Metal Material Processing Using Femtosecond Lasers: Theories, Principles, and Applications.

Metal material processing using femtosecond lasers is a useful technique, and it has been widely employed in many applications including laser microfabrication, laser surgery, and micromachining. The basic mechanisms of metal processing using femtosecond lasers are reviewed in this paper and the characteristics and theory of laser processing are considered. In addition to well-known processes, the recent progress relating to metals processing with femtosecond lasers, including metal material drilling, metal ablation thresholds, micro/nano-surface modification, printed circuit board (PCB) micromachining, and liquid metal (LM) processing using femtosecond lasers, is described in detail. Meanwhile, the application of femtosecond laser technology in different fields is also briefly discussed. This review concludes by highlighting the current challenges and presenting a forward-looking perspective on the future of the metal laser processing field.

Exploring the neurotoxicity of chiral dinotefuran towards nicotinic acetylcholine receptors: Enantioselective insights into species selectivity.

Dinotefuran is a chiral neonicotinoid that is widely distributed in environmental matrices, but its health risks to different organisms are poorly understood. This study investigated the neurotoxic responses of honeybee/cotton aphid nicotinic acetylcholine receptors (nAChRs) to chiral dinotefuran at the enantiomeric scale and demonstrated the microscopic mechanism of species selectivity in nAChR-mediated enantioselective neurotoxicity. The findings indicated that (S)-dinotefuran had a higher affinity for honeybee nAChR than (R)-dinotefuran whereas both enantiomers exhibited similar bioactivity toward cotton aphid nAChR. The results of dynamic neurotoxic processes indicated the association of conformational changes induced by chiral dinotefuran with its macroscopic neurotoxicity, and (R)-dinotefuran, which exhibit low toxicity to honeybee, was found to induce significant conformational changes in the enantioselective neurotoxic reaction, as supported by the average root-mean-square fluctuation (0.35 nm). Energy decomposition results indicated that electrostatic contribution (ΔGele) is the critical energy term that leads to substantial enantioselectivity, and both Trp-51 (－2.57 kcal mol-1) and Arg-75 (－4.86 kcal mol-1), which form a hydrogen-bond network, are crucial residues in mediating the species selectivity for enantioselective neurotoxic responses. Clearly, this study provides experimental evidence for a comprehensive assessment of the health hazards of chiral dinotefuran.

Promotion of nitrogen removal in a denitrification process elevated by zero-valent iron under low carbon-to-nitrogen ratio.

The nitrogen removal efficiency and distribution of microbial community in a denitrification process aided by zero-valent iron (ZVI) under low carbon-to-nitrogen ratio (C/N) were assessed in this study. Experimental results demonstrated that the nitrogen removal efficiency (TNRE) increased to 96.4 ± 2.72% and 63.3 ± 4.02% after continuous addition of ZVI with molar ratio of ZVI to nitrate (NO3--N) (ZVI/N) of 6 at C/N of 3 and 2, respectively, which was 4% and 7.7% higher than the blank one. Meanwhile, extracellular polymeric substance (EPS) could be used as electron transfer medium and endogenous carbon source for denitrification system and also the production of which increased by 28.43% and 53.10% under ZVI stimulation compared to the control group. Finally, a symbiotic system composed by autotrophic and heterotrophic denitrification bacteria was formed by aid of ZVI. This study proposed new insights into denitrification process improved by ZVI.

Principles and Applications of Resonance Energy Transfer Involving Noble Metallic Nanoparticles.

Over the past several years, resonance energy transfer involving noble metallic nanoparticles has received considerable attention. The aim of this review is to cover advances in resonance energy transfer, widely exploited in biological structures and dynamics. Due to the presence of surface plasmons, strong surface plasmon resonance absorption and local electric field enhancement are generated near noble metallic nanoparticles, and the resulting energy transfer shows potential applications in microlasers, quantum information storage devices and micro-/nanoprocessing. In this review, we present the basic principle of the characteristics of noble metallic nanoparticles, as well as the representative progress in resonance energy transfer involving noble metallic nanoparticles, such as fluorescence resonance energy transfer, nanometal surface energy transfer, plasmon-induced resonance energy transfer, metal-enhanced fluorescence, surface-enhanced Raman scattering and cascade energy transfer. We end this review with an outlook on the development and applications of the transfer process. This will offer theoretical guidance for further optical methods in distance distribution analysis and microscopic detection.

