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Abstract Background Herbal medicine combined with nanotechnology offers an alternative to the increasing burden of surgery and/or chemotherapy, the main therapeutics of oral carcinoma. Phytosomes are nano-vesicular systems formed by the interaction between phospholipids and phyto-active components via hydrogen bonding, exhibiting superior efficacy over pure phytocomponents in drug delivery. Methods Tetrahydrocurcumin (THC)-phytosomes were prepared by thin film hydration method. After characterization, in vitro cytotoxicity, antiproliferative capacity, antioxidant potential and full apoptotic workup were paneled on oral squamous cell carcinoma (SCC4) in comparison with native THC-solution and cisplatin (3.58 µg/mL intravenous injection), as positive controls. In addition, we tested the three medications on normal oral keratinocytes and gingival fibroblasts to attest to their tissue-selectivity. Results Successful preparation of THC-phytosomes using 1:1 molar ratio of THC to phospholipid exhibited significantly increased aqueous solubility, good colloidal properties, and complete drug release after one hour. On SCC4 cells, THC-phytosomes, at their dose-/time-dependency at ~ 60.06 µg/mL escalated cell percentages in the S-phase with 32.5 ± 6.22% increase, as well as a startling 29.69 ± 2.3% increase in apoptotic population. Depletion of the cell colonies survival to 0.29 ± 0.1% together with restraining the migratory rate by -6.4 ± 6.8% validated THC-phytosomes’ antiproliferative capacity. Comparatively, the corresponding results of THC-solution and cisplatin revealed 12.9 ± 0.9% and 25.8 ± 1.1% for apoptosis and 0.9 ± 0.1% and 0.7 ± 0.08% for colony survival fraction, respectively. Furthermore, the nanoformulation exhibited the strongest immuno-positivity to caspase-3, which positively correlated with intense mitochondrial fluorescence by Mitotracker Red, suggesting its implication in the mitochondrial pathway of apoptosis, a finding further explained by the enormously high Bax and caspase-8 expression by RT-qPCR. Finally, the THC groups showed the lowest oxidative stress index, marking their highest free radical-scavenging potential among the test groups. Conclusions THC-phytosomes are depicted to be an efficient nanoformulation that enhanced the anticancer efficacy over the free drug counterpart and the conventional chemotherapeutic. Additionally, being selective to cancer cells and less cytotoxic to normal cells makes THC-phytosomes a potential candidate for tissue-targeted therapy.

Background: Herbal medicine combined with nanotechnology offers an alternative to the increasing burden of surgery and/or chemotherapy, the main therapeutics of oral carcinoma. Phytosomes are nano-vesicular systems formed by the interaction between phospholipids and phyto-active components via hydrogen bonding, exhibiting superior efficacy over pure phytocomponents in drug delivery. Methods: Tetrahydrocurcumin (THC)-phytosomes were prepared by thin film hydration method. After characterization, in vitro cytotoxicity, antiproliferative capacity, antioxidant potential and full apoptotic workup were paneled on oral squamous cell carcinoma (SCC4) in comparison with native THC-solution and cisplatin (3.58 µg/mL intravenous injection), as positive controls. In addition, we tested the three medications on normal oral keratinocytes and gingival fibroblasts to attest to their tissue-selectivity. Results: Successful preparation of THC-phytosomes using 1:1 molar ratio of THC to phospholipid exhibited significantly increased aqueous solubility, good colloidal properties, and complete drug release after one hour. On SCC4 cells, THC-phytosomes, at their dose-/time-dependency at ~ 60.06 µg/mL escalated cell percentages in the S-phase with 32.5 ± 6.22% increase, as well as a startling 29.69 ± 2.3% increase in apoptotic population. Depletion of the cell colonies survival to 0.29 ± 0.1% together with restraining the migratory rate by -6.4 ± 6.8% validated THC-phytosomes' antiproliferative capacity. Comparatively, the corresponding results of THC-solution and cisplatin revealed 12.9 ± 0.9% and 25.8 ± 1.1% for apoptosis and 0.9 ± 0.1% and 0.7 ± 0.08% for colony survival fraction, respectively. Furthermore, the nanoformulation exhibited the strongest immuno-positivity to caspase-3, which positively correlated with intense mitochondrial fluorescence by Mitotracker Red, suggesting its implication in the mitochondrial pathway of apoptosis, a finding further explained by the enormously high Bax and caspase-8 expression by RT-qPCR. Finally, the THC groups showed the lowest oxidative stress index, marking their highest free radical-scavenging potential among the test groups. Conclusions: THC-phytosomes are depicted to be an efficient nanoformulation that enhanced the anticancer efficacy over the free drug counterpart and the conventional chemotherapeutic. Additionally, being selective to cancer cells and less cytotoxic to normal cells makes THC-phytosomes a potential candidate for tissue-targeted therapy. [ABSTRACT FROM AUTHOR]

The halopyrimidine 5-bromo-2′-deoxyuridine (BrdU) is an exogenous marker of DNA synthesis. Since the introduction of monoclonal antibodies against BrdU, an increasing number of methodologies have been used for the immunodetection of this synthesized bromine-tagged base analogue into replicating DNA. BrdU labeling is widely used for identifying neuron precursors and following their fate during the embryonic, perinatal, and adult neurogenesis in a variety of vertebrate species including birds, reptiles, and mammals. Due to BrdU toxicity, its incorporation into replicating DNA presents adverse consequences on the generation, survival, and settled patterns of cells. This may lead to false results and misinterpretation in the identification of proliferative neuroblasts. In this review, I will indicate the detrimental effects of this nucleoside during the development of the central nervous system, as well as the reliability of BrdU labeling to detect proliferating neuroblasts. Moreover, it will show factors influencing BrdU immunodetection and the contribution of this nucleoside to the study of prenatal, perinatal, and adult neurogenesis. Human adult neurogenesis will also be discussed. It is my hope that this review serves as a reference for those researchers who focused on detecting cells that are in the synthetic phase of the cell cycle.

Regulator of TElomere Length Helicase 1 (RTEL1) is a helicase required for telomere maintenance and genome replication and repair. RTEL1 has been previously shown to participate in the nuclear export of small nuclear RNAs. Here we show that RTEL1 deficiency leads to a nuclear envelope destabilization exclusively in cells entering S-phase and in direct connection to origin firing. We discovered that inhibiting protein import also leads to similar, albeit non-cell cycle-related, nuclear envelope disruptions. Remarkably, overexpression of wild-type RTEL1, or of its C-terminal part lacking the helicase domain, protects cells against nuclear envelope anomalies mediated by protein import inhibition. We identified distinct domains in the C-terminus of RTEL1 essential for the interaction with KPNB1 (importin β) and NUP153, respectively, and we demonstrated that, on its own, the latter domain can promote the dynamic nuclear internalization of peptides that freely diffuse through the nuclear pore. Consistent with putative functions exerted in protein import, RTEL1 can be visualized on both sides of the nuclear pore using high-resolution microscopy. In all, our work points to an unanticipated, helicase-independent, role of RTEL1 in connecting both nucleocytoplasmic trafficking and nuclear envelope integrity to genome replication initiation in S-phase. [ABSTRACT FROM AUTHOR]

