Nano/micro polystyrene (PS) beads have found many applications in different fields spanning from drug delivery, bio-diagnostics, and hybrid plasmonics to advanced photonics. The sizes of the PS beads ...are an important parameter, especially in plasmonic and photonic experiments. In this work, we demonstrate a quick and straightforward method to estimate the diameters of sub-microspheres (0.2 μm to 0.8 μm) using the transmission spectra of a close-packed monolayer of polystyrene beads on glass or quartz substrates. Experimental transmission spectra of the PS monolayers were verified against finite-difference time-domain (FDTD) simulation and showed good agreement. The effects of the substrates on the transmission spectra and, hence, the accuracy of the method were also studied by simulation, which showed that common transparent substrates only cause minor deviation of the PS bead sizes calculated by the proposed method.
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•6 compounds were isolated from Polygala aureocauda by chromatographic methods.•4 new and 5 known compounds were identified by analyses of NMR and MS spectra.•Cytotoxic effects of ...compounds towards A549 and MCF7 cancer cells.•Inhibitory effects of compounds on NO overproduction in RAW264.7 cells.
Polygala aureocauda Dunn. (Polygalaceae) has been widely used in Vietnamese traditional medicine for the treatment of hepatitis, nephritis, sonasthenia, anaemia, back pain, and knee fatigue. Chemical investigation of a methanol extract of P. aureocauda roots resulted in the isolation of four new oleanane triterpenoid saponins (polyaureosides A–D) and two known ones (polygalasaponin XLVIII and arilloside A). Their structures were elucidated by comprehensive spectroscopic methods, including 1D and 2D NMR and mass spectra. Among the isolates, arilloside A showed a modest anti-inflammatory effect through inhibiting NO overproduction in LPS-stimulated RAW264.7 macrophages, with an IC50 value of 47.4 μM.
The Painted Wolf Snake, Lycodon pictus, was recently described based on the type series from Trung Khanh and Ha Lang districts in Cao Bang Province, northern Vietnam. Herein, we report new findings ...and a range extension of the recently described species. One individual was collected close by the type locality, in Ha Lang District, Cao Bang Province, Vietnam and another one in Nonggang National Nature Reserve, Longzhou County, Guangxi Zhuang Autonomous Region, China, approximately 60 km apart from the type locality. Both specimens generally accorded with the morphological diagnosis of L. pictus provided in the original description. Molecular analyses supported the morphological findings: the newly collected specimens were approximately 0.3-0.9% (cyt b) genetically divergent from those of the type series. Molecular analyses also revealed that the holotype of L. pictus, for which no sequences were available so far, showed, based on the results of a formalin protocol, about 0.9-1.3% differentiation from the remaining type series, 0.5% from the new record from Cao Bang and 0.9% from the new record from China. Based on the morphological and molecular findings, we herein present the first country record of L. pictus from China, with a detailed morphological description of the specimen from Nonggang National Nature Reserve and slightly extend the original diagnosis of the species.
Four new 6,6,5-tricyclic terpenoids, named rhabdaprovidines D-G (1–4), were isolated from the Vietnamese sponge Rhabdastrella providentiae. The structures of 1–4 were elucidated by extensive analysis ...of HR-ESI-MS and NMR spectroscopy. The absolute stereochemistry of compounds 3 and 4 were determined by both experimental and theoretical calculated circular dichroism (CD) spectra. Compounds 1, 2, and 4 contained trans-syn-trans 6,6,5-tricyclic nucleus meanwhile compound 3 possessed trans-syn-cis ring junction. Compound 4 displayed novel structure by the presence of five rings and nine chiral carbon centers in the isomalabaricane triterpene backbone.
The dyslipidemia associated with obesity plays a major role in the development of atherosclerosis and cardiovascular disease. Dyslipidemia in childhood can progress in adult stage. APOE is one of the ...most important genes that regulate plasma lipid transport and clearance. The study aimed to assess whether the common APOE polymorphism is associated with lipid profiles and dyslipidemia, and it could be modulated by obesity-related traits (body mass index, waist circumference, hip circumference, and waist-to-hip ratio) in Vietnamese children.
A case-control study was designed including 249 cases with dyslipidemia and 600 controls without dyslipidemia. Dyslipidemia is defined as elevated total or low-density lipoprotein (LDL) cholesterol levels, or low levels of high-density lipoprotein (HDL) cholesterol. Genotype for APOE polymorphism (rs7412 and rs429358) was determined by the polymerase chain reaction and restriction fragment length polymorphism method. The association of APOE genotypes with plasma lipid disorders was tested by binary logistic regression analysis, taking into account the confounding factors of age, sex, residence, province and obesity-related traits.
