Catalytic Asymmetric Cyclizative Rearrangement of Anilines and Vicinal Diketones to Access 2,2-Disubstituted Indolin-3-ones

The efficient synthesis of chiral 2,2-disubstituted indolin-3-ones is of great importance due to its significant synthetic and biological applications. However, catalytic enantioselective methods for de novo synthesis of such heterocycles remain scarce. Herein, a novel cyclizative rearrangement of readily available anilines and vicinal diketones for the one-step construction of enantioenriched 2,2-disubstituted indolin-3-ones is presented. The reaction proceeds through a self-sorted [3+2] heteroannulation/regioselective dehydration/1,2-ester shift process. Only chiral phosphoric acid is employed to promote the entire sequence and simplify the manipulation of this protocol. Various common aniline derivatives are successfully applied to asymmetric synthesis as 1,3-binuclephiles for the first time. Remarkably, the observed stereoselectivity is proposed to originate from an amine-directed regio- and enantioselective ortho-Csp2-H addition of the anilines to the ketones. A range of synthetic transformations of the resulting products are demonstrated as well.

Harnessing developmental dynamics of spinal cord extracellular matrix improves regenerative potential of spinal cord organoids

Neonatal spinal cord tissues exhibit remarkable regenerative capabilities as compared to adult spinal cord tissues after injury, but the role of extracellular matrix (ECM) in this process has remained elusive. Here, we found that early developmental spinal cord had higher levels of ECM proteins associated with neural development and axon growth, but fewer inhibitory proteoglycans, compared to those of adult spinal cord. Decellularized spinal cord ECM from neonatal (DNSCM) and adult (DASCM) rabbits preserved these differences. DNSCM promoted proliferation, migration, and neuronal differentiation of neural progenitor cells (NPCs) and facilitated axonal outgrowth and regeneration of spinal cord organoids more effectively than DASCM. Pleiotrophin (PTN) and Tenascin (TNC) in DNSCM were identified as contributors to these abilities. Furthermore, DNSCM demonstrated superior performance as a delivery vehicle for NPCs and organoids in spinal cord injury (SCI) models. This suggests that ECM cues from early development stages might significantly contribute to the prominent regeneration ability in spinal cord.

NDRG2 alleviates photoreceptor apoptosis by regulating the STAT3/TIMP3/MMP pathway in mice with retinal degenerative disease

Photoreceptor apoptosis is the main pathological feature of retinal degenerative diseases; however, the underlying molecular mechanism has not been elucidated. Recent studies have shown that N-myc downstream regulated gene 2 (NDRG2) exerts a neuroprotective effect on the brain and spinal cord. In addition, our previous studies have confirmed that NDRG2 is expressed in mouse retinal photoreceptors and counteracts N-methyl-N-nitrosourea (MNU)-induced apoptosis. However, the underlying molecular mechanism remains unclear. In this study, we observed that the expression of NDRG2 was not only significantly inhibited in photoreceptors after MNU treatment but also after hydrogen peroxide treatment, and photoreceptor apoptosis was alleviated or aggravated after overexpression or knockdown of NDRG2 in the 661W photoreceptor cell line, respectively. The apoptosis inhibitor Z-VAD-FMK rescued photoreceptor apoptosis induced by MNU after NDRG2 knockdown. Next, we screened and identified tissue inhibitor of metalloproteinases 3 (TIMP3) as the downstream molecule of NDRG2 in 661W cells by using quantitative real-time polymerase chain reaction. TIMP3 exerts a neuroprotective effect by inhibiting the expression of matrix metalloproteinases (MMPs). Subsequently, we found that signal transducer and activator of transcription 3 (STAT3) mediated the NDRG2-associated regulation of TIMP3. Finally, we overexpressed NDRG2 in mouse retinal tissues by intravitreally injecting an adeno-associated virus with mouse NDRG2 in vivo. Results showed that NDRG2 upregulated the expression of phospho-STAT3 (p-STAT3) and TIMP3, while suppressing MNU-induced photoreceptor apoptosis and MMP expression. Our findings revealed how NDRG2 regulates the STAT3/TIMP3/MMP pathway and uncovered the molecular mechanism underlying its neuroprotective effect on mouse retinal photoreceptors.

Effects of Dietary Colostrum Basic Protein on Bone Growth and Calcium Absorption in Mice

Colostrum basic protein (CBP) is a trace protein extracted from bovine colostrum. Previous studies have shown that CBP can promote bone cell differentiation and increase bone density. However, the mechanism by which CBP promotes bone activity remains unclear. This study investigated the mechanism of the effect of CBP on bone growth in mice following dietary supplementation of CBP at doses that included 0.015%, 0.15%, 1.5%, and 5%. Compared with mice fed a normal diet, feeding 5% CBP significantly enhanced bone rigidity and improved the microstructure of bone trabeculae. Five-percent CBP intake triggered significant positive regulation of calcium metabolism in the direction of bone calcium accumulation. The expression levels of paracellular calcium transport proteins CLDN2 and CLDN12 were upregulated nearly 1.5-fold by 5% CBP. We conclude that CBP promotes calcium absorption in mice by upregulating the expression of the calcium-transporting paracellular proteins CLND2 and CLND12, thereby increasing bone density and promoting bone growth. Overall, CBP contributes to bone growth by affecting calcium metabolism.

