Tạp chí Phân tích Hóa, Lý và Sinh học

NGHIÊN CỨU XÁC ĐỊNH TỔNG HOẠT ĐỘ PHÓNG XẠ ALPHA, BETA TRONG CÁC MẪU NƯỚC THẢI ĐÃ XỬ LÝ TỪ QUÁ TRÌNH CHẾ BIẾN CÁC LOẠI QUẶNG SA KHOÁNG

Tue, 19 Mar 2024 08:04:02 +0700

The determination of gross alpha and beta activities in waters with the low dissolved solid materials
can be easily done. However, for the treatment of liquid wastes containing high radioactivity from the beach
sand mineral processing, a large amount of chemicals have been introduced to form soluble salts, which are
mainly NaCl, that contributes to the decrease in performance, and in sensitivity of the measurement,
resulting in the inaccurate or even impossible determination of the gross alpha and beta activities. The
method of separating radioactive elements from the interfering salt background by co-precipitation using
BaRa(SO4)2, and Fe(OH)3 was performed in this paper. The study was carried out on treated waste samples
from the beach sand mineral processing. The results showed that the efficiency of the radioactive elements
separation when the alpha activity was from 3.5 Bq/L and the beta from 2 Bq/L reached up to 95% and then
we could easily determine the gross alpha and beta radioactivity in the separated fractions with high
stability and accuracy. Limit of detection with alpha and beta for treated waste water from the beach sand
mineral processing was 0.0074 Bq/L and 0.021 Bq/L, respectively.

NGHIÊN CỨU XÁC ĐỊNH CÁC THÀNH PHẦN HÓA HỌC CỦA HẠT SIM RỪNG PHÚ QUỐC

Hồ Văn Hải, Phùng Thị Tính, Lê Văn Nhân — Tue, 19 Mar 2024 08:06:32 +0700

Rhodomyrtus tomentosa (Aiton) Hassk is a plant species belonging to the family Myrtaceae. It is
widely distributed and used as a rich-nutrient food and a traditional medicine in South and East South Asia
such as China, Thailand, Malaysia, and Vietnam. In Vietnam, the leaf, root, and fruits of R. tomentosa have
been used to nourish the blood system, against diarrhoea, cure stomach ailments, antiinflammatory. The
fruits of this plant are processed into wine, candy, syrup… The objective of the present study was to
investigate the phytochemical constituents of the methanol extract of the seeds of R. tomentosa using gas
chromatography–mass spectrometry (GC-MS). There were 31 phytochemicals detected in the methanol
extract of Rhodomyrtus tomentosa seeds, including: fatty acids and their esters (38.65%); pyrrogallols
(23.43%); terpenes, sterols and other aroma compounds. A variety of bioactive compounds was present in
the seeds of R. tomentosa such as 1,2,3-Benzenetriol (22.33%), 9,12-Octadecadienoic acid (Z,Z)- (19.87%),
n-Hexadecanoic acid (8.09%), Octadecanoic acid (2.96%), Vitamine E (2.94%), γ-Tocopherol (0.89%), γSitosterol (2.03%), Amyrin (1.78%), Cymene(1.45%), 5-Hydroxymethylfurfural (0.86%)…, which
possessed the ability to be antioxidant, antiinfectious, antiinflammatory, anticancer, antifungal, antiviral and
antibacterial, hypoglycemic, lipid-lowering, fat-reducing... This is the basis for developing applied research
using the extract of Rhodomyrtus tomentosa seeds in daily life as well as improving the economic value of
wild Rhodomyrtus tomentosa trees in Phu Quoc island district, Kien Giang province.

NGHIÊN CỨU THIẾT LẬP QUY TRÌNH PHÂN TÍCH PCBs TRONG MẪU TRẦM TÍCH BIỂN BẰNG PHƯƠNG PHÁP SẮC KÝ KHÍ DETECTOR CỘNG KẾT ĐIỆN TỬ (GC-ECD)

Tue, 19 Mar 2024 08:12:39 +0700

Polychlorinated Biphenyls (PCB) is one of 12 groups of Persistent Organic Pollutants (POPs) that the
Stockholm Convention regulates for safe management, emission reduction and progress towards complete
disposal since 2004. The use of PCBs in industry (e.g., capacitors and transformers, heat transfer and antihydraulic agents, explosion-proof additives, in paint resins, long-lasting pesticides, etc.) can lead to their
significant residues in environments such as soil, water and sediment. In this study, PCBs in the marine
sediment samples collected from the coastal area beside Dinh An, Tran De estuaries (Hau River) in Soc
Trang province was determined using gas chromatography with ECD detector. The study on selection of
sediment samples preparation was implemented for getting better recovery efficiency. The established
procedure for PCBs analysis showed that the detection limit of method (MDL) and the quantification limit of
method (MQL) of seven congeners were in the range of 0.051-0.060 µg/kg and 0.168-0.196 µg/kg,
respectively. The recovery was achieved from 70 to 120% with a relative standard deviation (RSD) lower
than 15%, and the relative error was about 10.3% with the analysis of a certified reference material (CRM).
The procedure for analysis of PCBs is thus sufficiently accurate, reliable and applicable to evaluate PCBs in
marine sediment samples. The content of PCBs in the above - mentioned samples ranged from 0.21 ± 0.02 to
57.22 ± 6.40 µg/kg.

