Harmonic mode‐locking (HML) is an important technique enabling the generation of high‐repetition‐rate ultrashort pulses. Using an emerging time‐stretch dispersive Fourier transform technique, the ...experimental observation of the entire buildup process of the passive HML state in an ultrafast fiber laser is reported here. It is unveiled that the whole process of HML buildup successively undergoes seven different ultrafast phases: raised relaxation oscillation, spectral beating behavior, birth of a giant pulse, self‐phase‐modulation‐induced instability, pulse splitting, repulsion and separation of multiple pulses, and a stable HML state. It is observed that the multiple HML pulses originate from a single‐pulse splitting phenomenon and a remarkable breathing behavior occurs at an early stage of the HML buildup process. The numerical results confirm that the effects of dispersive wave, gain depletion and recovery, and acoustic wave play key roles in the earlier, middle, and later stages of this HML buildup process, respectively; as well, the acoustic resonance in the single‐mode fiber stabilizes the final HML state of lasers.
The experimental observation of the entire buildup process of the passive harmonic mode‐locking (HML) state, which undergoes seven different ultrafast phases, is demonstrated. Multiple HML pulses originate from the single‐pulse splitting phenomenon. The acoustic resonance in the single‐mode fiber stabilizes the final HML state of lasers.
A copper-free Sandmeyer-type fluorosulfonylation reaction is reported. Utilizing Na2S2O5 and Selectfluor as the sulfur dioxide and fluorine sources, respectively, aryldiazonium salts were transformed ...into sulfonyl fluorides. The one-pot direct synthesis of sulfonyl fluorides from aromatic amines was also realized via in situ diazotization. The practicality of this method was demonstrated by the broad functional group tolerance, gram-scale synthesis, and late-stage fluorosulfonylation of natural products and pharmaceuticals.
Hypervolume is widely used as a performance indicator in the field of evolutionary multiobjective optimization (EMO). It is used not only for performance evaluation of EMO algorithms (EMOAs) but also ...in indicator-based EMOAs to guide the search. Since its initial proposal in the late 1990s, a wide variety of studies have been done on various topics, including hypervolume calculation, optimal μ-distribution, subset selection, hypervolume-based EMOAs, and extensions of the hypervolume indicator. However, currently there is no work to systematically survey the hypervolume indicator for these topics whereas it has been frequently used in the EMO field. This article aims to fill this gap and provide a comprehensive survey on the hypervolume indicator. We expect that this survey will help EMO researchers to understand the hypervolume indicator more deeply and thoroughly, and promote further utilization of the hypervolume indicator in the EMO field.
Abstract
Mode-locked lasers have been widely used to explore interactions between optical solitons, including bound-soliton states that may be regarded as “photonic molecules”. Conventional ...mode-locked lasers normally, however, host at most only a few solitons, which means that stochastic behaviours involving large numbers of solitons cannot easily be studied under controlled experimental conditions. Here we report the use of an optoacoustically mode-locked fibre laser to create hundreds of temporal traps or “reactors” in parallel, within each of which multiple solitons can be isolated and controlled both globally and individually using all-optical methods. We achieve on-demand synthesis and dissociation of soliton molecules within these reactors, in this way unfolding a novel panorama of diverse dynamics in which the statistics of multi-soliton interactions can be studied. The results are of crucial importance in understanding dynamical soliton interactions and may motivate potential applications for all-optical control of ultrafast light fields in optical resonators.
Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons and aggregation of α‐synuclein (α‐syn). Ferroptosis, a form of cell death induced by ...iron accumulation and lipid peroxidation, is involved in the pathogenesis of PD. It is unknown whether melatonin receptor 1 (MT1) modulates α‐syn and ferroptosis in PD. Here, we used α‐syn preformed fibrils (PFFs) to induce PD models in vivo and in vitro. In PD mice, α‐syn aggregation led to increased iron deposition and ferroptosis. MT1 knockout exacerbated these changes and resulted in more DA neuronal loss and severe motor impairment. MT1 knockout also suppressed the Sirt1/Nrf2/Ho1/Gpx4 pathway, reducing resistance to ferroptosis, and inhibited expression of ferritin Fth1, leading to more release of ferrous ions. In vitro experiments confirmed these findings. Knockdown of MT1 enhanced α‐syn PFF‐induced intracellular α‐syn aggregation and suppressed expression of the Sirt1/Nrf2/Ho1/Gpx4 pathway and Fth1 protein, thereby aggravating ferroptosis. Conversely, overexpression of MT1 reversed these effects. Our findings reveal a novel mechanism by which MT1 activation prevents α‐syn‐induced ferroptosis in PD, highlighting the neuroprotective role of MT1 in PD.