Remote Fault Diagnosis for the Powertrain System of Fuel Cell Vehicles Based on Random Forest Optimized with a Genetic Algorithm

To enhance the safety and reliability of fuel cell vehicles, a remote monitoring system based on 5th generation (5G) mobile networks and controller area networks (CANs) was designed, and a random forest (RF) algorithm for the fault diagnosis for eight typical malfunctions of its powertrain system was incorporated. Firstly, the information on the powertrain system was obtained through a 5G-based monitoring terminal, and the Alibaba Cloud IoT platform was utilized for data storage and remote monitoring. Secondly, a fault diagnosis model based on the RF algorithm was constructed for fault classification; its parameters were optimized with a genetic algorithm (GA), and it was applied on the Alibaba Cloud PAI platform. Finally, the performance of the proposed RF fault diagnosis model was evaluated by comparing it with three other classification models: random search conditioning, grid search conditioning, and Bayesian optimization. Results show that the model accuracy, F1 score, and kappa value of the optimized RF fault classification model are higher than the other three. The model achieves an F1 value of 97.77% in identifying multiple typical faults of the powertrain system, as validated by vehicle malfunction data. The method demonstrates the feasibility of remote monitoring and fault diagnosis for the powertrain system of fuel cell vehicles.

Immunoregulation of bovine lactoferrin together with osteopontin promotes immune system development and maturation

The immune system of infants is partly weak and immature, and supplementation of infant formula can be of vital importance to boost the development of the immune system. Lactoferrin (LF) and osteopontin (OPN) are essential proteins in human milk with immunoregulation function. An increasing number of studies indicate that proteins have interactions with each other in milk, and our previous study found that a ratio of LF : OPN at 1 : 5 (w/w, denoted as LOP) had a synergistic effect on intestinal barrier protection. It remains unknown whether LOP can also exert a stronger effect on immunoregulation. Hence, we used an in vitro model of LPS-induced macrophage inflammation and in vivo models of LPS-induced intestinal inflammation and early life development. We showed that LOP increased the secretion of the granulocyte-macrophage colony-stimulating factor (132%), stem cell factor (167%) and interleukin-3 (176%) in bone marrow cells, as well as thymosin (155%) and interleukin-10 (161%) in the thymus, more than LF or OPN alone during development, and inhibited changes in immune cells and cytokines during the LPS challenge. In addition, analysis of the components of digested proteins in vitro revealed that differentially expressed peptides may provide immunoregulation. Lastly, LOP increased the abundance of Rikenellaceae, Muribaculum, Faecalibaculum, and Elisenbergiella in the cecum content. These results imply that LOP is a potential immunomodifier for infants and offers a new theoretical basis for infant formula innovation.

Mimicked Spinal Cord Fibers Trigger Axonal Regeneration and Remyelination after Injury

Spinal cord injury (SCI) causes tissue structure damage and composition changes of the neural parenchyma, resulting in severe consequences for spinal cord function. Mimicking the components and microstructure of spinal cord tissues holds promise for restoring the regenerative microenvironment after SCI. Here, we have utilized electrospinning technology to develop aligned decellularized spinal cord fibers (A-DSCF) without requiring synthetic polymers or organic solvents. A-DSCF preserves multiple types of spinal cord extracellular matrix proteins and forms a parallel-oriented structure. Compared to aligned collagen fibers (A-CF), A-DSCF exhibits stronger mechanical properties, improved enzymatic stability, and superior functionality in the adhesion, proliferation, axonal extension, and myelination of differentiated neural progenitor cells (NPCs). Notably, axon extension or myelination has been primarily linked to Agrin (AGRN), Laminin (LN), or Collagen type IV (COL IV) proteins in A-DSCF. When transplanted into rats with complete SCI, A-DSCF loaded with NPCs improves the survival, maturation, axon regeneration, and motor function of the SCI rats. These findings highlight the potential of structurally and compositionally biomimetic scaffolds to promote axonal extension and remyelination after SCI.

Hypovirus infection induces proliferation and perturbs functions of mitochondria in the chestnut blight fungus

Introduction

The chestnut blight fungus, Cryphonectria parasitica, and hypovirus have been used as a model to probe the mechanism of virulence and regulation of traits important to the host fungus. Previous studies have indicated that mitochondria could be the primary target of the hypovirus.

Methods

In this study, we report a comprehensive and comparative study comprising mitochondrion quantification, reactive oxygen species (ROS) and respiratory efficiency, and quantitative mitochondrial proteomics of the wild-type and virus-infected strains of the chestnut blight fungus.

Results and discussion

Our data show that hypovirus infection increases the total number of mitochondria, lowers the general ROS level, and increases mitochondrial respiratory efficiency. Quantification of mitochondrial proteomes revealed that a set of proteins functioning in energy metabolism and mitochondrial morphogenesis, as well as virulence, were regulated by the virus. In addition, two viral proteins, p29 and p48, were found to co-fractionate with the mitochondrial membrane and matrix. These results suggest that hypovirus perturbs the host mitochondrial functions to result in hypovirulence.

Asymmetric Construction of α,α-Disubstituted Piperazinones Enabled by Benzilic Amide Rearrangement

An unprecedent asymmetric catalytic benzilic amide rearrangement for the synthesis of α,α-disubstituted piperazinones is reported. The reaction proceeds via a domino [4+1] imidazolidination/formal 1,2-nitrogen shift/1,2-aryl or alkyl migration sequence, employing readily available vicinal tricarbonyl compounds and 1,2-diamines as starting materials. This approach provides an efficient access to chiral C3-disubsituted piperazin-2-ones with high enantiocontrol, which are exceedingly difficult to access from the existing synthetic methodologies. The observed enantioselectivity was proposed to be controlled by dynamic kinetic resolution in the 1,2-aryl/alkyl migration step. The resulting densely functionalized products are versatile building blocks to bioactive natural products, drug molecules and their analogues.