THẨM ĐỊNH QUY TRÌNH ĐỊNH LƯỢNG THUỐC CHỐNG TĂNG HUYẾT ÁP AMLODIPINE BESYLATE DẠNG VIÊN NANG BẰNG PHƯƠNG PHÁP HPLC ĐẦU DÒ DAD

Trần Quang Đệ, Lê Hồng Thái, Nguyễn Cường Quốc, Trần Thanh Mến, Nguyễn Hoàng Sơn — Tue, 19 Mar 2024 08:17:21 +0700

The aim of this study was to validate a protocol for the determination of amlodipine besylate in capsules
using the HPLC method with a DAD detector at a wavelength of 237 nm. The HPLC separation was carried
out using a C18 column (25 cm × 4,6 mm; 5 μm) and the mobile phase system was used as CH3OH and
solution pH 3,0 (60:40) belonging to isocratic elution mode. The results of the validation proved that the
method showed good selectivity, linearity with R2
of 0,9997, a low limit of detection (LOD) of 1,27 ppm, a
limit of quantification (LOQ) of 3,8 ppm, an accuracy of 100,02%, and a precision of the method (RSD) of
less than 2%. In particular, the verified method was also applied to determine the amount of amlodipine
besylate in three real samples on the market, and the results indicated that the content of amlodipine
besylate in all three preparations was above 94% and qualified as prescribed by the Vietnam
Pharmacopoeia V.

NGHIÊN CỨU TẠO ĐĨA PHỦ HAPTEN-BSA DÙNG CHO PHÂN TÍCH NHANH DIOXIN BẰNG XÉT NGHIỆM MIỄN DỊCH LIÊN KẾT ENZYME

Tue, 19 Mar 2024 08:20:28 +0700

Dioxin is one of the organic compounds that are difficult to decompose, causing environmental
pollution and long-term effects on human health. The most reliable method for dioxin analysis is highresolution gas chromatography-mass spectrometry (HRGC/HRMS), but requires long analysis time, modern
equipment, and high cost. Currently, immunoassay methods have been used to rapidly detect and screen for
dioxin contamination in food and the environment. In particular, competitive ELISA is a method with high
sensitivity, good signal amplification of low concentrations and can detect many different toxic congeners in
the dioxin group. First, the antigen (hapten-BSA) was immobilized on a plate at 4°C overnight. After that,
ELISA reaction was performed on the hapten-coated wells, at room temperature. The immobilization step of
hapten-BSA onto the plate makes it difficult to analyze in the field, requires strict conditions and prolongs
the analysis time. Therefore, the creation of coated plate with hapten-BSA needs to be investigated. In this
study, coated plate with hapten-BSA was created with a hapten-BSA concentration of 0.5 µg/mL, using 5%
sucrose as a preservative, BSA concentration of blocking buffer is 0.5% and with a TCDD detection
threshold of 10 ppt in 12 month of storage. The successful creation of the coated plate with hapten-BSA
shortens the analysis time to about 4-5 hours, which is convenient for analysis and get results in the field.

ĐÁNH GIÁ SỰ HẤP PHỤ ION Pb2+ TRONG DUNG DỊCH NƯỚC TRÊN VẬT LIỆU THAN BÙN ĐƯỢC HOẠT HÓA

Tue, 19 Mar 2024 08:23:38 +0700

In this study, peat was activated with H3PO4 at a concentration of 2.0 M and dried at 105oC for 6 hours.
The samples after synthesis are characterized by several methods such as EDX, XRD, SEM, BET and
FTIR. The adsorption properties of the materials were evaluated through the removal of Pb2+ ions in
aqueous solution. Material characteristics showed that the activated peat sample had a higher specific
surface area and porosity than the raw peat sample. The study showed that the experimental data of Pb2+
ion adsorption on activated peat were well described according to both Langmuir and Freundlich
isotherm models, however, the Langmuir isotherm model was more suitable. The activated peat material
had a maximum adsorption capacity qm = 33.33 mg/g. In addition, the study also showed that the
adsorption of Pb2+ ions on activated peat follows the pseudo-second-order model. From the above
research results, it shows that the adsorbent material from peat has great potential in remove heavy metal
ions in aqueous solution.

