469 research outputs found

    Pemanfaatan Silika Mesopori Mcm-48-nh2 sebagai Adsorben Ion Cu2+

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    Ion Cu2+ merupakan unsur yang berbahaya jika terkontaminasi ke dalam lingkungan. Oleh karena itu, keberadaannya dalam lingkungan perairan harus dikurangi. Adsorpsi merupakan salah satu cara untuk mengurangi kandungan ion Cu2+ dalam larutan. Adsorpsi ion Cu2+ oleh MCM-48-NH2 dipelajari dengan variasi waktu kontak, pH, dan konsentrasi dari Cu2+. Isotermal Langmuir dan Freundlich digunakan untuk mempelajari isotermal adsorpsi Cu2+ oleh MCM-48-NH2. Hasil penelitian menunjukkan bahwa adsorpsi Cu2+ oleh MCM-48-NH2 lebih sesuai dengan isotermal adsorpsi Langmuir. Nilai kapasitas adsorpsi Cu2+ oleh MCM-48-NH2 adalah 0,52 mmol g-1.Kata Kunci : Adsorpsi, MCM-48-NH2, Cu2+, isotermal Cu2+ ion is an element harmful if contaminated into the environment. Therefore, its presence in the aquatic environment must be reduced. Adsorption is one method to reduce thecontent of Cu2+ ion in solution. Adsorption of Cu2+ ion by MCM-48-NH2 was studied with variation of contact time, pH, and concentration of Cu2+ ion. Langmuir and Freundlich models were used to study the adsorption isotherm of Cu2+ by MCM-48-NH2. The result showed that adsorption of Cu2+ by MCM-48-NH2 more suitable with Langmuir models. The adsorption capacity of Cu2+ by MCM-48-NH2 was 0.52 mmol g-1

    Penentuan Konstanta A dan K dalam Persamaan Mark-Houwink- Sakurada (MHS) untuk Menentukan Massa Molekul Poli (Asam Laktat) Diol

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    Poli(asam laktat) diol (PLA-OH) telah disintesis melalui reaksi polimerisasi kondensasi asam laktat dan 1,4-butanadiol. Berat molekul rata-rata (Mn, Mw, dan Mz) PLA-OH ditentukan dengan analisis menggunakan Gel Permeation Chromatography (GPC). Viskositas intrinsiknya diukur pada konsentrasi 0,2 g/dL dan temperatur 298 K menggunakan pelarut kloroform. Melalui metode numerik berhasil ditentukan nilai a dan K dalam persamaan Mark- Houwink-Sakurada untuk PLA-OH, yaitu [η] = 3,532 x 10-4Mv 0,628 = 3,532 x 10-4qMHS 0,628 = 3,415 x 10-4Mw 0,62

    Adapted MMSE and TYM cognitive tests: how much powerful in screening for Alzheimer�s disease in Iranian people

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    Alzheimer�s disease (AD) is a major global health priority and providing an efficient way for early diagnosis of people developing dementia is important. The Mini-Mental State Examination (MMSE, total score = 30) and Test Your Memory (TYM, total score = 50) are widely used as screening tests for cognitive function. In the present study 174 subjects including healthy people (CON group) and those having Alzheimer�s disease (AD group) were introduced to MMSE and TYM cognitive tests adjusted to Iranian population. Sensitivities and specificities with optimal cut-off scores, area under curve (AUC), positive predictive value (PPV) and negative predictive value (NPV) were measured for both tests. The MMSE scores of the CON and AD groups were 23.77 ± 0.327 and 10.88 ± 0.762, respectively. The TYM scores were 44.32 ± 0.389 and 14.37 ± 1.368 in the CON and AD participants, respectively. Findings in the MMSE test were: AUC = 0.962, optimal cut-off score = 18.5, sensitivity = 0.90 and specificity = 0.96. Values in the TYM test were: AUC = 0.991, optimal cut-off score = 31, sensitivity = 0.90 and specificity = 1. We found no correlation between the cognitive performance and age in the CON group but a positive correlation in the AD patients. On the other hand, t-test analysis indicated that achievement of the test scores are significantly sex dependent, with more scores attained by the females. Taken together, in regard to correct classification rate (CCR); the TYM test seems to be more appropriate for cognitive screening in our study. However, considering an analogous AUC, both tests are comparable and have high sensitivity and specificity for discriminating between people with and without AD. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group

    Dinamika Akumulasi Kadmium Pada Tanaman Kangkung Darat (Ipomoae reptans Poir)