Spinal cord tissue engineering via covalent interaction between biomaterials and cells

Noncovalent interactions between cells and environmental cues have been recognized as fundamental physiological interactions that regulate cell behavior. However, the effects of the covalent interactions between cells and biomaterials on cell behavior have not been examined. Here, we demonstrate a combined strategy based on covalent conjugation between biomaterials (collagen fibers/lipid nanoparticles) and various cells (exogenous neural progenitor cells/astrocytes/endogenous tissue-resident cells) to promote neural regeneration after spinal cord injury (SCI). We found that metabolic azido-labeled human neural progenitor cells conjugated on dibenzocyclooctyne-modified collagen fibers significantly promoted cell adhesion, spreading, and differentiation compared with noncovalent adhesion. In addition, dibenzocyclooctyne-modified lipid nanoparticles containing edaravone, a well-known ROS scavenger, could target azide-labeled spinal cord tissues or transplanted azide-modified astrocytes to improve the SCI microenvironment. The combined application of these covalent conjugation strategies in a rat SCI model boosted neural regeneration, suggesting that the covalent interactions between cells and biomaterials have great potential for tissue regeneration.

Compatibility optimization of a polyhedral-shape thermoelectric generator for automobile exhaust recovery considering backpressure effects

The output performance of thermoelectric generator using thermoelectric modules can be improved by optimizing the heat exchanger structure, but this may cause compatibility issues in the exhaust heat recovery process, such as high backpressure and poor performance for the internal combustion engine. In this study, a polyhedral-shape heat exchanger-based thermoelectric generator system for vehicle exhaust recovery was constructed for the uniform temperature and easy thermoelectric module layout, and the influencing factors of heat transfer and backpressure was evaluated using a realizable k-ϵ turbulence model, and the influence order was analyzed based on the analysis of variance method. Finally, a multi-objective grey wolf optimizer was used to improve the thermoelectric generator system based on the proposed compatibility performance index and optimization objective function. The findings show that the heat transfer performance and backpressure of heat exchanger is obviously affected by different fin length, fin width, fin intersection angle and fin spacing distance. Compared with the empty cavity structure based one and those without optimization, the optimized fin parameters not only obtain high power and satisfactory thermoelectric conversion efficiency, but also ensure low pressure drop and ideal temperature uniformity, which well meets the compatibility requirements for automobile exhaust recovery application.

Biological characteristics and genomic analysis of a novel Vibrio parahaemolyticus phage phiTY18 isolated from the coastal water of Xiamen China

Vibrio parahaemolyticus is a common pathogen usually controlled by antibiotics in mariculture. Notably, traditional antibiotic therapy is becoming less effective because of the emergence of bacterial resistance, hence new strategies need to be found to overcome this challenge. Bacteriophages, a class of viruses that lyse bacteria, can help us control drug-resistant bacteria. In this study, a novel Vibrio parahaemolyticus phage phiTY18 isolated from the coastal water of Xiamen was explored. Transmission electron microscopy showed that phiTY18 had an icosahedral head of 130.0 ± 1.2 nm diameter and a contractile tail of length of 66.7 ± 0.6 nm. The phage titer could reach 7.2×10¹⁰ PFU/mL at the optimal MOI (0.01). The phage phiTY18 had a degree of tolerance to heat and acid and base. At the temperature of 50°C (pH7.0, 1h) the survival phages reached 1.28×10⁶ PFU/mL, and at pH 5-9 (30°C, 1h), the survival phages was greater than 6.37×10⁷ PFU/mL Analysis of the phage one-step growth curve revealed that it had a latent period of 10min, a rise period of 10min, and an average burst size of the phage was 48 PFU/cell. Genome sequencing and analysis drew that phage phiTY18 had double-stranded DNA (191,500 bp) with 34.90% G+C content and contained 117 open reading frames (ORFs) and 24 tRNAs. Phylogenetic tree based on major capsid protein (MCP) revealed that phage phiTY18 (MW451250) was highly related to two Vibrio phages phiKT1024 (OM249648) and Va1 (MK387337). The NCBI alignment results showed that the nucleotide sequence identity was 97% and 93%, respectively. In addition, proteomic tree analysis indicated that phage phiTY18, phiKT1024, and Va1 were belong to the same virus sub-cluster within Myoviridae. This study provides a theoretical basis for understanding the genomic characteristics and the interaction between Vibrio parahaemolyticus phages and their host.

Model prediction of herbicide residues in soybean oil: Relationship between physicochemical properties and processing factors

The distribution and processing factors (PFs) of herbicides in cold-/hot-pressed soybean samples (n = 3) were studied on the laboratory scale. The hot-pressing process was found to have a significant effect on herbicide degradation in soybean samples. Specifically, for highly water-soluble pesticides with pK_ow > 2 in soybean oil, the PF values were generally > 1. Nonlinear curve fitting revealed that the PFs of herbicides in soybean oil were positively correlated with their octanol-water partition coefficients, but negatively correlated with their water solubility and melting points. A principal component analysis confirmed the dominant parameters among the herbicide PFs during soybean oil production. Using the physicochemical parameters of pesticides, the developed multiple linear regression model gave a fitting accuracy of ≥0.80 for predicting the theoretical PF values of pesticides in soybean oil products (0.39 < RMSE < 0.58). Thus, this model may be applicable for safety risk assessments and establishing maximum residue limits for pesticides in processed products.

