Construction and Application of a Pepsin-Functionalized Covalent Organic Framework with Prominent Chiral Recognition Ability.

The stable Pepsin@covalent organic framework (Pepsin@COF) were constructed base on matching COF pore diameter to pepsin dimension. It exhibits excellent chiral recognition capabilities (e. e. % up to 62.63 %) and potential for enantioseparation. Furthermore, a positive correlation between the immobilized enzyme activity and chiral recognition was revealed, offering insights for the design of biocatalytic nanosystems in chiral separation.

The potential of Rhein's aromatic amines for Parkinson's disease prevention and treatment: α-Synuclein aggregation inhibition and disaggregation of preformed fibers.

The aggregation of α-Syn is a pivotal mechanism in Parkinson's disease (PD). Effectively maintaining α-Syn proteostasis involves both inhibiting its aggregation and promoting disaggregation. In this study, we developed a series of aromatic amide derivatives based on Rhein. Two of these compounds, 4,5-dihydroxy-N-(3-hydroxyphenyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxamide (a5) and 4,5-dihydroxy-N-(2-hydroxy-4-chlorophenyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxamide (a8), exhibited good binding affinities to α-Syn residues, demonstrating promising inhibitory activity against α-Syn aggregation in vitro, with low IC50 values (1.35 and 1.08 µM, respectivly). These inhibitors acted throughout the entire aggregation process by stabilizing α-Syn's conformation and preventing the formation of ß-sheet aggregates. They also effectively disassembled preformed α-Syn oligomers and fibrils. Preliminary mechanistic insights indicated that they bound to the specific domain within fibrils, inducing fibril instability, collapse, and the formation of smaller aggregates and monomeric α-Syn units. This research underscores the therapeutic potential of Rhein's aromatic amides in targeting α-Syn aggregation for PD treatment and suggests broader applications in managing and preventing neurodegenerative diseases.

Template Based Synthesis of Porous Graphdiyne Nanosheet for Reversible and Fast NO2 Detection by UV Irradiation.

Two-dimensional graphdiyne (GDY) formed by sp and sp2 hybridized carbon has been found to be an efficient toxic gas sensing material by density functional theory (DFT). However, little experimental research concerning its gas sensing capability has been reported owing to the complex preparation process and harsh experimental conditions. Herein, porous GDY nanosheets are successfully synthesized through a facile solvothermal synthesis technique by using CuO microspheres (MSs) as both template and source of catalyst. The porous GDY nanosheets exhibit a broadband optical absorption, rendering it suitable for the light-driven optoelectronic gas sensing applications. The GDY-based gas sensor was demonstrated to have excellent reversible to NO2 behaviors at 25 °C for the first time. More importantly, higher response value and faster response-recovery time once exposed to NO2 gas molecules are achieved by the illumination of UV light. In this way, our work paves the way for the exploration of GDY-based gas detection experimentally.

Tn antigen promotes breast cancer metastasis via impairment of CASC4.

Breast cancer is one of the most serious and deadly cancers in women worldwide, with distant metastases being the leading cause of death. Tn antigen, a tumor-associated carbohydrate antigen, was frequently detected in breast cancer, but its exact role in breast cancer metastasis has not been well elucidated. Here we investigated the impact of Tn antigen expression on breast cancer metastasis and its underlying mechanisms. The expression of Tn antigen was induced in two breast cancer cell lines by deleting T-synthase or Cosmc, both of which are required for normal O-glycosylation. It showed that Tn-expressing cancer cells promoted epithelial-mesenchymal transition (EMT) and metastatic features as compared to Tn(-) control cells both in vitro and in vivo. Mechanistically, we found that cancer susceptibility candidate 4 (CASC4), a heavily O-glycosylated protein, was significantly downregulated in both Tn(+) cells. Overexpression of CASC4 suppressed Tn-induced activation of EMT and cancer metastasis via inhibition of Cdc42 signaling. Furthermore, we confirmed that O-glycosylation is essential for the functional role of CASC4 because defective O-glycosylated CASC4 (mutant CASC4, which lacks nine O-glycosylation sites) exerted marginal metastatic-suppressing effects in comparison with WT CASC4. Collectively, these data suggest that Tn-mediated aberrant O-glycosylation contributes to breast cancer metastasis via impairment of CASC4 expression and function.