Novel BCL-2 Inhibitor Lisaftoclax in Relapsed or Refractory Chronic Lymphocytic Leukemia and Other Hematologic Malignancies: First-in-Human Open-Label Trial.

PURPOSE: This global phase I trial investigated the safety, efficacy, pharmacokinetics, and pharmacodynamics of lisaftoclax (APG-2575), a novel, orally active, potent selective B-cell lymphoma 2 (BCL-2) inhibitor, in patients with relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (R/R CLL/SLL) and other hematologic malignancies (HMs). PATIENTS AND METHODS: Maximum tolerated dose (MTD) and recommended phase II dose were evaluated. Outcome measures were safety and tolerability (primary) and pharmacokinetic variables and antitumor effects (secondary). Pharmacodynamics in patient tumor cells were explored. RESULTS: Among 52 patients receiving lisaftoclax, MTD was not reached. Treatment-emergent adverse events (TEAEs) included diarrhea (48.1%), fatigue (34.6%), nausea (30.8%), anemia and thrombocytopenia (28.8% each), neutropenia (26.9%), constipation (25.0%), vomiting (23.1%), headache (21.2%), peripheral edema and hypokalemia (17.3% each), and arthralgia (15.4%). Grade ≥ 3 hematologic TEAEs included neutropenia (21.2%), thrombocytopenia (13.5%), and anemia (9.6%), none resulting in treatment discontinuation. Clinical pharmacokinetic and pharmacodynamic results demonstrated that lisaftoclax had a limited plasma residence and systemic exposure and elicited rapid clearance of malignant cells. With a median treatment of 15 (range, 6-43) cycles, 14 of 22 efficacy-evaluable patients with R/R CLL/SLL experienced partial responses, for an objective response rate of 63.6% and median time to response of 2 (range, 2-8) cycles. CONCLUSIONS: Lisaftoclax was well tolerated, with no evidence of tumor lysis syndrome. Dose-limiting toxicity was not reached at the highest dose level. Lisaftoclax has a unique pharmacokinetic profile compatible with a potentially more convenient daily (vs. weekly) dose ramp-up schedule and induced rapid clinical responses in patients with CLL/SLL, warranting continued clinical investigation.

Dissecting the Enantioselective Neurotoxicity of Isocarbophos: Chiral Insight from Cellular, Molecular, and Computational Investigations.

Chiral organophosphorus pollutants are found abundantly in the environment, but the neurotoxicity risks of these asymmetric chemicals to human health have not been fully assessed. Using cellular, molecular, and computational toxicology methods, this story is to explore the static and dynamic toxic actions and its stereoselective differences of chiral isocarbophos toward SH-SY5Y nerve cells mediated by acetylcholinesterase (AChE) and further dissect the microscopic basis of enantioselective neurotoxicity. Cell-based assays indicate that chiral isocarbophos exhibits strong enantioselectivity in the inhibition of the survival rates of SH-SY5Y cells and the intracellular AChE activity, and the cytotoxicity of (S)-isocarbophos is significantly greater than that of (R)-isocarbophos. The inhibitory effects of isocarbophos enantiomers on the intracellular AChE activity are dose-dependent, and the half-maximal inhibitory concentrations (IC50) of (R)-/(S)-isocarbophos are 6.179/1.753 µM, respectively. Molecular experiments explain the results of cellular assays, namely, the stereoselective toxic actions of isocarbophos enantiomers on SH-SY5Y cells are stemmed from the differences in bioaffinities between isocarbophos enantiomers and neuronal AChE. In the meantime, the modes of neurotoxic actions display that the key amino acid residues formed strong noncovalent interactions are obviously different, which are related closely to the molecular structural rigidity of chiral isocarbophos and the conformational dynamics and flexibility of the substrate binding domain in neuronal AChE. Still, we observed that the stable "sandwich-type π-π stacking" fashioned between isocarbophos enantiomers and aromatic Trp-86 and Tyr-337 residues is crucial, which notably reduces the van der Waals' contribution (ΔGvdW) in the AChE-(S)-isocarbophos complexes and induces the disparities in free energies during the enantioselective neurotoxic conjugations and thus elucidating that (S)-isocarbophos mediated by synaptic AChE has a strong toxic effect on SH-SY5Y neuronal cells. Clearly, this effort can provide experimental insights for evaluating the neurotoxicity risks of human exposure to chiral organophosphates from macroscopic to microscopic levels.

