A compact and closed-loop spin-exchange relaxation-free atomic magnetometer for wearable magnetoencephalography

Atomic magnetometers operated in the spin-exchange relaxation-free(SERF)regime are the promising sensor to replace superconducting quantum interference devices(SQUIDs)in the biomagnetism field.The SERF magnetometer with compact size and good performance is crucial to the new generation of wearable magnetoencephalography(MEG)system.In this paper,we developed a compact and closed-loop SERF magnetometer with the dimensions of 15.0×22.0×30.0 mm^(3)based on a single-beam configuration.The bandwidth of the magnetometer was extended to 675 Hz while the sensitivity was maintained at 22 f T/Hz^(1/2).A nearly 3-fold enhancement of the bandwidth was obtained in comparison with the open-loop control.The implementation of the closed-loop control also greatly improved the dynamic range,enabling the magnetometer to be robust against the disturbance of the ambient field.Moreover,the magnetometer was successfully applied for the detection of humanα-rhythm and auditory evoked fields(AEFs),which demonstrated the potential to be extended to multi-channel MEG measurements for future neuroscience studies.

A review of current research on spin currents and spin–orbit torques

Spintronics is a new discipline focusing on the research and application of electronic spin properties. After the discovery of the giant magnetoresistance effect in 1988, spintronics has had a huge impact on scientific progress and related applications in the development of information technology. In recent decades, the main motivation in spintronics has been efficiently controlling local magnetization using electron flow or voltage rather than controlling the electron flow using magnetization. Using spin-orbit coupling in a material can convert a charge current into a pure spin current(a flow of spin momenta without a charge flow) and generate a spin-orbit torque on the adjacent ferromagnets. The ability of spintronic devices to utilize spin-orbit torques to manipulate the magnetization has resulted in large-scale developments such as magnetic random-access memories and has boosted the spintronic research area. Here in, we review the theoretical and experimental results that have established this subfield of spintronics. We introduce the concept of a pure spin current and spin-orbit torques within the experimental framework, and we review transport-, magnetization-dynamics-, and opticalbased measurements and link then to both phenomenological and microscopic theories of the effect. The focus is on the related progress reported from Chinese universities and institutes, and we specifically highlight the contributions made by Chinese researchers.

Certain sulfonylurea drugs increase serum free fatty acid in diabetic patients:A systematic review and meta-analysis

BACKGROUND Sulfonylurea(SU)is a commonly used antidiabetic drugs effective for type 2diabetes mellitus.Previous studies have reported that the SU treatment could alter the serum free fatty acid(FFA)concentration in diabetic patients;however,their exact effects remain unknown.AIM To assess the impact of SU on the FFA level in diabetic patients.METHODS A systematic literature search was conducted by consulting the PubMed,EMBASE,Cochrane Library,Reference Citation Analysis(https://www.referencecitationanalysis.com/),and Web of Science databases from January 1,1991 to July 30,2021.Either a fixed-effects model or random-effects model was applied to study the association between SU treatment and FFA concentration according to the heterogeneity test.Two investigators independently performed data extraction.The mean difference(MD)and corresponding 95%confidence interval(CI)were used to measure effect size.R3.5.1 software was utilized for conducting statistical analyses.RESULTS A total of 13 studies with 2273 individuals were selected.Results indicated that FFA concentration increased slightly after treatment with SU(MD=0.08,95%CI:0.03-0.12,P<0.01).In addition,we found that SU treatment combined with other antidiabetics could also increase the concentration of serum FFA(MD=0.14,95%CI:0.01-0.28,P<0.01).Regarding the type of SU,there was no significant difference in FFA concentration with glimepiride or glibenclamide.FFA concentration was higher at≥12 wk(MD=0.09,95%CI:0.04-0.13)but not at<12 wk(MD=0.01,95%CI:-0.07-0.09).CONCLUSION SU treatment could increase the serum FFA concentration in diabetic patients.The fundamental underlying mechanism still needs further investigation.

CHD1 deletion stabilizes HIF1α to promote angiogenesis and glycolysis in prostate cancer

Chromodomain-helicase-DNA-binding protein 1(CHD1)deletion is among the most common mutations in prostate cancer(PCa),but its role remains unclear.In this study,RNA sequencing was conducted in PCa cells after clustered regularly interspaced palindromic repeat(CRISPR)/CRISPR-associated protein 9(Cas9)-based CHD1 knockout.Gene set enrichment analysis(GSEA)indicated upregulation of hypoxia-related pathways.A subsequent study confirmed that CHD1 deletion significantly upregulated hypoxia-inducible factor 1α(HIF1α)expression.Mechanistic investigation revealed that CHD1 deletion upregulated HIF1αby transcriptionally downregulating prolyl hydroxylase domain protein 2(PHD2),a prolyl hydroxylase catalyzing the hydroxylation of HIF1αand thus promoting its degradation by the E3 ligase von Hippel–Lindau tumor suppressor(VHL).Functional analysis showed that CHD1 deletion promoted angiogenesis and glycolysis,possibly through HIF1αtarget genes.Taken together,these findings indicate that CHD1 deletion enhances HIF1αexpression through PHD2 downregulation and therefore promotes angiogenesis and metabolic reprogramming in PCa.