4-Arylidene curcumin derivatives in vitro inhibit α-Synuclein aggregation and disaggregate the preformed fibril.

This study focuses on the misfolding and aggregation of α-Syn as a central mechanism linking various pathological processes in PD. Maintaining α-Syn proteostasis through suitable inhibitors emerges as an effective approach to prevent PD. A more efficient strategy for PD treatment involves disintegrating neurotoxic oligomers and fibrils into normal functional α-Syn using inhibitors. To this end, a series of 4-arylidene curcumin derivatives were synthesized with a sheet-like conjugated skeleton and higher binding energies with α-Syn residues. Among these derivatives, three candidate compounds exhibited promising α-Syn aggregation inhibitory activities in vitro, with IC50 values as low as 0.61 µM. The inhibitory action extended throughout the entire aggregation process, stabilizing α-Syn proteostasis conformation and preventing ß-sheets aggregation. Furthermore, the candidate compounds demonstrated effective disintegration capabilities against preformed α-Syn oligomers and fibrils. Initial mechanistic investigations indicated that the inhibitors may bind to a specific domain within the fibril, inducing fibril instability and subsequent collapse. This process resulted in the formation of a complex system of aggregates with smaller sizes and monomers. Overall, these findings provide valuable insights into the potential of 4-arylidene curcumin derivatives as therapeutic agents for targeting α-Syn aggregation in PD treatment.

Sex-specific associations of cardiovascular risk factors and coronary plaque composition for hemodynamically significant coronary artery stenosis: a coronary computed tomography angiography study.

BACKGROUND: It has been reported that there are sex differences in plaque composition and hemodynamically significant stenosis. This study aimed to explore the impact of sex on cardiovascular risk factors for specific plaque compositions and hemodynamically significant stenosis. METHODS: Data regarding demographics and cardiovascular risk factors were collected. Hemodynamically significant stenosis was identified by a computed tomography-derived fractional flow reserve of ≤ 0.8. Associations among cardiovascular risk factors, plaque composition, and hemodynamically significant stenosis were assessed using a multivariate binary logistic regression analysis across sexes. The discriminating capacity of diverse plaque components for hemodynamically significant stenosis was assessed by area under the receiver-operating characteristics curve with 95% confidence intervals. RESULTS: A total of 1164 patients (489 men and 675 women) were included. For men, hyperlipidemia and cigarette smoking were risk factors for each plaque component (all P < 0.05), and diabetes mellitus also predicted fibrotic components (P < 0.05). For women, risk factors for each plaque component were hypertension and diabetes mellitus (all P < 0.01). Nonetheless, hyperlipidemia (P < 0.05) was a specific risk factor for non-calcified components. Calcified components combined with fibrotic components showed superior discrimination of hemodynamically significant stenosis in men and calcified components alone in women (all P < 0.01). Hypertension (P < 0.01) was a risk factor for hemodynamically significant stenosis in women. In contrast, diabetes, hyperlipidemia, and cigarette smoking were risk factors for hemodynamically significant stenosis in men (all P < 0.05). CONCLUSIONS: In men, hemodynamically significant stenosis was predicted by a combination of calcified and fibrotic components with multiple risk factors. In women, hemodynamically significant stenosis was predicted by calcified components caused by a single risk factor. It might be a key point to improve prognosis by more precise risk management between men and women, which needs to be proved by further prospective trials.

Group V Chitin Deacetylases Influence the Structure and Composition of the Midgut of Beet Armyworm, Spodoptera exigua.