The structure, phase composition, wear resistance, and electrochemical behaviors of oxynitride films on the surface of austenitic 316L stainless steel substrates formed via plasma oxynitriding using gas mixtures of different compositions are studied. Plasma oxynitriding is carried out at a temperature of 425 °C for 2 h at various ratios of the gas mixtures, i.e., 25% O2 – 75% N2, 50% O2 – 50% N2, 75% O2 – 25% N2. The structure of the coatings is studied by scanning electron microscopy and x-ray diffraction. The wear resistance of the films is evaluated by sliding an alumina ball under dry conditions and in an SBF environment simulating body fluid conditions. The corrosion resistance of the films is determined in the SBF medium. It is shown that the formation of the S (111) and S (200) phase layer upon oxynitriding of steel 316L increases its wear and corrosion resistances. The films formed during the treatment at the gas ratio of 75% O2 – 25% N2, have the highest properties. [ABSTRACT FROM AUTHOR]

The paper investigates the effects of DC plasma nitriding on surface roughness, hardness, microstructure, micro-abrasion, and corrosion resistance of AISI 316L Austenitic Stainless (AS) steel. The nitriding has been conducted for durations ranging from 4 to 24 h at a temperature of 430 °C in a commercial vacuum furnace, Rübig PN90/70. Micro-abrasion resistance has been tested using the calotest device with a measurement diameter of craters produced on the sample surface after 10 to 60 s of wear. Corrosion resistance has been tested using the Electroimpedance Spectroscopy (EIS) method in a 3.5% NaCl water solution. The surface roughness parameters and hardness of the samples increased with longer nitriding times, attributed to the saturation of austenite and the formation of iron and chromium nitrides. Nitriding for longer than 8 h resulted in the formation of a thicker compound layer that is hard and brittle, leading to reduced wear resistance compared with shorter nitriding times. EIS measurements revealed that nitrided samples had lower corrosion resistance compared with the untreated sample. The corrosion stability was not significantly affected by nitriding time. Different nitriding times have a great influence on resistance to pitting corrosion. This study provides valuable insights into the effects of plasma nitriding on the properties of AS steel, highlighting the importance of optimizing nitriding parameters for specific applications. [ABSTRACT FROM AUTHOR]

Introduction: Intracellular communication is essential for the maintenance of the anterior pituitary gland plasticity. The aim of this study was to evaluate whether GPCR-Gai modulates basic fibroblast growth factor (FGF2)-induced proliferative activity in normal pituitary cell populations. Methods: Anterior pituitary primary cell cultures from Wistar female rats were treated with FGF2 (10ng/mL) or somatostatin analog (SSTa, 100nM) alone or coincubated with or without the inhibitors of GPCR-Gai, pertussis toxin (PTX, 500nM), MEK inhibitor (U0126, 100µM) or PI3K inhibitor (LY 294002, 10 mM). Results: FGF2 increased and SSTa decreased the lactotroph and somatotroph BrdU uptak2e (p<0.05) whereas the FGF2-induced S-phase entry was prevented by SSTa co-incubation in both cell types, with these effects being reverted by PTX, U0126 or LY294002 pre-incubation. The inhibition of lactotroph and somatotroph mitosis was associated with a downregulation of c-Jun expression, a decrease of phosphorylated (p) ERK and pAKT. Furthermore, SSTa was observed to inhibit the S-phase entry induced by FGF2, resulting in a further increase in the number of cells in the G1 phase and a concomitant reduction in the number of cells in the S phases (p< 0.05), effects related to a decrease of cyclin D1 expression and an increase in the expression of the cell cycle inhibitors p27 and p21. Discussion: In summary, the GPCR-Gai activated by SSTa blocked the proproliferative effect of FGF2 in normal pituitary cells via a MEK-dependent mechanism, which acts as a mediator of both anti and pro-mitogenic signals, that may regulate the principal effectors of the G1 to S-phase transition. [ABSTRACT FROM AUTHOR]

Simple Summary: Several procedures have been developed to infer cell-cycle time and the duration of the cycle phases, including tritiated thymidine autoradiography and the immunodetection of thymidine analogues after their incorporation into replicating DNA. These methods have supplied important insights to reveal, on fixed tissue sections and using light or electron microscopy, the proliferative behavior of different cell types under different experimental contexts. Thymidine analogous labeling has provided knowledge about cell growth kinetics that would never have been obtained by histological methods alone. Tritiated thymidine autoradiography, 5-bromo-2′-deoxyuridine (BrdU) 5-chloro-2′-deoxyuridine (CldU), 5-iodo-2′-deoxyuridine (IdU), and 5-ethynyl-2′-deoxyiridine (EdU) labeling have been used for identifying the fraction of cells undergoing the S-phase of the cell cycle and to follow the fate of these cells during the embryonic, perinatal, and adult life in several species of vertebrate. In this current review, I will discuss the dosage and times of exposition to the aforementioned thymidine analogues to label most of the cells undergoing the S-phase of the cell cycle. I will also show how to infer, in an asynchronous cell population, the duration of the G1, S, and G2 phases, as well as the growth fraction and the span of the whole cell cycle on the base of some labeling schemes involving a single administration, continuous nucleotide analogue delivery, and double labeling with two thymidine analogues. In this context, the choice of the optimal dose of BrdU, CldU, IdU, and EdU to label S-phase cells is a pivotal aspect to produce neither cytotoxic effects nor alter cell cycle progression. I hope that the information presented in this review can be of use as a reference for researchers involved in the genesis of tissues and organs. [ABSTRACT FROM AUTHOR]

Low-temperature thermochemical treatments are particularly suitable for use in the surface hardening of austenitic stainless steels without impairing their corrosion resistance. In fact, when using treatment media rich in nitrogen and/or carbon at relatively low temperatures (<450 °C for nitriding, <550 °C for carburizing), it is possible to inhibit the formation of chromium compounds and obtain modified surface layers that consist mainly of a supersaturated solid solution, known as expanded austenite or S-phase. It has been observed that this hard phase allows the enhancement of corrosion resistance in chloride-ion-containing solutions, while the results were contradictory for chloride-free acidic solutions. This overview aims to discuss the corrosion behavior of low-temperature-treated austenitic stainless steels, taking into account the different microstructures and phase compositions of the modified layers, as well as the different test environments and conditions. In particular, the corrosion behavior in both chloride-ion-containing solutions and chloride-free solutions (sulfuric acid, sulfate and borate solutions) is discussed. The analysis of the international literature presents evidence that the microstructure and phase composition of the modified layers have key roles in corrosion resistance, especially in sulfuric acid solutions. [ABSTRACT FROM AUTHOR]

IntroductionIntracellular communication is essential for the maintenance of the anterior pituitary gland plasticity. The aim of this study was to evaluate whether GPCR-Gαi modulates basic fibroblast growth factor (FGF2)-induced proliferative activity in normal pituitary cell populations.MethodsAnterior pituitary primary cell cultures from Wistar female rats were treated with FGF2 (10ng/mL) or somatostatin analog (SSTa, 100nM) alone or co-incubated with or without the inhibitors of GPCR-Gαi, pertussis toxin (PTX, 500nM), MEK inhibitor (U0126, 100µM) or PI3K inhibitor (LY 294002, 10 μM).ResultsFGF2 increased and SSTa decreased the lactotroph and somatotroph BrdU uptak2e (p

