N-Benzylated 5-Hydroxybenzothiophene-2-carboxamides as Multi-Targeted Clk/Dyrk Inhibitors and Potential Anticancer Agents

Numerous studies have reported that Dyrk1A, Dyrk1B, and Clk1 are overexpressed in multiple cancers, suggesting a role in malignant disease. Here, we introduce a novel class of groupselective kinase inhibitors targeting Dyrk1A, Dyrk1B, and Clk1. This was achieved by modifying our earlier selective Clk1 inhibitors, which were based on the 5-methoxybenzothiophene-2-carboxamide scaffold. By incorporating a 5-hydroxy group, we increased the potential for additional hydrogen bond interactions that broadened the inhibitory effect to include Dyrk1A and Dyrk1B kinases. Within this series, compounds 12 and 17 emerged as the most potent multi-kinase inhibitors against Dyrk1A, Dyrk1B, and Clk1. Furthermore, when assessed against the most closely related kinases also implicated in cancer, the frontrunner compounds revealed additional inhibitory activity against Haspin and Clk2. Compounds 12 and 17 displayed high potency across various cancer cell lines with minimal effect on non-tumor cells. By examining the effect of these inhibitors on cell cycle distribution, compound 17 retained cells in the G2/M phase and induced apoptosis. Compounds 12 and 17 could also increase levels of cleaved caspase-3 and Bax, while decreasing the expression of the antiapoptotic Bcl-2 protein. These findings support the further study and development of these compounds as novel anticancer therapeutics

Microstructure and Mechanical Properties of Nitride Coatings on a Type 304 Stainless Steel