Chitin deacetylase (CDA) can accelerate the conversion of chitin to chitosan, influencing the mechanical properties and permeability of the cuticle structures and the peritrophic membrane (PM) in insects. Putative Group V CDAs SeCDA6/7/8/9 (SeCDAs) were identified and characterized from beet armyworm Spodoptera exigua larvae. The cDNAs of SeCDAs contained open reading frames of 1164 bp, 1137 bp, 1158 bp and 1152 bp, respectively. The deduced protein sequences showed that SeCDAs are synthesized as preproteins of 387, 378, 385 and 383 amino acid residues, respectively. It was revealed via spatiotemporal expression analysis that SeCDAs were more abundant in the anterior region of the midgut. The SeCDAs were down-regulated after treatment with 20-hydroxyecdysone (20E). After treatment with a juvenile hormone analog (JHA), the expression of SeCDA6 and SeCDA8 was down-regulated; in contrast, the expression of SeCDA7 and SeCDA9 was up-regulated. After silencing SeCDAV (the conserved sequences of Group V CDAs) via RNA interference (RNAi), the layer of intestinal wall cells in the midgut became more compact and more evenly distributed. The vesicles in the midgut were small and more fragmented or disappeared after SeCDAs were silenced. Additionally, the PM structure was scarce, and the chitin microfilament structure was loose and chaotic. It was indicated in all of the above results that Group V CDAs are essential for the growth and structuring of the intestinal wall cell layer in the midgut of S. exigua. Additionally, the midgut tissue and the PM structure and composition were affected by Group V CDAs.

Immobilized glucose oxidase on hierarchically porous COFs and integrated nanozymes: a cascade reaction strategy for ratiometric fluorescence sensors.

Covalent organic frameworks (COFs) with uniform porosity, good stability, and desired biocompatibility can function as carriers of immobilized enzymes. However, the obstructed pores or partially obstructed pores have hindered their applicability after loading enzymes. In this study, the hierarchical COFs were prepared as an ideal support to immobilize glucose oxidase (GOD) and obtain GOD@COF. The hierarchical porosity and porous structures of COFs provided sufficient sites to immobilize GOD and increased the rate of diffusion of substrate and product. Moreover, N,Fe-doped carbon dots (N,Fe-CDs) with peroxidase-like activity were introduced to combine with GOD@COF to construct an enzyme-mediated cascade reaction, which is the basis of the sensor GOD@COF/N,Fe-CDs. The sensor has been successfully built and applied to detect glucose. The limit of detection was 0.59 µM for determining glucose with the proposed fluorescence sensor. The practicability was illustrated by detecting glucose in human serum and saliva samples with satisfactory recoveries. The proposed sensor provided a novel strategy that introduced COF-immobilized enzymes for cascade reactions in biosensing and clinical diagnosis.

Long non-coding RNA maternally expressed 3 (MEG3) regulates isoflurane-induced cognitive dysfunction by targeting miR-7-5p.

This study aimed to investigate the role and mechanism of long non-coding RNA maternally expressed gene 3 (MEG3) in cognitive dysfunction induced by isoflurane (ISO). Morrier water maze analysis was performed to evaluate the cognitive function of rats. Modified modified neurological severity score (mNSS) scores were assessed for neurological damage. The levels of MEG3 in hippocampal tissues of rats and hippocampal neuron cell lines HT22 were examined by reverse transcription-quantitative polymerase chain reaction (qRT-PCR). Moreover, the cell viability and apoptosis were assessed by the Cell Counting Kit-8 (CCK-8) and flow cytometry assay. Indicators of inflammation and oxidative stress were determined using enzyme-linked immunosorbent assay (ELISA) and commercial assay kits. Relationship between MEG3 and microRNA (miR)-7-5p was verified by the dual-luciferase reporter gene assay. MEG3 was increased in hippocampal tissues and HT22 after ISO treatment (p < 0.05). MEG3 downregulation alleviated the increase in neurological severity score and cognitive dysfunction caused by ISO treatment (p < 0.05). In vitro, MEG3 downregulation alleviates the decrease in cell activity and increased apoptosis induced by ISO. What's more, MEG3 reduction eliminated activation of neuroinflammation and oxidative stress promoted by ISO treatment in rats and HT22 (p < 0.05). MEG3 was confirmed to specifically bind to miR-7-5p. Inhibition of miR-7-5p eliminated the alleviating effects of MEG3 downregulation on cognitive dysfunction caused by ISO treatment. Decreased MEG3 alleviates cognitive dysfunction caused by ISO by targeting miR-7-5p and play a neuroprotective effect. We present a strategy for MEG3 as a potential target for brain protection during anesthesia.