Two surface modification techniques, the glow discharge plasma nitriding (GDPN) and the cathodic cage plasma nitriding (CCPN), were compared regarding the mechanical and tribological behavior of layers produced on AISI 316 stainless-steel surfaces. The analyses were carried out at the micro/nanoscale using nanoindentation and nanoscratch tests. The nitriding temperature (°C) and time (h) parameters were 350/6, 400/6, and 450/6. Morphology, structure, and microstructure were evaluated by X-ray diffraction, scanning electron and optical interferometry microscopies, and energy-dispersive X-ray spectroscopy. GDPN results in stratified modified surfaces, solidly integrated with the substrate, with a temperature-dependent composition comprising nitrides (γ'-Fe4N, ε-Fe2+xN, CrN) and N-solid solution (γN phase). The latter prevails for the low treatment temperatures. Hardness increases from ~2.5 GPa (bare surface) to ~15.5 GPa (450 °C). The scratch resistance of the GDPN-modified surfaces presents a strong correlation with the layer composition and thickness, with the result that the 400 °C condition exhibits the highest standards against microwear. In contrast, CCPN results in well-defined dual-layers for any of the temperatures. A top 0.3–0.8 µm-thick nitride film (most ε-phase), brittle and easily removable under scratch with loads as low as 63 mN, covers a γN-rich case with hardness of 10 GPa. The thickness of the underneath CCPN layer produced at 450 °C is similar to that from GDPN at 400 °C (3 µm); on the other hand, the average roughness is much lower, comparable to the reference surface (Ra ~10 nm), while the layer formation involves no chromium depletion. Moreover, edge effects are absent across the entire sample´s surface. In conclusion, among the studied conditions, the GDPN 400 °C disclosed the best tribo-mechanical performance, whereas CCPN resulted in superior surface finishing for application purposes. [ABSTRACT FROM AUTHOR]

Lattice distortion and amorphization of carbon-doped SUS304 by variation of the laser output were investigated in terms of phase formation and the bonding state. The laser output was changed by 10% in the range of 60% to 100% after covering the SUS304 with carbon paste. A graphite peak and expanded austenite (S-phase) peak were observed in the carbon-doped SUS304, and Rietveld refinement was performed to identify the lattice distortion. The lattice constant of SUS304 was initially 3.612 Å, but expansion lattice distortion occurred in the carbon-doped SUS304 as a result of the S phase formation and carbon doping, and the lattice constant increased to 3.964 Å (100% laser output). X-ray photoelectron spectroscopy analysis for the bonding state of the carbon-doped SUS304 showed that the sp2/sp3 ratio decreased from 3.21 (70% laser output) to 2.52 (100% laser output). The residual stress in the lattice was accumulated due to carbon doping by high thermal energy, which resulted in the formation of amorphous carbon. The bonding environment was represented by the ID/IG ratio using Raman analysis, and it increased from 0.55 (70% laser output) to 1.68 (100% laser output). During microstructure analysis of the carbon-doped SUS304, disordered structures by amorphization were observed in the carbon-doped SUS304 by the greater than 90% laser output. The amorphous carbon filled the lattice grains or voids to lubricate the surface, which improved the friction coefficient and wear rate from 0.23 and 7.63 mm3(Nm)−110−6 to 0.09 and 1.43 mm3(Nm)−110−6, respectively. [ABSTRACT FROM AUTHOR]

This study aimed to observe the thickening of the S-phase and Sα-phase of various stainless steels subjected to low-temperature direct current plasma nitriding using screen (S-DCPN). Austenitic stainless steel SUS304, ferritic stainless steel SUS430, and duplex stainless steel SUS329J4L were treated using two different screens for comparison, namely, a Ni screen and a steel plate cold commercial (SPCC) screen. Plasma nitriding was performed at 673 K for 300 min under a 75% N2 + 25% H2 atmosphere at 100 Pa pressure of the mixed gas. After nitriding treatment, the samples were examined using X-ray diffraction (XRD) and glow discharge optical emission spectrometry (GD-OES), and their cross-sectional microstructure and surface microstructure were examined using an electron probe micro analyzer (EPMA). Nitrided samples were also subjected to Vickers hardness and pitting corrosion tests. Examination of the SUS304 samples revealed thickening of its S-phase and higher surface hardness and pitting corrosion resistance when nitriding was done with the Ni screen. This was due to excess nitrogen diffusion into the sample due to presence of the Ni screen than with the SPCC screen. In the SUS430 samples, thickening of the Sα-phase was not be observed. When the Ni screen was used during nitriding, higher surface hardness and less pitting corrosion resistance of sample were observed, along with enhanced nitrogen diffusion than the SPCC screen was used. In the SUS329J4L samples, upon nitriding with Ni screen, thickening of the S-phase was observed and surface hardness and pitting corrosion resistance of the sample were higher, which was attributed to the enhanced nitrogen diffusion into the sample than when nitriding with the SPCC screen. [ABSTRACT FROM AUTHOR]

Tritiated thymidine autoradiography, 5-bromo-2′-deoxyuridine (BrdU) 5-chloro-2′-deoxyuridine (CldU), 5-iodo-2′-deoxyuridine (IdU), and 5-ethynyl-2′-deoxyiridine (EdU) labeling have been used for identifying the fraction of cells undergoing the S-phase of the cell cycle and to follow the fate of these cells during the embryonic, perinatal, and adult life in several species of vertebrate. In this current review, I will discuss the dosage and times of exposition to the aforementioned thymidine analogues to label most of the cells undergoing the S-phase of the cell cycle. I will also show how to infer, in an asynchronous cell population, the duration of the G1, S, and G2 phases, as well as the growth fraction and the span of the whole cell cycle on the base of some labeling schemes involving a single administration, continuous nucleotide analogue delivery, and double labeling with two thymidine analogues. In this context, the choice of the optimal dose of BrdU, CldU, IdU, and EdU to label S-phase cells is a pivotal aspect to produce neither cytotoxic effects nor alter cell cycle progression. I hope that the information presented in this review can be of use as a reference for researchers involved in the genesis of tissues and organs.

Low-temperature thermochemical treatments are particularly suitable for use in the surface hardening of austenitic stainless steels without impairing their corrosion resistance. In fact, when using treatment media rich in nitrogen and/or carbon at relatively low temperatures (

This study aimed to observe the thickening of the S-phase and Sα-phase of various stainless steels subjected to low-temperature direct current plasma nitriding using screen (S-DCPN). Austenitic stainless steel SUS304, ferritic stainless steel SUS430, and duplex stainless steel SUS329J4L were treated using two different screens for comparison, namely, a Ni screen and a steel plate cold commercial (SPCC) screen. Plasma nitriding was performed at 673K for 300 min under a 75％N2 + 25％H2 atmosphere at 100 Pa pressure of the mixed gas. After nitriding treatment, the samples were examined using X-ray diffraction (XRD) and glow discharge optical emission spectrometry (GD-OES), and their cross-sectional microstructure and surface microstructure were examined using an electron probe micro analyzer (EPMA). Nitrided samples were also subjected to Vickers hardness and pitting corrosion tests. Examination of the SUS304 samples revealed thickening of its S-phase and higher surface hardness and pitting corrosion resistance when nitriding was done with the Ni screen. This was due to excess nitrogen diffusion into the sample due to presence of the Ni screen than with the SPCC screen. In the SUS430 samples, thickening of the Sα-phase was not be observed. When the Ni screen was used during nitriding, higher surface hardness and less pitting corrosion resistance of sample were observed, along with enhanced nitrogen diffusion than the SPCC screen was used. In the SUS329J4L samples, upon nitriding with Ni screen, thickening of the S-phase was observed and surface hardness and pitting corrosion resistance of the sample were higher, which was attributed to the enhanced nitrogen diffusion into the sample than when nitriding with the SPCC screen. [ABSTRACT FROM AUTHOR]

