Polyamide 4 (PA4) is a biobased and biodegradable polyamide. The high hydrogen bond density of PA4 bestows it with a high melting point that is close to its thermal decomposition temperature, thereby ...limiting the melt processing of PA4. In this study, PA4 was blended with polyamide 6 (PA6) and further modified with copolyamide 4/6 (R46). The effects of composition on the crystallization behavior of the blends were studied. The results demonstrated that the binary PA4/PA6 (B46) and ternary PA4/PA6/R46 (B46/R46) blends formed two crystalline phases (PA4- and PA6-rich phases) through crystallization-induced phase separation. With increasing PA6 content, the thermal stability and crystallinity of the B46 blend increased and decreased, respectively, and the contribution of PA6 toward the crystallization of the PA4-rich phase diminished. Molecular dynamics simulations showed the molecular chain orientation of the B46 blends well. The melting points, crystallinities, and grain sizes of the B46/R46 blends were lower than those of the B46 blends. The crystallization of the PA4-rich phase was restrained by the dilution effect of molten-state PA6, and the nucleation and crystallization of the PA6-rich phase were promoted by the presence of crystallized PA4. The B46 blends with 30–40 wt% PA6 had the best mechanical properties.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We applied a multiscale approach coupling dissipative particle dynamics method with a drift-diffusion model to elucidate the photovoltaic properties of multiblock copolymers consisting of alternating ...electron donor and acceptor blocks. A series of hierarchical lamellae-in-lamellar structures were obtained from the self-assembly of the multiblock copolymers. A distinct improvement in photovoltaic performance upon the morphology transformation from lamella to lamellae-in-lamella was observed. The hierarchical lamellae-in-lamellar structures significantly enhanced exciton dissociation and charge carrier transport, which consequently contributed to the improved photovoltaic performance. On the basis of our theoretical calculations, the hierarchical nanostructures can achieve much enhanced energy conversion efficiencies, improved by around 25% compared with that of general ones, through structure modulation on the number and size of the small-length-scale domains via the molecular design of multiblock copolymers. Our findings are supported by recent experimental evidence and provide guidance for designing advanced photovoltaic materials with hierarchical structures.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Using dissipative particle dynamics simulation, structural evolution from concentric multicompartment micelles to raspberry-like multicompartment micelles self-assembled from linear ABC triblock ...copolymers in selective solvents was investigated. The structural transformation from concentric micelles to raspberry-like micelles can be controlled by changing either the length of B blocks or the solubility of B block. It was found that the structures with B bumps on C surface (B-bump-C) are formed at shorter B block length and the structures with C bumps on B surface (C-bump-B) are formed at relative lower solubility of B blocks. The formation of B-bump-C is entropy-driven, while the formation of C-bump-B is enthalpy-dominated. Furthermore, when the length of C blocks is much lower than that of B blocks, an inner-penetrating vesicle was discovered. The results gained through the simulations provide an insight into the mechanism behind the formation of raspberry-like micelles.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
A supercritical suspended abrasive water jet with dual inputs of pressure and heat is proposed to improve the cutting performance of the conventional suspended abrasive water jet in deep-sea ...environments. The paper studies the flow and kinetic characteristics of the supercritical suspended abrasive water jet. The CFD simulation method is proposed to investigate these characteristics by integrating a programmed database of supercritical water material properties with Ansys Fluent. The simulation and comparison show that abrasive particle density, abrasive particle size, inlet pressure, and water temperature affect the acceleration process of the abrasive particles. At the nozzle outlet, the velocity of the abrasive particles reaches over 95% of the supercritical water velocity. With the proposed supercritical abrasive water jet, the jet velocity is increased by 192.2% to 402.40 m/s compared to the conventional suspended abrasive water jet, reducing the amount of water used by 67.7% at a specified temperature of 773.15 K. Correspondingly, the medium kinetic energy is increased by 177.7% and the medium kinetic energy ratio is 2.78. The particle kinetic energy is increased by 723.2% and the particle kinetic energy ratio is 8.23.
