Construction of a redox-coupled pathway co-metabolizing glucose and acetate for high-yield production of butyl butyrate in Escherichia coli.

The carbon and energy efficiency of a biomanufacturing process is of crucial importance in determining its economic viability. Formate dehydrogenase has been demonstrated to be beneficial in regenerating NADH from formate produced during sugar metabolism, thereby creating energy-efficient systems. Nevertheless, introducing enzyme(s) for butyryl butyrate (BB) biosynthesis based on this system, only 1.64 g/L BB with 14.3 % carbon yield was obtained due to an imbalance in NADH-NAD+ turnover. To address the issue of NADH accumulation, a joint redox-balanced pathway for BB biosynthesis was developed in this study by coupling acetate and glucose metabolism. Following overexpression of acetyl-CoA synthetase in the BB-producing strain, acetate and glucose were co-utilized stoichiometrically and intracellular redox homeostasis was achieved. The engineered strain produced 29.02 g/L BB with carbon yield of 43.3 %, representing the highest yield ever reported for fermentative production of BB. It indicated the potential for developing a carbon- and energy-effective route for biomanufacturing.

Association of Systemic Inflammatory Response Index and Neutrophil-to-Lymphocyte Ratio on Unfavorable Functional Outcomes in Acute Ischemic Stroke Patients After Endovascular Therapy.

BACKGROUND: Inflammatory markers for the prognosis of acute ischemic stroke (AIS) with endovascular therapy remain unclear. The purpose of this study was to investigate the association between the systemic inflammatory response index (SIRI) and neutrophil-to-lymphocyte ratio (NLR) with unfavorable functional outcomes at 90-day in individuals of AIS who underwent endovascular therapy. METHODS: A total of 128 AIS patients who had endovascular therapy were enrolled from the Nanjing Stroke Registry between September 2019 and November 2022. Peripheral venous blood was collected from patients within 24 h of admission for information on the following parameters: neutrophil count, lymphocyte count, and monocyte count. Then, the SIRI and NLR values were calculated and the association among SIRI, NLR, and modifled Rankin Scale scores 90 days after endovascular therapy was examined via univariate and multivariate logistic analyses. Receiver operating characteristic curves were utilized to determine the best threshold for SIRI and NLR in predicting negative neurological outcomes following endovascular treatment for patients with AIS. RESULTS: A total of 128 participants were evaluated, among which 50% had unfavorable outcomes. Linear regression analysis showed that the best threshold for SIRI was >1.407 (odds ratio = 1.265; 95% confidence interval, 1.071-1.493; P = 0.006), and for NLR it was >5.347 (odds ratio = 1.088; 95% confidence interval, 1.007-1.175; P = 0.033). These results revealed NLR and SIRI as significant predictors of unfavorable outcomes at 90 days. The area under the curve for SIRI and NLR in predicting 90-day adverse outcomes was 0.643 and 0.609, respectively. CONCLUSIONS: Higher SIRI and NLR levels at admission may lead to unfavorable outcomes at 90 days for AIS patients with endovascular therapy.

Daphnetin Ameliorates Neuropathic Pain via Regulation of Microglial Responses and Glycerophospholipid Metabolism in the Spinal Cord.

Neuropathic pain (NP) is a common type of chronic pain caused by a lesion or disease of the somatosensory nervous system. This condition imposes a considerable economic burden on society and patients. Daphnetin (DAP) is a natural product isolated from a Chinese medicinal herb with various pharmacological activities, such as anti-inflammatory and analgesic properties. However, the underlying mechanisms of these effects are not fully understood. In the present study, we aimed to investigate DAP's anti-inflammatory and analgesic effects and explore the underlying mechanisms of action. The NP model was established as chronic constrictive injury (CCI) of the sciatic nerve, and pain sensitivity was evaluated by measuring the mechanical withdrawal threshold (MWT) and thermal withdrawal threshold (TWT). The activation of microglia in the spinal dorsal horn was measured via immunofluorescence staining. Protein levels were measured using a western blot assay. Using a mass-spectrometry proteomics platform and an LC-MS/MS-based metabolomics platform, proteins and metabolites in spinal cord tissues were extracted and analyzed. DAP treatment ameliorated the MWT and TWT in CCI rats. The expression of IL-1ß, IL-6, and TNF-α was inhibited by DAP treatment in the spinal cords of CCI rats. Moreover, the activation of microglia was suppressed after DAP treatment. The elevation in the levels of P2X4, IRF8, IRF5, BDNF, and p-P38/P38 in the spinal cord caused by CCI was inhibited by DAP. Proteomics and metabolomics results indicated that DAP ameliorated the imbalance of glycerophospholipid metabolism in the spinal cords of CCI rats. DAP can potentially ameliorate NP by regulating microglial responses and glycerophospholipid metabolism in the CCI model. This study provides a pharmacological justification for using DAP in the management of NP.

Correlation of Peripheral Blood Inflammatory Indicators to Prognosis After Intravenous Thrombolysis in Acute Ischemic Stroke: A Retrospective Study.

Purpose: According to many previous studies, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR) and hypersensitive C-reactive protein (CRP) are commonly used as important indicators to assess the prognosis of intravenous thrombolysis in AIS patients. Based on this, we used two novel biomarkers C-NLR (CRP/neutrophil-to-lymphocyte ratio) and C-LMR (CRP×lymphocyte-to-monocyte ratio) to investigate their correlation with 90-day outcomes in AIS patients after intravenous thrombolysis. Patients and Methods: A total of 204 AIS patients who received intravenous thrombolysis at the Stroke Center of Jiangsu Province Hospital of Chinese Medicine from January 2021 to December 2022 were retrospectively included. All patients were followed up 90 days after thrombolysis to assess their prognosis. Patients with a modified Rankin scale score (mRS) of 3-6 were included in the unfavorable outcome group, and those with a score of 0-2 were included in the favorable outcome group. Logistic regression analysis, receiver operating characteristic (ROC) curve, and Kaplan-Meier survival curve were used to investigate the association between C-NLR, C-LMR, and 90-day prognosis in AIS patients treated with early intravenous thrombolysis. Results: C-NLR (OR=1.586, 95% CI=1.098~2.291, P=0.014) and C-LMR (OR=1.099, 95% CI=1.025~1.179, P=0.008) were independent risk factors for 90-day prognosis of AIS patients treated with early intravenous thrombolysis. The higher C-NLR and C-LMR were associated with unfavorable prognosis. Conclusion: C-NLR and C-LMR can be used as biomarkers to predict prognosis of AIS patients treated with early intravenous thrombolysis.

Precision in wheat flour classification: Harnessing the power of deep learning and two-dimensional correlation spectrum (2DCOS).

Wheat flour is a ubiquitous food ingredient, yet discerning its various types can prove challenging. A practical approach for identifying wheat flour types involves analyzing one-dimensional near-infrared spectroscopy (NIRS) data. This paper introduces an innovative method for wheat flour recognition, combining deep learning (DL) with Two-dimensional correlation spectrum (2DCOS). In this investigation, 316 samples from four distinct types of wheat flour were collected using a near-infrared (NIR) spectrometer, and the raw spectra of each sample underwent preprocessing employing diverse methods. The discrete generalized 2DCOS algorithm was applied to generate 3792 2DCOS images from the preprocessed spectral data. We trained a deep learning model tailored for flour 2DCOS images - EfficientNet. Ultimately, this DL model achieved 100% accuracy in identifying wheat flour within the test set. The findings demonstrate the viability of directly transforming spectra into two-dimensional images for species recognition using 2DCOS and DL. Compared to the traditional stoichiometric method Partial Least Squares Discriminant Analysis (PLS_DA), machine learning methods Support Vector Machines (SVM) and K-Nearest Neighbors (KNN), and deep learning methods one-dimensional convolutional neural network (1DCNN) and residual neural network (ResNet), the model proposed in this paper is better suited for wheat flour identification, boasting the highest accuracy. This study offers a fresh perspective on wheat flour type identification and successfully integrates the latest advancements in deep learning with 2DCOS for spectral type identification. Furthermore, this approach can be extended to the spectral identification of other products, presenting a novel avenue for future research in the field.

Relationship of Day-by-Day Blood Pressure Variability and Admission Stroke Severity in Acute Ischemic Stroke.

OBJECTIVES: Research on the association between stroke severity and day-by-day blood pressure variability (BPV) in acute ischemic stroke (AIS) is rare as the majority focus on the blood pressure (BP) or the short-term BPV. Our study aims to explore the exact roles of daily BPV through the 7-day commencement on stroke severity in AIS. METHODS: The study included 633 patients with AIS, defining AIS as the time from the beginning of symptom up to 7 days with recording BP twice a day as well as calculating the daily BPV, and then matching them to the stroke severity. The logistic regression models were used to evaluate associations between stroke severity and day-by-day BPV. We used the smooth curve fitting to identify whether there was a nonlinear association. In addition, the subgroup analyses were performed using the logistic regression. RESULTS: According to the modified National Institutes of Health Stroke Scale score, 301 (47.5%) patients were allocated to the mild stroke group and 332 (52.5%) to the moderate-to-severe stroke group. In terms of stroke categories, we found no significant difference between BP at admission or mean BP. However, the moderate-to-severe stroke group exhibited higher daily BPV. The multiple logistic regression analysis indicated that day-by-day BPV was positively correlated to stroke severity [odds ratio (OR)=1.05, 95% CI:1.01-1.1, P =0.03 for SBP-SD; OR=1.08, 95% CI:1.01-1.15, P =0.03 for SBP-CV; OR=1.04, 95% CI:1.01-1.07, P =0.015 for SBP-SV). CONCLUSIONS: High day-by-day BPV in AIS was associated with more severe stroke independent of BP levels.

Synaptic-like transmission between neural axons and arteriolar smooth muscle cells drives cerebral neurovascular coupling.

Neurovascular coupling (NVC) is important for brain function and its dysfunction underlies many neuropathologies. Although cell-type specificity has been implicated in NVC, how active neural information is conveyed to the targeted arterioles in the brain remains poorly understood. Here, using two-photon focal optogenetics in the mouse cerebral cortex, we demonstrate that single glutamatergic axons dilate their innervating arterioles via synaptic-like transmission between neural-arteriolar smooth muscle cell junctions (NsMJs). The presynaptic parental-daughter bouton makes dual innervations on postsynaptic dendrites and on arteriolar smooth muscle cells (aSMCs), which express many types of neuromediator receptors, including a low level of glutamate NMDA receptor subunit 1 (Grin1). Disruption of NsMJ transmission by aSMC-specific knockout of GluN1 diminished optogenetic and whisker stimulation-caused functional hyperemia. Notably, the absence of GluN1 subunit in aSMCs reduced brain atrophy following cerebral ischemia by preventing Ca2+ overload in aSMCs during arteriolar constriction caused by the ischemia-induced spreading depolarization. Our findings reveal that NsMJ transmission drives NVC and open up a new avenue for studying stroke.

Association of fasting blood glucose level with 90-day unfavorable outcome in acute ischemic stroke patients.

OBJECTIVES: Fasting blood glucose (FBG) is a risk factor for Acute Ischemic Stroke (AIS). We aimed to systematically assess the association of FBG level and 90-day unfavorable outcome in AIS patients. METHODS: FBG levels and related information of the patients were collected at admission. The unfavorable outcome was defined as 90-day mRS 3-6. FBG levels were analyzed as continuous variables and tertiles (Q1-Q3). Odds ratios and 95% confidence intervals were calculated by using multivariate logistic regression analysis. RESULTS: Overall, 677 AIS patients were included. FBG were significantly associated with unfavorable outcome at 90 days (adjusted OR 1.15 [95%Cl, 1.05-1.25], P = 0.002). Participants were categorized based on the FBG tertile cut-off points, the Odds ratios was 2.55-fold higher in Q3 than those in Q1 after adjusting (OR 2.55[95%Cl, 1.23-5.3], p = 0.012). Threshold effect analysis showed when FBG ≥ 5.5 mmol/L, the correlation between FBG and 90-day unfavorable outcome increased significantly. Subgroup analysis showed that there was no significant interaction between FBG and 90-day unfavorable outcome. Non-diabetic AIS patients with hyperglycemia (FBG ≥ 7 mmol/L) have a worse prognosis in comparison to those with normal glucose (FBG ˂ 5.6 mmol/L) (OR 8.59 [ 95%Cl, 2.24-32.97], p = 0.002). CONCLUSION: FBG is an independent predictor of 90-day unfavorable outcome after stroke in AIS patients. When FBG ≥ 5.5 mmol/L, the risk of 90-day unfavorable outcome increases significantly.

Effects of Manufactured Sand and Steam-Curing Temperature on the Compressive Strength of Recycled Concrete with Different Water/Binder Ratios.

New building materials (manufactured sand and recycled coarse aggregates) can conserve raw materials and protect the environment. Prefabricated members can shorten the construction time of a structure. To use manufactured sand and recycled coarse aggregate in the preparation of precast member concrete, an economical and practical steam-curing scheme must be developed such that the compressive strength of precast manufactured sand recycled concrete (MRC) meets the requirements for hoisting. The effects of different steam-curing temperatures (standard curing, 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C) on the compressive strength of MRC with three water/binder ratios (W/B) (0.46, 0.42, and 0.38) were studied. In addition, the microstructure of MRC was examined using a scanning electron microscope. The equivalent age-compressive strength model was used to estimate the recycled concrete with manufactured sand. The results showed that the strength of MRC with a water-cement ratio of 0.46, 0.42, and 0.38 reached 33.9, 38.7, and 45.1 MPa, respectively, after 28 days of standard curing. The results also indicated that an increase in the steam-curing temperature had a positive effect on the early compressive strength of MRC and a negative effect on the 28 d compressive strength. This behavior was more obvious for MRC with a low W/B ratio. For MRC with a W/B of 0.46, 0.42, and 0.38, after steam-curing for 6 h, the compressive strength reached 32-65%, 36-70%, and 40-77% of the design strength, respectively. The optimum steam-curing temperatures for MRC with W/B of 0.46, 0.42, and 0.38 were 60 °C, 60 °C, and 50 °C. A decrease in W/B has a negative impact on the accuracy of MRC estimation using the equivalent age-compressive strength model. The maximum deviation of the prediction was within 10%, and the accuracy of the model was acceptable. This study provides a useful reference for the production of prefabricated MRC components in factories and subsequent construction.

Admission thyroid function in relation to 90-day outcome of acute ischemic stroke.

OBJECTIVE: Thyroid function may be useful prognostic predictor of acute ischemic stroke. However, the relationship between thyroid function and stroke prognosis remains controversial. We aimed to explore the correlation between thyroid function at admission and 90-day functional outcome in patients with acute ischemic stroke. METHODS: Our data were collected from patients with AIS (acute ischemic stroke) registered in the Stroke Center of Jiangsu Provincial Hospital of Chinese Medicine from January 2021 to July 2021.The outcome was divided into good outcome as mRS (Modified Rankin Scale) score <3, poor outcome as mRS≥3 (including hemorrhage, recurrence, and death within 90 days after stroke).Univariate, multivariate logistic regression analysis, tertile analysis and subgroup analysis were used to evaluate the relationship between TSH (Thyroid-stimulating hormone), FT3 (Free Triiodothyronine), FT4 (Free thyroxine) and 90-day outcome. RESULTS: 699 patients with AIS were included in this study. In univariate analysis, FT3 was negatively correlated with poor outcome of AIS patients at 90-day, TSH was not statistically correlated with 90-day outcome. Multivariate analysis showed that FT3 was negatively correlated poor outcome of AIS patients at 90-day. After adjusting for potential confounders, TSH was negatively correlated with poor outcome. Participants were categorized based on the tertile cut-off points of FT3 and TSH. With the increase of TSH value, the incidence of poor outcomes in Q3 was 0.57 times higher than that of Q1. Similarly, with the increase of FT3 value, the incidence of poor outcomes in Q3 is 0.3 times than that of Q1. CONCLUSIONS: FT3 and TSH were negatively correlated with poor 90-day outcome in patients with AIS. Measurement of thyroid function on admission may provide independent prognostic information for 90-day outcome of AIS.

Multi-objective sustainable supply chain network optimization based on chaotic particle-Ant colony algorithm.

For the optimal design of the sustainable supply chain network, considering the comprehensiveness of the problem factors, considering the three aspects of economy, environment and society, the goal is to minimize the establishment cost, minimize the emission of environ-mental pollution and maximize the number of labor. A mixed integer programming model is established to maximize the efficiency of the supply chain network. The innovation of this paper, first, is to consider the impact of economic, environmental and social benefits in a continuous supply chain, where the environmental benefits not only consider carbon emissions but also include the emissions of plant wastewater, waste and solid waste as influencing factors. Second, a multi-objective fuzzy affiliation function is constructed to measure the quality of the model solution in terms of the overall satisfaction value. Finally, the chaotic particle ant colony algorithm is proposed, and the problem of premature convergence in the operation of the particle swarm algorithm is solved. Experimental results show that the PSCACO algorithm proposed in this paper is compared with MOPSO, CACO and NSGA-II algorithms, and the convergence effect of the algorithm is concluded to be more effective to verify the effectiveness and feasibility of chaotic particle ant colony algorithm for solving multi-objective functions, which proposes a new feasible solution for the supply chain management.

Daphnetin Improves Neuropathic Pain by Inhibiting the Expression of Chemokines and Inflammatory Factors in the Spinal Cord and Interfering with Glial Cell Polarization.

Neuropathic pain (NP) is a common pain disease that seriously affects the quality of life and physical and mental health of patients. Daphnetin is extracted from the Daphne giraldii Nitsche and has the structure of 7,8-dihydroxy coumarin. As a natural product, daphnetin displays a wide range of pharmacological activities, such as analgesia and anti-inflammatory activities, but whether it is able to improve NP through anti-inflammatory effects is unknown. Therefore, this paper intends to investigate the mechanism of daphnetin in improving NP rats affected by the intrathecal injection of tumor necrosis factor-α (TNF-α) from the perspective of anti-inflammation. Our results showed that daphnetin significantly improved hyperalgesia in NP rats. Daphnetin inhibited the activation and polarization of glial cells and neurons in the spinal cord of NP rats and reduced the expression of mRNA and protein of inflammatory factors and chemokine pairs in the spinal cord. Daphnetin inhibited the polarization of human microglia cell 3 (HMC3) cells and human glioma cells (U251) cells toward M1 microglia and A1 astrocytes, respectively, and induced the conversion of M1 microglia and A1 astrocytes to M2 microglia and A2 astrocytes, respectively. In conclusion, daphnetin ameliorates NP by inhibiting the expression of inflammatory factors and chemokines and the polarization of glial cells in the spinal cord of NP rats. This study provides a theoretical basis for the treatment of NP with daphnetin to expand the clinical application of daphnetin.

Daphnetin alleviates neuropathic pain in chronic constrictive injury rats via regulating the NF-κB dependent CXCL1/CXCR2 signaling pathway.

CONTEXT: Daphnetin is a natural product with anti-inflammatory, antioxidant, and neuroprotective properties. Reports have found that it has a strong analgesic effect; however, its analgesic mechanism is unknown. OBJECTIVE: We explored the effect and mechanism of daphnetin on neuropathic pain (NP). MATERIALS AND METHODS: The rat model of NP was established by ligation of the sciatic nerve. Male Sprague-Dawley rats were divided into six groups: Control, Model, Sham, morphine (0.375 mg/kg), and daphnetin (0.0625 and 0.025 mg/kg). Rats were intrathecally injected with drugs or normal saline once daily for three days. Hyperalgesia was evaluated by mechanical withdrawal threshold (MWT) and thermal withdrawal threshold (TWT). Protein levels were detected using ELISA, immunofluorescence, and western blotting. RESULTS: Compared to the Model group, daphnetin improved TWT (46.70 °C vs. 42.20 °C) and MWT (45.60 g vs. 23.60 g), reduced the expression of interleukin-1ß (0.99 ng/g vs. 1.42 ng/g), interleukin-6 (0.90 ng/g vs. 1.52 ng/g), and tumor necrosis factor-α (0.93 ng/g vs. 1.52 ng/g) in the sciatic nerve. Daphnetin decreased the expression of toll-like receptor 4 (TLR4) (0.47-fold), phosphorylated inhibitor of NF-κB (p-IKBα) (0.29-fold), nuclear factor kappaB (NF-κB) (0.48-fold), glial fibrillary acidic protein (GFAP) (0.42-fold), CXC chemokine ligand type 1 (CXCL1) (0.84-fold), CXC chemokine receptor type 2 (CXCR2) (0.78-fold) in the spinal cord. DISCUSSION AND CONCLUSIONS: Daphnetin alleviates NP by inhibiting inflammation and astrocyte activation in the spinal cord, providing theoretical support for the extensive clinical treatment of NP.

Relationship between mean blood pressure during hospitalization and clinical outcome after acute ischemic stroke.

OBJECTIVE: The optimal blood pressure (BP) targets for acute ischemic stroke are unclear. We aimed to assess the relationship between Mean BP and clinical outcomes during hospitalization. MATERIALS AND METHODS: We included 649 patients with Acute ischemic stroke (AIS) from December 2020 to July 2021. BP was measured daily, and mean blood pressure was calculated. Clinical events recorded within 90 days of randomization were: recurrent ischemic stroke, symptomatic intracranial hemorrhage, and death. The modified Rankin Scale (mRS) was used to measure primary outcomes 3 months after AIS. Logistic multiple regression analysis was performed by statistical software R. RESULT: There is a nonlinear U-shaped relationship between SBP and poor outcomes. This means higher SBP and lower SBP will increase the incidence of poor outcomes. The optimal mean SBP during hospitalization was 135-150 mmHg, and patients with SBP < 135mmhg OR 2.4 [95% Cl, (1.16 ~ 4.97)], P = 0.018; and > 150mmhg OR 2.04 [95% Cl, 1.02 ~ 4.08], p = 0.045 had a higher probability of poor outcomes. CONCLUSION: Our study shows that the optimal SBP of patients with AIS during hospitalization was 135-150 mmHg. The findings suggest that the relationship between mean SBP and 3-month functional outcome after AIS was U-shaped. Both higher SBP and lower SBP lead to poor prognosis in AIS patients.

Terahertz phase shift sensing and identification of a chiral amino acid based on a protein-modified metasurface through the isoelectric point and peptide bonding.