XÁC NHẬN GIÁ TRỊ SỬ DỤNG CỦA PHƯƠNG PHÁP UPLC/MS/MS ĐỂ PHÂN TÍCH HÀM LƯỢNG TINOPAL CBS-X TRONG GẠO

Nguyễn Kiều Hưng, Lê Văn Cường, Nguyễn Thu Hằng, Trần Văn Lương — Tue, 19 Mar 2024 00:00:00 +0700

A method based on ultra high performance liquid chromatography coupled with tandem mass spectrometry
(UPLC/MS/MS) as development for simple and rapid determination of the residues of tinopal CBS - X in
rice products. The sample were extracted by 4 % phosphoric acid in acetonitrile and then analyzed in
multiple reaction monitoring (MRM) mode. The mobile phase was composed of solvent A (water) and
solvent B (acetonitrile). Gradient program was performed as follows: 0 - 0.5 min, 80% A; 0.5 - 4.0 min, 20%
A and at initial condition. Total run time is 8 min. The flow rate was settled at 0.3 ml/min with an injection
volume of 10 μl. Under the optimized conditions, the linear range for tinopal CBS - X is 1.0 – 10 ng/g, the
linear correlation coefficients are more than 0.99. The limits of quantification of tinopal CBS - X are 2.20
ng/g. The recoveries of tinopal CBS - X ranged from 93.50 % - 118.3 % with relative standard deviation
(RSD) between 0.96 – 12.06 %. The method was validated according to the Directive 2002/657/EC and
subsequently applied to 18 samples of rice products.

NGHIÊN CỨU THÀNH PHẦN HÓA HỌC VÀ HOẠT TÍNH SINH HỌC CỦA TINH DẦU LÁ VỐI (CLEISTOCALYX OPERCULATUS ROXB.) TRỒNG Ở TỈNH PHÚ THỌ

Trần Thị Hằng, Quách Thị Thanh Vân, Nguyễn Văn Sơn — Tue, 19 Mar 2024 08:28:45 +0700

The aim of this study was to determine chemical composition, and evaluate the antioxidant and antibacterial
activities of the essential oil from leaves of Cleistocalyx operculatus Roxb. grown in Phu Tho province. The
Gas chromatography-mass spectrometry (GC-MS) analyses of the essential oil of Cleistocalyx operculatus
Roxb. leaves led to the identification of 21 components. Its major constituents were (Z)--ocimene (60.59%),
(E)--ocimene (11.96%), -pinene (9.23%) and myrcene (6,22%). Antibacterial activity assays were
performed on the essential oil using the agar well method. The results indicated that the essential oil
showed antibacterial effects against Staphylococcus aureus, Pseudomonas aeruginosa and Candida
albicans, especially Pseudomonas aeruginosa antibacterial ability was much higher than that of cefotaxime
as an antibiotic. In the DPPH assay, the essential oil exhibited antioxidant activity with EC50 were 13828
g/mL.

ĐÁNH GIÁ THÀNH PHẦN POLYPHENOL VÀ HOẠT TÍNH ỨC CHẾ TYROSINASE CỦA CÁC DỊCH CHIẾT LÁ CALLISIA FRAGRANS

Nguyễn Hoàng Khuê Tú, Nguyễn Lâm Hải My, Trương Huỳnh Anh Vũ — Tue, 19 Mar 2024 08:31:04 +0700

Callisia fragrans (C. fragrans) belongs to the family Commelinaceae and has wide applications in
the pharmaceutical field. The leaves were extracted by distillation in 40% methanol. The volatile extract (M)
was collected, while the extract remaining in the flask was fractionated with the obtained ethyl acetate
extract (Y) and the remaining extract after passing ethyl acetate (B). Total polyphenols (TPCs) of extracts in
(M), (Y) and (B) were determined spectrophotometrically using Folin Ciocalteu reagent, with Gallic acid
used as standard. The TPCs of (M), (Y) and (B) were determined as 4.7 ± 0.22 mg GAE/g, 17.91 ± 0.0031
mg GAE/g, 47.11 ± 0.22 mg GAE/g dry weight, respectively. By liquid chromatography – mass spectrum,
gallic acid and 1-O-(E)-caffeoyl-4,6-di-O-galloyl-β-D-glucopyranose were detected in (B). Furthermore,
tyrosinase inhibition was detected in extract (B) by tyrosinase inhibition assay due to the highest TPC
content, using kojic acid as standard due to its tyrosinase inhibitory ability. Relative inhibition of (B) was
17.29% and IC50 was 64.47 ± 0.06 µg/mL, equivalent to 2/3 the potency of kojic acid. Research has also
succeeded in creating microcapsules containing TPC. The study on C. fragrans contribute to the
pharmaceutical field.