Plasma nitrocarburizing has been widely used to improve the hardness of stainless steels without affecting their good corrosion resistance property. The process is usually carried out by using gas discharge of N and C containing gases, with admixing H2 or Ar gas or H2-Ar in combination. The aim of the present work was to study and compare the effects of H2, Ar and H2-Ar gas in combination, admixed with N2-C2H2 gas mixture on the surface properties of austenitic stainless steels (viz. AISI 304 and 304L). The process was carried out at 400 °C and 500 Pa for 5 h. The treated samples were analyzed for their structural, mechanical, and electrochemical properties using x-ray diffractometer, scanning electron microscope, Vickers microhardness tester and potentiodynamic polarization testing instruments. Nitride- and carbide-free S-phase dual-layers were observed after plasma nitrocarburizing and their thicknesses varied with the different gas mixtures. Also, optical emission spectra of the gas discharges were recorded during the process and it was seen that the intensities of CH radical (431.44 nm) and CN radical (388.43 nm) lines were greater for Ar containing discharges. Hardness and pitting corrosion resistance were observed to be better with hydrogen compared to the other gas mixtures. Moreover, AISI 304 exhibited greater improvements in the surface hardness and corrosion resistance properties compared to AISI 304L. [ABSTRACT FROM AUTHOR]

ABSTRACT The protozoan Toxoplasma gondii is a highly successful obligate intracellular parasite that, upon invasion of its host cell, releases an array of host-modulating protein effectors to counter host defenses and further its own replication and dissemination. Early studies investigating the impact of T. gondii infection on host cell function revealed that this parasite can force normally quiescent cells to activate their cell cycle program. Prior reports by two independent groups identified the dense granule protein effector HCE1/TEEGR as being solely responsible for driving host cell transcriptional changes through its direct interaction with the cyclin E regulatory complex DP1 and associated transcription factors. Our group independently identified HCE1/TEEGR through the presence of distinct repeated regions found in a number of host nuclear targeted parasite effectors and verified its central role in initiating host cell cycle changes. Additionally, we report here the time-resolved kinetics of host cell cycle transition in response to HCE1/TEEGR, using the fluorescence ubiquitination cell cycle indicator reporter line (FUCCI), and reveal the existence of a block in S-phase progression and host DNA synthesis in several cell lines commonly used in the study of T. gondii. Importantly, we have observed that this S-phase block is not due to additional dense granule effectors but rather is dependent on the host cell line background and contact inhibition status of the host monolayer in vitro. This work highlights intriguing differences in the host response to reprogramming by the parasite and raises interesting questions regarding how parasite effectors differentially manipulate the host cell depending on the in vitro or in vivo context. IMPORTANCE Toxoplasma gondii chronically infects approximately one-third of the global population and can produce severe pathology in immunologically immature or compromised individuals. During infection, this parasite releases numerous host-targeted effector proteins that can dramatically alter the expression of a variety of host genes. A better understanding of parasite effectors and their host targets has the potential to not only provide ways to control infection but also inform us about our own basic biology. One host pathway that has been known to be altered by T. gondii infection is the cell cycle, and prior reports have identified a parasite effector, known as HCE1/TEEGR, as being responsible. In this report, we further our understanding of the kinetics of cell cycle transition induced by this effector and show that the capacity of HCE1/TEEGR to induce host cell DNA synthesis is dependent on both the cell type and the status of contact inhibition.

Two surface modification techniques, the glow discharge plasma nitriding (GDPN) and the cathodic cage plasma nitriding (CCPN), were compared regarding the mechanical and tribological behavior of layers produced on AISI 316 stainless-steel surfaces. The analyses were carried out at the micro/nanoscale using nanoindentation and nanoscratch tests. The nitriding temperature (°C) and time (h) parameters were 350/6, 400/6, and 450/6. Morphology, structure, and microstructure were evaluated by X-ray diffraction, scanning electron and optical interferometry microscopies, and energy-dispersive X-ray spectroscopy. GDPN results in stratified modified surfaces, solidly integrated with the substrate, with a temperature-dependent composition comprising nitrides (γ’-Fe4N, ε-Fe2+xN, CrN) and N-solid solution (γN phase). The latter prevails for the low treatment temperatures. Hardness increases from ~2.5 GPa (bare surface) to ~15.5 GPa (450 °C). The scratch resistance of the GDPN-modified surfaces presents a strong correlation with the layer composition and thickness, with the result that the 400 °C condition exhibits the highest standards against microwear. In contrast, CCPN results in well-defined dual-layers for any of the temperatures. A top 0.3–0.8 µm-thick nitride film (most ε-phase), brittle and easily removable under scratch with loads as low as 63 mN, covers a γN-rich case with hardness of 10 GPa. The thickness of the underneath CCPN layer produced at 450 °C is similar to that from GDPN at 400 °C (3 µm); on the other hand, the average roughness is much lower, comparable to the reference surface (Ra ~10 nm), while the layer formation involves no chromium depletion. Moreover, edge effects are absent across the entire sample´s surface. In conclusion, among the studied conditions, the GDPN 400 °C disclosed the best tribo-mechanical performance, whereas CCPN resulted in superior surface finishing for application purposes.

Modern brazing filler metals for brazing high-temperature nickel alloys are complex alloys, where the components should provide the required level of strength, high-temperature resistance, high-temperature corrosion resistance and other service properties of brazed joints. However, establishing the optimum composition to obtain the desired set of properties is a non-trivial task, requiring considerable investment of time and money. The work is a study of applicability of the method of mathematical modeling of thermodynamic processes (CALPHAD) during development of multicomponent filler metals for brazing high-temperature nickel alloys. During performance of investigations, using CALPHAD computational procedure, melting temperature ranges were determined for a number of alloys of Ni-Cr-Co-Al-(Me)-Ta system. Calculated data were obtained on the influence of adhesion-active elements of groups IV and V of the periodic table on liquidus temperature and phase composition of the base nickel alloy. In particular, their impact on the quantity and thermal stability of ?'-phase and s-phase was determined. Thermodynamic calculated data, obtained with application of mathematical modeling method, were used during development and investigation of a number of promising filler metals for brazing high-temperature nickel alloys, including single-crystal high-temperature nickel alloy ZhS-32VI. [ABSTRACT FROM AUTHOR]

The apical damage kinase, ATR, is activated by replication stress (RS) both in response to DNA damage and during normal S-phase. Loss of function studies indicates that ATR acts to stabilize replication forks, block cell cycle progression and promote replication restart. Although checkpoint failure and replication fork collapse can result in cell death, no direct cytotoxic pathway downstream of ATR has previously been described. Here, we show that ATR directly reduces survival by inducing phosphorylation of the p50 (NF-κB1, p105) subunit of NF-кB and moreover, that this response is necessary for genome maintenance independent of checkpoint activity. Cell free and in vivo studies demonstrate that RS induces phosphorylation of p50 in an ATR-dependent but DNA damage-independent manner that acts to modulate NF-кB activity without affecting p50/p65 nuclear translocation. This response, evident in human and murine cells, occurs not only in response to exogenous RS but also during the unperturbed S-phase. Functionally, the p50 response results in inhibition of anti-apoptotic gene expression that acts to sensitize cells to DNA strand breaks independent of damage repair. Ultimately, loss of this pathway causes genomic instability due to the accumulation of chromosomal breaks. Together, the data indicate that during S-phase ATR acts via p50 to ensure that cells with elevated levels of replication-associated DNA damage are eliminated.

