45 research outputs found
Isolation and cytotoxicity of triterpenes from the roots of Phyllanthus pulcher Wall. ex Müll. Arg. (Euphorbiaceae).
The dried powdered roots of Phyllanthus pulcher Wall. ex Müll. Arg. (Euphorbiaceae), were sequentially extracted with dichloromethane (DCM), ethyl acetate (EtOAc) and methanol (MeOH). The extracts were tested for cytotoxic activity against three human cancer cell lines: MCF-7 (breast), NCI-H460 (lung) and DU-145 (prostate). The DCM extract exhibited the strongest cytotoxic activity compared with EtOAc and MeOH extracts. Hence from the DCM extract, five pentacyclic triterpenes, 3α-acetoxyl-25-hydroxyolean-12-en-28-oic acid (1), glochidone (2), 12(13)-dehydro-3α-acetoxyolean-28-oic acid (3), lupanyl acetate (4) and glochidonol (5) were isolated and identified by spectroscopic analyses (1H NMR, 13C NMR, FT-IR, UV, DEPT, HMQC, HMBC and HREIMS). This is the first report on the isolation of 4 from a natural source, whereas 1 and 3 have already been isolated from the families Hamamelidaceae and Compositae (Asteraceae), respectively. However this is the first study reporting the presence of 1 and 3 in the Euphorbiaceae family. The isolated tritepenes 1-5 were tested against the three human tumour cell lines as stated above. Only compounds 1 and 5 exhibited cytotoxic activity, 5 being most potent with IC50 values ranging 7.5–13.4 µg/mL (17.1–30.5 µM)
Adsorbents from rice husk and shrimp shell for effective removal of heavy metals and reactive dyes in water
Widespread contamination by heavy metals (HMs) and dyes poses a major health risk to people and ecosystems requiring effective treatment. In this work, rice husk (RH) and shrimp shells were extracted to obtain amorphous silica and chitosan, respectively, which were utilized to produce nano-chitosan-coated silica (NCCS). To ensure the stability of the nanoparticles, silica was freeze-dried after being coated with nano-chitosan. Functional groups (–NH2, –OH, P]O) from chitosan nanoparticles (CNPs) were introduced to the surface of silica during this process. Dyes such as brilliant green (BG), methylene blue (MB) and reactive brown (RB) as well as HMs (Cr6+, Pb2+, Cd2+, Ni2+) were removed by adsorbents. CNPs showed the highest adsorption capacity for RB (59.52 mg/g) among dyes and Cr6+ (42.55 mg/g) among HMs. CNPs showed the highest adsorption capacity for HMs among different adsorbents. Although NCCS and CNPs showed similar adsorption capabilities for HMs and dyes, NCCS showed the best stability. The adsorption performance decreased as RB \u3e Cr6+ \u3e MB \u3e BG \u3e Pb2+ \u3e Cd2+ \u3e Ni2+. The adsorption reactions followed both pseudo-first-order and second-order kinetics, and was spontaneous from thermodynamic analysis. In summary, the waste-derived adsorbents demonstrated excellent potential for removing HMs and dyes from water, while supporting effective management solid waste
Adsorbents from Rice Husk and Shrimp Shell for Effective Removal of Heavy Metals and Reactive Dyes in Water
Widespread contamination by heavy metals (HMs) and dyes poses a major health risk to people and ecosystems requiring effective treatment. In this work, rice husk (RH) and shrimp shells were extracted to obtain amorphous silica and chitosan, respectively, which were utilized to produce nano-chitosan-coated silica (NCCS). To ensure the stability of the nanoparticles, silica was freeze-dried after being coated with nano-chitosan. Functional groups (-N
Nano-refrigerants and nano-lubricants in refrigeration : synthesis, mechanisms, applications, and challenges
Addressing global energy security and environmental concerns, the utilization of nano-refrigerants and nano-lubricants has emerged as an innovative path for enhancing heat transfer. This research focuses on enhancing the thermophysical properties, heat transfer efficiency, and tribological characteristics of nanofluids—nanoparticles dispersed in refrigerants or lubricants. These nanofluids have demonstrated significant potential in applications such as cooling, air conditioning systems, and heat transfer equipment including pumps and pipes. A comprehensive understanding of parameters like thermal conductivity, viscosity, pressure drop, pumping power, and energy performance is delivered, with the aim of enhancing the overall efficiency of refrigeration systems, particularly the coefficient of performance (COP). Additionally, the review covers existing research on flow and pool boiling heat transfer, nano-lubricant tribological enhancement, and nano-refrigerant condensation. The study also addresses the challenges associated with the use of nano-refrigerants and nano-lubricants and offers a prospective outlook for their usage. These novel nanofluids are anticipated to emerge as effective solutions for increasing the COP and reducing energy consumption in the industrial sector, thus extending beyond the scope of previous efforts in this field. This review could serve as a valuable resource for a broad audience interested in this novel approach to energy efficiency