本研究以中空陰極放電離子鍍著法及陰極電弧離子鍍著法將氮化物鍍膜如氮化鈦(TiN)、氮化鉻(CrN)及氮化鋁鈦(TiAlN)等材料鍍著於AISI 304不銹鋼基材上，利用X光繞射儀(XRD)、掃瞄式電子顯微鏡(SEM)、歐傑電子能譜儀(AES)、穿透式電子顯微鏡(TEM)並配合能量耗失能譜儀(EELS)進行微結構與化學成分分析。機械性質方面的研究則以上述兩種鍍著技術所被覆之氮化鈦進行拉伸及硬度測試。 由X光繞射結果發現由上述兩種鍍著技術所被覆之氮化物鍍膜皆具有(111)優選方向。由穿透式電鏡橫截面(Cross-section)試片的觀察可以發現氮化物鍍膜具有斜柱狀晶結構(Tapered columnar structure)，在鍍膜與不銹鋼基材界面附近呈現微細晶粒，而隨著鍍膜厚度的增加，在鍍膜表面有最大的晶粒尺寸。此外，由中空陰極放電離子鍍著法所鍍著之鈦介層具有柱狀結構，而由陰極電弧離子鍍著法所鍍著之鈦介層則為等軸晶結構。在鈦介層與不銹鋼基材間存在著鐵鈦介金屬化合物如FeTi及Fe2Ti等相。在中空陰極放電離子鍍著法所鍍著之氮化鈦-鈦雙層鍍膜中，發現氮化鈦的晶粒延續柱狀的鈦晶粒成長。此現象亦存在於陰極電弧離子鍍著法所鍍著之氮化鋁鈦-氮化鈦雙層鍍膜中。另外在氮化鋁鈦鍍層內發現氮化鋁鈦具有週期性7.7 nm的超晶格結構。 機械性質方面以中空陰極放電離子鍍著法鍍著氮化鈦於不銹鋼線上，再利用拉伸試驗進行測試。由實驗結果發現不銹鋼線周圍鍍膜厚度不均且鍍膜破壞的機制與鍍膜厚度有關；在鍍膜厚區呈現週期性的裂紋，而在薄區則有呈現45的裂紋。經由計算結果可知鍍膜與基材間的剪力強度、界面極限剪應力強度及結合強度分別為15.36、9.87及1.06 GPa。 對於陰極電弧離子鍍著系統，針對基材偏壓及基材與靶材距離探討其鍍著參數對氮化鈦鍍膜微結構及硬度的影響。由實驗結果得知在不同偏壓下(-100V至-300V)鍍膜厚度及硬度值隨著距靶材距離減少而增加，其硬度值介於2200 40與1880 10之間。 微粒的產生為陰極電弧離子鍍著製程特有的現象。本研究針對氮化鈦、氮化鉻以及氮化鋁鈦鍍膜中的微粒，以上述之分析儀器加以研究探討。研究結果顯示氮化物鍍膜中的微粒外觀呈現花蕾的形狀，金屬核心位於內部下方的位置，外面包圍著一層氮化物鍍膜。由電子能量耗失能譜分析發現，在氮化鈦微粒中，金屬鈦含氧量高達22 at.%；而外層的氮化鈦則包含有TiN0.26、 -TiN0.3、 Ti2N及TiN等相的存在。在氮化鉻微粒的分析中，金屬鉻含氧量為4.6 at.%；而周圍的氮化鉻層，從內部到微粒表面，氮及氧的含量分別從1.8增加至38 at.%及5.2增加至9.5 at.%。從選區繞射的結果發現外層的氮化物只有CrN相存在。基於上述實驗的結果，提出一個微粒形成的機制，與文獻上認為微粒為純金屬組成有不同的解釋。Nitride coatings of TiN, CrN and TiAlN deposited by hollow cathode discharge ion plating (HCD-IP) and cathodic arc ion plating (CAIP) techniques with or without interlayers ( Ti or Cr ) on a type 304 stainless steel are studied. Microstructure and chemistry of the ion-plated nitride coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Auger electron microscopy (AES) and transmission electron microscopy (TEM) with electron energy loss spectroscopy (EELS). Mechanical properties of the TiN coatings deposited by HCD-IP and CAIP techniques were evaluated by tensile and hardness tests. X-ray diffraction results show that the nitride coatings deposited by either HCD-IP or CAIP techniques have strong (111) preferred orientation. Cross-section TEM observation reveals that the nitride coatings have a tapered columnar structure growing from fine equiaxial grains near the coating-steel interface to large columnar grains near the coating surface. The Ti interlayer deposited by HCD-IP technique has columnar structure, but equiaxial grains exist in the Ti interlayer deposited by CAIP technique. It is also found that the FeTi and Fe2Ti intermetallic compounds were formed between the Ti-steel interface. Good epitaxial relations are observed in the TiN-Ti bilayer deposited by HCD-IP technique and in the TiAlN-TiN bilayer deposited by CAIP technique. The TiAlN coating has a supperlattice structure with periodicity about 7.7 nm. Mechanical properties of HCD ion-plated TiN coatings with non-uniform film thickness on steel wires were evaluated by tensile test. The failure mechanism of the TiN films upon tensile loading is found to be dependent on the coating thickness. Opening mode prevailed in the thick coatings where periodic cracks perpendicular to the tensile axis developed; on the other hand, shearing mode took place in the thin coatings where cracks inclined to the tensile axis by 45. On the basis of the experimental observation and the theoretical calculation, the shear strength of the TiN, the ultimate shear strength and the bonding strength of the TiN-steel interfaces were estimated to be 15.36, 9.87 and 1.06 GPa, respectively. In the CAIP system, two important parameters (substrate bias and specimen-to-target distance) were studied to understand their effects on the microstructure and hardness of the TiN coatings. The results show that the thickness of the TiN coatings increases with decreasing specimen-to-target distance. The hardness ranging from 2200 40 to 1880 10, decreases with specimen-to-target distance for different substrate biases ranging from -100 to -300 V. Formation of macroparticles in the coatings is a characteristic of the CAIP process. Macroparticles of TiN, CrN and TiAlN in the nitride coatings were studied by SEM, plan-view and cross-section TEM with EELS. The results show that most of the macroparticles in arc ion-plated nitride coatings have the shape of a bud, in which the metal locates at the bottom center, and the outerlayer consist of nitride coating. By EELS analysis of the TiN macroparticle, it is found that the core region consists of metallic Ti with high content of oxygen, up to 22 at.%; while the outlayer is composed of a wide variety of titanium nitrides including TiN0.26, -TiN0.3, Ti2N and TiN. In the analysis of the CrN macroparticle, the content of oxygen is 4.6 at.% in the core region of Cr. In the surrounded CrN layer, the atomic concentrations of the nitrogen and oxygen increase from 1.8 to 38 at.% and 5.2 to 9.5 at.% from mid-layer to surface of the macroparticle, respectively. It is only the CrN phase identified by selected area diffraction (SAD) pattern in the outer layer of macroparticle. A formation mechanism for the macroparticles is proposed based on the analytical results, which is different from the conventional argument that the macroparticles consist of only metal phase.Cover 摘要 Abstract Contents List of tables Figure captions Chapter 1. Introduction Chapter 2. Theoretical basis 2.1 Hollow cathode discharge ion plating (HCD 2.2 Cathodic arc ion plating (CAIP) 2.3 Basic modes of thin film growth 2.4 Film-substrate interfaces 2.5 Structure zone model 2.6 Thermal stress in nitride coatings 2.7 Ultimate shear strength 2.8 Transverse stress of TiN-coated stainless steel wires 2.9 Electron energy loss spectroscopy in transmission electron microscope Chapter 3. Experimental procedure 3.1 Deposition of TiN, CrN and TiAlN coatings 3.2 Characterization and microanalysis 3.3 Mechanical property evaluation Chapter 4. Results and discussion 4.1 Microcharacterization of TiN, CrN and TiAlN coatings 4.2 Thermal stress in the nitride coatings 4.3 Interfacial mechanical properties and fracture morphology of a TiN-coated steel wire upon tensile loading 4.4 Effects of processing parameters on the microstructure and hardness of the arc ion-plated TiN on a type 304 stainless steel 4.5 Macroparticles in arc ion-plated nitride coatings Chapter 5. Conclusions References Appendix Publication list 誌謝 作者簡