Active screen plasma nitriding (ASPN) has recently emerged as an alternative nitriding technology with the potential to eliminate problems such as edge effect, arcing, and hollow cathode effects, associated with conventional direct current plasma nitriding technology. Amorphous hydrogenated carbon (a-C:H) is a thin film characterized by high hardness, a low friction coefficient, and superior wear resistance. However, the high residual stress of the a-C:H leads to poor adhesion between the a-C:H film and substrate. This study's objective was to investigate the properties of samples obtained by a duplex treatment (i.e., ASPN and a-C:H coating) of SUS304 austenitic stainless steel. The ASPN treatment was performed in 25% N2 + 75% H2 atmosphere for 5 h at 673 K under 600 Pa. An a-C:H film was coated using RF plasma-enhanced chemical vapor deposition in the presence of methane for 90 min. The results indicated that an a-C:H film with an S-phase interlayer formed after the duplex treatment of ASPN and a-C:H coating. Moreover, this treatment improved the adhesion and wear properties of the resulting sample.

• Phagocytosis in keratinocytes is enhanced by UVB and by oxidative stress. • Oxidative stress causes keratinocytes to accumulate in S-phase of the cell cycle. • Phagocytosis is enhanced by synchronizing keratinocytes to S-phase. • Phagocytosis in S-phase keratinocytes is abolished by a calcium ion chelator. Phagocytosis is an essential process that maintains cellular homeostasis. In the epidermis, the phagocytosis of melanosomes into keratinocytes is important to protect their DNA against damage from ultraviolet B (UVB) radiation. Furthermore, it is considered that UVB activates the phagocytosis by keratinocytes but the detailed mechanism involved is not fully understood. To clarify the mechanism of UVB-enhanced phagocytosis in keratinocytes, we investigated the relationship between the phagocytic ability of keratinocytes and the cell cycle stage of keratinocytes. The phagocytic ability of keratinocytes was evaluated using the incorporation of fluorescent beads after exposure to UVB or oxidative stress. S-phase was evaluated by BrdU incorporation and immunostaining of cyclin D1. Intracellular calcium levels of keratinocytes were measured using the probe Fluo-4AM. The phagocytosis of fluorescent beads into keratinocytes was enhanced by UVB and also by oxidative stress. We found that keratinocytes exposed to UVB or oxidative stress were at S-phase of the cell cycle. Furthermore, keratinocytes synchronized to S-phase showed a higher phagocytic ability according to the increased intracellular ROS level. The UVB-enhanced phagocytosis and entrance into S-phase of keratinocytes was abolished by ascorbic acid, a typical antioxidant. Keratinocytes synchronized to S-phase and exposed to UVB or oxidative stress had increased levels of intracellular calcium and their enhanced phagocytic abilities were diminished by the calcium ion chelator BAPTA-AM. Taken together, intracellular oxidative stress induced by intracellular calcium influx mediates the UVB-enhanced phagocytic ability of keratinocytes accumulating at S-phase of the cell cycle. [ABSTRACT FROM AUTHOR]

Under nitrogen plasma immersion ion implantation, the energy density per pulse E Pulse /A was found to be proportional to the amount of the N-expanded austenite phase (γ N) in a superaustenitic stainless steel, as previously seen for an austenitic-ferritic alloy. Since γ N occurs in a range of stoichiometries, the parameter was also contrasted with the ion fluence Γ, which affects the retained dose. Γ varies inversely with E Pulse /A and influences oppositely the properties of the modified surfaces. The temperature was the same among the treatments (320 °C) to rule out thermal diffusion as an extra variable. The increase of E Pulse /A (for applied voltages 6.2–10.4 kV) produces thicker layers (1.4–2.2 µm), as an increase in lattice defects and stresses enhances N-diffusion, while high Γ values favor the N-saturation at the top surface for the opposite reason. The lowest E pulse /A (6.2–9.5 kV) result in brittle cases with a possible thin nitrides layer on top, whereas γ N prevails in the ductile layer produced by the highest one (10.4 kV). The N-concentration governs the strength against plastic deformation: hardness varies up to 32% from the highest (6.2 kV) to the lowest Γ treatment (10.4 kV). In summary, the correlation of E pulse /A with Γ is indispensable for controlling properties of the modified surfaces for performance purposes. [Display omitted] ● The energy density per pulse E Pulse /A controls the γ N amount in superaustenitic SS. ● At the same PIII temperature, the layer thickness grows with E Pulse / A (1.4-2.2 µm). ● The role of implantation defects and lattice stresses in the N diffusion is evidenced. ● E Pulse /A and ion fluence Γ vary inversely and rule synergistically the surface properties. ● The N-concentration in the layer increases with Γ and governs its mechanical strength. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis and biological evaluation of [Pd(L)(OH 2)Cl] complex (where L = 2,2′-(pyridin-2-ylmethylene)bis(5,5-dimethylcyclohexane-1,3-dione) as a novel promising anticancer candidate. The complex was characterized by single-crystal X-ray diffraction and other various spectroscopic techniques. Besides, the optimized structure was determined through DFT calculations revealing that the coordination geometry of [Pd(L)(OH 2)Cl] complex is square planar. The binding propensity of [Pd(L)(OH 2)Cl] complex with DNA and BSA was assessed by the spectrophotometric method. The antimicrobial profile of the ligand and its [Pd(L)(OH 2)Cl] complex was screened against clinically important bacterial strains. [Pd(L)(OH 2)Cl] complex showed promising activity against these microorganisms. Pd(L)(OH 2)Cl] complex exhibited a potent antiproliferative potential compared to its ligand against different human cancer cells (A549, HCT116, MDA-MB-231, and HepG2) with less toxic effect against normal cells (WI-38). Additionally, [ Pd(L)(OH 2)Cl] complex exerted its anticancer effects against the most responsive cells (HCT116 cells; IC 50 = 11 ± 1 μM) through suppressing their colony-forming capabilities and triggering apoptosis and cell cycle arrest at S phase. Quantitative PCR analysis revealed a remarkable upregulation of the mRNA expression level of p53 and caspase-3 by 4.8- and 5.9-fold, respectively, relative to control. Remarkable binding properties and non-covalent interactions between L and its [Pd(L)(OH 2)Cl] complex with the binding sites of different receptors including CDK2, MurE ligase, DNA, and BSA were established using molecular docking. Based on our results, [Pd(L)(OH 2)Cl] complex is an intriguing candidate for future investigations as a potential anticancer drug for the treatment of colon cancer. [Pd(L)(OH 2)Cl] complex was synthesized and characterized by X-ray crystallography. [Pd(L)(OH 2)Cl] complex binding potentials towards different receptors were evaluated using docking. Anticancer activity was evaluated using MTT, apoptotic, and cell cycle assays. Caspase-3 and p53 expression levels were upregulated by 4.8- and 5.9-fold compared to control cells using qRT-PCR analysis. [Display omitted] • A new palladium complex was synthesized and confirmed through X-ray investigation. • [Pd(L)(OH 2)Cl] complex showed good antibacterial effects and DNA/BSA-binding potentials. • The complex revealed a potent cytotoxicity against different human cancer cells. • Caspase-3 and p53 expression levels were significantly upregulated using qPCR analysis. • Docking showed binding properties of [Pd(L)(OH 2)Cl] complex towards different receptors. [ABSTRACT FROM AUTHOR]

Indonesian black rice cv Cempo Ireng was evaluated for cancer prevention using a T47D cell line model. Methanolic extract of black rice bran (BRB) showed cytotoxicity with an IC50 of 522.13 µg/ml. This result was in contrast to water extract of BRB, which yielded an IC50 of more than 6000 µg/ml. From the methanolic extract of BRB, its 6 fractions were found from the preparative TLC performance, with Rf values ranging from 0 to 0.97. According to the MTT assay of all fractions, fraction 3 (F3) had the lowest IC50 (60.17 ± 1.72µg/ml), while fraction 2 (F2) had an IC50 of 64.3 ± 0.61µg/ml. However, F2 showed the highest induction of apoptosis, i.e. about 75.39 ± 0.43% compared to the T47D cells without treatment (control) (about 8.39 ± 0.16%) and with doxorubicin treatment (about 41.30 ± 0.08%). Furthermore, fraction 5 (F5) not only induced apoptosis but also increased the S-phase arrest percentage (60.36 ± 2.07%), which was significantly higher than for the other treatments. Therefore, each fraction of BRB showed different cytotoxic responses to T47D cells.

