scEpiTools: a database to comprehensively interrogate analytic tools for single-cell epigenomic data

Recent advances in single-cell sequencing technologies provide significant implications for understanding cellular heterogeneity,developmental biology,and disease mechanisms.To fully exploit the potential of these data,numerous tools have been proposed for upstream and downstream analyses.In the the single-cell RNA sequencing(scRNA-seq)community,scRNA-tools(Zappia et al.,2018)was proposed to help researchers navigate the plethora of tools by category.Since its inception,scRNA-tools has been widely used and its updated version further reveals trends in the field with over 1000 collected tools(Zappia and Theis,2021),providing a valuable guidance in selecting tools for analyses.

Non-isolated stacked bidirectional soft-switching DC-DC converter with PWM plus phase-shift control scheme

In this paper, a non-isolated stacked bidirectional DC-DC converter with zero-voltage-switching(ZVS) is introduced for the high step-up/step-down conversion systems. The extremely narrow turn-on and/or turn-off duty cycle existing in the conventional bidirectional buck-boost converters can be extended due to the stacked module configuration for large voltage conversion ratio applications. Furthermore, the switch voltage stress is halved because of the series connection of half bridge modules. The PWM plus phase-shift control strategy is employed, where the duty cycle is adopted to regulate the voltages between the input and output sides and the phaseshift angle is applied to achieve the power flow regulation.This decoupled control scheme can not only realize seamless bidirectional transition operation, but also achieve adaptive voltage balance for the power switches. In addition, ZVS soft-switching operation for all active switches is realized to minimize the switching losses. Finally, a prototype of 1 kW operating at 100 kHz is built and tested to demonstrate the effectiveness of the proposed converter and the control strategy.

A composite of Ni-Fe-Zn layered double hydroxides/biochar for atrazine removal from aqueous solution

This study assembled corn stalk-derived biochar(BC)with layered double hydroxide(LDH)through a rapid coprecipitation of biochar and metal(Ni/Fe/Zn)hydroxide precipitates.A BC and LDH composite(BC-LDH)and modified BC-LDH material after heating(BC-LDH-P)were prepared successfully for atrazine adsorptive removal.The physicochemical properties of the synthesized samples were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared(FT-IR),and X-ray photoelectron spectroscopy(XPS).Batch experiments were conducted to study the sorption of atrazine onto BC,BC-LDH,and BC-LDH-P from the aqueous solution.The adsorption of atrazine onto BC-LDH and BC-LDH-P were performed following with the pseudo-second-order kinetic model,and the sorption isotherms agreed well with the Freundlich fitting model.The adsorption amounts of the three materials are arranged in descending order is as follows:BC-LDH-P>BC-LDH>BC(143.15>123.10>95.93 mg g−1,respectively).Due to the high crystallinity of the LDH material and the high binding degree with biochar,Ni/Fe/Zn-LDH biochar composites offer a potential alternative to a carbon-based adsorbent for atrazine removal from aqueous solution.