ĐÁNH GIÁ CHẤT LƯỢNG SÂM NON HÀN QUỐC ĐƯỢC NUÔI TRỒNG KHÍ CANH TẠI VIỆT NAM

Tue, 19 Mar 2024 08:34:35 +0700

The objective of this study is to evaluate the growth and functional components of ginseng sprouts
aeroponically grown in Vietnam. One-year-old ginseng roots were used in a controlled-environmental
aeroponic system including, temperature, humidity, light, pH, and EC. The growth characteristics of ginseng
sprouts consisting of plant height, stem length, plant weight, and stem diameter were measured after 30 days
of transplanting. Furthermore, functional components (total saponin, total polysaccharide, and total
flavonoid) in root, leaf and stem were also extracted. Results showed that the plant height and stem length of
ginseng sprouts grown in Vietnam were higher than those grown in South Korea. The content of saponin
and flavonoid in the leaf and stem was higher than that in the root, whereas the content of polysaccharides
in the leaf and stem was lower than that in the root. Additionally, the content of ginsenosides (e.g. Rg1, Re,
Rf, Rb1) in ginseng sprouts grown in Vietnam was lower than those grown in South Korea in both
traditional farming and aeroponical methods.

TỔNG HỢP, TÍNH CHẤT CÁC PHỨC CHẤT CỦA Tb(III), Dy(III), Yb(III) VỚI HỖN HỢP PHỐI TỬ BENZOIC VÀ 2,2’-DIPYRIDINE-N-OXIDE

Nguyễn Thị Hiền Lan, Nguyễn Thị Tố Loan — Tue, 19 Mar 2024 08:37:29 +0700

This paper presents the synthesis of several complexes of Ln (III) (Ln: Tb, Dy, Yb) with mixed ligands
(benzo c and 2,2’-dipyridine-N-oxide). They are represented by the general formula of
Ln(Benz)2(DipyO)(H2O)2 (Ln: Tb, Dy, Yb; Benz-
: Benzoate, D p O: 2,2’-dipyridine-N-oxide). The
characterization of these complexes has been studied by IR, thermal analysis, mass, and emission
spectroscopy approaches. The results from IR spectroscopy suggested that complexes had been synthesized
successfully, and the coordination modes of the ligands to Ln(III) centres had been investigated by IR
spectroscopy. Mass spectroscopy findings showed that the synthesized complexes were monomers and
that they are stable. In addition, thermal analysis indicates that they are all quite stable to heat. The
emission spectra of the Tb(Benz)2(DipyO)(H2O)2 displayed three bands arising from the
5D4 → 7F5 dominant transition located at 545 nm, the weaker 5D4 → 7F6,
5D4 → 7F4 transitions located at
490 and 587 nm, respectively. The emission spectra of the Yb(Benz)2(DipyO)(H2O)2 displayed one band at
452 nm, meaning the 2F5/2→2
I7/2 energy level of Yb3+ was observed. The results of our study demonstrated
that these complexes exhibited room-temperature photoluminescence.

NGHIÊN CỨU TỔNG HỢP VẬT LIỆU XÚC TÁC QUANG CuO/UiO-66-NO2 ỨNG DỤNG XỬ LÝ CHẤT HỮU CƠ TRONG NƯỚC

Trịnh Lê Thiện, Đinh Thị Hiên, Phùng Thị Ngọc, Lê Thanh Sơn, Trịnh Xuân Đại — Tue, 19 Mar 2024 08:40:28 +0700

CuO/UiO-66-NO2 composite photocatalysts were successfully synthesized. The as-fabricated samples were
characterized by XRD, FT-IR, and UV-Vis DRS techniques. The photocatalytic activity of the materials was
evaluated by the decomposition of methylene blue (MB) under visible light. The influence of several factors
such as pH of solution and dosage of the catalyst on the photodegradation was studied. The optimum
conditions for the synthesis of the catalyst were also determined. Under optimal conditions, it was found that
100% of MB was removed due to the adsorption in darkness and the degradation in visible light illumination
within 200 min. The kinetics of the photocatalytic process were investigated and compared with pseudofirst-order and pseudo-second-order. The experiment data revealed that the kinetics of the photodegradation
fitted with the pseudo-first-order model and relatively fitted with the pseudo-second-order.

TỔNG HỢP, TÍNH CHẤT PHÁT QUANG CỦA CÁC PHỨC CHẤT TẠO BỞI Nd3+, Sm3+, Eu3+ VỚI HỖN HỢP PHỐI TỬ SALICYLIC VÀ 2,2’-DIPYRIDINE-N-OXIDE