Concomitant malignant tumors and pregnancy present many difficult questions to both clinicians and patients. Due to no specific guidelines, each aspect of clinical management requires special ...considerations. This current report presents a rare case of a 38-year-old pregnant woman at gestational age 33 weeks with complaints of weakness of her right limbs for 2 weeks. After successive cesarean section and craniotomy, a diagnosis of lung large cell neuroendocrine carcinoma (LCNEC) metastatic to the brain was eventually made. Next generation sequencing (NGS) showed ALK-EML4 gene fusion. Immediately afterwards she was started on the targeted therapy with the ALK inhibitor alectinib. Ten months later, all known lesions exhibited a rapid regression, and no new brain metastases were found. Consequently, the therapeutic effect was considered as a partial response. Then, we review the previous literature using PubMed on maternal malignant brain tumors diagnosed during pregnancy, or lung LCNEC associated with ALK fusion, or ALK inhibitors treatment among the pregnant women, eventually, and discuss the concerns of dealing with these patients.
Dysregulation of cell cycle progression (CCP) is a trait that distinguishes cancer from other diseases. In several cancer types, CCP-related genes serve as the primary risk factor for prognosis, but ...their role in cutaneous melanoma remains unclear.
Data from cutaneous melanoma patients were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Using a Wilcoxon test, the level of CCP-related gene expression in cutaneous melanoma patient tissues was compared to that in normal skin tissues. Logistic analysis was then utilized to calculate the connection between the CCP-related genes and clinicopathological variables. The important functions of the CCP-related genes were further investigated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and single-sample Gene Set Enrichment Analysis (ssGSEA). Univariate and multivariate Cox analyses and Kaplan-Meier analysis were used to estimate the association between CCP-related genes and prognosis. In addition, using Cox multivariate analysis, a nomogram was constructed to forecast the influence of CCP-related genes on survival rates.
High expression of CCP-related genes was associated with TNM stage, age, pathological grade, and Breslow depth (P < 0.05). Multivariate analysis demonstrated that CCP-related genes were an independent factor in overall survival and disease-specific survival. High levels of gene expression originating from CCP were shown by GSEA to trigger DNA replication, the G1-S specific transcription factor, the mitotic spindle checkpoint, and the cell cycle. There was a negative association between CCP-related genes and the abundance of innate immune cells. Finally, we revealed that knockdown of cell division cycle-associated gene 3 (CDCA3) significantly suppressed the proliferation and migration ability of cutaneous melanoma cells.
According to this study, CCP-related genes could serve as potential biomarkers to assess the prognosis of cutaneous melanoma patients and are crucial immune response regulators.
The relationship between the breakup of eastern Gondwanaland and the Kerguelen plume activity is a subject of debate. The Cona mafic rocks are widely exposed in the Cona area of the eastern Himalaya ...of south Tibet, and are studied in order to evaluate this relationship. Cona mafic rocks consist predominantly of massive basaltic flows and diabase sills or dikes, and are divided into three groups. Group 1 is composed of basaltic flows and diabase sills or dikes and is characterized by higher TiO
2 and P
2O
5 content and OIB-like trace element patterns with a relatively large range of
ɛNd(
T) values (+
1.84 to +
4.67). A Group 1 diabase sill has been dated at 144.7
±
2.4 Ma. Group 2 consists of gabbroic sills or crosscutting gabbroic intrusions characterized by lower TiO
2 and P
2O
5 content and “depleted” N-MORB-like trace element patterns with relatively higher, homogeneous
ɛNd(
T) values (+
5.68 to +
6.37). A Group 2 gabbroic diabase dike has been dated at 131.1
±
