Sulfate reduction behavior in pressure-bearing leachate saturated zone

Attention should be paid to the sulfate reduction behavior in a pressure-bearing leachate saturated zone.In this study,within the relative pressure range of 0–0.6 MPa,the ambient temperature with the highest sulfate reduction rate of 50℃ was selected to explore the difference in sulfate reduction behavior in a pressure-bearing leachate saturated zone.The results showed that the sulfate reduction rate might further increase with an increase in pressure;however,owing to the effect of pressure increase,the generated hydrogen sulfide (H_(2)S) could not be released on time,thereby decreasing its highest concentration by approximately 85%,and the duration extended to about two times that of the atmospheric pressure.Microbial community structure and functional gene abundance analyses showed that the community distribution of sulfate-reducing bacteria was significantly affected by pressure conditions,and there was a negative correlation between disulfide reductase B(dsrB) gene abundance and H_(2)S release rate.Other sulfate reduction processes that do not require disulfide reductase A (dsrA) and dsrB genes may be the key pathways affecting the sulfate reduction rate in the pressure-bearing leachate saturated zone.This study improves the understanding of sulfate reduction in landfills as well as provides a theoretical basis for the operation and management of landfills.

Highly integrated watch for noninvasive continual glucose monitoring

This article reports a highly integrated watch for noninvasive continual blood glucose monitoring.The watch employs a Nafion-coated flexible electrochemical sensor patch fixed on the watchband to obtain interstitial fluid(ISF)transdermally at the wrist.This reverse iontophoresis-based extraction method eliminates the pain and inconvenience that traditional fingerstick blood tests pose in diabetic patients’lives,making continual blood glucose monitoring practical and easy.All electronic modules,including a rechargeable power source and other modules for signal processing and wireless transmission,are integrated onto a watch face-sized printed circuit board(PCB),enabling comfortable wearing of this continual glucose monitor.Real-time blood glucose levels are displayed on the LED screen of the watch and can also be checked with the smartphone user interface.With 23 volunteers,the watch demonstrated 84.34%clinical accuracy in the Clarke error grid analysis(zones A+B).In the near future,commercial products could be developed based on this lab-made prototype to provide the public with noninvasive continual glucose monitoring.

Two types of ultrafast mode‑locking operations from an Er‑doped fber laser based on germanene nanosheets

As a member of Xenes family,germanene has excellent nonlinear saturable absorption characteristics.In this work,we prepared germanene nanosheets by liquid phase exfoliation and measured their saturation intensity as 0.6 GW/cm^(2) with a modulation depth of 8%.Then,conventional solitons with a pulse width of 946 fs and high-energy noise-like pulses with a pulse width of 784 fs were obtained by using germanene nanosheet as a saturable absorber for a mode-locked Erbium-doped fber laser.The characteristics of the two types of pulses were investigated experimentally.The results reveal that germanene has great potential for modulation devices in ultrafast lasers and can be used as a material for creation of excellent nonlinear optical devices to explore richer applications in ultrafast photonics.

Single-molecule RNA capture-assisted droplet digital loop-mediated isothermal amplification for ultrasensitive and rapid detection of infectious pathogens

To minimize and control the transmission of infectious diseases,a sensitive,accurate,rapid,and robust assay strategy for application on-site screening is critical.Here,we report single-molecule RNA capture-assisted digital RT-LAMP(SCADL)for point-of-care testing of infectious diseases.Target RNA was captured and enriched by specific capture probes and oligonucleotide probes conjugated to magnetic beads,replacing laborious RNA extraction.Droplet generation,amplification,and the recording of results are all integrated on a microfluidic chip.In assaying commercial standard samples,quantitative results precisely corresponded to the actual concentration of samples.This method provides a limit of detection of 10 copies mL−1 for the N gene within 1 h,greatly reducing the need for skilled personnel and precision instruments.The ultrasensitivity,specificity,portability,rapidity and user-friendliness make SCADL a competitive candidate for the on-site screening of infectious diseases.