Nguyễn Thị Hiền Lan, Nguyễn Thị Tố Loan — Tue, 19 Mar 2024 08:42:55 +0700

In this paper, the luminescent properties of three synthesis complexes of Ln (III) (Ln: Nd, Sm, Eu) with mixed
l nds (s l l nd 2,2’-dipyridine-N-oxide) are described. The complexes correspond to their general
formula of Ln(Sal)2(DipyO)(H2O)2 (Ln: Nd, Eu; Sal-
: l l , D p O: 2,2’-dipyridine-N-oxide) and
Sm(Sal)2(DipyO). The products were characterized by IR, thermal analysis, mass, and emission
spectroscopy. The findings from IR spectroscopy suggested that complexes had been synthesized
successfully, in which three of them consisted of neutral monomeric molecules. The thermal analysis
indicated that they were all quite stable to heat. The luminescent spectra of the Eu(Sal)2(DipyO)(H2O)2
displayed five bands arising from the 5D0 –
7F2 dominant transition located at 614 nm, whereas the
weaker 5D0 –
7F1,
5D0 –
7F4 transitions located at 592 and 700 nm, respectively. Notably, the weakest 5D0 –
7F0,
5D0 –
7F3 transitions were located at 579, 652 nm, respectively. The luminescent spectra of the
Sm(Sal)2(DipyO) displayed three weak bands at 561, 598, and 645 nm, arising from 4G5/2 –
6H5/2,
4G5/2 –
6H7/2,
4G5/2 –
6H9/2 transitions. These complexes demonstrated photoluminescence under UV light at room
temperature.

TỔNG HỢP, CẤU TRÚC VÀ KHẢ NĂNG PHÁT HUỲNH QUANG CỦA MỘT SỐ PHỨC CHẤT ZINC(II)-SALOPHEN CHỨA DẪN XUẤT 2- HYDROXY-1-NAPHTHALDEHYDE

Tue, 19 Mar 2024 08:45:59 +0700

Five complexes of Zn(II) were synthesized by reaction between Zn(CH3COO)2.2H2O with 2-hydroxy-1-
naphthaldehyde and the derivations of 1,2-phenylenediamine. Their structures were characterized by IR,
ESI-MS and 1H NMR spectroscopy. The results showed that in these complexes, the molar ratios of Zn(II)
and the ligands are 1:1, Zn(II) is bound to the ligands through O and Nimine. Studies on the optical properties
of the complexes showed that the complexes in solid form emitted luminescence stronger than in solution.
When changing the substituent group on phenylene, the emission wavelengths of the complexes did not
change much, but the emission intensity changed in the order of substituents Br > H > F > Me > Cl (for
solid form) and Cl > Br> F > Me > H (for solution).

TỔNG HỢP, KHẢO SÁT TÍNH CHẤT QUANG VÀ HOẠT TÍNH XÚC TÁC QUANG CỦA VẬT LIỆU NANO CeO2:0,04Sm3+ , xEu3+

Tue, 19 Mar 2024 08:56:34 +0700

In this work, Sm3+/Eu3+
co-dopped CeO2 phosphor was synthesized through sol-gel method combined with
temperature calcination at 600℃. The crystal structure of powders was characterized by X-ray diffraction,
and it revealed that all studied samples were single-phase with the cubic fluorite-type structure and space
group Fm
3
m. The scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS) and
photoluminescence (PL) spectra were employed to characterize the samples. The photoluminescence
measurements displayed that all the samples had excellent optical properties at room temperature. Under
404 nm excitation, the CeO2: Sm3+ exhibited typical peaks at 567, 604, and 653 nm corresponding to
transitions 4G5/2→6HJ (J = 5/2, 7/2, 9/2) of Sm3+. Meanwhile, CeO2:0,04Sm3+, xEu3+ phosphors exhibited
strong orange-red emission both Sm3+ and Eu3+. The photocatalytic performance of CeO2:0,04Sm3+
, xEu3+
nanocomposites was tested under ultraviolet irradiation on an aqueous solution of methylene blue (MB) dye
using an UV-C lamp. The degree of degradation was monitored by absorption spectroscopy. The
photocatalytic degradation efficiency of CeO2:0,04Sm3+
, 0,04Eu3+ was above 95% within only 90 min of
irradiation.

CHẾ TẠO VẬT LIỆU ĐIỆN CỰC DƯƠNG (NH4)0,5V2O5 DẠNG THANH ĐỊNH HƯỚNG ỨNG DỤNG CHO ĐIỆN CỰC DƯƠNG TRONG ẮC QUY NATRI – ION

Tue, 19 Mar 2024 08:59:48 +0700

Sodium-ion batteries (SIBs) have gathered considerable attention as a potential alternative to lithium-ion
batteries (LIBs), due to their abundant sodium resources, cost-effectiveness, and safety. However, a
significant challenge in SIBs development lies in identifying high-performance cathode materials with
exceptional rate capability and long-term cycling stability. This work explores the potential of (NH4)0.5V2O5
as a promising cathode candidate for SIBs. The layered structural (NH4)0.5V2O5 was synthesized by
hydrothermal method with the precursors V2O5, NH3 solution and HCOOH at 200oC for 24 hours. The
structural and morphological properties were investigated by X-ray diffraction (XRD), scanning electron
microscopy (SEM) and Raman scattering spectroscopy. (NH4)0.5V2O5 demonstrated reversible intercalation
of Na+
ion with a specific capacity of 95 mAh.g-1
at rate C/5 in potential 1.5-4 V (vs. Na+
/Na) thus
highlighting its potential as a high-performance SIBs cathode material.

