The Microstructure and Mechanical Properties of Si3N4f/BN/SiBCN Microcomposites Fabricated by the PIP Process.

SiBCN ceramics based on SiC, BN and Si3N4 structures have good comprehensive properties such as high-temperature resistance, oxidation resistance, creep resistance and long life, which makes it one of the very promising ceramic material systems in military and aerospace fields, etc. In this study, SiBCN ceramics, as well as Si3N4f/BN/SiBCN microcomposites, were prepared by a polymer infiltration pyrolysis method using PBSZ as the polymer precursor. The PBSZ was completely ceramized by pyrolysis at 900 °C. The weight loss and elemental bonding forms of the products after the pyrolysis of the precursors hardly changed from 600 °C to 900 °C. After pyrolysis at 600 °C for 4 h and using the BN coating obtained from twice deposition as the interfacial phase, a more desirable weak interface of fiber/matrix with a binding strength of 21.96 ± 2.01 MPa can be obtained. Si3N4f/BN/SiBCN ceramic matrix microcomposites prepared under the same pyrolysis conditions have a relatively good tensile strength of 111.10 MPa while retaining a weak interface between the fibers and the matrix. The results of the study provide more theoretical and methodological support for the application of new composite structural ceramic material systems.

Verification of blood flow path reconstruction mechanism in distal sigmoid colon and rectal cancer after high IMA ligation through preoperative and postoperative comparison by manual subtraction CTA.

INTRODUCTION: We aimed to investigate manual subtraction computed tomography angiography (MS-CTA) to further confirm the distribution and classification of LCA (left colic artery) ascending/descending branches, then observe the postoperative blood flow path to illustrate how the above branches evolved to postoperative blood path. MATERIAL AND METHODS: 89 patients with distal sigmoid and rectal cancer were referred in our observation and underwent MS-CTA between June 2020 and March 2022. We classified the distribution of LCA and confirmed whether there exists AMCA (accessory middle colic artery). Then we planned blood flow path based on the classification of LCA branches before operation. High ligation was applied in regular radical surgery. During operation, we carefully protect the bifurcation of ascending and descending LCA. Then we compared the planned blood flow path with the actual postoperative blood flow path to verify the mechanism we proposed previously. RESULTS: Of 89 patients, 82 cases met our criteria, we summarized 6 distribution pattens of LCA ascending and descending branches. These preoperative pattens are consistent with the inspection during operation. The postoperative blood flow path of 6 pattens is evolved from the above adjacent anastomotic branches and is consistent with the planned blood flow path. We also found 2 cases with IMA stenosis and 1 case with SMA stenosis under pathological condition, and their compensatory blood flow path is in accordance with our theory. The rate of the anastomotic leakage in our study group is relatively low (7.3%). CONCLUSION: MS-CTA could confirm the distribution of LCA and AMCA, display accurate postoperative blood reconstruction path after IMA high ligation, and it further verified the mechanism we proposed previously, which is the proximal anastomotic branches forming new blood flow path from high-pressure area to the low-pressure area. This mechanism might be helpful for performing accurate laparoscopic sigmoid and rectal cancer surgery.

Bioactivity of hamamelitannin, flavokawain A, and triacetyl resveratrol as natural compounds: Molecular docking study, anticolon cancer, and anti-Alzheimer potentials.

In this study, we worked on anticolon cancer effects and anti-Alzheimer's disease with molecular docking studies. Hamamelitannin, flavokawain A, and triacetyl resveratrol compounds showed good inhibitory activities on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. The inhibition effects of flavokawain A, hamamelitannin, and triacetyl resveratrol on AChE and BuChE enzymes were determined spectrophotometrically conforming to Ellman. IC50 values of these enzymes were ranging between 0.95 ± 0.12 and 93.27 ± 8.14 nM for AChE and 5.71 ± 0.77 and 52.10 ± 8.41 nM for BuChE. The inhibitory activities of some chemical compounds such as flavokawain A, hamamelitannin, and triacetyl resveratrol were assessed by performing the molecular docking study in the presence of AChE and BuChE. Also, the features of the ligand-enzyme complex had value of -7.722 kcal/mol for flavokawain A against AChE and -5.530 kcal/mol against BuChE. The molecular docking calculations indicated the probable interactions and their characteristics at an atomic level. Due to the outcomes gained from docking, the affinity of the chemical compounds to the enzymes was considerable. In vitro cell viabilities of flavokawain A, hamamelitannin, and triacetyl resveratrol with various concentrations on SW620, DLD-1, HT29, HCT8, and HCT116 were investigated by MTT assay with Doxorubicin as the control compound.

EGF-functionalized lipid-polymer hybrid nanoparticles of 5-fluorouracil and sulforaphane with enhanced bioavailability and anticancer activity against colon carcinoma.

The present research work describes development of dual drug-loaded lipid-polymer hybrid nanoparticles (LPHNPs) of anticancer therapeutics for the management of colon cancer. The epidermal growth factor (EGF)-functionalized LPHNPs coloaded with 5-fluorouracil (FU) and sulforaphane (SFN) were prepared by one-step nanoprecipitation method. Box-Behnken design was applied for optimizing the material attributes and process parameters. The optimized LPHNPs revealed particle size 198 nm, polydispersity index 0.3, zeta potential -25.3 mV, and drug loading efficiency 19-20.3% for 5-FU and SFN, respectively. EGF functionalization on LPHNPs was confirmed from positive magnitude of zeta potential to 21.3 mV as compared with the plain LPHNPs. In vitro drug release performance indicated sustained and non-Fickian mechanism release nature of the drugs from LPHNPs. Anticancer activity evaluation in HCT-15 colon cancer cells showed significant reduction (p < 0.001) in the cell growth and cytotoxicity of the investigated drugs from various treatments in the order: EGF-functionalized LPHNPs > plain LPHNPs > free drug suspensions. Overall, the research work corroborated improved treatment efficacy of EGF-functionalized LPHNPs for delivering chemotherapeutic agents for the management of colon carcinoma.

Covalent Coupling-Stabilized Transition-Metal Sulfide/Carbon Nanotube Composites for Lithium/Sodium-Ion Batteries.

Transition-metal sulfides (TMSs) powered by conversion and/or alloying reactions are considered to be promising anode materials for advanced lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, the limited electronic conductivity and large volume expansion severely hinder their practical application. Herein, we report a covalent coupling strategy for TMS-based anode materials using amide linkages to bind TMSs and carbon nanotubes (CNTs). In the synthesis, the thiourea acts as not only the capping agent for morphology control but also the linking agent for the covalent coupling. As a proof of concept, the covalently coupled ZnS/CNT composite (CC-ZnS/CNT) has been prepared, with ZnS nanoparticles (∼10 nm) tightly anchored on CNT bundles. The compact ZnS-CNT heterojunctions are greatly beneficial to facilitating the electron/ion transfer and ensuring structural stability. Due to the strong coupling interaction between ZnS and CNTs, the composite presents prominent pseudocapacitive behavior and highly reversible electrochemical processes, thus leading to superior long-term stability and excellent rate capability, delivering reversible capacities of 333 mAh g-1 at 2 A g-1 over 4000 cycles for LIBs and 314 mAh g-1 at 5 A g-1 after 500 cycles for SIBs. Consequently, CC-ZnS/CNT exhibits great competence for applications in LIBs and SIBs, and the covalent coupling strategy is proposed as a promising approach for designing high-performance anode materials.