Principle and Applications of Multimode Strong Coupling Based on Surface Plasmons.

In the past decade, strong coupling between light and matter has transitioned from a theoretical idea to an experimental reality. This represents a new field of quantum light-matter interaction, which makes the coupling strength comparable to the transition frequencies in the system. In addition, the achievement of multimode strong coupling has led to such applications as quantum information processing, lasers, and quantum sensors. This paper introduces the theoretical principle of multimode strong coupling based on surface plasmons and reviews the research related to the multimode interactions between light and matter. Perspectives on the future development of plasmonic multimode coupling are also discussed.

Cinnamon and Aspirin for Mild Ischemic Stroke or Transient Ischemic Attack: A Pilot Trial.

PURPOSE: Cinnamon can reduce levels of blood lipids, blood glucose, and inflammation, which are risk factors for ischemic stroke and transient ischemic attack (TIA).The goal of this study was to observe the safety and efficacy of aspirin combined with cinnamon in the treatment of patients with mild stroke or TIA. METHODS: This pilot study included patients with mild stroke or TIA treated at Guangdong Provincial People's Hospital-Nanhai Hospital between January 2014 and December 2016. The primary end point was recurrent stroke (within 90 days after the first attack; intention-to-treat analysis). The secondary end points included biochemical indices, carotid color Doppler ultrasound, safety indices, and adverse reactions. FINDINGS: A total of 122 patients were included, including 62 in the aspirin-cinnamon group (41 men and 21 women; mean age, 62.0 [3.5] years) and 60 in the aspirin-placebo group (40 men and 20 women; mean age, 63.0 [3.2] years). The number of participants with recurrent stroke was two (3.2%) and nine (15.0%) in the aspirin-cinnamon group and the aspirin-placebo group, respectively (P = 0.002). Compared with aspirin-cinnamon, aspirin-placebo rates of unstable plaque and severe vascular stenosis were higher, whereas the rate of mild vascular stenosis with aspirin-cinnamon was higher than with aspirin-placebo (P < 0.05). One case of mild to moderate upper gastrointestinal bleeding in each group was observed. IMPLICATIONS: Among patients with TIA or mild ischemic stroke, the combination of cinnamon and aspirin could be superior to aspirin alone for reducing the risk of 90-day recurrent stroke.

Autologous Endothelial Progenitor Cells Transplantation for Acute Ischemic Stroke: A 4-Year Follow-Up Study.

Transplantation of endothelial progenitor cells (EPCs) is a proven safe and effective method for treatment of cerebral ischemia in animal experiments. However, safety and efficacy need to be determined in clinical trials. We performed a two-center, randomized, placebo-controlled phase I/IIa trial with blinded outcome assessment on 18 patients with acute cerebral infarct within the middle cerebral artery territory, and followed for up to 4 years. Autologous ex vivo expanded EPCs were injected intravenously in the EPC group, and patients who received saline or autologous bone marrow stromal cells served as control groups. Mortality of any cause, adverse events, and new-onset comorbidities were monitored. Changes in neurological deficits were assessed at different time points. We found no toxicity events or infusional or allergic reactions in any treated group. Three patients in the placebo group died during the 4-year follow-up. We found that the EPC group had fewer serious adverse events compared with the placebo-controlled group, although there were no statistical differences in mortality among the three groups. Furthermore, there was no significant difference in neurological or functional improvement observed among the three groups, except for the Scandinavia Stroke Scale score at 3 months between the EPC group and placebo-controlled group. Autologous transplantation of EPCs appears to improve long-term safety in acute cerebral infarct patients, supporting the feasibility of this novel method for treatment of ischemic stroke (ClinicalTrials.gov: NCT01468064). Stem Cells Translational Medicine 2019;8:14-21.

