Chloride Resistance of Concrete Containing Palm Oil Fuel Ash

Experimental study was conducted to investigate the chloride resistance of concrete containing palm oil fuel ash (POFA). Ground POFA was used to partially replace Portland cement Type I, by 20% by weight of binder in order to prepare POFA concrete.  Water cement ratio of 0.28 was used and high water reducing admixture was added to maintain workability. POFA concrete was investigated and tested for compressive strength at ages of 7, 28 and 90 days. Rapid chloride penetration test (ASTM C1202) and salt ponding test (ASTM C1543) were conducted on standard concrete specimens to investigate the chloride resistance of concrete.  The results showed that the compressive strength of POFA concrete was improved comparing with plain concrete. The results of chloride penetration tests revealed that significant improvement in terms of chloride resistance could be obtained by using 20 % of ground POFA in concrete mix as cementing replacement material

Immunolocalization of neurokinin 1 receptor in WHO grade 4 astrocytomas, oral squamous cell and urothelial carcinoma

Neurokinin-1 receptor (NK-1R) induces inflammatory reactions in peripheral tissues but its regulatory effects in target tissues is dependent on receptor signalling. Substance P (SP) has a high affinity for the NK-1R, to which it binds preferentially. We aimed to investigate the expression of NK-1R in World Health Organization (WHO) grade 4 astrocytomas as well as in oral squamous cell carcinoma (OSCC) and urothelial carcinoma, and its association with disease progression.The study included tissue samples from 19 brain astrocytomas, 40 OSCCs and 10 urothelial carcinomas. NK-1R expression was quantitatively assessed in the tumour cells using immunohistochemistry. The relationship between NK-1R expression in astrocytomas and recurrence-free interval has been explored.The results showed that the NK-1R was intensely expressed in patients with WHO grade 4 astrocytoma, OSCC and urothelial carcinoma. However, cases clinically diagnosed as a low-grade cancer showed reduced NK-1R expression.NK-1R is overexpressed in all cases of WHO grade 4 astrocytoma, OSCC and urothelial carcinoma. The ubi-quitous presence of SP/NK-1R complex during tumour development and progression suggests a possible therapeutic key strategy to use NK-1R antagonist as an adjuvant therapy in the future

Structural behaviour of composite beams with cold formed steel section

The use of composite beam in buildings has known to be more economical compared to bare steel beams with hot-rolled steel section, as the composite action between steel and concrete results in significant savings in steel weight and reduce the beam depth. However, the use of composite beam with cold-formed steel of lipped C-channel is yet to be established as the structural behavior of such beam is not well understood. This study presents and discusses the behavior of composite beam with cold formed steel section and innovative shear connectors. The composite beam comprises two cold formed steel of lipped C-sections oriented back to back to form I-steel beam and perpendicular metal decking concrete slab. Three types of bracket shear connectors namely single bracket (SBSC), double bracket (DBSC) and hot rolled plate (HPSC) shear connectors were developed and used; the proposed shear connectors were fixed to the web of steel beam by bolts. In addition, headed stud (HSSC) shear connector welded to the top flange of cold formed steel beam was also investigated. Push tests in accordance with Eurocode 4 were carried out to determine the strength capacity and ductility of the proposed shear connectors. Sequentially, full-scale beam tests were conducted to investigate the actual behavior of the composite beam with the proposed shear connectors. The length of full-scale specimen between supports is 4000 mm. Theoretical validation for the experimental results was performed based on the plastic analysis of composite beam. The experimental results of push tests showed very good strength with extreme deformation capacity for all bracket shear connectors suggesting that they are strong and ductile enough to provide composite action between steel beam and concrete slab. Also, it was observed that strength capacity of shear connector increases as the thickness of steel beam increases. For headed stud shear connectors, the stud possess strength capacity as high as its predicted strength. The results of full-scale beam tests showed very good agreement as compared to theoretical values that predicted based on push test results. The bending resistance and stiffness of the composite beams were improved up to 170% and 270% respectively as compared to non-composite cold formed steel beam. Composite beam with HSSC shear connectors showed the best performance as compared to composite beams with SBSC, DBSC and HPSC shear connectors. Also, the results showed that the bending resistance of the composite beam increases as the thickness of steel beam increases. It is concluded that the proposed composite beams with cold formed steel section are strong enough to be used in small and medium size buildings