Developments in nanoparticles enhanced biofuels and solar energy in Malaysian perspective: a review of state of the art
The rapid rise in global oil prices, the scarcity of petroleum sources, and environmental concerns have all created severe issues. As a result of the country’s rapid expansion and financial affluence, Malaysia’s energy consumption has skyrocketed. Biodiesel and solar power are currently two of the most popular alternatives to fossil fuels in Malaysia. These two types of renewable energy sources appear to be viable options because of their abundant availability together with environmental and performance competence to highly polluting and fast depleting fossil fuels. The purpose of adopting renewable technology is to expand the nation’s accessibility to a reliable and secure power supply. The current review article investigates nonconventional energy
sources added with nanosized metal particles called nanomaterials including biodiesel and solar, as well as readily available renewable energy options. Concerning the nation’s energy policy agenda, the sources of energy demand are also investigated. The article evaluates Malaysia’s existing position in renewable energy industries, such as biodiesel and solar, as well as the impact of nanomaterials. This review article discusses biodiesel production, applications, and government policies in Malaysia, as well as biodiesel consumption and recent developments in the bioenergy sector, such as biodiesel property modifications utilizing nanoparticle additions. In addition, the current review study examines the scope of solar energy, different photovoltaic
concentrators, types of solar energy harvesting systems, photovoltaic electricity potential in Malaysia, and the experimental setup of solar flat plate collectors (FPC) with nanotechnology
Clinical and biochemical characteristics of people experiencing post-coronavirus disease 2019-related symptoms: A prospective follow-up investigation
BackgroundPost-acute coronavirus disease 2019 (COVID-19) syndrome, also known as long COVID, is a prolonged illness after the acute phase of COVID-19. Hospitalized patients were known to have persisting symptoms of fatigue, headache, dyspnea, and anosmia. There is a need to describe the characteristics of individuals with post-COVID-19 symptoms in comparison to the baseline characteristics.PurposeTo investigate the clinical and biochemical characteristics of people who recovered from COVID-19 after 6 months of discharge from the hospital.MethodsThis was a prospective follow-up investigation of hospitalized and discharged COVID-19 patients. Adult patients admitted to King Saud University Medical City, Riyadh, Saudi Arabia, with laboratory-confirmed COVID-19 and discharged were recruited. The baseline demographic information, comorbidities, vital signs and symptoms, laboratory parameters, COVID-19 therapy, and outcomes were collected from the medical records. Blood samples were collected for cytokines estimation. A detailed interview about signs and symptoms was undertaken during the follow-up.ResultsHalf of the followed-up people reported experiencing at least one of the COVID-19-related symptoms. The mean blood pressure was found higher in follow-up. People with the symptoms were characterized by low lymphocyte count, lower serum calcium levels, and hyperglycemia compared to people without any post-COVID-19 symptoms. Cytokines IL-8, VEGF, and MCP-1 were higher in people with the most frequent symptoms.ConclusionPeople with post-COVID-19 symptoms were characterized by lower lymphocyte count, lower serum calcium levels, and hyperglycemia compared to people without symptoms. Individuals with the most frequent post-COVID-19 symptoms had higher baseline pro-inflammatory, chemotactic, and angiogenic cytokines
SARS-CoV-2 Infection Is at Herd Immunity in the Majority Segment of the Population of Qatar.