CHẾ VẬT LIỆU NANO CARBON TỪ THAN CỐC ĐỊNH HƯỚNG ỨNG DỤNG LÀM ANODE TRONG PIN Li-ION

Đỗ Trà Hương, Nguyễn Thị Nga, Nguyễn Văn Tú, Nguyễn Quốc Dũng — Tue, 19 Mar 2024 09:07:26 +0700

Successfully fabricated porous carbon (CDC) nanomaterials from coke (CD) by Hummer method. The
fabricated nanomaterials are porous, with an average size of 30 - 40 nm. CDC electrode works well, stably
with capacitance retention of 74.7% after 1000 cycles. The constant current discharge method determined
the CDC specific capacitance to be 118 F/g corresponding to a current density of 0.01 A. The specific
capacitance decreased with increasing current density. CDC electrodes conducted electricity well. The
charge transfer resistance was very small. The results on the electrochemical properties of the material
showed that the energy storage capacity of the CDC material was good and stable.

NGHIÊN CỨU CHẾ TẠO HỆ VI KIM VẬT LIỆU POLYVINYLACOHOL BẰNG PHƯƠNG PHÁP KHẮC LASER TẠO KHUÔN

Đỗ Thị Mỹ Hạnh, Phạm Thu Uyên, Trần Thanh Phương, Nguyễn Thành Dương — Tue, 19 Mar 2024 09:09:38 +0700

Microneedles (MN) offer an attractive, painless, and minimally invasive approach for drug delivery through
the skin. In this study, we describe a method for fabricating MN molds with controlled microstructures.
Microfabrication using laser ablation was employed to create patterns on the surface of PDMS sheets to
obtain MN molds, which were then replicated twice to produce PDMS molds and used with PVA material
for micro-needle fabrication. During the fabrication process, the microstructure of the MN molds was
controlled by varying laser parameters. The resulting MNs produced from these molds had dimensions of
approximately 1500 µm and could withstand forces ranging from 0.77 N to 0.93 N. Additionally, different
concentrations of PVA were investigated to determine the optimal conditions for fabricating micro-needle
systems with suitable mechanical properties. The study also assessed the characteristics of the microneedle
system, such as durability and effective drug delivery capability. The results demonstrated that at a PVA
concentration of 10%, the microneedles exhibited the best characteristics. The findings have shown the
feasibility of using PVA microneedles for drug distribution, offering a promising solution to address the
limitations of conventional drug delivery methods.

NGHIÊN CỨU CHẾ TẠO THIẾT BỊ VI LƯU GIÚP PHÂN LẬP EXOSOME TỪ MÔI TRƯỜNG ĐỒNG NUÔI CẤY TẾ BÀO UNG THƯ VÀ TẾ BÀO THÀNH MẠCH MÁU

Nguyễn Thị Phương Nga, Trịnh Văn Giáp, Nguyễn Thành Dương — Tue, 19 Mar 2024 09:12:41 +0700

The angiogenesis, the formation of new blood vessels, is crucial for nourishing and developing cells as well
as restoring the damaged area. In cancer, angiogenesis plays a crucial role by promoting the formation of
new blood vessels to feed cancer cells. These cells actively release signals that stimulate surrounding tissues
to initiate and facilitate the process of angiogenesis. Exosomes, extracellular vesicles isolated from cancer
cells, have been identified as a precursor for understanding the mechanism of angiogenesis and developing
new cancer treatments. Therefore, the evaluation of exosome formation, properties, and the application of
exosome as anti-angiogenic drugs carrier for cancer treatment has been widely interested. The main
purpose of this research is to fabricate a microfluidics device for co-culturing cancer cells and blood vessel
cells, in order to isolate and identify exosome characteristics and their effects on the development of
HUVEC cells. In this study, we fabricated a microfluidic device that can be cultured simultaneously with
two types of cells from commercially available materials - PMMA machined by laser engraving and PEGDA
hydrogel. The microfluidic device consisted of 3 layers, including 2 layers of PMMA (24 x 50 mm) and a
layer of cover glass. The isolated exosome form HepG2 cells had the average size around 65.4 nm by
dynamic light scatering (DLS) measurement. Further, HUVEC cells can develop faster at a rate of about 2
times with the present of exosomes from HeG2 cells than single cell culture. Thus, the device is a promising
approach to future cancer treatment with wide range of applications.