Brillouin scattering has been widely exploited for advanced photonics functionalities such as microwave photonics, signal processing, sensing, lasing, and more recently in micro- and nano-photonic ...waveguides. Most of the works have focused on the opto-acoustic interaction driven from the core region of micro- and nano-waveguides. Here we observe, for the first time, an efficient Brillouin scattering generated by an evanescent field nearby a single-pass sub-wavelength waveguide embedded in a pressurised gas cell, with a maximum gain coefficient of 18.90 ± 0.17 m
W
. This gain is 11 times larger than the highest Brillouin gain obtained in a hollow-core fibre and 79 times larger than in a standard single-mode fibre. The realisation of strong free-space Brillouin scattering from a waveguide benefits from the flexibility of confined light while providing a direct access to the opto-acoustic interaction, as required in free-space optoacoustics such as Brillouin spectroscopy and microscopy. Therefore, our work creates an important bridge between Brillouin scattering in waveguides, Brillouin spectroscopy and microscopy, and opens new avenues in light-sound interactions, optomechanics, sensing, lasing and imaging.
Here we report a method for the site-selective intermolecular C(sp3)–H amination of carboxamides by merging transition-metal catalysis and the hydrogen atom transfer strategy. The reaction proceeds ...through a sequence of favorable single-electron transfer, 1,5-hydrogen atom transfer, and C–N cross-coupling steps, thus allowing access to a series of desired products. This reaction could accommodate a wide diversity of nitrogen nucleophiles as well as demonstrate excellent chemoselectivity and functional group compatibility.
Purposes
Highly concentrated monoclonal antibody (mAb) formulations for subcutaneous administration are becoming increasingly preferred within the biopharmaceutical industry for ease of use and ...improved patient compliance. A common phenomenon observed in the industry is that osmolality detected via freezing-point depression (FPD) in high-concentration mAb formulations is much higher than the theoretical concentrations, yet the occurrence of this phenomenon and its possible safety issues have been rarely reported.
Methods
The current study summarized theoretical osmolality of U.S. Food and Drug Administration approved high-concentration mAb formulations and evaluated effects of high osmolality on safety using hemolysis experiments for the first time. Two mAbs formulated at 150 mg/mL were used as models and configured into two isotonic solutions: a, a theoretically calculated molarity in the isotonic range (H) and b, an osmolality value measured via the FPD in the isotonic range (I). The H and I formulations of each mAb were individually subjected to hemolysis experiments, and the hemolysis rates of the two formulations of the same mAb were compared. Besides, the effect of mAb concentration on osmolality detected by FPD was explored as well.
Results
The results indicated that the hemolysis rates were similar between the H and I formulations of mAbs at the same sample addition volume, and the osmolality values increased approximately linearly with the increase in mAb concentration.
Conclusions
High osmolality for high-concentration mAb formulations would not affect product safety and the excipients could be added at relatively high levels to maintain product stability, especially for labile products.
Establishing a reasonable and effective feature system is the basis of credit risk early warning. Whether the system design is appropriate directly determines the accuracy of the credit risk ...evaluation results. In this paper, we proposed a feature system through a validity index with maximum discrimination and commercial banks' loan profit maximization. First, the first objective function is the minimum validity index constructed by the intra-class, between-class, and partition coefficients. The maximum difference between the right income and wrong cost is taken as the second objective function to obtain the optimal feature combination. Second, the feature weights are obtained by calculating the change in profit after deleting each feature with replacement to the sum of all change values. An empirical analysis of 3, 425 listed companies from t -1 to t -5 time windows reveals that five groups of feature systems selected from 614 features can distinguish between defaults and non-defaults. Compared with 14 other models, it is found that the feature systems can provide at least five years' prediction and enable financial institutions to obtain the maximum profit.
PDF