6.1 Ma. Group 3 basaltic lavas are interbedded with the Late Jurassic–Early Cretaceous pelitic sediments; they have compositions transitional between Groups 1 and 2 and flat to slightly enriched trace element patterns. Sr–Nd isotopic data and REE modeling indicate that variable degrees of partial melting of distinct mantle source compositions (enriched garnet–clinopyroxene peridotite for Group 1 and spinel-lherzolite for Group 2, respectively) could account for the chemical diversity of the Cona mafic rocks. Geochemical similarities between the Cona mafic rocks and the basalts probably created by the Kerguelen plume based on spatial–temporal constraints seem to indicate that an incubating Kerguelen plume model is more plausible than a model of normal rifting (nonplume) for the generation of the Cona mafic rocks. Group 1 is interpreted as being related to the incubating Kerguelen plume–lithosphere interaction; Group 2 is likely related to an interaction between anhydrous lithosphere and rising depleted asthenosphere enriched by a “droplet” originating from the Kerguelen plume, while Group 3 may be attributed to thermal erosion resulting in the partial melting of lithosphere during the long-term incubation of a magma chamber/pond at a shallow crustal level. The Cona mafic rocks are probably related to a progressively lithospheric thinning beneath eastern Gondwanaland from 150–145 Ma to 130 Ma. Our new observations seem to indicate that the Kerguelen plume may have started its incubation as early as the latest Jurassic or earliest Cretaceous period and that the incubating Kerguelen plume may play an active role in the breakup of Greater India, eastern India, and northwestern Australia.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Changes in blood composition are often closely related to physiological and pathological lesions in the body, and the detection of cells can help early diagnosis, treatment and prognosis. A ...microfluidic chip for cell detection was developed based on pneumatic microvalve and micropump, whose main functions include quantitative shunting, micro mixing with large volume ratio, impedance test and absorbance test, etc. The overall structure includes a cover plate, a middle layer and a substrate. The cover plate and the substrate were made of the borosilicate glass, and the middle layer was fabricated with organic polymer PDMS. The mixing performance of inner ribbed mircomixer and the influence of key parameters on the performance were investigated. The simulation results show that the inner ribbed micromixer has excellent mixing performance.
Full text
Available for:
BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
In the present work, we designed a multicompartment gel by taking advantage of the ABC graft copolymer with a solvophilic A backbone and solvophobic B and C grafts. The mechanical properties of such ...designed gels were investigated by a combination of dissipative particle dynamics simulation and a nonequilibrium deformation technique. The extensional moduli of multicompartment gels were found to be dependent on polymer concentration and architectural parameters of the graft copolymers (the sequence of graft arms and the position of the graft points). The graft copolymer solutions undergo a sol–gel transition as the polymer concentration increases. This leads to an abrupt increase in the extensional modulus. The studies also revealed that the multicompartment gels of graft copolymers exhibit higher extensional moduli than those of nonmulticompartment gels of graft copolymers and triblock copolymer gels. The position of graft points plays another important role in determining the extensional moduli of the multicompartment gels. The effects of graft positions on the gel modulus were found to be associated with the bridging fraction of graft copolymer chains. The results gained through the present work may provide useful guidance for designing high-performance gels.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
As a key piece of equipment in underwater production system, a reliability study of deep-sea connectors has important theoretical significance and engineering value for increasing fault-free ...operation time, improving engineering safety, and reducing maintenance costs. However, the diverse failure modes of connectors and the lack of high-quality and credible reliability data can lead to biased analysis outcomes. To tackle this problem, this study aims to establish a reliability model for deep-sea horizontal clamp connectors. Based on the actual engineering background, a fault tree model for deep-sea horizontal clamp connectors is developed, and the distribution types of bottom events are analyzed concerning the failure mechanism. To enhance the model’s credibility, a multi-source information approach is employed, combining prior product information, expert experience, and design information to quantitatively solve the reliability probability of the connector. The expert experience is quantified using the fuzzy quantitative analysis method, while the design information is estimated by developing a corrosion prediction model combined with grey theory. Thus, the reliability assessment of deep-sea horizontal clamp connectors is completed. Factory Acceptance Test (FAT) is performed on the improved connectors, and the closed-loop work of reliability analysis is completed.
PDF