The corrosion behavior of austenitic stainless steel after low-temperature liquid oxy-nitriding (LON) was investigated by exposing in H 2 S/CO 2 -saturated liquid and vapor environments up to 720 h at 60 °C. The corrosion rates before and after LON were compared by the weightlessness method, and the microstructure as well as the corrosion scales were characterized using surface analysis methods. The results indicated that the composite S-phase layer with the outer Fe 3 O 4 layer and the inner nitrogen-rich sublayer could improve the corrosion performance in H 2 S/CO 2 -saturated environment. The base material (BM) suffered local corrosion first, which then transformed into uniform corrosion. As a comparison, The LON sample, covered with a thin corrosion product layer, indicated slight local corrosion. The excellent corrosion resistance of the S-phase should be attributed to the blocking effect of the continuous Fe 3 O 4 film as well as the suppression of the atomic mobility by the nitrogen-containing supersaturated solid solution. • The difference in the corrosion behavior of austenitic stainless steel in the vapor and liquid phases is analyzed. • In the H 2 S/CO 2 -saturated liquid/vapor phase, the corrosion rate of the LON sample is 93.1% lower than that of the BM. • The nitrogen atoms in the S-phase can increase the local pH value and accelerate the passivation in acidic environments. • The continuous Fe 3 O 4 layer can effectively block offensive ions. • Supersaturated nitrogen could suppress the atomic mobility thereby reducing the dissolution of metal atoms. [ABSTRACT FROM AUTHOR]

This study aims to draw an exact boundary for microstructural and mechanical behaviors in terms of pulsed plasma nitriding conditions. The pulsed plasma nitriding treatment was applied to AISI 304 austenitic stainless steel at different temperatures and durations. Results reveal that nitriding depth increased as process temperature and duration increase. The nitriding depth remarkably increased at 475°C for 8 h and at 550°C for 4 h. An austenite structure was transformed into a metastable nitrogen-oversaturated body-centered tetragonal expanded austenite (S-phase) during low-temperature plasma nitriding. The S-phase was converted to CrN precipitation at 475°C for 8 h and at 550°C for 4 h. Surface hardness and fatigue limit increased through plasma nitriding regardless of process conditions. The best surface hardness and fatigue limit were obtained at 550°C for 4 h because of the occurrence of CrN precipitation. [ABSTRACT FROM AUTHOR]

Checkpoints maintain the order of cell cycle events during DNA damage or incomplete replication. How the checkpoint response is tailored to different phases of the cell cycle remains poorly understood. The S-phase checkpoint for example results in the slowing of replication, which in budding yeast occurs by Rad53-dependent inhibition of the initiation factors Sld3 and Dbf4. Despite this, we show here that Rad53 phosphorylates both of these substrates throughout the cell cycle at the same sites as in S-phase, suggesting roles for this pathway beyond S-phase. Indeed, we show that Rad53-dependent inhibition of Sld3 and Dbf4 limits re-replication in G2/M, preventing gene amplification. In addition, we show that inhibition of Sld3 and Dbf4 in G1 prevents premature initiation at all origins at the G1/S transition. This study redefines the scope of the ‘S-phase checkpoint’ with implications for understanding checkpoint function in cancers that lack cell cycle controls.

Plasma nitriding is an effective surface hardening treatment for austenitic stainless steels. During plasma nitriding, s‐phase formation takes place which is not only responsible for high hardness and wear resistance but also for good corrosion resistance. In order to estimate the thickness of the s‐phase for austenitic stainless steel in a plasma nitriding process, an empirical model is devised. A number of plasma nitriding processes of austenitic stainless steel (304 L) were carried out with varying treatment temperature from 360 °C to 450 °C and process duration ranging from 10 hours to 24 hours with constant pressure, voltage, pulse‐to‐pause‐ratio and gas mixture. A time‐temperature dependent s‐phase formation coefficient is determined by measuring the thickness of the s‐phase using a scanning electron microscope (SEM) and glow discharge optical emission spectroscopy (GDOES). The developed model is verified by three controlled experiments. This model fits the thickness of the s‐phase with an error of less than 6 %. [ABSTRACT FROM AUTHOR]

Plasma nitriding offers great potenzial for improving the wear properties of austenitic steels. Here, the austenitic standard grades 1.4307 and 1.4404, as well as the titanium‐stabilized grades 1.4541 and 1.4571 were investigated regarding the influence of the material condition on the nitriding result and corrosion behavior. Special focus was put on the influence of the Ti‐stabilisation. In addition, it was investigated to what extent corrosion properties are influenced by cold‐forming induced defect structures. In comparison to 1.4307 and 1.4404, less nitrogen is incorporated in areas with forming martensite in titanium‐stabilized austenitic steels and lower nitriding temperatures, while an increased diffusion of nitrogen is observed, when only slip bands are present. The corrosion resistance is generally improved by the plasma nitriding parameters used for this study. In general, a higher thickness of the S‐phase, which forms during the plasma nitriding, results in better corrosion resistance and higher surface hardness. The titanium stabilization inhibits nitrogen diffusion in the presence of deformation induced martensite at lower nitriding temperatures and promotes diffusion in the presence of deformation induced slip bands. [ABSTRACT FROM AUTHOR]

UNS S31603 stainless steel (SS) substrates were covered by reactive magnetron-sputtering with protective SS coatings of the same steel specification. A mechanical characterization study (through nano-, micro- and macro-hardness tests) of samples obtained under two different sputtering conditions and varying the N2 gas flow rate was carried out. This contribution aimed at appraising the effects of varying the nitrogen flow rate on hardness, elastic modulus, and susceptibility to indentation-induced crack formation of the coated SSs. Nitrogen-free samples displayed body-centered cubic (BCC) films with 9.0-9.4 GPa hardness and 203-206 GPa elastic modulus, while their susceptibility to indentation-induced cracking varied between superior and moderated among the two sets of sputtering conditions studied. Samples alloyed with 4-6 N at-% displayed a predominantly face-centered cubic (FCC) structure, 9.4 GPa hardness, 196-218 GPa elastic modulus, and superior resistance to crack formation. Samples with 11.5-22.0 N at-% were fully composed of the FCC structure, displayed 12.4-15.2 GPa hardness, 188-193 GPa elastic modulus, and moderated resistance to indentation-induced crack formation. Samples with 47.0 N at-% displayed FCC compound nitride structure, for which hardness and elastic modulus were 8.1 GPa and 139 GPa, respectively. These samples displayed low resistance to crack formation.

