In vitro antiplasmodial properties of selected plants of Sabah

The antiplasmodial activity of the crude extracts of thirty plant species collected from Sabah was evaluated using chloroquine-sensitive strain (D10) and chloroquine-resistant strain (Gombak A) of Plasmodium falciparum. Significant activities were observed for the bark extract of Polyalthia insignis (IC50 3.89 and 11.89 µg/ml against Gombak A and D10, respectively), the leaf extracts of Kopsia dasyrachis (4.62 µg/ml against Gombak A) and Litsea elliptibacea (IC50 8.88 µg/ml against Gombak A), as well as the leaf and bark extracts of Neouvaria acuminatissima (IC50 6.90-10.08 and 0.69 µg/ml against Gombak A and D10, respectively), and the bark extract of Polyalthia microtus (IC50 9.0 and 12.12 µg/ml against Gombak A and D10, respectively)

Diversitas dan Distribusi Alga Merah (Rhodophyta) di Perairan Pulau Ternate

Red algae (Rhodophyta) are low-level plants that generally grow attached to certain substrates such as coral, mud, sand, rocks and other massive objects. This type of algae take nutrients from the substrate by diffusion through the walls from its thallus. This alga prefers habitat of clear waters that have substrate base of coral, dead coral, volcanic rocks or massive objects. Red algae can be found in intertidal, subtidal to coastal areas with strong waves and currents as well as in mangrove area. This study aims to determine the diversity and distribution patterns and associations of red algae in seagrass ecosystems and coastal coral reefs of Ternate Island. The method used in this study is a descriptive method with sampling by line-transect quadrat (1x1 meter). The sampling locations were divided into three stations. Data were analyzed descriptively and the number of red algae (Rhodophyta) found at each station was included in a distribution map based on depth and density index. The results showed that the total number of individuals found at the three stations was 33, where ST II dominated with 12 with an average of 3 individuals per depth. Distribution of individuals per depth at ST II was highest at a depth of 10 m with 4 individuals, followed by a depth of 5 and 15 m each with 3 individuals, a depth of 25 m was 1 individual, and no individual was found at 20 m depth. Substrate type at a depth of 10 m was dominated by coral and sandy fractures that could support well the growth and development of red algae.  Alga merah (Rhodophyta) merupakan tumbuhan tingkat rendah yang umumnya tumbuh melekat pada substrat tertentu seperti pada karang, lumpur, pasir, batu dan benda keras lainnya. Salah satu alga yang penting untuk diteliti adalah alga merah (Rhodophyta). Jenis alga ini mengambil nutrisi dari substrat secara difusi melalui dinding thallus-nya sedangkan habitatnya adalah perairan jernih yang mempunyai substrat dasar batu karang, batuan vulkanik dan benda-benda yang bersifat massive yang berada di dasar perairan. Alga merah dapat ditemukan pada daerah intertidal, subtidal sampai daerah tubir dengan ombak besar dan arus deras serta di hutan mangrove. Penelitian ini bertujuan untuk mengetahui diversitas dan pola sebaran serta asosiasi alga merah pada ekosistem lamun dan terumbu karang pesisir Pulau Ternate. Metode yang digunakan pada penelitian ini adalah metode deskriptif dengan pengambilan sampel secara line transek kuadrat (1x1 meter). Lokasi pengambilan sampel dibedakan menjadi tiga stasiun. Data dianalisis secara deskriptif dan jumlah alga merah (Rhodophyta) yang ditemukan pada setiap stasiun di tuangkan dalam peta distribusi berdasarkan data kedalaman serta indeks kepadatannya.  Hasil penelitian menunjukkan bahwa total individu yang ditemukan pada ketiga stasiun adalah sebanyak 33, dimana pada ST II mendominasi dengan jumlah 12 dengan rata-rata perkedalaman adalah 3 individu. Sebaran individu perkedalaman ST II terbanyak pada kedalaman 10 m sebanyak 4 individu, diikuti kedalaman 5 dan 15 m masing-masing adalah 3 individu, kedalaman 25 m sebanyak 1 individu, sedangkan pada kedalaman 20 m tidak ditemukan. Tipe pada kedalam 10 m didominasi oleh patahan karang dan berpasir dimana pada kondisi substrat tersebut dapat mendukung pertumbuhan dan perkembangan alga merah.

Dual effect of thiol addition on fluorescent polymeric micelles: ON-to-OFF emissive switch and morphology transition

YesThe morphology transition from micelles to vesicles of a solution-state self-assembled block copolymer, containing a fluorescent dye at the core–shell interface, has been induced by an addition–elimination reaction using a thiol, and has been shown to be coupled to a simultaneous ON-to-OFF switch in particle fluorescence.EPSRC and the IAS at the University of Warwic

Chloroform Fraction from Methanol Extract of Starfish Acanthaster planci Stimulates Catfish (Clarias sp.) Macrophage Immunomodulatory Activity