[Co(III)(cyclen)Cl2]Cl is selectively cytotoxic to human leukaemia cells.

Co(III)-cyclen complexes are known to cause DNA strand breaks by hydrolytically cleaving the phosphodiester backbone via a mechanism that does not require oxidation. Here, we report the first cytotoxicity study of [Co(III)(cyclen)Cl(2)]Cl (2), the parental example of this class of agent, which reveals that (2) is selectively toxic towards CCRF-CEM (IC(50)=32+/-10 microM), THP-1 (IC(50)=110+/-40 microM), and HL-60 (IC(50)=70+/-35 microM) human leukaemia cells, compared to human skin and lung fibroblasts (IC(50)>10 mM). Investigations of its effect on CCRF-CEM cells show it kills by apoptosis which was characterised by microscopy, flow cytometry, and in vitro NMR experiments. The latter involved measurement of the ratio of methylene and methyl (1)H resonances at 1.3 and 0.9 ppm, respectively, associated with the externalisation of membrane bound phosphatidyl serine. The NMR data indicate increasing lactate production during apoptosis, which implies involvement of the intrinsic mitochondrial pathway, a notion supported by down-regulation of Bcl-2 and up-regulation of Bax levels as detected by Western blotting.

In vitro assessment of novel transcription inhibitors and topoisomerase poisons in rhabdomyosarcoma cell lines.

PURPOSE: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Current chemotherapy regimes include the topoisomerase II poison etoposide and the transcription inhibitor actinomycin D. Poor clinical response necessitate identification of new agents to improve patient outcomes. METHODS: We assessed the in vitro cytotoxicity (MTT assay) of DNA intercalating agents in five established human RMS cell lines. These include novel classes of transcription inhibitors and topoisomerase poisons, previously shown to have potential as anti-cancer agents. RESULTS: Amongst the former agents, bisintercalating bis(9-aminoacridine-4-carboxamides) linked through the 9-position, and bis(phenazine-1-carboxamides) linked via their side chains, are compared with established transcription inhibitors. Amongst the latter, monofunctional acridine-4-carboxamides related to N-[2-(dimethylamino)ethyl]acridine-4-carboxamide, DACA, are compared with established topoisomerase poisons. CONCLUSIONS: Our findings specifically highlight the topoisomerase poison 9-amino-DACA, its 5-methylsulphone derivative, AS-DACA, and the bis(phenazine-1-carboxamide) transcription inhibitor MLN944/XR5944, currently in phase I trial, as candidates for further research into new agents for the treatment of RMS.

DNA threading bis(9-aminoacridine-4-carboxamides): effects of piperidine sidechains on DNA binding, cytotoxicity and cell cycle arrest.

We describe the synthesis of a series of DNA-threading bis(9-aminoacridine-4-carboxamides) comprising ethylpiperidino and N-methylpiperidin-4-yl sidechains, joined via neutral flexible alkyl chains, charged flexible polyamine chains and a semi-rigid charged piperazine linker. Their cytotoxicity towards human leukaemic cells gives IC(50) values ranging from 99 to 1100 nM, with the ethylpiperidino series generally being more cytotoxic than the N-methylpiperidin-4-yl series. Measurements with supercoiled DNA indicate that they bisintercalate.

Fast colorimetric detection of copper ions using L-cysteine functionalized gold nanoparticles.

This communication reports an efficient visual detection method of Cu2+ by L-cysteine functionalized gold nanoparticles in aqueous solution. Upon exposure to Cu2+, the gold nanoparticle solution changed from red to blue, in response to surface plasmon absorption of dispersed and aggregated nanoparticles. This colorimetric sensor allows a rapid quantitative assay of Cu2+ down to the concentration range of 10(-5) M. Recognition of Cu2+ and formation of the aggregates are proposed to occur via a 2 : 1 sandwich complex between L-cysteine and Cu2+.