The efficient sensing of amino acids, especially the distinction of their chiral enantiomers, is important for biological, chemical, and pharmaceutical research. In this work, a THz phase shift sensing method was performed for amino acid detection based on a polarization-dependent electromagnetically induced transparency (EIT) metasurface. More importantly, a method for binding the specific amino acids to the functional proteins modified on the metasurface was developed based on the isoelectric point theory so that the specific recognition for Arginine (Arg) was achieved among the four different amino acids. The results show that via high-Q phase shift, the detection precision for L-Arg is 2.5 × 10-5 g /ml, much higher than traditional sensing parameters. Due to the specific electrostatic adsorption by the functionalized metasurface to L-Arg, its detection sensitivity and precision are 22 times higher than the other amino acids. Furthermore, by comparing nonfunctionalized and functionalized metasurfaces, the D- and L-chiral enantiomers of Arg were distinguished due to their different binding abilities to the functionalized metasurface. Therefore, this EIT metasurface sensor and its specific binding method improve both detection precision and specificity in THz sensing for amino acids, and it will promote the development of THz highly sensitive detection of chiral enantiomers.

The core of maintaining neuropathic pain: Crosstalk between glial cells and neurons (neural cell crosstalk at spinal cord).

BACKGROUND: Neuropathic pain (NP) caused by the injury or dysfunction of the nervous system is a chronic pain state accompanied by hyperalgesia, and the available clinical treatment is relatively scarce. Hyperalgesia mediated by pro-inflammatory factors and chemokines plays an important role in the occurrence and maintenance of NP. DATA TREATMENT: Therefore, we conducted a systematic literature review of experimental NP (PubMed Medline), in order to find the mechanism of inducing central sensitization and explore the intervention methods of hyperalgesia caused by real or simulated injury. RESULT: In this review, we sorted out the activation pathways of microglia, astrocytes and neurons, and the process of crosstalk among them. It was found that in NP, the microglia P2X4 receptor is the key target, which can activate the mitogen-activated protein kinase pathway inward and then activate astrocytes and outwardly activate neuronal tropomyosin receptor kinase B receptor to activate neurons. At the same time, activated neurons continue to maintain the activation of astrocytes and microglia through chemokines on CXCL13/CXCR5 and CX3CL1/CX3CR1. This crosstalk process is the key to maintaining NP. CONCLUSION: We summarize the further research on crosstalk among neurons, microglia, and astrocytes in the central nervous system, elaborate the ways and connections of relevant crosstalk, and find potential crosstalk targets, which provides a reference for drug development and preclinical research.

Chiral enantiomer recognition of amino acids enhanced by terahertz spin beam separation based on a Pancharatnam-Berry metasurface.

The highly sensitive detection and identification of chiral biochemical substances have attracted extensive attention. Terahertz (THz) spectroscopy and sensing technology have obvious advantages in non-contact and label-free biochemical detection, but the THz chiral spectral response of chiral biochemical substances is too weak to realize highly sensitive chiral enantiomer recognition. Herein, we propose a method of spin beam deflection and separation by using a Pancharatnam-Berry (PB) metasurface to enhance the THz chirality response of chiral amino acids, realizing the identification of chiral enantiomers of the same kind of amino acid. The conjugate spin transmittances and circular dichroism (CD) spectra of d- and l-tyrosine samples on the PB metasurface were measured by an angle-resolved THz time-domain polarization spectroscopy system, and their CD values reached 16.4° and -11.6° at a deflection angle of ±33°, respectively, which were enhanced by about 9.3 and 11.9 times compared with the maximum CD values of the sample without the metasurface. Therefore, this THz chiral sensing method based on a PB metasurface has great potential in highly sensitive chirality identification and enhancement for chiral substances.

The protective effect of Eleutheroside E against the mechanical barrier dysfunction triggered by lipopolysaccharide in IPEC-J2 cells.

