Heat flux sensors (HFSs) are extensively used in combustion-related applications to collect important engineering data. However, most non-water cooling HFSs lack the durability to survive in the ...harsh, high-temperature environments where they are employed. A new type of thin-film HFS based on a W-5Re/W-26Re thermocouple has been developed for high-temperature heat flux measurement. The sensor consists of 136 pairs of micron-sized W-5Re/W-26Re thin-film thermocouples, an SiO 2 thermal-resistance layer, and an AlN substrate. The SiO 2 layer is sandwiched between the substrate and thermocouples, and allows the measurement of temperature differences arising from the difference in thermal conductivity between the substrate and the SiO 2 layer. A protective layer with a sandwich structure prevents the tungsten-rhenium thin film from oxidizing at high temperatures in air. This small HFS with a protective layer can survive for 1 h in 1000°C air. Calibration data show that the HFS exhibits repeatable and fast thermal responses when a pulsed heat flux of 1000 kW/<inline-formula> <tex-math notation="LaTeX">\text{m}^{2} </tex-math></inline-formula> is applied, and its sensitivity is 3.8*<inline-formula> <tex-math notation="LaTeX">10^{-6} </tex-math></inline-formula> V/(kW/<inline-formula> <tex-math notation="LaTeX">\text{m}^{2} </tex-math></inline-formula>). The experimental data agree with the simulated results. It can be concluded from the experimental results that the tungsten-rhenium thin film has a good thermoelectric response to high temperatures after the size is reduced to a micron. Thus the developed HFS can be a suitable alternative for applications in thermal systems, such as engines, turbines, and rockets.
Glioblastoma (GBM) is one of the most challenging malignant brain tumors to treat. Herein, we describe a nanoenzyme hemostatic matrix strategy with the tumor cavity in situ application that ...simultaneously serves as photothermal agent and induces immunogenic cell death after GBM surgical resection to enhance the antitumor immunity and delay tumor recurrence. The hemostatic matrix system (Surgiflo@PCN) contains Surgiflo, a multispace structure that can be used to penetrate different shapes of tumor cavities to prevent postoperative tumor cavity hemorrhage. As well, porous palladium–copper nanoclusters (PCNs) have adjustable enzyme-like activities (oxidase, peroxidase, and catalase) responsible for formation of reactive oxygen species (ROS) under near-infrared (808 nm) laser irradiation. When the Surgiflo@PCN entered the resected tumor cavity, the first action was the direct killing of glioma cells via ROS and photothermal therapy (PTT). The second action was the induction of immunogenic cell death by PCN-enhanced oxidative stress and PTT, which reversed the immunosuppressive tumor microenvironment and enhanced the antitumor immune response. This eradicated residual glioma cells and prevented recurrence. The collective findings demonstrate that Surgiflo@PCN kills glioma cells directly through ROS and PTT and enhances antiglioma immunity and kills glioma cells indirectly. The “one-stone, two-birds” strategy could become an effective photothermal immunotherapy in GBM patients.
Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, ranks one of the most dangerous pathogens for its large deaths toll. Due to its characteristic extremely slow ...growth, the conventional culture-based protocol cannot meet the requirement for the efficient diagnosis of M. tuberculosis-induced tuberculosis. With our previously isolated mycobacteriophage SWU1, we tried to develop a mycobacteriophage-based protocol for detecting Mycobacterium genus. In this work, Mycobacterium smegmatis (M. smegmatis) was used as a model due to its similar physiological features as pathogenic M. tuberculosis, much faster growth and nonpathogenic property. Mycobacteriophage SWU1-functionalized magnetic particles (SWU1-MPs) were used as highly efficient separation carriers for the viable host M. smegmatis. After a replication cycle of approximate 60 min, the cells of M. smegmatis were disrupted by the progeny mycobacteriophages to release intracellular adenosine triphosphate (ATP). The bioluminescent (BL) signal of released ATP was collected to quantitate the amount of M. smegmatis. For the developed protocol, the detection range is 5.0 × 102 to 5.0 × 105 CFU mL−1, and the detection limit is 3.8 × 102 CFU mL−1 (S/N = 3). Furthermore, the protocol can exclude the potential interference of 3 non-pathogenic mycobacteria and 6 other bacterial species. It has been successfully applied to quantitate M. smegmatis in human urine, human saliva, and human serum. The results demonstrate its application potential for a simple, fast, and specific diagnosis of M. tuberculosis infection.
A facile bioluminescent protocol was developed for the detection of mycobacteria by using mycobacteriophage SWU1 as a recognition agent for separating mycobacteria and a disruption agent for releasing intracellular ATP. Display omitted
•A mycobacteriophage-based protocol was developed to detect Mycobacterium genus.•Mycobacteriophage-functionalized magnetic particles were utilized to separate and disrupt the target mycobacteria.•The protocol showed high sensitivity and specificity for bioluminescent detection of mycobacteria.
Precise regulation of chromosome segregation during oocyte meiosis is of vital importance to mammalian reproduction. Anaphase promoting complex/cyclosome (APC/C) is reported to play an important role ...in metaphase‐to‐anaphase transition. Here we report that cell division cycle 23 (Cdc23, also known as APC8) plays a critical role in regulating the oocyte chromosome separation. Cdc23 localized on the meiotic spindle, and microinjection of Cdc23 siRNA caused decreased ratios of metaphase‐to‐anaphase transition. Loss of Cdc23 resulted in abnormal spindles, misaligned chromosomes, errors of homologous chromosome segregation, and production of aneuploid oocytes. Further study showed that inactivation of spindle assembly checkpoint and degradation of Cyclin B1 and securin were disturbed after Cdc23 knockdown. Furthermore, we found that inhibiting spindle assembly checkpoint protein Msp1 partly rescued the decreased polar body extrusion and reduced the accumulation of securin in Cdc23 knockdown oocytes. Taken together, our data demonstrate that Cdc23 is required for the chromosome segregation through regulating the spindle assembly checkpoint activity, and cyclin B1 and securin degradation in meiotic mouse oocytes.
The lysin LysGH15, which is derived from the staphylococcal phage GH15, demonstrates a wide lytic spectrum and strong lytic activity against methicillin-resistant Staphylococcus aureus (MRSA). Here, ...we find that the lytic activity of the full-length LysGH15 and its CHAP domain is dependent on calcium ions. To elucidate the molecular mechanism, the structures of three individual domains of LysGH15 were determined. Unexpectedly, the crystal structure of the LysGH15 CHAP domain reveals an "EF-hand-like" calcium-binding site near the Cys-His-Glu-Asn quartet active site groove. To date, the calcium-binding site in the LysGH15 CHAP domain is unique among homologous proteins, and it represents the first reported calcium-binding site in the CHAP family. More importantly, the calcium ion plays an important role as a switch that modulates the CHAP domain between the active and inactive states. Structure-guided mutagenesis of the amidase-2 domain reveals that both the zinc ion and E282 are required in catalysis and enable us to propose a catalytic mechanism. Nuclear magnetic resonance (NMR) spectroscopy and titration-guided mutagenesis identify residues (e.g., N404, Y406, G407, and T408) in the SH3b domain that are involved in the interactions with the substrate. To the best of our knowledge, our results constitute the first structural information on the biochemical features of a staphylococcal phage lysin and represent a pivotal step forward in understanding this type of lysin.
Purpose. Type 2 diabetes mellitus is considered as one of the risk factors for cognitive impairment. DPP4 inhibitors are effective drugs for the treatment of type 2 diabetes mellitus. However, the ...relationship between DPP4 inhibitors and cognitive dysfunction remains unclear. Therefore, we used a meta-analysis to determine the association between DPP4 inhibitors and cognitive impairment in type 2 diabetes mellitus. Methods. We systematically searched PubMed, CNKI, and the Cochrane Library at the time of establishment, 2022, and then made inclusion criteria and screened strategies to identify studies with more precise correlations. Results. We included 10 studies with 5,583 participants. The data showed that DPP4 inhibitors significantly reduced the incidence rate of cognitive impairment in type 2 diabetes mellitus (SMD: 0.99; 95% CI 0.59, 1.38). Furthermore, there was a linear correlation found between cognitive impairment in type 2 diabetes mellitus and fasting blood glucose, 2-hour postprandial blood glucose, and glycosylated hemoglobin. DPP4 inhibitors decreased fasting blood glucose (FPG) (SMD: 0.52; 95% CI −0.68, −0.37), blood glucose (2hPPG) at 2 hours after the meal (SMD: 0.82; 95% CI, −1.2, −0.43), and HbA1c (SMD: 0.34; 95% CI −0.48, −0.21). All data were statistically significant (P<0.0001). Furthermore, we conducted subgroup analyses of the following measures at various treatment durations and ages: cognitive scores, fasting blood glucose, glycosylated hemoglobin, and two-hour postprandial blood glucose. Conclusion. DPP4 inhibitors significantly improved type 2 diabetic mellitus individuals’ cognitive impairment and reduced fasting blood glucose, 2-hour postprandial blood glucose, and glycosylated hemoglobin. Subgroup analysis showed that people aged 60 to 70 years had better treatment effects at 0–180 days. This trial is registered with CRD42023399473.
Cobalt-based sulfides with variable valence states and unique physical and chemical properties have shown great potential as oxygen evolution reaction (OER) catalysts for electrochemical ...water-splitting reactions. However, poor morphological characteristics and a small specific surface area limit its further application. Here, hexagonal single-crystal two-dimensional (2D) CoS nanosheets with different thicknesses are successfully prepared by an atmospheric-pressure chemical vapor deposition method. Because of the advantages of the 2D structure, more exposed catalytic active sites, better reactant adsorption ability, accelerated electron transfer, and enhanced electrical conductivities can be achieved from the thinnest 5 nm CoS nanosheets (CoS-5), significantly improving OER performance. The electrochemical tests manifest that CoS-5 show an overpotential of 290 mV at 10 mA cm–2 and a Tafel slope of 65.6 mV dec–1 in the OER in an alkaline solution, superior to those for other thicknesses of CoS, bulk CoS, and RuO2. For the mechanistic investigation, the lowest charge transfer resistance (R ct) and the highest double-layer capacitance (C dl) were obtained for CoS-5, demonstrating the faster OER kinetics and the larger active area. Density functional theory calculations further reveal the enhanced density of states around the Fermi level and higher H2O molecule adsorption energy for thinner CoS nanosheets, promoting its intrinsic catalytic activity. Moreover, the two-electrode system with CoS-5 as the anode and Pt/C as the cathode requires only 1.56 V to attain 10 mA cm–2 in the overall water-splitting reaction. We believe that this study will provide a fresh view for thickness-dependent catalytic performance and offers a new material for the study of electronic and energy devices.
The photocatalytic activity of Bi4Ti3O12 is limited by the lack of active sites and rapid carrier recombination. In this work, the problems mentioned above are effectively solved by using a dual ...functional CuS load on the surface of Bi4Ti3O12. The CuS can be used as electron trapping sites to play a role as a cocatalyst, and form p-n junction with the Bi4Ti3O12 under irradiation through the properties of p-type semiconductor. The dual functionality of CuS effectively promotes carrier separation and enhances the photocatalytic degradation activity. The photocatalytic rate of Bi4Ti3O12 with optimal loading amount of CuS is ∼1.8 and ∼2.7 times as high as that of the Bi4Ti3O12 and the CuS, respectively. The photocatalytic mechanism of the Bi4Ti3O12–CuS system is investigated in detail.
•CuS can be used as electron trapping sites to play a role as a cocatalyst.•CuS form p-n junction with Bi4Ti3O12 under irradiation through the properties.•The dual functionality of CuS effectively promotes carrier separation.
The Chipu Mississippi Valley-type (MVT) deposit is located on the southwest (SW) margin of the Sichuan Basin. Occurrence of plentiful organic matter (bitumen) at this deposit and abundant hydrocarbon ...reservoirs in the SW Sichuan Basin implies a link between lead-zinc mineralization and hydrocarbon systems in this area. The high δ
34
S values of most metal sulphides from the different ore stages suggest that H
2
S-bearing gases and/or thermochemical sulphate reduction (TSR) by organic matter could have been the source of reduced sulphur involved in ore formation. Sulphides with small positive to negative δ
34
S values can be attributed to organically bound sulphur at the Chipu deposit. Carbon and oxygen isotopic compositions from sparry carbonates suggest mixing of organic carbon with seawater-derived carbon in the mineralization process. From the early to the later ore stages, δ
13
C
PDB
values of ore-hosting carbonates are increasingly more negative, which indicates strengthening of the TSR role during mineralization. Hydrogen and oxygen isotopes in fluid inclusions in the quartz gangue indicate the provenance of the ore-forming fluids in the hydrocarbons. Moreover, some extremely low hydrogen isotope values suggest the addition of hydrogen from the same source. The low H/C ratios and high non-hydrocarbon component of the bitumen (Zhang et al.
2010
) also suggest that the organic matter may have been involved in TSR and subjected to a strong oxidation by ore-bearing fluids. This study attempts to explain the lead-zinc mineralization process and the role of organic matter in it. As there is a demonstrable relationship between the evolution of the hydrocarbons and regional lead-zinc mineralization along the SW edge of the Sichuan Basin, we propose a possible model in which the MVT mineralization coincided with the degradation of hydrocarbon reservoirs due to the large-scale migration of basinal fluids, most likely driven by the late Indosinian orogeny in response to the closure of the Palaeo-Tethys Ocean.
Lithium plating, induced by fast charging and low-temperature charging, is one of the reasons for capacity fading and causes safety problems for lithium-ion batteries. Hence, reliable and effective ...non-destructive detection methods for lithium plating are needed. In this research, electrochemical impedance and internal resistance for batteries are measured during the rest period after charging. The results for lithium plating batteries and normal batteries are compared and analyzed. Lithium plating detection is realized with multiple indicators extracted from electrochemical impedance and internal resistance results. The effectiveness of the proposed detection methods is verified by the experiments conducted with commercial large-capacity batteries. The proposed methods have further potential to be used in battery management systems to realize online detection of lithium plating and improve the safety of battery systems.
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