In comparison with ε3/ε3 carriers, the ε4 carriers had the highest concentration of serum TC and LDL-C in cases and controls (P ≤ 0.001), while ε2 carriers had the lowest. Carriers without TT haplotype had higher serum TC than those with TT haplotype. The ε4 carriers had higher hypoalphalipoproteinemia risk than ε3/ε3 carriers (OR = 2.78, P = 0.02) before and after adjustment for age, gender, residence and obesity-related traits.
The study suggested that the APOE genotype and haplotype significantly associated with plasma TC and LDL-C level in Vietnamese children. The association of APOE genotype with hypoalphalipoproteinemia was independent of obesity-related traits.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Acute renal failure due to primary renal Burkitt lymphoma in children is extremely rare. We report a case with acute secondary renal failure in a 4-year-old boy who presented with abdominal pain, ...anorexia, and vomiting. Abdominal computed tomography scans showed bilateral nephromegaly with multiple hypoenhancing regions. Renal biopsy confirmed Burkitt lymphoma. There was no lymphadenopathy or evidence of other solid organ involvement. The patient was responsive to treatment using the EPOCH-R protocol (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab). Here, we describe the clinical and imaging features associated with this rare entity.
Phytochemical investigation resulted in isolation of one new ursane-type triterpene glycoside, asiaticoside G (
1) and nine known compounds from the leaves of
Centella asiatica. The anti-inflammatory ...activities of the isolated compounds were investigated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Asiaticoside G (
1) potently inhibited the production of nitric oxide and tumor necrosis factor-α with inhibition rates of 77.3% and 69.0%, respectively, at the concentration of 100
μM.
One new ursane-type triterpenoid glycoside, asiaticoside G (
1), five triterpenoids, asiaticoside (
2), asiaticoside F (
3), asiatic acid (
4), quadranoside IV (
5), and 2α,3β,6β-trihydroxyolean-12-en-28-oic acid 28-
O-α-
l-rhamnopyranosyl-(1→4)-β-
d-glucopyranosyl-(1→6)-β-
d-glucopyranosyl ester (
6), and four flavonoids, kaempferol (
7), quercetin (
8), astragalin (
9), and isoquercetin (
10) were isolated from the leaves of
Centella asiatica. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. The structure of new compound
1 was determined to be 2α,3β,23,30-tetrahydroxyurs-12-en-28-oic acid 28-
O-α-
l-rhamnopyranosyl-(1→4)-β-
d-glucopyranosyl-(1→6)-β-
d-glucopyranosyl ester. The anti-inflammatory activities of the isolated compounds were investigated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Asiaticoside G (
1) potently inhibited the production of nitric oxide and tumor necrosis factor-α with inhibition rates of 77.3% and 69.0%, respectively, at the concentration of 100
μM.
Bột sấy phun cao chiết trâm vỏ đỏ (Syzygium zeylanicum (L.) DC.) là sản phẩm giàu polyphenol, có hoạt tính kháng oxy hóa và kháng đái tháo đường in vitro cao. Nghiên cứu này nhằm mục đích đánh giá ...động học của quá trình suy giảm hàm lượng polyphenol và hoạt tính sinh học của bột sấy phun cao chiết Trâm vỏ đỏ. Nghiên cứu được thực hiện trong điều kiện kích thích ở nhiệt độ 40 và 60°C, và độ ẩm tương đối là 75 và 90% trong 50 ngày. Kết quả cho thấy, tốc độ suy giảm hàm lượng polyphenol và hoat tính sinh học của bột sấy phun cao chiết Trâm vỏ đỏ phụ thuộc vào nhiệt độ và độ ẩm bảo quản. Bột sấy phun bảo quản ở điều kiện 40°C và độ ẩm tương đối thấp (75%) giữ được các hoạt tính sinh học ổn định hơn, với thời gian bán rã và suy giảm 90% hoạt tính lần lượt là 346,57 ngày và 1.151,29 ngày; hệ số nhiệt động (Q10) là 1,5 và năng lượng kích hoạt (Ea) là 35.125,4 J mol-1. Sự phân hủy của hàm lượng polyphenol tuân theo mô hình bậc nhất và hằng số phân hủy nằm trong khoảng 0,002 – 0,006 ngày−1.
Three new constituents (1-3) were isolated from the whole plant of Balanophora laxiflora. Their chemical structures were elucidated by extensive analysis of high-resolution electrospray ionization ...mass spectrometry and nuclear magnetic resonance spectroscopy. Absolute configurations of new compounds were determined by circular dichroism spectra and modified Mosher’s method. The isolated compounds weakly inhibited on both NO production and COX-2 mRNA expression in RAW264.7 macrophages.
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