Study on Dangerous Acupuncture Needling Depth at Yamen (GV15) for Atlantoaxial Dislocation based on MRI and CT

Background: The depth of acupuncture at GV15 significantly changes with atlantoaxial dislocation (AAD). Magnetic resonance imaging (MRI) and computed tomography (CT) are the current methods for assessing acupuncture depth. However, the acupuncture depth in patients with AAD and the best evaluation method for acupuncture have not been thoroughly studied. Objectives: Based on MRI and 3D CT imaging measurements, dangerous needling depths for perpendicular acupuncture and oblique acupuncture in patients with AAD and normal anatomy were obtained. The application value of MRI and 3D CT in evaluating acupuncture depth is discussed. Methods: From January 2018 to December 2021, patients with AAD (120 patients) and control patients without AAD (124 patients) diagnosed and treated at the Upper Cervical Spine Research Center of the China-Japan Friendship Hospital were selected. All patients were enrolled. Both groups included patients with normal body types (BMI 18.5-23.9). The two groups of patients underwent plain cervical MRI scans and three-dimensional plain CT scans, and the dangerous needling depth of the perpendicular spur and the oblique spur were measured on sagittal images. Results: No significant differences were observed between the two measurements (MRI and CT) (P<0.05). The dangerous needling depths in the AAD group were as follows: male straight stab: 45.33±5.17 mm, male oblique stab: 48.58±4.41 mm, female straight thorn: 44.17±7.80 mm, and female oblique thorn: 47.49±7.32 mm. The dangerous needling depths for the control group were as follows: male straight thorn: 47.72±5.06 mm, male oblique thorn: 42.69±5.53 mm, female straight thorn: 44.63±5.85 mm, and female oblique thorn: 39.88 ± 6.18 mm. Conclusions: Acupuncture depth at the dumb point of the AAD changed significantly. The clinical acupuncture depth should not exceed this safe depth. Both CT and MRI can be used to assess dangerous needling depth at GV15.

Circulating proteomic biomarkers related to the development of chronic thromboembolic pulmonary hypertension in patients with acute pulmonary embolism

Background

Chronic thromboembolic pulmonary hypertension (CTEPH), known as a complication of acute pulmonary embolism (PE), can be attributed to both persistent organized thrombi and small-vessel disease. It has been reported that patients with acute PE are more likely to develop CTEPH or have a worse prognosis in follow-up if they have pulmonary hypertension (PH) or right ventricular dysfunction in their acute phase; in acute PE, increased pulmonary arterial pressure can be induced by a combination of mechanical obstruction and pulmonary vasoconstriction. However, it remains unknown whether contributors to the increase pulmonary arterial pressure in acute phase would persistently influence the pulmonary vasculature, which could further lead to the development and progression of CTEPH.

Purpose

To investigate underlying contributors related to pulmonary hypertension in acute PE that would persistently influence the pulmonary vasculature in the development of CTEPH, and to explore potential biomarkers predictive of CTEPH in acute PE.

Methods

Plasma from patients with acute PE were collected and classified into Group 1 (with PH) and Group 2 (without PH) according to the presence of PH, which was defined by echocardiographic estimated “high probability” of PH as recommended in the 2015 ESC/ERS Guidelines for the diagnosis and treatment of PH. In addition, plasma from patients with acute PE who had not developed PH both in their acute and follow-up phase but had persistent thrombi (Group 3) were also studied and compared to that of CTEPH patients (Group 4). Differential expression proteins (DEPs) between 4 groups were identified in terms of data-independent acquisition-based quantitative proteomic analysis.

Results

Twenty-two DEPs were identified between Group1 and Group 2, and 105 DEPs were identified between Group 3 and Group 4. Among two groups of DEPs, 8 proteins were in common: antithrombin-III, osteopontin, properdin, desmoplakin, C1QA (complement C1q subcomponent subunit A), LDHA (L-lactate dehydrogenase A chain), IGKV1D-33 (immunoglobulin kappa variable 1D-33) and PEPD (Xaa-Pro dipeptidase). The level of LDHA, antithrombin-III, osteopontin and properdin were decreased both in acute PE patients with PH and CTEPH patients, while the level of desmoplakin, C1QA and IGKV1D-33 were increased in the above two groups. Regarding PEPD, its level was lower in acute patients with PH but was higher in CTEPH. Based on underlying pathogenic mechanism and the percentage of missing value, osteopontin, properdin, desmoplakin, C1QA, LDHA and PEPD were further validated as potential biomarkers predictive of CTEPH in acute PE.

Conclusions

Contributors to the increase pulmonary arterial pressure in acute PE can be further involved in the development of CTEPH, and these proteins can be potential biomarkers to help guide the management and follow-up strategy in acute PE.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (CIFMS; No. 2017-12M-1-009); National Key Research and Development Program of China (No: 2016YFC1304400) Differential expression proteinsRelative intensity of proteins

Stereoselective behaviors of the fungicide triadimefon and its metabolite triadimenol during malt storage and beer brewing

The stereoselective behaviors of triadimefon (TF) and its metabolite triadimenol (TN) during barley storage and beer brewing were studied by supercritical fluid chromatography-tandem mass spectrometry to shed light on potential security risks. Matrix-matched calibration curves were constructed for barley and beer, with determination coefficients (r²) ≥ 0.9991. Average recoveries of 77.2-107.5 % and relative standard deviations within 15.0 % were observed. The degradation of the TF enantiomers during storage followed pseudo-first-order kinetics, and S-TF was degraded in preference to R-TF with the half-life ranges 18.5-36.5 d and 20.4-69.3 d, respectively. During beer brewing, the TF enantiomers (enantiomer fraction, 0.44-0.56) were selectively metabolized into TN stereoisomers (diastereomer fraction, 0.43-0.58). The total pesticide content of beer was 93.3 % lower than that of raw grain, whereby the TF content declined by up to 100 % and the TN stereoisomers were reduced by 35.1 %. The processing factors of all the brewing steps were less than one, illustrating that beer consumption is safer after its commercial processing. Furthermore, the TF enantiomers showed different behaviors upon fermentation by two yeast strains. Thus, this work is a useful reference for assessing the food safety risk posed by individual pesticide enantiomers and their contribution to environmental pollution.

