Effect of Size and Location of Square Web Openings on the Entire Behavior of Reinforced Concrete Deep Beams

This paper presents an experimental and numerical study which was carried out to examine the influence of the size and the layout of the web openings on the load carrying capacity and the serviceability of reinforced concrete deep beams. Five full-scale simply supported reinforced concrete deep beams with two large web openings created in shear regions were tested up to failure. The shear span to overall depth ratio was (1.1). Square openings were located symmetrically relative to the midspan section either at the midpoint or at the interior boundaries of the shear span. Two different side dimensions for the square openings were considered, mainly, (200) mm and (230) mm. The strength results proved that the shear capacity of the deep beam is governed by the size and location of web openings. The experimental results indicated that the reduction of the shear capacity may reach (66%). ABAQUS finite element software program was used for simulation and analysis. Numerical analyses provided un-conservative estimates for deep beam load carrying capacity in the range between (5-21%). However, the maximum scatter of the finite element method predictions for first diagonal and first flexural cracking loads was not exceeding (17%). Also, at service load the numerical of midspan deflection was greater than the experimental values by (9-18%)

ADSORPTIVE REMOVAL OF DOXYCYCLINE FROM AQUEOUS SOLUTION USING GRAPHENE OXIDE/HYDROGEL COMPOSITE

Objective: Preparation of novel, safe, and low-cost composite by addition of graphene oxide (GO) to polyvinylpyrrolidone-acrylic acid composite (PVP-AAc) to remove the doxycycline hydrochloride (D) from polluted aquatic environment. Methods: Different concentrations of D were used to study the adsorption process of the antibiotic on the surface of GO/(PVP-AAc) hydrogel composite. The aquatic solution of D was used for studying the adsorption process through a series of different experiments to determine the contact time, adsorbate amount, appropriate temperature, the preferred pH, ionic strength, adsorption kinetics and isotherms on the adsorbent surface of GO/PVP-AAc composite. Fourier transform infrared (FT-IR) spectroscopy and Field-emission scanning electron microscopy (FE-SEM) were used to detect the structure, functional groups and surface morphology of the composite before and after D adsorption. Results: Doxycycline is adsorb on the surface of GO/PVP-AAc hydrogel composite through by physical interactions. The adsorption kinetics correlated to the pseudo-second-order model, contact time studies of D equal to 180 min and the high R2 value of 0.98 indicates that Langmuir isotherm model better fitted to the data for the removal of D at 15 °C. The results of thermodynamic parameters show that the nature of the adsorption process is physical, exothermic, orderly and spontaneous. The adsorption capacity of D favors the acidic media. When NaCl is added to the solution, the adsorption capacity of D will increase. Conclusion: Graphene oxide/PVP-AAc composite is a novel, worthy and efficient adsorbent for the removal of the doxycycline polluted the water because of its low cost, hydrophilic properties, large surface area and special structure that give impressive dispersible activity in aquatic solutions

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Comparative Bioequivalence Studies of doxysam and doxycycline (Pfizer) by reversed phase HPLC.

Isocratic high performance liquid chromatography on reversed phase a (150x 4.6 mm I.D), 5 ?m ?-Bondapak RP-8 column (with acidic mobile phase allow the separation of doxcycycline hydrochloride with low detection limit of 0.2 µg/ml detected by UV set at 226 nm. The method was validated for Doxycycline between 0.156- to 5 µg/ml. The concentration of doxycycline was assessed in two single dose randomized crossover studies with intervals of one week between two period. In sera of 20 adults healthy male volunteers with average age of (42 + 10) year, body weight 48-85 kg, body height of (160-185cm) after a single dose of doxycycline hydrochoride 100 mg in form of capsules were orally administrated for both formulations. The blood samples (2ml) were drawn concomitantly from 0.5 – 24 hours. µg The pharmacokinetics parameter were obtained from the mean serum concentration measured at various sampling times for both formulations. The maximum peak concentration (Cmax) of doxycycline reference drug from Pfizer In serum was (3.1 +0.094 µg /ml) attained in 2 hrs. While the maximum concentration (Cmax) of test drug doxysam (2.8 +0.098 µg /ml) attained in about 2 hrs, both drug have long elimination time with half time of approximately (13 hrs.) Both test and reference drug were show no significant difference in pharmacokinetics parameters, so they were considered to be bioequivalent

Behavior of reinforced concrete deep beam with web openings strengthened with (CFRP) sheet

Deep beams are used in various applications in reinforced concrete (R.C.) structures. There have been continuous efforts to enhance and improve the performance of these crucial elements in (R.C.) structures by using several strengthening techniques such as using the carbon fiber-reinforced polymer (CFRP). However, by exploring the literature, none of the previously conducted experimental tests have studied the propagation of cracks beneath the (CFRP) sheets. In this research, the propagation of the first diagonal crack, which takes place beneath the (CFRP), is investigated by modeling sixteen (R.C.) deep beams with different opening sizes. Two shear span/ depth ratios (a/h) are studied numerically using the finite element analysis tool (ABAQUS). All models are validated using the concrete damage plasticity (CDP) model, and their results are found similar to the experimental results obtained by other authors. Results show that the Finite Element models catch the real behavior of the (R.C.) deep beams. In addition, the (CFRP) sheets are found to enhance the failure load capacity as well as the flexural crack remarkably. Moreover, the (CFRP) increases the load required to cause the first diagonal crack for models with (a/h) equals 0.9, while there is a slight change in this load for models with (a/h) equals 1.1

Rapid microwave fabrication of new nanocomposites based on Tb-Co-O nanostructures and their application as photocatalysts under UV/Visible light for removal of organic pollutants in water

Herein, a novel and stable Tb-Co-O nanocomposite photocatalyst is fabricated through a one-pot microwave route for 2 min (600 W, 20 s On, 60 s Off), which is introduced as UV/Visible light active catalysts in wastewater treatment. Employing various combined parameters of Tb:Co ratio, pH adjustment agents, chemical and natural templates, the resulting nanostructures displayed the intrinsic structure nature, narrow size distribution, good optical properties, and excellent photocatalytic efficiency. The formation of Tb-Co-O nanostructures and their features were verified via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and ultraviolet–visible diffuse reflection spectroscopy (DRS) technologies. Detailed physic-chemical measurements exhibited that all as-prepared nano-photocatalysts possesses both cubic (TbO1.81) and orthorhombic (TbCoO3) crystal structures. Furthermore, optical characterization by DRS developed light-sensitive channelization with band-gap energies at approximately 2.95 and 3.20 eV for Tb-Co-O nanocomposites. Finally, the photocatalytic studies of the resulting nanocomposites were compared by determining the elimination of Erythrosine (EY), Acid Violet 7 (AV7), and Acid Black 1(AB1) under UV and Visble light illumination. As a results, the TbCoO3/TbO1.81 nanocomposties with molar ratio of 1:3 (Tb:Co), valerian distillate as natural directing agent and ethylenediamine (en) as alkaline template yielded the optimum degradation percentage of 88 % for EY dye under the reaction condition of 10 ppm dye concentration in the presence UV light toward other pathways. Also, we proposed a mechanistic insight of photodegradation based on the radical scavengers, which revealed that h+ did the important role, and OH• and •O2− represented an irrelevant role in the degradation of EY. The current study offer an effective way for development of a high-efficiency Tb-Co-O photocatalyst in eliminating dyes from contaminant water

Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality