Display omitted
The first objective of this study was to optimize a supersaturatable self-nanoemulsifying drug delivery system (S-SNEDDS) containing silymarin through the investigation of the single ...and synergistic effect of either SNEDDS or a precipitation inhibitor on dissolution efficiency (DE) of silymarin. The bioavailability and hepatoprotective activity of S-SNEDDS were then compared to those of a branded product (Legalon®, Meda). SNEDDS containing silymarin was developed by titration technique, and Poloxamer 407 was selected as the optimal precipitation inhibitor by using casting film and solvent-shift method. The interaction of silybin (the major active constituent of silymarin) and the polymer was then determined by differential scanning calorimetry, powder X-ray diffractometry (PXRD), Fourier transforms infrared spectroscopy and 1H NMR analysis. The combination of two techniques including SNEDDS and addition of 10% of Poloxamer 407 remarkably increased DE4h (88.28%) compared to the reference product (6.41%). The relative bioavailability of S-SNEDDS versus Legalon® was about 760%. The hepatoprotective activity of S-SNEDDS in CCl4-induced mice was also superior to the commercial product in declining both the levels of serum transaminases (ALT, AST) and lipid peroxidation as well as glutathione and superoxide dismutase (SOD) activities under tested doses calculated as silybin (10, 25 and 50 mg/kg). These biopharmaceutical and pharmacological advantages of S-SNEDDS indicated prospects in the development of a novel product that offers lower strength of silymarin while enhancing therapeutic outcomes.
Nowadays, breast cancer is one of the leading cancers in Vietnam, and it causes approximately 6000 deaths every year. The rate of breast cancer patients was calculated as 26.4/100000 persons in 2018. ...There are 21,555 new cases reported in 2020. However, these figures can be reduced with early detection and diagnosis of breast cancer disease in women through mammographic imaging. In many hospitals in Vietnam, there is a lack of experienced breast cancer radiologists. Therefore, it is helpful to develop an intelligent system to improve radiologists' performance in breast cancer screening for Vietnamese patients. Our research aims to develop a convolutional neural network-based system for classifying breast cancer X-Ray images into three classes of BI-RADS categories as BI-RADS 1 ("normal"), BI-RADS 23 ("benign") and BI-RADS 045 ("incomplete and malignance"). This classification system is developed based on the convolutional neural network with ResNet 50. The system is trained and tested on a breast cancer image dataset of Vietnamese patients containing 7912 images provided by Hanoi Medical University Hospital radiologists. The system accuracy uses the testing set achieved a macAUC (a macro average of the three AUCs) of 0.754. To validate our model, we performed a reader study with the breast cancer radiologists of the Hanoi Medical University Hospital, reading about 500 random images of the test set. We confirmed the efficacy of our model, which achieved performance comparable to a committee of two radiologists when presented with the same data. Additionally, the system takes only 6 seconds to interpret a breast cancer X-Ray image instead of 450 seconds interpreted by a Vietnamese radiologist. Therefore, our system can be considered as a "second radiologist," which can improve radiologists' performance in breast cancer screening for Vietnamese patients.
The aim of this study was to determine combined effect of mineral admixtures namely fly ash, silica fume as an alternative for cement, and fine aggregate including natural whiter sand (NWS) and ...finely ground quartz sand as partial replacement of natural river sand (NRS) on the mechanical properties of ultrahigh performance concrete (UHPC) containing steel fiber. Concrete was produced by replacing NRS with 22% upto 100% of NWS consists of particle sizes of 5 to 1800 µm, simultaneously combined with binding materials like fly ash (20, 30 and 40%) and silica fume (5 to 15%) as a substitute for cement in mixtures containing Dramix® 3D steel fiber 65/35 at 100kg/m3, and water curing temperature variation ranging follow ambient temperature from 28-34°C. The results indicated that the NRS was replaced with 100% NWS of 5...1800 µm fraction by weight of NRS, in UHPC containing 20% of fly ash combined with silica fume at the replacement levels of 5 to 15% contributed to improved mechanical properties. Detailed, compressive strength of UHPC obtained values 122, 128, 117, 115.3, and 118.5 MPa respectively. Similar results were also observed for the splitting tensile strength attained at 11.6, 11.9, 11.5, 10.5, 10.2 MPa, respectively, while flexural strength values range between 18.8 to 25.4 MPa. These values higher than compared to that of the NRS reference specimens without containing NWS at 28 days of curing. The achieved experimental results demonstrated that the addition of locally available NWS can be a good substitute for NRS, and therefore, can be effectively used in construction activities, which in turn reduces the depletion on the NRS resources. Furthermore, utilization of by-product materials reduces the carbon footprint of cementitious composites production as well as environmental pollution concerns.
the article discusses the effect of the complex of active mineral additives consisting of silica and fly ash, and a fine aggregate, including finely ground natural-white quartz sand for partial ...replacement of river sand, on the mechanical properties of high-strength concrete containing steel fiber.
high-strength concrete containing Dramix
3D 65/35 steel fiber in the amount of 100 kg per 1 m
of concrete mixture was suggested where 22% to 100% of river sand was replaced by finely ground white natural sand of the particle size of 5 to 1800 μm and containing the complex of active mineral additives for partial replacement of cement as part of a multicomponent binder, consisting of low-calcium fly ash of thermal power plants and silica and containing, respectively, 20, 30, 40% fly ash and from 5 to 15% silica by weight of the binder.
research results have shown that 100% replacement of river sand with finely ground natural white sand, in concrete containing 20% of the mass as part of a multicomponent binder, fly ash and from 5 to 15% by weight of silica, contributes to the increase of its strength properties: the values of concrete compressive strength after 28 days were in the range from 118.5 to 128 MPa, tensile strength during bending and splitting, respectively, from 18.8 to 25.4 MPa and from 10.2 to 11.9 MPa, which is higher than the strength of concrete samples containing river sand.
the achieved results have demonstrated the efficiency of using finely ground natural white sand as an alternative to river sand for producing high-strength concrete, thus helping to save the river sand resources in Vietnam. The use of fly ash and micro silicon, which are power and metallurgy wastes, as part of a multicomponent binder in order to partially replace cement reduces the carbon footprint in the production of binders and will also have a beneficial effect on environmental protection against industrial waste pollution.
Introduction. The underground structures of the coastal zone in Vietnam are periodically flooded with seawater, which causes corrosion of concrete. Therefore, the aim of the study is to increase the ...corrosion resistance of coastal underground concrete structures by modifying the structure of concrete with a complex of mineral additives obtained mainly from local raw materials, including micro- and nanosilicon, fly ash from thermal power plants and finely ground white quartz sand. In addition, it requires development of a mathematical model describing the processes of mass transfer in conditions of liquid corrosion of concrete underground structures in coastal zone, to assess their durability. Methods. The development of concrete mixtures, the study of their properties and properties of concrete, were carried out in accordance with the requirements of current Russian and Vietnamese standards. Results and Discussion. The results of experimental studies confirmed the possibility of using local raw materials to create modifying additives and obtain corrosion-resistant concretes with high performance. It was found that with an increase in the content of white quartz sand in the concrete mixture, the compressive strength of concrete increased rapidly at an early age of hardening up to 7 days, after which its growth rate gradually decreased. Replacing 60 % of river sand with white quartz sand provided the highest compressive strength, axial tension and flexural tension of concrete, which can be explained by the fact that white quartz sand is finer than river sand, and this increases the density of the concrete structure. In addition, an increase in the density of concrete can be explained by a decrease in water absorption and an increase in resistance to sulfate corrosion with an increase in the content of white quartz sand in the concrete mixture instead of river sand, as well as with the introduction of 1–1.5 % nanosilicon. Conclusions. For the construction of underground structures in the coastal zone of Vietnam, we developed corrosion-resistant concrete compositions based on local raw materials with high strength characteristics and low water absorption. A mathematical model is proposed to solve the problem of determining the mass transfer of Ca2+ ions in the system "concrete structure – moist soil – coastal area" to control the processes of mass transfer during the corrosive destruction of concrete underground structures in coastal zones periodically flooded with seawater, in order to predict their operational durability.
User profiles representing users’ preferences and interests play an important role in many applications of personalized recommendation. With the rapid growth of social platforms, there is a critical ...need for efficient solutions to learn user profiles from the information they shared on social platforms so as to improve the quality of recommendation services. The problem of user profile learning is significantly challenging due to difficulty in handling data from multiple sources, in different formats and often associated with uncertainty. In this paper, we introduce an integrated approach that combines advanced Machine Learning techniques with evidential reasoning based on Dempster-Shafer theory of evidence for user profiling and recommendation. The developed methods for user profile learning and multi-criteria collaborative filtering are demonstrated with experimental results and analysis that show the effectiveness and practicality of the integrated approach. A proposal for extending multi-criteria recommendation systems by incorporating user profiles learned from different sources of data into the recommendation process so as to provide better recommendation capabilities is also highlighted.