17β-Oestradiol Attenuates the Photoreceptor Apoptosis in Mice with Retinitis Pigmentosa by Regulating N-myc Downstream Regulated Gene 2 Expression

Retinitis pigmentosa (RP) is a heterogeneous group of retinal degenerative diseases in which the final pathological feature is photoreceptor cell apoptosis. Currently, the pathogenesis of RP remains poorly understood and therapeutics are ineffective. 17β-Oestradiol (βE2) is universally acknowledged as a neuroprotective factor in neurodegenerative diseases and has manifested neuroprotective effects in a light-induced retinal degeneration model. Recently, we identified N-myc downstream regulated gene 2 (NDRG2) suppression as a molecular marker of mouse retinal photoreceptor-specific cell death. βE2 has also been reported to regulate NDRG2 in salivary acinar cells. Therefore, in this study, we investigated whether βE2 plays a protective role in RP and regulates NDRG2 in photoreceptor cells. To this end, we generated RP models and observed that βE2 not only reduced the apoptosis of photoreceptor cells, but also restored the level of NDRG2 expression in RP models. Then, we showed that siNDRG2 inhibits the anti-apoptotic effect of βE2 on photoreceptor cells in a cellular RP model. Subsequently, we used a classic oestrogen receptor (ER) antagonist to attenuate the effects of βE2, suggesting that βE2 exerted its effects on RP models via the classic ERs. In addition, we performed a bioinformatics analysis, and the results indicated that the reported oestrogen response element (ERE) sequence is present in the promoter region of the mouse NDRG2 gene. Overall, our results suggest that βE2 attenuated the apoptosis of photoreceptor cells in RP models by maintaining NDRG2 expression via a classic ER-mediated mechanism.

The BDNF Val66Met polymorphism impacts victim's moral emotions following interpersonal transgression

Immoral behaviors make individuals abominate and punish transgressors. Inspired by the associations between the Val66Met polymorphism of brain-derived neurotropic factor (BDNF) gene and emotional responses following negative events, we investigated whether this polymorphism was also associated moral emotions such as punishment and forgiveness following interpersonal transgression. To do so, we categorized 340 individuals according to the BDNF Val66Met and assessed moral emotions by using 12 hypothetic scenarios in different conditions of intention and interpersonal consequence. The results indicated that this polymorphism was significantly associated with moral aversion and punishment towards transgressors. Victims with the Val/Val genotype expressed less aversion and punishment than the Met carriers, regardless of intention and interpersonal consequence. Moreover, this polymorphism was associated with forgiveness. Victims with the Val/Val genotype expressed more forgiveness than the Met carriers. Taken together, these findings highlight the importance of the BDNF Val66Met to moral emotions.

Fault diagnosis in a current sensor and its application to fault-tolerant control for an air supply subsystem of a 50 kW-Grade fuel cell engine

The safety, reliability and stability of air supply subsystems are still problems for the commercial applications of fuel cells; therefore, engine fault diagnosis and fault-tolerant control are essential to protect the fuel cell stack. In this study, a fault diagnosis and fault-tolerant control method based on artificial neural networks (ANNs) has been proposed. The offline ANN modification model was trained with a Levenberg–Marquardt (LM) algorithm based on other sensors' signals relevant to the current sensor of a 50 kW-grade fuel cell engine test bench. The output current was predicted via the ANN identification model according to other relevant sensors and compared with the sampled current sensor signal. The faults in the current sensor were detected immediately once the difference exceeded the given threshold value, and the invalid signals of the current sensor were substituted with the predictive output value of the ANN identification model. Finally, the reconstructed current sensor signals were sent back to a fuel cell controller unit (FCU) to adjust the air flow and rotate speeds of the air compressor. Experimental results show that the typical faults in the current sensor can be diagnosed and distinguished within 0.5 s when the threshold value is 15 A. The invalid signal of current sensor can be reconstructed within 0.1 s. Which ensures that the air compressor operate normally and avoids oxygen starvation. The proposed method can protect the fuel cell stack and enhance the fault-tolerant performance of air supply subsystem used in the fuel cell engine, and it is promising to be utilized in the fault diagnosis and fault-tolerant control of various fuel cell engines and multiple sensor systems.

A fault diagnosis and fault-tolerant control method based on artificial neural networks is proposed. Faults were detected immediately once the difference exceeded the set threshold, and the invalid signals were substituted with the predictive output value.

Diagnostic value of fecal B cell activating factor in patients with abdominal discomfort

Fecal calprotectin has successfully been widely recommended as a sensitive biomarker of inflammatory bowel diseases (IBD). Recently, we have identified an excellent new fecal biomarker, B cell activating factor (BAFF), as being as effective as fecal calprotectin for diagnosing intestinal inflammation. In this study, a total of 230 patients with abdominal discomfort were prospectively enrolled and fecal samples were collected within 24 h before the endoscopic examinations. We show that fecal BAFF levels were significantly higher in patients with ulcerative colitis (median = 1549 pg/g, P < 0·0001), Crohn's disease (median = 735 pg/g, P < 0·0001), gastric cancer (median = 267 pg/g, P < 0·0001) and colorectal cancer (median = 533 pg/g, P < 0·0001) than those in healthy groups (median = 61 pg/g), while the values of which in patients with gastric polyps, colorectal polyps, esophagitis/gastritis/duodenitis and peptic ulcer were in the range of healthy individuals (P > 0·05). An optimal cut-off value at 219·5 pg/g of fecal BAFF produced sensitivity, specificity, positive predictive and negative predictive values of 85, 91, 84 and 92%, respectively, for IBD or carcinoma. Our results therefore indicate a potential role for fecal BAFF as a sensitive screening parameter for IBD and gastrointestinal carcinoma, as well a useful tool to select patients with abdominal discomfort for further endoscopic examinations.