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    J. Akta Kimia Indonesia 2(1) 2009One heavy metal, which is potential as pollutant, is cadmium that has been\ud accumulated in soil and sediment. Although, cadmium is non essential element for plants, it\ud is easily adsorbed and accumulated by various plants. The negative effect of cadmium on\ud plants is that it can prevent the absorption of nutrition so that the plant growth will be\ud inhibited and then the plant will die. Therefore, it is necessary to reduce the concentration of\ud cadmium to be used as good growth media. Several methods of heavy metal accumulation,\ud such as physical, chemical and biological methods, have been used, but the three methods\ud have been considered as less effective methods. The use of plants to accumulate heavy metals\ud in polluted soil is considered as a good method because the method is a safe method and can\ud increase the soil fertility. In this research, accumulation of cadmium has been conducted by\ud using Ipomeae reptans Poir. Result showed that the highest concentration that can be\ud accumulated by I. reptans Poir was 3317.68 mg/kg of dried mass with the plantation time of\ud 21 days. The increase of concentration in the growth media increased the cadmium\ud concentration accumulated. The high accumulation of cadmium showed that I. reptans Poir is\ud a hyperaccumulator plant for cadmium. The bioconcentration value was higher than 1,\ud whereas the translocation factor was lower than 1 indicating that the accumulation\ud mechanism was phytostabilization

    Does this case hold the answer to one of the worse types of pain in medicine--that of loin pain haematuria syndrome (LPHS)

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    A patient with loin pain haematuria syndrome suffering chronic throbbing pulsing pain overlaid with prolonged periods of incapacitating colic and overnight vomiting was presented 10 months following diagnosis. Ultrasound was normal. No renal or ureteral stones, or filling defects were seen on CT. At cytoscopy, bladder and urethra were normal, and bloody urine effluxed from the left ureteric orifice. The ureters were normal at diagnosis, and developed new abutting non‐penetrating calcifications by 8 months. Pain episodes of complete incapacitating intensity of 2–4 h duration were reduced to 10 min with 5 mg crushed tadalafil administered at onset. If tadalafil was delayed to after onset, the original course of agony resulted. Daily tadalafil reduced loin pain intensity, but not the exacerbations. Tadalafil efficacy may indicate that the pain exacerbations are due to spasm of ureter smooth muscle. 5 mg tadalafil taken at onset alleviated severe loin pain exacerbations in this case of loin pain haematuria syndrome

    Production, Characterization, and Toxicity Test of L-asparaginase from Vibrio alginolyticus Bacterial Symbiont of Green Algae Caulerpa lentillifera

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    L-asparaginase is an enzyme that can be used as an anticancer therapeutic agent. This study aimed to optimize fermentation time for production, optimization, and to test the toxicity of L-asparaginase from Vibrio alginolyticus (V. alginolyticus) bacterial symbiont of green algae Caulerpa lentillifera (C. lentillifera). The activity of L-asparaginase enzyme assay and the toxicity test were done by using the Nessler method and the Brine Shrimp Lethality Test (BSLT) method respectively. The results show L-asparaginase with 66 hours of fermentation time indicates the highest enzyme activity. L-asparaginase mentioned has an optimum enzyme activity of 17.99 U/mL for 30 minutes of incubation time at 37 °C, and pH 7.5. The BSLT results show LC50 value of 17.83 μg/mL indicating the enzyme is bio-toxic with high-level toxicity, which can continue for cytotoxicity tests on cancer cells

    Investigating and validation numerical measures of corneal topographic data in LASIK surgery outcome using wavelet transform

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    In this paper we have approached to new method for analyzing the merit of LASIK operation using multiscalar analysis of discrete corneal topographic height data and transform it into a space-scale space using wavelet analysis technique, and to demonstrate the clinical applicability of these computations in the post-LASIK cornea. Forty patients who were candidate for LASIK operation were selected and seen preoperatively and their corneal topographic images were achieved. Then 6 weeks after operation, patients were assessed using corneal topographic analysis (TMS-1), subjective refraction, and the best-corrected visual acuity (VA). After that, Two-dimensional biorthogonal wavelets with the order 6.8 at the scales j=4 revealed the following parameters: root-mean square (RMSDEV) and mean absolute (MEANDEV) deviation and maximum absolute height of the peaks or pitches (MAXPEAK) relative to the reference surface specified with the approximation component of scale j=4. It has shown that MEANDEV and MAXPEAK were correlated with the VA at the follow-up. ©2006 IEEE
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