KHẢO SÁT KHẢ NĂNG TÍCH LŨY ĐỒNG TỪ ĐẤT TRỒNG VÀ NGUY CƠ RỦI RO SỨC KHỎE KHI SỬ DỤNG MỘT SỐ LOẠI THẢO MỘC TRỒNG TRÊN ĐẤT Ô NHIỄM

Lê Thị Thanh Trân, Lê Thị Hà — Tue, 19 Mar 2024 09:14:56 +0700

In this study, the accumulation levels of copper in the biomass of certain herbs, including oregano, celery,
gotu kola, and purple perilla when grown on contaminated copper soil, were investigated. The results
showed that copper had the potential to accumulate in plants, with the highest accumulation in the roots,
decreasing in the stems and leaves. When grown in copper contaminated soil ranging from 50 to 1500 ppm,
the accumulation of copper decreased in the following order: oregano roots (8.28 ÷ 103.05 ppm) > purple
perilla roots (8.14 ÷ 66.98 ppm) > gotu kola roots (6.10 ÷ 39.95 ppm) > celery roots (5.40 ÷ 31.74 ppm) >
oregano stems + leaves (2.59 ÷ 24.02 ppm) > purple perilla stems + leaves (3.56 ÷ 16.45 ppm) > gotu kola
stems + leaves (3.62 ÷ 16.74 ppm) > celery stems + leaves (1.75 ÷ 7.16 ppm). Health risk indices for adults
and children when using these herbs were also assessed. The THQs (Target Hazard Quotients) for copper
increased in the following order: celery < purple perilla < oregano < gotu kola, and THQs for children
were higher than those for adults.

SO SÁNH HẠT NANO SELEN CHẾ TẠO BẰNG BỨC XẠ CHÙM TIA ĐIỆN TỬ VÀ BỨC XẠ GAMMA VÀ ĐỘ ỔN ĐỊNH CỦA CHÚNG

Tue, 19 Mar 2024 09:18:30 +0700

Trong công trình này, các hạt nano selen (SeNPs) được tạo ra bằng cách chiếu xạ sử dụng máy gia tốc
chùm tia điện tử và nguồn gamma Co-60. Các đặc trưng của hạt SeNPs thu được được xác định bằng cách
đo UV-Vis, DLS để xác định phân bố hạt theo kích thước và đo điện thế zeta. DLS cũng được đo ở các thời
gian bảo quản khác nhau (1 – 6 tháng) theo nhiệt độ bảo quản (4 °C và 27 °C). Kết quả thu được chỉ ra
rằng các hạt SeNPs được tổng hợp bằng chùm tia điện tử và chiếu xạ gamma có cùng phạm vi phân bố hạt
theo kích thước. Độ ổn định của hệ hạt SeNPs tạo thành trong pha lỏng bảo quản ở nhiệt độ mát (4 °C) tốt
hơn ở nhiệt độ phòng (27 °C).

PHÁT TRIỂN PHƯƠNG PHÁP XÁC ĐỊNH CHẤT CHỐNG CHÁY CƠ PHỐT PHO Ở MẪU CÁ BẰNG PHƯƠNG PHÁP QuEChERS CẢI TIẾN KẾT HỢP GC-MS/MS

Bui Quang Minh, Phung Thi Anh Tuyet, Pham Thi Phuong, Dao Hai Yen — Tue, 19 Mar 2024 09:22:51 +0700

Chất chống cháy cơ phốt pho được sử dụng rộng rãi như hợp chất ngăn chặn sự cháy trong nhiều lĩnh vực,
đặc biệt là ngành điện – điện tử. Do đó, các hợp chất này dễ dàng phát tán ra môi trường, gây ô nhiễm đất,
nước, không khí và sinh vật. Tuy nhiên, các nghiên cứu phân tích hàm lượng các hợp chất chống cháy cơ
phốt pho ở cá biển còn chưa được quan tâm ở Việt Nam. Bằng việc cải tiến phương pháp chiết QuEChERS,
cụ thể là tối ưu điều kiện hóa hơi dung môi, kết hợp sắc kí khí ghép nối khối phổ hai lần, phương pháp phân
tích trong nghiên cứu này phù hợp để phân tích hàm lượng vết hợp chất chống cháy trong cá biển Việt Nam.
Dung môi hóa hơi dưới dòng khí N2 ở 1°C tối ưu được hiệu suất thu hồi của các chất nằm trong khoảng 82
– 102%. Với phương pháp được phát triển, hiệu suất thu hồi của các hợp chất ở nồng độ 1, 50 và 100 ng/g
lần lượt dao động trong các khoảng 91,3 – 108,2%, 92,8 – 103,7% và 92,4 – 103,7%, giới hạn phát hiện và
giới hạn định lượng của phương pháp lần lượt từ 0,05 đến 0,10 ng/g và từ 0,15 đến 0,30 ng/g, và các giá trị
lệch chuẩn tương đối của độ tái lặp phương pháp đều nhỏ hơn 20%. Phương pháp được ứng dụng để phân
tích trên 15 mẫu cá (thuộc 5 loài, Psettodes erumei, Sillago sihama, Rastrelliger kanagurta, Decapterus
macarellus, Selaroides leptolepis), với hàm lượng OPFR dao động trong khoảng 39,0 – 181,5 ng/g khối
lượng khô. Kết quả phân tích các mẫu cá cho thấy các hợp chất có chứa clo trong cấu trúc có hàm lượng
lớn hơn các hợp chất chỉ chứa các chuỗi hidrocacbon.