Abstract ISO 5832-1 stainless steel specimens were plasma nitrided at different nitrogen potentials. The main goal was to obtain the S-phase with different nitrogen concentrations and free of chromium-based precipitates. The control of nitrogen potential was made by pulsing the gas at predetermined times: 10/10, 05/15, 02/18, and 01/19, where the numbers represent the time in minutes that the nitrogen flow was kept on/off, respectively. For all pulsing conditions, the nitriding was carried out at 450 °C for 2 hours. After nitriding, specimens were characterized by means of optical (OM) and electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and microhardness. Results show that the nitrided layer thickness decreases with decreasing times of nitrogen pulse, and that lower times of nitrogen flow lead to lower precipitation of chromium nitrides. It can be thus concluded that the use of intermittent nitrogen flow is an alternative to control the nitrided layer in terms of thickness, hardness, and the amount of nitrogen present in phase ɣN (S-phase).

Summary: In CRISPR-Cas9-assisted knockin (KI) in zygotes, a remaining challenge is routinely achieving high-efficiency KI of large (kilobase-sized) DNA elements. Here, we focus on the timing of pronuclear injection and establish a reliable homologous recombination (HR)-based method to generate large KIs in zygotes compared with two other types of KI strategies involving distinct DNA repair pathways. At the ROSA26 locus, pronuclear injection with CRISPR RNA (crRNA), trans-activating crRNA (tracrRNA), and Cas9 protein at the S phase by using the HR-based method yields the most efficient and accurate KIs (up to 70%). This approach is also generally effective for generating large KI alleles at other gene loci. We further apply our method to efficiently obtain biallelic ROSA26 KIs by sequential injection into both pronuclei. Our results suggest that delivery of genome editing components and donor DNA into S-phase zygotes is critical for efficient KI of large DNA elements.

Low-temperature treatments have become a valuable method for improving the surface hardness of stainless steels, and thus their tribological properties, without impairing their corrosion resistance. By using treatment temperatures lower than those usually employed for nitriding or carburizing of low alloy steels or tool steels, it is possible to obtain a fairly fast (interstitial) diffusion of nitrogen and/or carbon atoms; on the contrary, the diffusion of substitutional atoms, as chromium atoms, has significantly slowed down, therefore the formation of chromium compounds is hindered, and corrosion resistance can be maintained. As a consequence, nitrogen and carbon atoms can be retained in solid solutions in an iron lattice well beyond their maximum solubility, and supersaturated solid solutions are produced. Depending on the iron lattice structure present in the stainless steel, the so-called “expanded austenite” or “S-phase”, “expanded ferrite”, and “expanded martensite” have been reported to be formed. This review summarizes the main studies on the characteristics and properties of these “expanded” phases and of the modified surface layers in which these phases form by using low-temperature treatments. A particular focus is on expanded martensite and expanded ferrite. Expanded austenite–S-phase is also discussed, with particular reference to the most recent studies.

Cerebellar neurons are generated from the rhombic lip and the neuroepithelium. In this study, we analyze the histogenesis of the cerebellar neuroepithelium in terms of cellular kinetics. The experimental animals are the offspring of pregnant dams injected with 5-bromo-2ʹ-deoxyuridine (BrdU) on embryonic day 13. We infer the fraction of S-phase cells by examining a range of survival times after a single BrdU-exposure and a cumulative BrdU-labeling sequence, which allow for the derivation of cell-cycle parameters and phase durations. The current results indicate that the dose of BrdU employed (35 mg/kg) provides saturation S-phase labeling from at least 1 h after marker delivery. The duration of G2, mitotic phase, and G1 are 1.2, 0.5, and 6.9 h, respectively. The duration for the S-phase, growth fraction, and the whole cycle are obtained on the basis of two proliferative models, steady-state and exponential growth. Both models provided similar results. In conclusion, our results indicate that the steady-state and the cumulative S-phase labeling paradigms can be adopted to analyze cell cycle parameters in the cerebellar neuroepithelium. Current results can help in understanding the regulatory mechanisms of cerebellar histogenesis and the cell biological mechanisms of the proliferative cycle of the neuroepithelium. [ABSTRACT FROM AUTHOR]

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or γN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

The halopyrimidine 5-bromo-2'-deoxyuridine (BrdU) is an exogenous marker of DNA synthesis. Since the introduction of monoclonal antibodies against BrdU, an increasing number of methodologies have been used for the immunodetection of this synthesized bromine-tagged base analogue into replicating DNA. BrdU labeling is widely used for identifying neuron precursors and following their fate during the embryonic, perinatal, and adult neurogenesis in a variety of vertebrate species including birds, reptiles, and mammals. Due to BrdU toxicity, its incorporation into replicating DNA presents adverse consequences on the generation, survival, and settled patterns of cells. This may lead to false results and misinterpretation in the identification of proliferative neuroblasts. In this review, I will indicate the detrimental effects of this nucleoside during the development of the central nervous system, as well as the reliability of BrdU labeling to detect proliferating neuroblasts. Moreover, it will show factors influencing BrdU immunodetection and the contribution of this nucleoside to the study of prenatal, perinatal, and adult neurogenesis. Human adult neurogenesis will also be discussed. It is my hope that this review serves as a reference for those researchers who focused on detecting cells that are in the synthetic phase of the cell cycle., Competing Interests: None

Cellular reduction of carcinogenic chromium(VI) causes several forms of Cr-DNA damage with different genotoxic properties. Chromate-treated cultured cells have shown a strong proapoptotic activity of the DNA damage-sensitive transcription factor p53. However, induction of p53 transcriptional targets by Cr(VI) in rodent lungs was weak or undetectable. We examined Cr(VI) effects on the p53 pathway in human cells with restored levels of ascorbate that acts as a principal reducer of Cr(VI) in vivo but is nearly absent in standard cell cultures. Ascorbate-restored H460 and primary human cells treated with Cr(VI) contained higher levels of p53 and its Ser15 phosphorylation, which were induced by ATR kinase. Cr(VI)-stimulated p53 phosphorylation occurred in S-phase by a diffusible pool of ATR that was separate from the chromatin-bound pool targeting DNA repair substrates at the sites of toxic mismatch repair (MMR) of Cr-DNA adducts. Even when more abundantly present than after exposure to the radiomimetic bleomycin, Cr(VI)-stabilized p53 showed a much more limited activation of its target genes in two types of primary human cells. No increases in mRNA were found for nucleotide excision repair factors and a majority of proapoptotic genes. A weak transcription activity of Cr(VI)-upregulated p53 was associated with its low lysine acetylation in the regulatory C-terminal domain, resulting from the inability of Cr(VI) to activate ATM in ascorbate-restored cells. Thus, p53 activation by ascorbate-metabolized Cr(VI) represents a limited genome-protective response that is defective in upregulation of DNA repair genes and proapoptotic transcripts for elimination of damaged cells. [ABSTRACT FROM AUTHOR]