Soil erosion substantially implicates global nutrient and carbon cycling of the land surface. Its monitoring is crucial for assessing and managing global land productivity and socio-economy. The ...Zhuoshui River Basin, the largest catchment, in Taiwan is highly susceptible to soil erosion by water due to extremely high rainfall, rugged terrain, easily eroded soil, and intensively agricultural cultivation over the steep land. Hence, this study examines the annual soil erosion rate for 2005, 2011, and 2019 and the average long-term soil erosion and sediment yield (SY) during 2005–2019. Coupling of the Revised Universal Soil Loss Equation (RUSLE) and sediment delivery ratio (SDR) models is implemented using remote sensing and GIS techniques. The soil erosion rate is classified into five classes, namely
mild
(0–10 t ha
−1
year
−1
),
moderate
(10–50 t ha
−1
year
−1
),
moderately severe
(50–100 t ha
−1
year
−1
),
severe
(100–150 t ha
−1
year
−1
), and
very severe
(> 150 t ha
−1
year
−1
). Over one half of the total area is categorized as
moderate
and
moderately severe
classes, and one-third of the whole basin as
severe
and
very severe
classes. Recently,
mild
and
moderate
classes increase, while
moderately severe
,
severe
, and
very severe
decrease. During 2005–2019, the annual soil loss rate ranges from 0.00 to 6,881.88 t ha
−1
year
−1
with an average rate of 122.94 t ha
−1
year
−1
. Among the SDR models, the RUSLE combined with the SDR model with the length and slope gradient of mainstream shows satisfactory sediment yield estimation. Predictably, the downstream receives a massive sediment delivery from all upper streams (246.06 × 10
6
t year
−1
), and the percent bias values for all sub-basins are below ± 39.0%. The study provides a rapid approach to investigate soil erosion and sediment yield, and it can be applied to the other basins in Taiwan. More importantly, information about spatial patterns of soil erosion and SY is critical to establish suitable measures to achieve effective watershed planning and optimize the regional productivity and socio-economy. The proposed approach is potentially to identify risk areas, conduct scenario estimation for management, and perform spatiotemporal comparison of soil erosion, while adjustment in the empirical formulas of the proposed approach may be needed when it is applied to the other regions, especially outside Taiwan.
The B-site oxide mixing technique has been used to fabricate 0.8Pb(Zr
0.48
Ti
0.52
)O
3
–0.2Pb(Zn
1/3
Nb
2/3
)
0.625
(Mn
1/3
Nb
2/3
)
0.375
O
3
(PZT–PZMnN) +
x
wt.% ZnO nanoparticle ceramics, where
...x
= 0.0, 0.20, 0.25, 0.30, 0.35, 0.40, and 0.45. The perovskite PZT–PZMnN +
x
wt.% ZnO solid solution was sintered at 950°C. Presence of tetragonal and rhombohedral phases in the sintered PZT–PZMnN + 0.35 wt.% ZnO compound at room temperature was confirmed by simultaneously investigating the structure, microstructure, and dielectric properties. The largest grain size was exhibited by the PZT–PZMnN + 0.35 wt.% ZnO nanoparticle ceramic near the morphotropic phase boundary. For this composition, small rhombohedral domains with 71° or 108° domain walls were observed around relatively large tetragonal domains with 180° and 90° domain walls. The width of these domains was found to be about 100 nm. The PZT–PZMnN ceramics exhibited the following optimal properties at this ZnO nanoparticle content of 0.35 wt.%: electromechanical coupling factors of
k
p
of 0.60 and
k
t
of 0.46, piezoelectric constant
d
31
of 130 pC N
−1
, mechanical quality factor
Q
m
of 1280, high remanent polarization
P
r
of 30.4 μC cm
−2
, and low coercive field
E
c
of 6.2 kV cm
−1
, making it a promising material for use in high-intensity ultrasound applications.
HER-2/ErbB2/Neu(HER-2), a member of the epidermal growth factor receptor family, is specifically overexpressed on the surface of breast cancer cells and serves a therapeutic target for breast cancer. ...In this study, we aimed to isolate DNA aptamer (Ap) that specifically bind to a HER-2 overexpressing SK-BR-3 human breast cancer cell line, using SELEX strategy. We developed a novel multifunctional composite micelle with surface modification of Ap for targeted delivery of paclitaxel. This binary mixed system consisting of Ap modified pluronic F127 and chitosan could enhance PTX loading capacity and increase micelle stability. Polymeric micelles had a spherical shape and were self-assemblies of block copolymers of approximately 86.22 1.45 nm diameter. PTX could be loaded with high encapsulation efficiency (83.28 0.13%) and loading capacity (9.12 0.34%). The release profile were 29%-35% in the first 12 h and 85%-93% after 12 d at pH 7.5 of receiving media. The IC50 doses by MTT assay showed the greater activity of nanoparticles loaded paclitaxel over free paclitaxel and killed cells up to 95% after 6 h. These results demonstrated unique assembly with the capacity to function as an efficient detection and delivery vehicle in the biological living system.
PDF