THÀNH PHẦN HOÁ HỌC CỦA LÁ LOÀI MỘC LAN TIẾP

Tue, 19 Mar 2024 09:26:28 +0700

Chi Magnolia thuộc họ Magnoliaceae, phân bố ở châu Mỹ và châu Á. Nhiều loài trong chi này có giá trị
chữa bệnh và được đưa vào các bài thuốc dân gian. Mộc lan Tiếp (Magnolia tiepii) là một loài đặc hữu của
Việt Nam, hiện có rất ít các nghiên cứu về thành phần hoá học. Quá trình nghiên cứu hoá sinh thực vật đã
phân lập được năm hợp chất bao gồm (+)-pinorecinol (1), lariciresinol (2), blumenol A (3),
dehydrovomifoliol (4) và eleutheroside B (5) từ dịch chết methanol của lá loài Mộc lan Tiếp. Cấu trúc của
các hợp chất được làm sáng tỏ bằng các phương pháp phân tích phổ cộng hưởng từ (1D, 2D-NMR), phổ
khối lượng (MS), quang phổ lưỡng sắc tròn (CD) và so sánh với các dữ liệu phổ. Đây là các hợp chất lần
đầu tiên được công bố từ loài này.

KHẢO SÁT THÀNH PHẦN HÓA HỌC VÀ HOẠT TÍNH KHÁNG KHUẨN CỦA THÂN VÀ LÁ CÂY MƯỚP ĐẮNG (Momordica charantia L.)

Tue, 19 Mar 2024 09:32:53 +0700

Nghiên cứu này nhằm mục đích bước đầu khảo sát hoạt tính kháng khuẩn của các cao chiết từ thân và lá
cây Mướp đắng, lựa chọn cao chiết có hoạt tính tốt nhất để khảo sát thành phần hóa học nhằm tìm hiểu mối
liên hệ giữa hoạt tính sinh học và cấu trúc hóa học của các hợp chất có trong cây Mướp đắng (Momordica
charantia L.). Kết quả cho thấy cao chiết ethyl acetate thể hiện hiệu quả kháng khuẩn tốt theo phương pháp
khuếch tán đĩa thạch trên các chủng vi khuẩn là tác nhân gây bệnh chính cho các loài thủy sản. Cao chiết
ethyl acetate đều kháng lại 03 dòng vi khuẩn Aeromonas hydrophila, Aeromonas dhakensis, và Vibrio
parahaemolyticus với giá trị MIC ≤ 0,3125 mg/mL. Kết quả bước đầu khảo sát thành phần hóa học cho
thấy, từ cao phân đoạn ethyl acetate của thân và lá cây Mướp đắng, 03 hợp chất đã được phân lập và nhận
danh là 3β,7β,25-trihydroxycucurbita-5, (23E)-dien-19-al (1), protocatechuic acid (2), và afzelin (3). Cấu
trúc hóa học của các hợp chất này được xác định bằng phương pháp phổ NMR và so sánh với các tài liệu đã
công bố. Đồng thời, hợp chất (1) và (3) phân lập được cũng cho hiệu quả kháng khuẩn tốt đối với khuẩn
Aeromonas hydrophila. Những kết quả này cho thấy thân và lá cây Mướp đắng là một dược liệu tiềm năng
chứa các hợp chất thể hiện hoạt tính kháng khuẩn tốt.

NGHIÊN CỨU VI NHŨ TƯƠNG DỊCH CHIẾT CÀ PHÊ XANH ROBUSTA

Tue, 19 Mar 2024 09:37:12 +0700

Nghiên cứu tạo chiết xuất hạt cà phê xanh Robusta bằng phương pháp tạo nhũ tương nano nước-dầu-dung
môi thu được nhũ tương nano nước dầu chứa các chất có hoạt tính sinh học là 2,1% caffeine, tổng axit
chlorogenic là 40%, 1,29% dầu, ngoài ra còn có quinic, ferulic và caffeic axit. Nhũ tương nano đạt kích
thước 100-200 nm, PDI đạt 0,5 và thế zeta 150mV khi có phụ gia chiết chọn lọc là chất hoạt động bề mặt
nhũ tương hoá nhỏ hơn 1,5% tạo vi nhũ tương nano ổn định ở pH 4,5 với mật độ 1,305 g/ml và tổng CGA
cao hơn. Dịch chiết hạt cà phê xanh dạng nhũ tương nano được thử nghiệm hoạt tính chống oxy hoá với kết
quả SC50 là 68,34ppm, có hiệu quả chống lại Gr (-) P. aeruginosa, Gr (+) S. Aureus và mốc F. oxysporum
ở nồng độ ức chế tối thiểu MIC 0,012 - 0,025 g/ml và khả năng gây độc tế bào đối với tế bào Hep-G2 ở
IC50 là 31,5ppm có CS(%) là 16,11%.