Low temperature plasma nitriding and nitrocarburizing were experimented to study the effect of these treatments on the surface hardness and the expanded martensite layer (α' N layer) thickness of the AISI 630 martensitic precipitation hardening stainless steel. Plasma nitrided samples show thicker α' N layer thickness (about 16 µm) but their corrosion resistances are worse than the untreated sample. On the other hand, plasma nitrocarburized samples show better corrosion resistance, whereas their α' N layer thickness values (around 10 µm) are very low. But the surface hardness values of both the nitrided and nitrocarburized samples are quite similar (approximately 1250 HV 0.05). The purpose of the present study is to combine the beneficial effects of both plasma nitriding and plasma nitrocarburizing. Therefore, in order to get a higher surface hardness and thicker α' N layer thickness with good corrosion behavior, a series of combination of simultaneous nitriding and nitrocarburizing were investigated. This process is termed here as " Multiple Nitriding-Nitrocarburizing process ". The highest surface hardness (around 1350 HV 0.05), highest α' N layer thickness (around 16 µm) and best corrosion resistance are achieved when treated with this noble process, compared to single plasma nitriding or single plasma nitrocarburizing process. • This research is based on experiments to develop know-how that can be applied directly in the industrial field. • Thus, it is a kind of technology development process through trial and error methods. • The originality of this work is to combine these two beneficial properties of nitriding and nitrocarburizing processes. • Repetition of a combination of nitriding and nitrocarburizing processes is made for the first time in my laboratory. • Optimized conditions for thicker α' N layer thickness, higher surface hardness and good corrosion resistance were finalized. [ABSTRACT FROM AUTHOR]

During the first rapid divisions of early development in many species, the DNA:cytoplasm ratio increases until the midblastula transition (MBT) when transcription resumes and cell cycles lengthen. S phase is very rapid in early embryos, about 20–30 times faster than in differentiated cells. Using a combination of DNA fiber studies and a Xenopus laevis embryonic in vitro replication system, we show that S phase slows down shortly after the MBT owing to a genome wide decrease of replication eye density. Increasing the dNTP pool did not accelerate S phase or increase replication eye density implying that dNTPs are not rate limiting for DNA replication at the Xenopus MBT. Increasing the ratio of DNA:cytoplasm in egg extracts faithfully recapitulates changes in the spatial replication program in embryos, supporting the hypothesis that titration of soluble limiting factors could explain the observed changes in the DNA replication program at the MBT in Xenopus laevis. [ABSTRACT FROM AUTHOR]

The morphological evolution behavior of S-phase in 2024 aluminum alloy under uniaxial tensile creep test at 448 and 463 K under 175, 200 and 225 MPa was studied in detail by HRTEM. Results showed that the S-phase was arranged in the zigzag manner, similar to a zebra pattern, under tensile stress at 448-463 K. And it maintained cubic structure, remarkably grew along the tension direction under uniaxial tensile stress, but grew minimally perpendicular to the stress direction. Compared with applied stress, the temperature had a greater effect on the growth of S-phase. The length of S-phase reached 100 ± 20 nm after testing for 24 h at 448 K under 200 MPa and 200 ± 50 nm after testing for 18 h at 463 K under 175 MPa. The S-phase not only grew significantly in length but also coarsened at 463 K, the lamellar structure becoming fuzzy, which caused the alloy to enter the tertiary creep stage, unsuitable for creep-aging forming. [ABSTRACT FROM AUTHOR]

Numerous studies exploring oncogenic Ras or manipulating physiological Ras signalling have established an irrefutable role for Ras as driver of cell cycle progression. Despite this wealth of information the precise signalling timeline and effectors engaged by Ras, particularly during G1, remain obscure as approaches for Ras inhibition are slow-acting and ill-suited for charting discrete Ras signalling episodes along the cell cycle. We have developed an approach based on the inducible recruitment of a Ras-GAP that enforces endogenous Ras inhibition within minutes. Applying this strategy to inhibit Ras stepwise in synchronous cell populations revealed that Ras signaling was required well into G1 for Cyclin D induction, pocket protein phosphorylation and S-phase entry, irrespective of whether cells emerged from quiescence or G2/M. Unexpectedly, Erk, and not PI3K/Akt or Ral was activated by Ras at mid-G1, albeit PI3K/Akt signalling was a necessary companion of Ras/Erk for sustaining cyclin-D levels and G1/S transition. Our findings chart mitogenic signaling by endogenous Ras during G1 and identify limited effector engagement restricted to Raf/MEK/Erk as a cogent distinction from oncogenic Ras signalling. [ABSTRACT FROM AUTHOR]

Indonesian black rice cv Cempo Ireng was evaluated for cancer prevention using a T47D cell line model. Methanolic extract of black rice bran (BRB) showed cytotoxicity with an IC50 of 522.13 µg/ml. This result was in contrast to water extract of BRB, which yielded an IC50 of more than 6000 µg/ml. From the methanolic extract of BRB, its 6 fractions were found from the preparative TLC performance, with Rf values ranging from 0 to 0.97. According to the MTT assay of all fractions, fraction 3 (F3) had the lowest IC50 (60.17 ± 1.72µg/ml), while fraction 2 (F2) had an IC50 of 64.3 ± 0.61µg/ml. However, F2 showed the highest induction of apoptosis, i.e. about 75.39 ± 0.43% compared to the T47D cells without treatment (control) (about 8.39 ± 0.16%) and with doxorubicin treatment (about 41.30 ± 0.08%). Furthermore, fraction 5 (F5) not only induced apoptosis but also increased the S-phase arrest percentage (60.36 ± 2.07%), which was significantly higher than for the other treatments. Therefore, each fraction of BRB showed different cytotoxic responses to T47D cells. [ABSTRACT FROM AUTHOR]

Austenitic steels are known for their high corrosion resistance, but at the same time exhibit low hardness and wear resistance. While plasma nitriding improves tribological properties, it also affects corrosion behavior depending on the electrolyte. In this paper, a model should be present, that allows to predict the thickness of the s-Phase and the change of the corrosion behavior in plasma nitriding processes for austenitic stainless steels. For this purpose, different processes under specific variation of the temperature ranging from 360 °C to 450 °C and duration of 10 h to 24 h were performed. Other process parameters such as the voltage or gas mixture remained constant. There are two stages in the developed model: the first one allows the prediction of the s-Phase thickness by isothickness curves. The second stage implements an evaluation system of the corrosion resistance. By assigning numerical values for the observed corrosion, a quantitative comparison is allowed, which is represented by a color scaling. A model was created to estimate the thickness of the s-phase and the change in corrosion behavior in plasma nitriding processes for austenitic stainless steels in advance. With this tool, the user can see how much one property is affected at the expense of the other. [Display omitted] • Prediction of s-Phase thickness after plasma nitriding of 316L • Evaluation of corrosion resistance after different plasma nitriding by a formula • Visualization of s-Phase thickness and corrosion behavior after plasma nitriding • Development of a tool for simultaneous optimization of surface properties of 316L [ABSTRACT FROM AUTHOR]

Fatigue tests were performed on the forged aluminum alloy EN AW-2618A in the T61 state. Different stress ratios (R = −1, R = 0.1) were selected to study the influence of mean stress on fatigue life. Two overaged states (10 h/230 °C, 1000 h/230 °C) were also tested to investigate the influence of overaging on fatigue life. Transmission electron microscopy (TEM) was used to characterize the precipitates (S-phase), which are mainly responsible for the strength of the alloy. A fractographic analysis was also performed to determine the failure mode. Overaging reduces the fatigue life compared to the T61 state. The longer the aging time, the lower the fatigue resistance. The reason is the decrease in (yield) strength, which correlates with the radius of the S-phase: the precipitate radius increases by a factor of approximately two for the overaged states compared to the initial state. The analysis of the fracture surfaces showed crack initiation occurs predominantly on the outer surface and is associated with the primary phases. [ABSTRACT FROM AUTHOR]