CpATG8, a Homolog of Yeast Autophagy Protein ATG8, Is Required for Pathogenesis and Hypovirus Accumulation in the Chest Blight Fungus

Autophagy is a degradation system in the cell, involved in the turnover of cellular components, development, differentiation, immune responses, protection against pathogens, and cell death. Autophagy is induced by nutrient starvation, in which cytoplasmic components and organelles are digested via vacuoles/lysosomes. In this study, by using electron microscopy, we observed that hypovirus CHV1-EP713 infection of Cryphonectria parasitica, the causative agent of chestnut blight disease, caused proliferation of autophagic-like vesicles. This phenomenon could be mimicked by treating the wild-type strain of the fungus EP155 with the autophagy induction drug rapamycin. Some of the hypovirulence-associated traits, including reduced pigmentation and conidiation, were also observed in the rapamycin-treated EP155. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) revealed that genes involved in autophagy were up-regulated in expression. Deletion of cpatg8, a gene encoding a homolog of ATG8 in Saccharomyces cerevisiae, resulted in attenuation of virulence and reduction in sporulation, as well as accumulation of the double-stranded viral RNA. Furthermore, virus-encoded p29 protein was found to co-localize with CpATG8, implying that the viral protein may interfere with the function of CpATG8. Taken together, these findings show that cpatg8 can be regulated by the hypovirus and is required for virulence and development of the fungus and accumulation of viral dsRNA in chestnut blight fungus.

Determination of p11 multifunctional protein in human body fluids by enzyme-linked immunosorbent assay

Objectives

The diagnosis of major depressive disorder (MDD) is symptom based due to the lack of biological biomarker. p11 protein was recently found to be an important factor mediating depression-like states and antidepressant responses. The aim of the study was to assess whether p11 protein in urine can serve as a potential biomarker for major depression, and the relationship of its levels among urine, serum and cerebrospinal fluid (CSF).

Methods

We obtained urine samples from 13 drug-free MDD patients and 13 age- and gender-matched healthy controls. We also collected urine, serum and cerebrospinal fluid samples from 13 of fracture patients or cesarean section patients in the spinal anesthesia. The concentrations of p11 protein were measured using ELISA.

Results

In MDD patients, urine levels of p11 protein were all less than the minimum detectable concentration of the ELISA kit. The urine levels of p11 were detectable only in one healthy control. In the spinal anesthesia patients, we can detect p11 concentrations in both serum and urine in only two patients. Besides, levels of p11 were detectable in the serum of one patient and urine of another patient. We were unable to measure CSF levels of p11 in all patients.

Conclusions

Concentrations of p11 protein in the body fluids are very low and unstable. The sensitivity of the current p11 ELISA kit is currently unsatisfactory, requiring the development of an ELISA kit of higher sensitivity to determine whether p11 in body fluids can serve as biomarker for depression.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Effects of a proteasome inhibitor on the NF-κB signalling pathway in experimental osteoarthritis

OBJECTIVES

To evaluate the effects of the proteasome inhibitor MG-132 on the expression of nuclear factor (NF)-κB p65, inhibitor (I)-κB, tumour necrosis factor (TNF)-α, and interleukin (IL)-1β in the cartilage and synovial tissues of rats with osteoarthritis (OA), and to investigate the role that the ubiquitin/proteasome system (UPS) plays in the OA process.

METHOD

A total of 144 adult male Sprague Dawley rats were randomly assigned to four groups: anterior cruciate ligament transaction (ACLT) + MG-132 (ACLT/M), ACLT + dimethylsulfoxide (ACLT/D), sham surgery (Sham), and naïve + MG-132 (naïve/M). Pathological morphology was undertaken. mRNA expression levels of NF-κB p65, I-κB, TNF-α, and IL-1β were determined using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The activities of the 20S proteasome chymotrypsin-like and peptidylglutamyl-peptide hydrolase-like enzymes were measured using fluorospectrophotometry.

RESULTS

The Mankin scores at all time points in ACLT/M rats were significantly lower than those in ACLT/D rats (p < 0.05). Despite the NF-κB p65 in the synovial tissue at 2 weeks after surgery and IL-1β in the cartilage tissue at 12 weeks after surgery, mRNA expression levels of NF-κB p65, IL-1β, and TNF-α at other time points in ACLT/M were significantly lower than those in ACLT/D (p < 0.05). mRNA levels of I-κB in the cartilage tissue in ACLT/M were significantly higher than those in ACLT/D at 2 weeks after surgery (p < 0.05). mRNA levels of I-κB in the synovial tissue in ACLT/M were higher than those in ACLT/D at all time points, and the difference was significant at 4 weeks after surgery (p < 0.05). MG-132 decreased the activities of the 20S proteasome chymotrypsin-like and peptidylglutamyl-peptide hydrolase-like enzymes in the cartilage and synovial tissues of rats.

CONCLUSIONS

The proteasome inhibitor MG-132 delays the progress of OA by alleviating synovial inflammation and protecting the articular cartilage tissue.