Rare earth element lanthanum protects against atherosclerosis induced by high-fat diet via down-regulating MAPK and NF-κB pathways.

Rare earth elements, which are extensively used in environmental protection, medicine, food, aerospace and other fields, have attracted widespread attention in recent years. However, the effect on atherosclerosis and its biological mechanism remains unclear. To elucidate these problems, here we performed a study that Apolipoprotein E-deficient mice were fed with high-fat diet to promote the development of atherosclerosis, meanwhile, mice were received 0.1, 0.2, 1.0, 2.0 mg/kg lanthanum nitrate (La(NO3)3) for 12 weeks. The results showed that La(NO3)3 prominently inhibited aorta morphological alternations by histopathological examination. Meanwhile, La(NO3)3 regulated serum lipids, including reducing total cholesterol and increasing high-density lipoprotein. Moreover, the oxidative stress was alleviated by La(NO3)3 intervention through enhancing superoxide dismutase and glutathione, and decreasing malondialdehyde levels. In addition, enzyme-linked immunosorbent assay analysis showed La(NO3)3 could ameliorate the dysfunction of vascular endothelium with declined endothelin-1 and increased prostacyclin. Furthermore, Western blot analysis indicated that La(NO3)3 significantly down-regulated inflammation-mediated proteins including phosphorylated p38 mitogen-activated protein kinases (p-p38 MAPK), monocyte chemo-attractant protein, intercellular adhesion molecule-1, nuclear factor-kappa B p65 (NF-κB p65), tumor necrosis factor-α, interleukin-6 and interleukin-1ß, whereas up-regulated the inhibitor of NF-κB protein. In conclusion, La(NO3)3 ameliorates atherosclerosis by regulating lipid metabolism, oxidative stress, endothelial dysfunction and inflammatory response in mice. The potential mechanism associates with the inhibition of MAPK and NF-κB signaling pathways.

Facile separation of enantiomers via covalent organic framework bonded stationary phase.

Covalent organic frameworks (COFs), a type of crystalline polymers, have attracted increasing interest because of their controllability of geometry and functionality. Featuring infinitely extended networks and tremendous interaction sites, COFs emerge as a potential platform for separation science. Here, a novel chiral COF (ß-CD COFBPDA) constructed by the imine condensation of 4,4'-biphenyldicarboxaldehyde and heptakis(6-amino-6-deoxy)-ß-cyclodextrin was introduced into an electrochromatographic system via a photopolymerization method and applied to the separation of enantiomers. The structure and properties of as-synthesized ß-CD COFBPDA were investigated by powder X-ray diffraction (PXRD) patterns, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and N2adsorption-desorption isotherms. It was proved that ß-CD COFBPDA was provided with larger pore size and BET surface area. The ß-CD COFBPDA coating endowed the chiral stationary phase with superior three-dimensional orientation, and realized satisfactory separation with improved selectivity and column efficiency for a dozen racemic drugs. Under the optimized conditions, homatropine, ondansetron, metoprolol, terbutaline, tulobuterol, and promethazine were all baseline separated with resolution values of 2.24, 2.03, 1.65, 1.62, 1.60, and 1.58, respectively. The results indicate the high perspective of COF modified stationary in enantioseparation.

