2%. The mycosynthesized Ag-NPs were assessed for antimicrobial as well as photocatalytic activities. The antimicrobial results indicated that the synthesized Ag-NPs possess notable antibacterial efficacy against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli, with minimum inhibitory concentrations (MICs) of Ag-NPs ranging from 62.5 to 250 μg/mL. Moreover, the biosynthesized Ag-NPs demonstrated weak antifungal activity against Aspergillus brasiliensis and Candida albicans, with MICs of 500 and 1,000 μg/mL, respectively. In addition, the mycosynthesized Ag-NPs exhibited photocatalytic activity toward acid black 2 (nigrosine) dye under both light and dark stimulation. Notably, After 300 min exposure to light, the nigrosine dye was degraded by 93%. In contrast, 51% degradation was observed after 300 min in darkness. In conclusion, Ag-NPs were successfully biosynthesized using endophytic A. hiratsukae and also exhibited antimicrobial and photocatalytic activities that can be used in environmental applications

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

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Wood sawdust waste-derived nano-cellulose as a versatile reinforcing agent for nano silica cement composites: a systematic study on its characterization and performance

Abstract The development of sustainable construction materials is a pressing concern for researchers worldwide, as the cement industry is a major contributor to environmental degradation. The incorporation of nano-materials with cement composites has emerged as a promising solution to sustainable materials production. In this study, the effect of the addition of nano cellulose produced from wood sawdust waste on the performance of cement-based nano-silica composite was investigated. The nano-materials were incorporated at low concentrations and in gel form to eliminate the need for any advanced dispersion techniques. The results indicated that the addition of even low concentrations of nano cellulose significantly enhanced the compactness and mechanical properties of the cement matrix. The crack propagation was observed to be arrested with better adherence to the cement hydration product, which resulted from the presence of nano-silica. The nano cellulose fibers were found to bridge the calcium silicate hydrate products, arresting the propagation of cracks at their initial condition. The high pozzolanic reactivity of nano-silica ensured a minimal amount of calcium hydroxide, which is a significant contributor to the carbon footprint of cement production. Overall, the findings of this study suggest that the incorporation of nano cellulose from wood sawdust waste with cement-based nano-silica composite can lead to the development of sustainable and high-performance building materials with improved mechanical properties and reduced environmental impact

Role of color Doppler ultrasonography and multidetector computed tomography angiography in diagnosis of uterine arteriovenous malformations

Aim of work: To assess the role of color Doppler ultrasonography and multidetector computed tomography angiography (MDCTA) in diagnosis of uterine arteriovenous malformations (AVMs). Methodology: Twenty patients were referred to the radiodiagnosis and imaging department, faculty of medicine, Tanta University from obstetric and gynecology department. All patients were suspected clinically to have uterine arteriovenous malformations. All were subjected to history taking regarding clinical state, laboratory investigation and color Doppler ultrasonography and multidetector computed tomography angiography of the pelvis. Results: Color Doppler ultrasound sensitivity was 100% in detecting a uterine hypervascular lesion and highly suggesting the diagnosis of uterine AVM and the sensitivity of MDCT angiography was 100% in diagnosing and evaluating uterine AVM. Conclusion: Doppler US can strongly suggest the presence of AVM but patient should undergo CT angiography for definitive diagnosis and possible embolization, as CTA helps in providing valuable cross sectional anatomical details about the lesion, its extent and its surroundings

Utilizing residual sensing slots to enhance energy efficiency of opportunistic cognitive radio networks

In Broadband Communications (BBC), terms like “Green Communication (GC)”, “Energy Efficiency (EE)”, and “Opportunistic Cognitive Radio (OCR)” are pursuing methods for saving energy consumption while accomplishing communications. Good implementations of these terms/concepts contribute in reducing pollution and preserve nature resources. Forthcoming mobile generations will face many tradeoffs between EE considerations versus system performance parameters especially throughput. In a multi-channel OCR system, the Secondary User (SU) senses some selected candidate primary channels based on a “belief” concept. This belief state represents the occupancy/vacancy state of the primary channel and is deduced via a Partial Observation Markov Decision Process (POMDP). Within the OCR transmission frame, a fixed time-period at the beginning of this frame is dedicated for sensing multi primary channels. The SU performs the sensing needed to explore the state of occupancy/vacancy/fading of primary channels -within the sensing period- by dedicating a sensing slot for sensing each primary channel, then, SU updates its channel state belief accordingly. SU may not find it necessary to continue sensing more channels -using more sensing slots- in case of “low belief”, “bad CSI”, “highly believed to be occupied”, or even “sleep” if no candidate channels exist. This will lead to residual (not used) sensing slots which will be a wasted time in the frame time interval. This paper proposes an enhanced algorithm (to a previous work Feng and Gan, 2015) where these unused sensing slots are utilized to enhance the system EE. This is done by manipulating extended variable time induced from using these residual slots to extend the available transmission time. This induced variable time will increase throughput while keeping sensing energy. The metric used in this work is the Normalized Energy Efficiency (NEE) which is in consistence with many research directions in this field. In Feng and Gan (2015), the obtained NEE results reached ∼93% after about 20 transmitted frames, as well as, when 20 primary channels exist in the system. This work proposed an enhanced optimum and approximate algorithms that obtain as high as ∼135% of NEE after about 20 transmitted frames, they also obtained ∼228% using the optimum algorithm, or, ∼138% using the approximate algorithm when 20 primary channels are available. Keywords: Green cellular, Energy efficiency, Cognitive radio, Partially observable Markov decision process, Heterogeneous wireless network

An Enhanced Indoor Positioning Technique Based on a Novel Received Signal Strength Indicator Distance Prediction and Correction Model

Indoor positioning has become a very promising research topic due to the growing demand for accurate node location information for indoor environments. Nonetheless, current positioning algorithms typically present the issue of inaccurate positioning due to communication noise and interferences. In addition, most of the indoor positioning techniques require additional hardware equipment and complex algorithms to achieve high positioning accuracy. This leads to higher energy consumption and communication cost. Therefore, this paper proposes an enhanced indoor positioning technique based on a novel received signal strength indication (RSSI) distance prediction and correction model to improve the positioning accuracy of target nodes in indoor environments, with contributions including a new distance correction formula based on RSSI log-distance model, a correction factor (Beta) with a correction exponent (Sigma) for each distance between unknown node and beacon (anchor nodes) which are driven from the correction formula, and by utilizing the previous factors in the unknown node, enhanced centroid positioning algorithm is applied to calculate the final node positioning coordinates. Moreover, in this study, we used Bluetooth Low Energy (BLE) beacons to meet the principle of low energy consumption. The experimental results of the proposed enhanced centroid positioning algorithm have a significantly lower average localization error (ALE) than the currently existing algorithms. Also, the proposed technique achieves higher positioning stability than conventional methods. The proposed technique was experimentally tested for different received RSSI samples&rsquo; number to verify its feasibility in real-time. The proposed technique&rsquo;s positioning accuracy is promoted by 80.97% and 67.51% at the office room and the corridor, respectively, compared with the conventional RSSI trilateration positioning technique. The proposed technique also improves localization stability by 1.64 and 2.3-fold at the office room and the corridor, respectively, compared to the traditional RSSI localization method. Finally, the proposed correction model is totally possible in real-time when the RSSI sample number is 50 or more