Eleutheroside E (EE) exhibits immunocompetence, antioxidant, and anti-inflammatory activity. Lipopolysaccharide (LPS) can elicit a strong immune response. In vitro experiments were used to explore whether EE protects intestinal porcine jejunum epithelial cells (IPEC-J2) barriers from LPS stress. The experiment was divided into group C (control group: complete medium), group E (group C + 0.1 mg/mL EE), group L (group C + 10 µg/mL LPS), and group EL (adding 0.1 mg/mL EE for 6 h, and then adding 10 µg/mL LPS for culture). Finally, the cell proliferation, permeability, mRNA expression of cytokines, mRNA and protein expression of tight junctions (TJs) were analyzed. The result show that, when compared to the C group, EE significantly promoted the proliferation of IPEC-J2 at 58 h and showed low permeability (P < 0.05), the anti-inflammatory cytokines IL-10 and TGF-ß mRNA expression were increased extremely significantly, the inflammatory cytokines IL-6, TNF-α, and IFN-γ mRNA expression were extremely significantly decreased (P < 0.01), the mRNA and protein expression of TJ were significantly increased in group E (P < 0.05). However, LPS showed a damaging effect. EL group compared with L group, the cell index (CI) value was higher at 58 h (P < 0.05), the permeability was significantly lower (P < 0.05), the mRNA expressions of the inflammatory cytokines were down-regulated(P < 0.01), and the TJ mRNA and protein relative expression were increased (P < 0.05). In summary, the addition of EE protects the LPS-induced increase in permeability of IPEC-J2, potentially by expressing high levels of TJ proteins and inhibiting the increase of inflammatory cytokines.

Terahertz polarization sensing for protein concentration and a crystallization process on a reflective metasurface.

Terahertz (THz) waves have attracted much attention in the field of biosensing due to advantages including non-destructiveness, being label-free, and high-sensitivity detection. Here we have experimentally demonstrated a THz polarization sensing method based on reflective metasurface sensors for detecting concentrations of protein solutions and their crystallization process. The protein with varying concentrations has been detected by five different polarization parameters, which show different spectral responses and sensing sensitivities. The sensing accuracy can reach the order of ng/mm2. Furthermore, the crystallization process of the protein sample from the dissolved state to the crystalline has been dynamically measured by polarization sensing, of which the highest sensitivity can reach 0.67 °/%. Therefore, this new sensing platform can have broad development prospects in the trace matter detection of the biological sample.

Spatiotemporal variations of dissolved CH4 concentrations and fluxes from typical freshwater types in an agricultural irrigation watershed in Eastern China.

Inland freshwater ecosystems are of increasing concerns in global methane (CH4) budget in the atmosphere. Agricultural irrigation watersheds are a potential CH4 emission hotspot owing to the anthropogenic carbon and nutrients loading. However, large-scale spatial variations of CH4 concentrations and fluxes in agricultural catchments remain poorly understood, constraining an accurate regional estimate of CH4 budgets. Here, we examined the spatiotemporal variations of dissolved CH4 concentrations and fluxes from typical freshwater types (ditch, reservoir and river) within an agricultural irrigation watershed from Hongze catchment, which is subjected to intensive agricultural and rural activities in Eastern China. The dissolved CH4 concentrations and fluxes showed similar temporal variations among the three freshwater types, with the highest rates in summer and the lowest rates in winter. The total CH4 emission from this agricultural irrigation watershed was estimated to be 0.002 Gg CH4 yr-1, with annual mean CH4 concentration and flux of 0.12 µmol L-1 and 0.58 mg m-2 d-1, respectively. Diffusive CH4 fluxes varied in samples taken from different freshwater types, the annual mean CH4 fluxes for ditch, reservoir and river were 0.31 ± 0.06, 0.71 ± 0.13 and 0.72 ± 0.25 mg m-2 d-1, respectively. Among three freshwater types, the CH4 fluxes were the lowest in ditch, which was associated with the lowest responses of CH4 fluxes to water dissolved oxygen (DO), nitrate nitrogen (NO3--N) and sediment dissolved organic carbon (DOC) concentrations in ditch. In addition, water velocity and wind speed were significantly lower in ditch than in reservoir and river, suggesting that they also played important roles in explaining the spatial variability of dissolved CH4 concentrations and fluxes. These results highlighted a need for more field measurements with wider spatial coverage and finer frequency, which would further improve the reliability of flux estimates for assessing the contribution of agricultural watersheds to the regional and global CH4 budgets.