Neuroprotective effect of miR-212-5p on isoflurane-induced cognitive dysfunction by inhibiting neuroinflammation.

BACKGROUND: Isoflurane is a commonly used inhalation anesthetic in the clinic, which can induce cognitive dysfunction and neuroinflammation. miR-212-5p has been demonstrated to be involved in the neuronal system and play vital roles in memory formation. Its function in the learning and memory impairment and neuroinflammation induced by isoflurane was investigated in this study. METHODS: Cognitive dysfunction rat models were established by 3% isoflurane inhalation. The neurological function was evaluated by the modified Neurological Severity Scale. The learning and memory ability of rats was assessed by the Morris water maze test. The expression level of miR-212-5p was analyzed by RT-qPCR, and the protein levels of proinflammatory cytokines were detected by ELISA. RESULTS: Isoflurane induced cognitive dysfunction in rats with the neurological scores and the escape latency increased, and time spent in the target quadrant decreased. The protein levels of IL-1ß, IL-6, and TNF-α were increased in isoflurane treated rats. miR-212-5p was downregulated in cognitive impairment rats. The upregulation of miR-212-5p by the agomir injection decreased the neurological scores of rats and increased the learning and memory ability of impaired rats. Moreover, the neuroinflammation was inhibited by the overexpression of miR-212-5p. CONCLUSION: miR-212-5p showed a neuroprotective effect in isoflurane-induced cognitive dysfunction rats by inhibiting neuroinflammation.

Hsa_circ_0079662 induces the resistance mechanism of the chemotherapy drug oxaliplatin through the TNF-α pathway in human colon cancer.

The aim of the study was to research the biological functions of circRNA (hsa_circ_0079662) and its underlying mechanism in colorectal cancer. Drug-resistant cell lines (HT29-LOHP, HCT116-LOHP, HCT8-LOHP) were separately dealt with oxaliplatin concentration gradient (0.1-10 µmol/L). Real-time PCR, Western blotting, dual-luciferase assay, miRNA pull-down assay, coimmunoprecipitation and ELASA were performed to explore the mechanism of chemotherapy drug oxaliplatin resistance in CRC. The results showed that the expression of hsa_circ_0079662 was increased in drug-resistant cell lines by RT-PCR. The expression of HOXA9, TRIP6, Vcam-1, VEGFC, MMP3, MMP9 and MMP14 was higher by Western blotting. Interaction between HOXA9 and TRIP6 in CO-IP detection. Additionally, the cytokines TNF-α, IL-1 and IL-6 were also found. In conclusion, hsa_circ_0079662, as a ceRNA binding with hsa-mir-324-5p, can regulate target gene HOXA9 and induced the mechanism of chemotherapy drug oxaliplatin resistance in CRC through the TNF-α pathway in human colon cancer.

National Safety Survey of Animal-use Commercial Probiotics and Their Spillover Effects From Farm to Humans: An Emerging Threat to Public Health.

BACKGROUND: Human-use probiotics have recently been associated with clinical infections and antibiotic resistance transfer, raising public concern over their safety. However, despite their extensive application in aquaculture and animal husbandry, the safety of animal-use probiotics remains poorly described. METHODS: We evaluated the safety of 92 animal-use probiotics from China. The pattern of spread of pathogens from probiotics and the consequent public health implications were also examined by conducting in-field genomic surveillance at 2 farms. RESULTS: A total of 123 probiotic Bacillus species isolates were obtained from 92 brands of probiotics, of which 45 isolates were resistant to antibiotics. Notably, 33.7% of probiotic products were contaminated with life-threatening pathogens such as Klebsiella pneumoniae. Genomic surveillance at a chicken farm identified an anthrax toxin-positive Bacillus cereus strain in a probiotic product used as a feed supplement, which was transferred into the groundwater and to a nearby fish farm. Following up retrospective analysis of the surveillance data during 2015-2018 in 3 provinces retrieved 2 B. cereus strains from human with intestinal anthrax symptoms and confirmed the transmission of B. cereus from farm to human. Surveillance of anthrax toxin revealed that cya was detected in 8 of 31 farms. CONCLUSIONS: This study provides the first national safety survey of animal-use probiotics in China and confirms the spillover effects of probiotics from the farms to human. These results suggest that the large-scale application of pathogen-containing probiotics leads to the transfer of pathogens, with worrisome implications for public health. Good Manufacturing Practice should be implemented during the production of all probiotics.Animal-use probiotic products are frequently contaminated with viable pathogenic bacteria. This study revealed that virulent probiotic organisms and contaminating pathogens were colonized with farm animals and shed into the environment, which facilitated the transfer of pathogens to humans.