Effect of Photoillumination on Gold-Nanoparticle-Assisted Chemical Etching of Silicon

Metal-assisted chemical etching (MacEtch) has attracted considerable attention for its ability to fabricate micro- and nanostructures with high aspect ratios and its applications in other microelectromechanical fields. However, few studies have reported the effect of photoillumination on MacEtch. In this study, gold nanoparticles (GNPs) were deposited on the surface of a Si wafer by using the fluoride-assisted galvanic replacement reaction, and then, the effect of photoillumination on the MacEtch of the Si wafer was investigated. The etched depth increased linearly with etching time from 0–45 min and was considerably larger in the illuminated area than the nonilluminated area. A lag time was observed for the MacEtch of the nonilluminated area. However, no lag time was observed in the illuminated area. The trapping of light by the GNPs on the Si substrate surface during the MacEtch process enhanced the etching efficiency due to localized surface plasmon resonance

To control floating drug delivery system in a simulated gastric environment by adjusting the Shell layer formulation

Abstract Background Gastroretentive drug delivery system (GDDS) are novel systems that have been recently developed for treating stomach diseases. The key function of all GDDS systems is to control the retention time in the stomach. However, research into the bulk density or entanglement of polymers, especially regarding their effects on drug float and release times, is scarce. Methods In this research, we prepared the floating core-shell beads carrying tetracycline. The ratio of chitosan and xanthan gum in the shell layer was changed to modify polymer compactness. Tetracycline was encapsulated in the alginate core. Results Using scanning electron microscopy (SEM) techniques, we observed that the shell formulation did not change the bead morphology. The cross-sectional images showed that the beads were highly porous. The interaction between anionic xanthan gum and cationic chitosan made the shell layer dense, resisting to the mass transfer in the shell layer. Due to the high mass transfer resistance to water penetration, the longer float and delivery time were caused by the dense surface of the beads. The cell culture demonstrated that floating core-shell beads were biocompatible. Importantly, the beads with tetracycline showed a significant prolonged anti-bacterial effect. Conclusion Research results proved that the floating and releasing progress of core-shell beads can be well controlled by adjusting the shell layer formulation that could promote the function of gastroretentive drugs

Novel Gold Dendritic Nanoforests Combined with Titanium Nitride for Visible-Light-Enhanced Chemical Degradation

In this study, gold dendritic nanoforests (Au DNFs)-titanium nitride (TiN) composite was firstly proposed for visible-light photodegradation of pollutants. A high-power impulse magnetron sputtering system was used to coat TiN films on silicon wafers, and a fluoride-assisted galvanic replacement reaction was applied to deposit Au DNFs on TiN/Si substrates. Scanning electron microscope images and X-ray diffraction patterns of TiN/Si, Au DNFs/Si, and Au DNFs/TiN/Si samples verified that this synthesis process was accurately controlled. The average reflectance of Au DNFs/Si and Au DNFs/TiN/Si considerably declined to approximately 10%, because the broadband localized surface plasmon resonances of Au DNFs cause broadband absorbance and low reflectance. In photocatalytic performance, 90.66 ± 1.41% 4-nitrophenol was successfully degraded in 180 min by Au DNFs/TiN/Si under visible-light irradiation. Therefore, Au DNFs/TiN/Si has the chance to be a visible-light photocatalyst for photodegradation of pollutants

Localized Electroless Ag Plating at a Tip Apex for Scanning Kelvin Probe Microscopy

A typical probe for scanning Kelvin probe microscopy (SKPM) consists of an atomic force microscopy (AFM) probe with a metallic coating. Such probes result in a large sensing area and lead to poor spatial resolution due to the stray-field effect. With electroless Ag plating (EAP), we employed an AFM system to form a Ag nanodot (AND) at the apex of the probe tip, which reduces the sensing area of the SKPM probe, thereby suppressing the stray-field effect. It was revealed that the tip with an AND structure had improved the spatial resolution in SKPM. Our experimental results showed that the EAP process can be completed in a few seconds, implying that localized EAP is a simple and rapid process for preparing an AND structure at the tip apex in SKPM measurements

Structural and mechanical properties of magnetron sputtered Ti–V–Cr–Al–N films

Ti–V–Cr–Al–N films were prepared by dc magnetron co-sputtering by utilizing TiVCr and Al targets. By using glancing incidence X-ray diffraction, a single NaCl solid solution phase with (2 0 0) preferred orientation for the Al-doped films was revealed, as opposed to the undoped films that possessed predominantly (1 1 1) preferred orientation. This indicates that Al addition can lead to the enhancement of adatom mobility and consequently, to a thermodynamically favorable (2 0 0) orientation. This also leads to grain growth and increased surface roughness. However, based on results from transmission electron microscopy, the microstructure morphology seemed independent of the Al concentration, implying that adatom mobility is not sufficient for the barriers present at the grain boundaries. Accordingly, hardness was enhanced by the increase in Al concentration