[Quality control of zhuanggu shenjin capsules]

Studies have been made on the microscopic identification of red jinseng, dog bone, indian bread, yanhusuo and datura flower in Zhuanggu Shenjin Capsules, as well as on the identification of ginsengside and tetrahydropalmatine by TLC and the determination of icariin by dual wavelength TLC-scanning. The content of the latter compound should be no less than 0.380mg/g and the average rate of recovery 97.62% (n = 5).

Overexpression of human apolipoprotein B-100 in transgenic rabbits results in increased levels of LDL and decreased levels of HDL

In this study, and 80-kb human genomic DNA fragment spanning the human apoB gene was used to generate transgenic New Zealand White rabbits that expressed human apoB-100. The concentration of human apoB in the plasma of the transgenic rabbits ranged between 5 and 100 mg/dL. The transgenic rabbits had nearly threefold elevations in the plasma levels of triglycerides and cholesterol compared with nontransgenic controls. Nearly all the cholesterol and human apoB in the plasma was in the LDL fraction. Pronounced triglyceride enrichment of the LDL fraction was a striking feature of human apoB overexpression in the transgenic rabbits, in which the LDL fraction contained more than 75% of the plasma triglycerides. The triglyceride-enriched LDL particles were smaller and more dense than the native rabbit LDL and contained markedly increased amounts of apoE and apoC-III. In the nontransgenic control animals most of the triglycerides were in the VLDL, and most of the apoE and apoC-III were in the VLDL and HDL fractions. In addition to increased LDL levels, overexpression of human apoB in rabbits resulted in lower plasma levels of HDL cholesterol and apoA-I. In our prior studies on transgenic mice expressing human apoB, we documented triglyceride-rich LDL and reduced levels of HDL cholesterol. These prior findings in mice, together with the present findings in transgenic rabbits, suggest that triglyceride-rich LDL and lowered levels of HDL cholesterol may be hallmark features of apoB overexpression.

Role of nucleotides in intestinal development and repair: implications for infant nutrition

Dietary sources of nucleotides may be conditionally essential nutrients. Rapidly growing tissues such as the intestinal epithelium and lymphoid cells lack significant capacity for de novo synthesis of nucleotides and require exogenous sources of purine and pyrimidine bases. Dietary purines are not significantly incorporated into hepatic nucleic acids, but pyrimidines are. Both are taken up by intestinal cells with excess purines converted to uric acid. Nucleotides are important for normal development, maturation and repair of the gastrointestinal tract. Human milk is the best source of nucleotides for young infants because cow's milk is lacking in nucleotide content. It is likely that infant formulas should have sources of nucleotides added to more closely duplicate human milk and provide these substrates for maximal intestinal development and repair.

The effect of nutritional additives on anti-infective factors in human milk

It has become a common practice to supplement human milk with a variety of additives to improve the nutritive content of the feeding for the premature infant. Twenty-two freshly frozen human milk samples were measured for lysozyme activity, total IgA, and specific IgA to Escherichia coli serotypes 01, 04, and 06. One mL aliquots were mixed with the following: 1 mL of Similac, Similac Special Care, Enfamil, Enfamil Premature Formula, and sterile water; 33 mL of Poly-Vi-Sol, 33 mg of Moducal, and 38 mg of breast-milk fortifier, and then reanalyzed. Significant decreases (41% to 74%) in lysozyme activity were seen with the addition of all formulas; breast-milk fortifier reduced activity by 19%, while no differences were seen with Moducal, sterile water, or Poly-Vi-Sol. No differences were seen in total IgA content, but some decreases were seen in specific IgA to E. coli serotypes 04 and 06. E. coli growth was determined after 3 1/2 hours of incubation at 37 degrees C after mixing. All cow-milk formulas enhanced E. coli growth; soy formulas and other additives preserved inhibition of bacterial growth. Nutritional additives can impair anti-infective properties of human milk, and such interplay should be considered in the decision on the feeding regimen of premature infants.

Sucrase-alpha-dextrinase in the rat. Postinsertional conversion to inactive molecular species by a carbohydrate-free diet

Absence of dietary carbohydrate decreases both activities of intestinal brush border sucrase-alpha-dextrinase. We examined the molecular mechanism causing this decrease. Adult rats were fed chow (70% CHO) or matched carbohydrate-free (CHO-free) diet for 7 d. Sucrase activity decreased by 50% in whole homogenates and brush borders. Enzyme kinetics revealed no change in sucrose affinity (CHO-free Km = 18 mM, chow Km = 21 mM), but fewer active sites (CHO-free Vmax = 2,720, chow Vmax = 5,000 mumol/min per g protein). Intraintestinal pulse-labeling of [35S]methionine in vivo revealed no differences in incorporation into sucrase. Immunoreactive sucrase protein, assayed by ELISA and rocket immunoelectrophoresis, increased twofold per milliunit of sucrase enzymatic activity in CHO-free jejunum. Total immunosucrase (St), the sum of active and inactive enzyme (St = Sa+Si), was unchanged with carbohydrate withdrawal, but > 50% of the sucrase protein became inactive. SDS-PAGE of sucrase immunoprecipitates revealed alteration of alpha, beta, and gamma subunits in CHO-free animals: (a) alpha and beta subunits migrated farther (mass change--2 kD); and (b) the alpha subunit became diffuse or was a doublet and was less abundant than the beta subunit. Rather than representing loss of sucrase protein, the decline in sucrase activity is achieved with structural subunit changes, probably involving postinsertional processing.