Recombinant expression and functional analysis of antimicrobial Siganus oraminl-amino acid oxidase using the Bac-to-Bac baculovirus expression system.

Siganus oraminl-amino acid oxidase (SR-LAAO), isolated from the serum of Siganus oramin, is an innate immune protein with significant antibacterial activity. The aim of this study was to express SR-LAAO in insect cells using a baculovirus expression system and evaluate the function of the recombinant SR-LAAO. To this end, an optimized sequence of the SR-LAAO gene was designed and synthesized, based on the codon bias of insect cells. Bacmid shuttle vectors and recombinant baculovirus were successfully constructed, and the recombinant baculovirus was transfected into Sf9 insect cells. The antibacterial activity and enzymatic characteristics of the recombinant SR-LAAO were investigated. The results showed that the pFastBac-optiSR-LAAO shuttle vectors and Bacmid-optiSR-LAAO were correctly constructed. The Sf9 insect cells exhibited significant cytopathic effects following infection with Bacmid-optiSR-LAAO and Bacmid; the specific PCR analysis proved that the recombinant baculovirus was successfully constructed. The immunofluorescence assay revealed that the recombinant baculovirus rSR-LAAO was abundantly expressed in infected Sf9 insect cells; the results of SDS/PAGE and Western blot analyses showed that a specific band appeared at about 60 kDa. Moreover, the crude rSR-LAAO enzyme displayed strong antibacterial activity against aquatic pathogens, particularly Streptococcus agalactiae and Streptococcus iniae. In addition, the results of catalase interference test implied that the antibacterial activity of rSR-LAAO was directly associated with (H2O2 production). The results of the rSR-LAAO enzymatic characteristics test indicated that the Km value with l-Lysine as a substrate was 16.61 mM when the temperature was under 37 °C, and the optimum pH was 7. The antibacterial activity of rSR-LAAO could be completely inhibited by 10 mg/mL of pepsin, trypsin, and proteinase K compared with both methanol and acetone. Adding an equal volume of ethanol had a minimal impact on the antibacterial activity of rSR-LAAO. The crude enzyme could maintain a high level of antibacterial activity against both Gram-positive and -negative bacteria from 4 °C to 30 °C. In the present study, SR-LAAO was successfully expressed in Sf9 cells using the baculovirus expression system, and provides basic references for further research into the role of LAAO in marine animals and the development of new antimicrobial drugs.

Non-specific immune factors differences in coelomic fluid from polian vesicle and coelom of Apostichopus japonicus, and their early response after evisceration.