Strength Capacity and Failure Mode of Shear Connectors Suitable for Composite Cold Formed Steel Beams: Numerical Study

In this paper, the findings of numerical modeling of the composite action between normal concrete and Cold-Formed Steel (CFS) beams are presented. To obtain comprehensive structural behavior, the numerical model was designed using 3-D brick components. The simulation results were correlated to the experimental results of eight push tests, using three types of innovative shear connectors in addition to standard headed stud shear connectors, with two different thicknesses of a CFS channel beam. The proposed numerical model was found to be capable of simulating the failure mode of the push test as well as the behavior of shear connectors in order to provide composite action between the cold-formed steel beam and concrete using the concrete damaged plasticity model

Chloride resistance of concrete containing palm oil fuel ash

Experimental study was conducted to investigate the chloride resistance of concrete containing palm oil fuel ash (POFA). Ground POFA was used to partially replace Portland cement Type I, by 20% by weight of binder in order to prepare POFA concrete. Water cement ratio of 0.28 was used and high water reducing admixture was added to maintain workability. POFA concrete was investigated and tested for compressive strength at ages of 7, 28 and 90 days. Rapid chloride penetration test (ASTM C1202) and salt ponding test (ASTM C1543) were conducted on standard concrete specimens to investigate the chloride resistance of concrete. The results showed that the compressive strength of POFA concrete was improved comparing with plain concrete. The results of chloride penetration tests revealed that significant improvement in terms of chloride resistance could be obtained by using 20 % of ground POFA in concrete mix as cementing replacement material

Spectrofluorometric quantitative analysis of aripiprazole based on quenching of natural derived carbon quantum dots in spiked human plasma

Abstract Autism spectrum disorder is a significant concern worldwide, particularly in Middle Eastern countries. Aripiprazole, a psychiatric medicine that works as a partial agonist at D2 receptors, is often used for autism-related behavior issues in children. Monitoring the therapy of aripiprazole could enhance the safety and effectiveness of treatment for autistic individuals. The purpose of this study was to develop a highly sensitive and environmentally friendly method for analysis of aripiprazole in plasma matrix. To achieve this, water-soluble N-carbon quantum dots were produced from a natural green precursor, guava fruit, and used in fluorescence quenching spectroscopy to determine the presence of aripiprazole. The synthesized dots were analyzed and characterized using transmission electron microscopy and Fourier transform infrared spectroscopy, and they showed a strong fluorescence emission peak at 475 nm. The proposed method was validated according to ICH M10 guidelines and was shown to be highly sensitive, allowing for nanoscale determination of aripiprazole in plasma matrix. Additionally, the method was compared to a previously reported spectrophotometric method, and it was found to be more sensitive and consistent with the principles of green analytical chemistry

Extracranial metastasis of brain glioblastoma outside CNS: Pathogenesis revisited

Abstract Background The most prevalent malignant tumor of the CNS in adults is glioblastoma. Despite undergoing surgery and chemoradiotherapy, the prognosis remains unfavorable, with a median survival period ranging between 15 and 20 months. The incidence of glioblastoma metastasis outside CNS is uncommon with only 0.4%–2% reported rate, compared to other tumors that exhibit a 10% incidence rate of metastasis to the brain. On average, it takes about 11 months from the time of initial diagnosis for the tumor to spread beyond CNS. Consequently, the prognosis for metastatic glioblastoma is grim, with a 6‐month survival rate following diagnosis. Findings The rarity of extracranial metastasis is attributed to the blood–brain barrier and lack of a lymphatic drainage system, although rare cases of hematogenous spread and direct implantation have been reported. The possible mechanisms remain unclear and require further investigation. Risk factors have been widely described, including previous craniotomy or biopsies, ventricular shunting, young age, radiation therapy, prolonged survival time, and tumor recurrence. Due to the lack of understanding about extracranial metastasis of glioblastoma pathogenesis, no effective treatment exists to date. Aggressive chemotherapies are not recommended for metastatic glioblastoma as their side effects may worsen the patient prognosis. Conclusion The optimal treatment for extracranial metastasis of glioblastoma requires further investigation with a wide inclusion of patients. This review discusses the possible causes, factors, and underlying mechanisms of glioblastoma metastasis to different organs