Catfish (Clarias sp.) is Indonesia's most important and popular freshwater commodity, widely cultured and intensively grown. This study is aimed to find out the effects of the chloroform fraction from a methanol extract of Acanthaster planci on non-specific immunity in Clarias sp. Thin Layer Chromatography analysis of the methanol extract's chloroform fraction yielded three fractions: FrKl3.1, FrKl3.2, and FrKl3.3. The FrKl3.3 fraction of Acanthaster planci had a significant influence on Phagocytic Activity at doses of 0.1 (54.09 ± 8.99 %), 0.3 (48.16 ± 3.34 %), 0.5 (50.39 ± 5.71 %), and 0.7 mg/kg Body Weight (46.58 ± 0.37 %). At 0.5 mg/kg Body Weight (4.03 ± 1.40 %), the Phagocytic Index of FrKl3.2 was significantly higher than the control. At 0.5 mg/kg Body Weight (38.22 ±1.43 cell 106/ml) and 0.7 mg/kg BW (40.41 ± 1.92 cell 106/ml), the number of leukocytes/white blood cells was significantly higher than the control. Nitroblue Tetrazolium and Total Plasma Protein were not significantly different from the control. Based on the results,  the FrKl3.3 was leading on phagocytic capacity and number of leukocytes

Rapid translocation of nanoparticles from the lung airspaces to the body

Nano-size particles show promise for pulmonary drug delivery, yet their behavior after deposition in the lung remains poorly understood. In this study, a series of near-infrared (NIR) fluorescent nanoparticles were systematically varied in chemical composition, shape, size and surface charge, and their biodistribution and elimination were quantified in rat models after lung instillation. We demonstrate that nanoparticles with hydrodynamic diameter (HD) less than ≈34 nm and a noncationic surface charge translocate rapidly from the lung to mediastinal lymph nodes. Nanoparticles of HD < 6 nm can traffic rapidly from the lungs to lymph nodes and the bloodstream, and then be subsequently cleared by the kidneys. We discuss the importance of these findings for drug delivery, air pollution and carcinogenesis

Designed polyelectrolyte shell on magnetite nanocore for dilution-resistant biocompatible magnetic fluids.

Magnetite nanoparticles (MNPs) coated with poly(acrylic acid-co-maleic acid) polyelectrolyte (PAM) have been prepared with the aim of improving colloidal stability of core-shell nanoparticles for biomedical applications and enhancing the durability of the coating shells. FTIR-ATR measurements reveal two types of interaction of PAM with MNPs: hydrogen bonding and inner-sphere metal-carboxylate complex formation. The mechanism of the latter is ligand exchange between uncharged -OH groups of the surface and -COO(-) anionic moieties of the polyelectrolyte as revealed by adsorption and electrokinetic experiments. The aqueous dispersion of PAM@MNP particles (magnetic fluids - MFs) tolerates physiological salt concentration at composition corresponding to the plateau of the high-affinity adsorption isotherm. The plateau is reached at small amount of added PAM and at low concentration of nonadsorbed PAM, making PAM highly efficient for coating MNPs. The adsorbed PAM layer is not desorbed during dilution. The performance of the PAM shell is superior to that of poly(acrylic acid) (PAA), often used in biocompatible MFs. This is explained by the different adsorption mechanisms; metal-carboxylate cannot form in the case of PAA. Molecular-level understanding of the protective shell formation on MNPs presented here improves fundamentally the colloidal techniques used in core-shell nanoparticle production for nanotechnology applications

IMMUNOSTIMULATORY EFFECT OF FATTY ACID FROM STAR FISH (ACANTHASTER PLANCI) ON LYMPHOCYTE PROLIFERATION IN-VITRO

The aims of this study were to investigate lymphocyte proliferation activity and to identify chemical constituents of active fractions of star fish Acanthaster planci. A. planci was collected from Ternate Island, North Moluccas, extracted with distilled methanol and water, partitioned with gradient chloroform-hexane-methanol-water and fractionated in column chromatography using silica gel and hexane-ethyl acetate-methanol. The active compound had been purified by Thin Layer Chromatography (TLC) and identified by Gas Chromatography-Mass Spectrometry (GC-MS). The lymphocyte proliferation activity was measured based on % Stimulation Index (SI) from sample absorbency and control absorbency. The result showed that the 3 fractions of hexane fraction exhibited lymphocyte proliferation activity. Fraction 1 was able to increase lymphocyte proliferation at 48 hours and 72 hours by 55% (80 µl/ml) and 88% (160 µl/ml) increase, and fraction 2 had 77% (160 µl/ml) and 86% (640 µl/ml) increase. Meanwhile, fraction 3 had 75% (640 µl/ml) and 89% (640 µl/ml) increase. Metabolite analysis of active fraction using GC-MS yielded a number of chemical constituents that was dominated by fatty acid. The study concluded that star fish A. planci from Ternate Island has a potential source of immunostimulator

The relationship between workload and performance of research university academics in Malaysia: the mediating effects of career commitment and job satisfaction

The purpose of this study is to test the relationship between job workload and academic performance among university academic staff in Malaysia. The paper also attempts to discuss and then seek empirical evidence to the two mediational paths (namely, career commitment and job satisfaction) that explain the focal relationship between job workload and academic performance. To test the three proposed hypotheses, the study used cross-sectional data collected from academic staff serving in Malaysian Research Universities (MRUs). The final sample of 191 valid and complete responses was analysed using SmartPLS 3.3.3 to test the hypotheses. Results showed that workload is negatively related to academic staff performance. In addition, job satisfaction mediates workload and academic staff performance linkage. These findings reinforce the importance of job satisfaction as an influencing factor against the deleterious effect of job workload and academic staff performance. The study has shown that, contrary to our expectations, career commitment does not mediate the relation between job workload and academic staff performance. Going forward, this study provides new insights about the effect of job workload on the performance of university academic staff through intervening variables