BACKGROUND: Qatar experienced a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic that disproportionately affected the craft and manual worker (CMW) population, who comprise 60% of the total population. This study aimed to assess ever and/or current infection prevalence in this population. METHODS: A cross-sectional population-based survey was conducted during July 26 to September 09, 2020, to assess both anti-SARS-CoV-2 positivity through serological testing and current infection positivity through polymerase chain reaction (PCR) testing. Associations with antibody and PCR positivity were identified through regression analyses. RESULTS: The study included 2641 participants, 69.3% of whom were <40 years of age. Anti-SARS-CoV-2 positivity was 55.3% (95% CI, 53.3%-57.3%) and was significantly associated with nationality, geographic location, educational attainment, occupation, and previous infection diagnosis. PCR positivity was 11.3% (95% CI, 9.9%-12.8%) and was significantly associated with nationality, geographic location, occupation, contact with an infected person, and reporting 2 or more symptoms. Infection positivity (antibody and/or PCR positive) was 60.6% (95% CI, 58.6%-62.5%). The proportion of antibody-positive CMWs who had a prior SARS-CoV-2 diagnosis was 9.3% (95% CI, 7.9%-11.0%). Only seven infections were ever severe, and only 1 was ever critical-an infection severity rate of 0.5% (95% CI, 0.2%-1.0%). CONCLUSIONS: Six in every 10 CMWs in Qatar have been infected, suggestive of reaching the herd immunity threshold. Infection severity was low, with only 1 in every 200 infections progressing to be severe or critical. Only 1 in every 10 infections had been previously diagnosed, which is suggestive of mostly asymptomatic or mild infections
A study on estimating the prevalence of vitamin B12 deficiency in elderly population with dementia
Aim & Objective: The aim of our study was to determine the prevalence of major types of dementia in our population and to specifically look at the prevalence of B12 deficient dementias.Methodology: A prospective cohort study involving 100 elderly patients with dementia.Results: In our study population, vascular dementia (38%) was more common than Alzheimers (20%) probably due to the high prevalence of diabetes and hypertension.The proportion of reversible dementias were much higher (25%) than other earlier studies and the most common among these was B12 deficiency (19%).bThe average duration to presentation was much shorter in B12 deficiency (10 months). MMSE was much lower in B12 deficiency (13) compared to irreversible causes (16).Thus shorter duration, severe dementia, focal neurological signs and vegetarian diet was significantly associated with development of B12 deficiency. In the diagnosis of B12 deficiency, MCV, peripheral blood smear and LDH had relatively low sensitivities (62.5%, 71% &72.4% respectively) but very high specificities (98.7%, 96.9% &97.5% respectively). B12 deficiency seems to affect more of registration and calculation whereas Alzheimer‘s seems to affect more of orientation and recall. There was a significant and marked improvement in MMSE after treatment in pure B12 deficient patients (by 10 points) if they presented within 1 year of symptoms. There was improvement in other neurological parameters except myelopathy. Multi-infarct state was significantly associated with risk factors- diabetes, hypertension, dyslipidemia, non-vegetarian diet and alcohol intake.Conclusion: Considering this marked improvement and a high prevalence of B12 deficiency in elderly population, we recommend that B12 levels to be done for all elderly dementia patients as it is a potentially treatable cause which can make marked improvement in a patient‘s memory and quality of life
A study on renal function in chronic liver disease
Aim & Objectives: To determine the usefulness of serum creatinine and creatinine clearance as parameters in assessing renal function abnormalities in patients with chronic liver disease.Methodology: Inpatients in the medical ward/IMCU admitted with chronic liver disease with seemingly normal renal function were included in this analytical study which was conducted from June 2018 to October 2019. Lab investigations including complete Liver function test, Renal function tests, Viral marker for hepatitis B, Urine analysis, 24 hour urine volume and Urine creatinine was done and results noted. Results: In the present study, Age of the patients ranged from a minimum of 22 years to a maximum of 58 years. The mean age was 42.14 years. Out of the 43 patients of cirrhosis, the cause of liver disease was attributed to alcoholism in 21 patients. 6 patients were found to be positive for Hepatitis B surface antigen. There was no significant variation in blood urea levels in all the three groups. Eighteen percent ie, five out of the twenty-eight patients with creatinine clearance more than 60 ml / minute by Cockcroft gault formula were found to have creatinine clearance values less than 40 ml/minute when done by timed urine collection. Serum bilirubin levels were found to have no significant correlation with renal function.Conclusion: Finally we conclude that, In chronic liver disease, serum creatinine alone is not a reliable marker to assess renal dysfunction. Calculating creatinine clearance by using Cockcroft Gault formula over estimates renal function in cirrhotics
Keywords: Liver diseases, Renal Function, Creatinine, Cockcroft Gault Formula
Inorganic hole conductor based perovskite photoelectric conversion device with high operational stability at long term
The invention relates to an optoelectronic and/or photoelectrochemical device comprising a conductive support layer, n-type semiconductor, a sensitizer or light-absorber layer, a hole transporting layer, a spacer layer and a back contact, wherein the n-type semiconductor is in contact with the sensitizer or light-absorber layer, the sensitizer or light-absorber layer comprises a perovskite or metal halide perovskite material, the hole transporting layer is in direct contact with the sensitizer or light-absorber layer and comprises an inorganic hole transporting material or inorganic p-type semiconductor, the spacer layer is between the hole transporting layer and the back contact and comprises a material being different from the inorganic hole transporting material and the material of the back contact