HPLC analysis of discrete haptoglobin isoform N-linked oligosaccharides following 2D-PAGE isolation.

Glycosylation is a common but variable modification that regulates glycoprotein structure and function. We combined small format 2D-PAGE with HPLC to analyse discrete human haptoglobin isoform N-glycans. Seven major and several minor haptoglobin isoforms were detected by 2D-PAGE. N-Glycans released from Coomassie-stained gel spots using PNGase were labeled at their reducing termini with 2-aminobenzamide. HPLC analysis of selected major isoform N-glycans indicated that sialic acid composition determined their separation by isoelectric focussing. N-Glycans from two doublets of quantitatively minor isoforms were also analysed. Although separation of each pair of doublets was influenced by sialylation, individual spots within each doublet contained identical N-glycans. Thus, heterogeneity in minor haptoglobin isoforms was due to modifications distinct from N-glycan structure. These studies describe a simple method for analysing low abundance protein N-glycans and provide details of discrete haptoglobin isoform N-glycan structures which will be useful in proteomic analysis of human plasma samples.

Could redox-switched binding of a redox-active ligand to a copper(II) centre drive a conformational proton pump gate? A synthetic model study.

A proposal for a redox-linked conformational gate to proton translocation--a proton pump gate--based upon a transition-metal redox-switchable hemilabile ligand (RHL) system is made. Consideration of the requirements for such a system reveals copper(II) to be the ideal metal centre. To test the proposal and, thereby, to provide an artificial proton pump gate, the copper coordination chemistry of three tris(pyridylmethyl)amine (tpa) ligands with one "leg" (PY*) substituted at the 6-position of the pyridine ring by a dimethoxyphenyl (L(1)), a hydroquinone (H(2)L(2)) or a quinone (L(3)) substituent has been investigated. Crystal structures of sp-[Cu(kappa(4)N-L(1))Cl]Cl.3 H(2)O (sp=square pyramidal), sp-[Cu(kappa(3)N-H(2)L(2))Cl(2)] and tbp-[Cu(kappa(4)N,kappaO-HL(2))][PF(6)] (tbp=trigonal bipyramidal) have been determined. The Cu(I) complexes [Cu(L)(MeCN)(n)](+) (L=L(1), H(2)L(2)) display physicochemical properties consistent with a "dangling" PY* leg; from the NMR spectra, the barriers to inversion of the ligand amine donor for the Cu(I) complexes are estimated to be within the range of about 30-45 kJ mol(-1). In the Cu(II) complexes, coordination of the PY* leg is finely balanced and critically depends on the nature of the PY* substituent and the availability of potential co-ligand(s). For example, tbp-[Cu(kappa(4)N-L(1))Cl](+) reacts cleanly with Cl(-) ions to afford sp-[Cu(kappa(3)N-L(1))Cl(2)]; Vis/NIR spectrophotometric titrations suggest the affinity of tbp-[Cu(kappa(4)N-L(1))Cl](+) for Cl(-) ion in dichloromethane is 9.7 x 10(2) and is at least 10(4)-fold greater than that of tbp-[Cu(kappa(4)N-L(3))Cl](+). The complex sp-[Cu(kappa(3)N-H(2)L(2))Cl(2)] has a "dangling" PY* leg, in which an intramolecular OH(hydroquinone).N(pyridine) hydrogen bond "ties-up" the pyridyl nitrogen atom, and reacts with Brønsted bases to give tbp-[Cu(kappa(4)N,kappaO-HL(2))](+). Two-electron oxidation of sp-[Cu(kappa(3)N-H(2)L(2))Cl(2)] is linked to loss of two protons and a conformational change, and affords tbp-[Cu(kappa(4)N-L(3))Cl](+). The [Cu(kappa(3)N-H(2)L(2))Cl(2)]-[Cu(kappa(4)N-L(3))Cl](+) system provides a first demonstration of the critical step in the proposed proton pumping cycle, namely a redox-driven and proton-linked conformational change. The possible biological relevance of this work to proton pumping in cytochrome c oxidase is mentioned.