Simulation design of P–I–N-type all-perovskite solar cells with high efficiency

According to the good charge transporting property of perovskite, we design and simulate a p–i–n-type all-perovskite solar cell by using one-dimensional device simulator. The perovskite charge transporting layers and the perovskite absorber constitute the all-perovskite cell. By modulating the cell parameters, such as layer thickness values, doping concentrations and energy bands of n-, i-, and p-type perovskite layers, the all-perovskite solar cell obtains a high power conversion efficiency of 25.84%. The band matched cell shows appreciably improved performance with widen absorption spectrum and lowered recombination rate, so weobtain a high J_（sc） of 32.47 m A/cm^2. The small series resistance of the all-perovskite solar cell also benefits the high J_（sc）. The simulation provides a novel thought of designing perovskite solar cells with simple producing process, low production cost and high efficient structure to solve the energy problem.

A facile cell culture device for studying nuclear and mitochondrial response of endothelial cells to hydrostatic pressure

There is no clear consensus regarding how cells respond to hydrostatic pressure. This is largely attributable to the high heterogeneity among cell types and the diverse custom-made devices used in previous studies. The aim of this work was to develop a facile device that could mimic various pressure environments and then delineate the cellular response to pressure stimulus. The device described here achieved both stable and periodic pressurization without oxygen deprivation. The biological utility of the device was assessed using human umbilical vein endothelial cells. We found more stereoscopic nuclear morphology and re-distribution of lamin A/C under high hydrostatic pressure compared to control cells. Mass spectrometry-based proteomics analysis showed significant changes in mitochondria-related pathways. Western blot analysis confirmed that high hydrostatic pressure induced a tendency toward mitochondrial fusion. Increased mitochondrial activity was observed as well. In conclusion, this device can be readily applied in biological research and extend our understanding of cellular mechano-sensation and the associated changes in mitochondrial behaviors.

A titanium dioxide nanorod array as a high-affinity nano-bio interface of a microfluidic device for efficient capture of circulating tumor cells

Nanomaterials show promising opportunities to address clinical problems （such as insufficient capture of circulating tumor cells; CTCs） via the high surface area-to-volume ratio and high affinity for biological cells. However, how to apply these nanomaterials as a nano-bio interface in a microfluidic device for efficient CTC capture with high specificity remains a challenge. In the present work, we first found that a titanium dioxide （TiO2） nanorod array that can be conveniently prepared on multiple kinds of substrates has high affinity for tumor cells. Then, the TiO2 nanorod array was vertically grown on the surface of a microchannel with hexagonally patterned Si micropillars via a hydrothermal reaction, forming a new kind of a micro-nano 3D hierarchically structured microfluidic device. The vertically grown TiO2 nanorod array was used as a sensitive nano-bio interface of this 3D hierarchically structured microfluidic device, which showed high efficiency of CTC capture （76.7% ± 7.1%） in an artificial whole-blood sample.

Utilizing a microfluidic device to enrich and fluorescently detect circulating tumor cells

Circulating tumor cells(CTCs)are cancer cells that have propagated from primary tumor sites,spreading into the bloodstream as the cellular origin of fatal metastasis,and to secondary tumor sites.Capturing and analyzing CTCs is a kind of‘‘liquid biopsy'of the tumor that provides information about cancer changes over time and tailoring treatment[1].CTC enrichment and detection remains technologically challenging due to their extremely low concentra-

A practical guide to promote informatics-driven efficient biotopographic material development

Micro/nano topographic structures have shown great utility in many biomedical areas including cell therapies,tissue engineering,and implantable devices.Computer-assisted informatics methods hold great promise for the design of topographic structures with targeted properties for a specific medical application.To benefit from these methods,researchers and engineers require a highly reusable“one structural parameter-one set of cell responses”database.However,existing confounding factors in topographic cell culture devices seriously impede the acquisition of this kind of data.Through carefully dissecting the confounding factors and their possible reasons for emergence,we developed corresponding guideline requirements for topographic cell culture device development to remove or control the influence of such factors.Based on these requirements,we then suggested potential strategies to meet them.In this work,we also experimentally demonstrated a topographic cell culture device with controlled confounding factors based on these guideline requirements and corresponding strategies.A“guideline for the development of topographic cell culture devices”was summarized to instruct researchers to develop topographic cell culture devices with the confounding factors removed or well controlled.This guideline aims to promote the establishment of a highly reusable“one structural parameter-one set of cell responses”database that could facilitate the application of informatics methods,such as artificial intelligence,in the rational design of future biotopographic structures with high efficacy.