Coelomic fluid contains a population of coelomocytes, enzymes, nutrients and kinds of molecules that could be essential for Apostichopus japonicus live. The coelom and polian vesicle are the main tissues that hold the most coelomic fluid in the animal, but whether there exists any immunological difference of the coelomic fluid from the two tissues remains unknown. In this study, we first extracted the coelomic fluid both from the coelom and polian vesicle, and compared their non-specific immune factors. It was found that the ACP and AKP activities in the polian vesicle were significantly higher than those in the coelom, but it was contrary for the SOD and CAT. Meanwhile, the expression levels of several immune-related genes including AjC3-2, AjMKK3/6, AjTLR3 and AjToll in the polian vesicle were significantly lower than those in the coelom. Besides, the early changes of non-specific immune factors were further monitored after eviscerated. During 7 days post evisceration, the immunoenzymes activities of ACP, AKP, SOD and CAT were decreased first and then recovered gradually in the coelomic fluid from the coelom. In the polian vesicle, the ACP and AKP activities showed a similar trend with the coelom, while the SOD and CAT activities showed a transitory increase during 2 h post evisceration (hpe) to 12 hpe. Moreover, the expression profiles of the immune-related genes in the coelom reached the peak at 3 days post evisceration (dpe), while their expression levels in the polian vesicle reached the peak at 7 dpe. All the results suggested that the immunocompetence of coelomic fluid differed in the coelom and polian vesicle, and thus may exert their respective immunological functions. It was likely that the respond speed in the coelom would be faster than that in the polian vesicle after evisceration. Our data will provide a basis for better understanding of the immune defense mechanism of A. japonicus.

Fluorescent paper-based sensor based on carbon dots for detection of folic acid.

Paper-based devices have been very much in the foreground of analytical science recently. This work innovatively proposed a fluorescent paper-based sensor (FPS) constructed on a hybrid polydimethylsiloxane (PDMS)/paper platform where cellulose papers functionalized with carbon dots (CDs) as fluorophores by Schiff base chemistry were loaded on the grooves array of a designed PDMS plate. As a proof of concept, the performance of FPS was investigated with folic acid (FA) as the target analyte. Under optimal conditions, FPS enabled a rapid fluorescence quenching response to FA via inner filter effect in a wide range of 1-300 µmol L-1 with the limit of detection of 0.28 µmol L-1. The feasibility of FPS was further verified by the detection of FA in orange juice and urine samples with satisfactory results. The covalent modification of CDs on paper endowed the FPS with good assay reproducibility and stability. Interestingly, FPS achieved a more sensitive assay of FA than the conventional strategy, by which the same CDs were directly used to detect FA in a solution-based system. The FPS illuminated a novel strategy for construction of reliable and sensitive assays based on paper-based devices. It is of paramount importance for its practical application in biosensing and clinical diagnosis. Graphical abstract.

Temperature controlled switchable exchange bias and coercivity in spin glass/ferromagnet multilayers under tilting magnetizing.

A modified Monte Carlo method is used to study the temperature dependence of exchange bias and coercivity behaviors in ferromagnetic layers sandwiched by spin glass layers based on three stacking structures. An interesting phenomenon of 100% temperature controlled switch between the exchange bias field and coercivity is observed. Angular dependence of exchange bias field and coercivity behaviors indicate that there exists a minimum nonzero angle between the magnetic field and ferromagnet/spin glass easy axis, depending on the stacking structure, to achieve a complete switch. We further study the thermal remnant magnetization, the Zeeman and exchange energy behaviors during hysteretic measurements and the magnetic training effect at different temperatures, designating that the spin glassy dynamics is crucial for such a smooth and full switch. This finding shows potential in designing an applicable thermally assisted read/write switchable spintronic devices, achieved simply by rotational magnetizing and nanostructure engineering.

Drift Reduction of a 4-DOF Measurement System Caused by Unstable Air Refractive Index.

Laser beam drift greatly influences the accuracy of a four degrees of freedom (4-DOF) measurement system during the detection of machine tool errors, especially for long-distance measurement. A novel method was proposed using bellows to serve as a laser beam shield and air pumps to stabilize the refractive index of air. The inner diameter of the bellows and the control mode of the pumps were optimized through theoretical analysis and simulation. An experimental setup was established to verify the feasibility of the method under the temperature interference condition. The results indicated that the position stability of the laser beam spot can be improved by more than 79% under the action of pumping and inflating. The proposed scheme provides a cost-effective method to reduce the laser beam drift, which can be applied to improve the detection accuracy of a 4-DOF measurement system.