Effects of microwave radiation on anti-infective factors in human milk

In intensive care nurseries it has become common practice to use microwave thawing of frozen human milk for more rapid accessibility. Twenty-two freshly frozen human milk samples were tested for lysozyme activity, total IgA, and specific secretory IgA to Escherichia coli serotypes 01, 04, and 06. The samples were heated by microwave for 30 seconds at a low- or high-power setting and then reanalyzed. One-mL aliquots of 10 additional human milk samples were microwaved at low (20 degrees C to 25 degrees C), medium (60 degrees C to 70 degrees C), and high (greater than or equal to 98 degrees C) setting before the addition to each of 1 mL of diluted E coli suspension. E coli growth was determined after 3 1/2 hours of incubation at 37 degrees C. Microwaving at high temperatures (72 degrees C to 98 degrees C) caused a marked decrease in activity of all the tested antiinfective factors. E coli growth at greater than or equal to 98 degrees C was 18 times that of control human milk. Microwaving at low temperatures (20 degrees C to 53 degrees C) had no significant effect on total IgA, specific IgA to E coli serotypes 01 and 04, but did significantly decrease lysozyme and specific IgA to E coli serotype 06. Even at 20 degrees C to 25 degrees C, E coli growth was five times that of control human milk. Microwaving appears to be contraindicated at high temperatures, and questions regarding its safety exist even at low temperatures.

Intestinal lactase in the neonatal rat. Maturational changes in intracellular processing and brush-border degradation

The mechanism of decline in the catalytic activity of intestinal lactase during neonatal maturation has not been defined, but a shift in the lactase subunit synthesis from an active 130-kDa subunit to an inactive 100-kDa species has now been noted in the adult rat (Quan, R., Santiago, N. A., Tsuboi, K. K., and Gray, G. M. (1990) J. Biol. Chem. 265, 15882-15888). The subunit structure, synthesis, intracellular assembly, and subsequent degradation of lactase from the brush-border surface membrane was examined in 15-day-old pre-weaned and 30-day-old post-weaned intact rats. Lactase was labeled intraintestinally with [35S]methionine, isolated from Triton-solubilized membranes with monospecific polyclonal anti-lactase, and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The protein-stained gel revealed subunits of 225 and 130 kDa, the latter species predominating in both the pre- and post-weaned state. The distinct adult-type 100-kDa moiety was present in post-weaned animals while only a trace of a slightly larger (approximately 110 kDa) species was observed in pre-weaned animals. Quantitation of radioactivity in newly synthesized lactase revealed an increasing prominence of the 100-kDa species in post-weaned rats (130/100 incorporation ratio: pre-weaned 6.2; post-weaned 3.3). Accumulation of newly labeled lactase in brush-border membranes after intraperitoneal [35S]methionine labeling was similar in both groups at 3 h. Despite these comparable rates of lactase synthesis, assembly and insertion in the pre- and post-weaned state, subsequent removal of the 130-kDa unit was more rapid in post-weaned animals (t1/2 = 11 h; pre-weaned t1/2 = 37 h). In intact rats, the neonatal maturational decline in lactase catalytic activities involves both a shift to production of the inactive 100-kDa subunit and increased membrane surface degradation of the active 130-kDa subunit.

Intestinal lactase. Shift in intracellular processing to altered, inactive species in the adult rat

The regulatory mechanism of decline in catalytic activity for intestinal lactase (lactase-phlorizin hydrolase, beta-galactosidase) as mammals mature has not been defined. Solubilized intestinal brush-border membranes from adult male rats (greater than 4 months of age, 200-400 g) were examined by high performance liquid Zorbax GF-450 chromatography, subjected to denaturing acrylamide electrophoresis, blotted to nitrocellulose, and identified by specific polyvalent anti-lactase. Three major species were present within the 235-kDa active lactase peak (225, 130, and 100 kDa). The 100-kDa moiety was also prominent in the approximately 300-kDa region of the GF-450 effluent, suggesting it is a catalytically inactive oligomer. In vivo synthesis and assembly of lactase by intraintestinal pulse [( 35S]methionine, 5 min) and chase (15-120 min) revealed rapid (15 min of chase; maximum, 60 min) intracellular synthesis in the endoplasmic reticulum-Golgi fraction of multiple species (64, 100, 130, 175, and 225 kDa). The 64-kDa species disappeared from the intracellular membrane compartment and was not transferred to the brush-border surface. The 175-kDa moiety appeared to be processed to the 225-kDa unit prior to relocation to the surface membrane. By 120 min, the 100-kDa species became the predominant (approximately 60%) radiolabeled unit in both endoplasmic reticulum-Golgi and brush border. In the adult rat, lactase is assembled in multiple molecular forms that are differentially processed: (a) intracellular degradation (64-kDa unit) or (b) transfer to the brush-border surface as catalytically active (225 and 130 kDa) or inactive (100 kDa) species. Although substantial synthesis of lactase proteins prevails, major changes in processing appear to serve as an important regulatory mechanism producing the maturational decline of catalytic activity. The accompanying article (Castillo, R. O., Reisenauer, A. M., Kwong, L. K., Tsuboi, K. K., Quan, R., and Gray, G. M. (1990) J. Biol. Chem. 265, 15889-15893) extends our studies to synthesis and assembly during the neonatal period of maturation.

Effect of dietary nucleosides on growth and maturation of the developing gut in the rat

Dietary nucleoside (DN) as a precursor for nucleic acid synthesis may be important for rapidly dividing cells, since gut epithelial cells have limited capacity for de novo purine and pyrimidine synthesis. We evaluated in a controlled blinded study the effect of added nucleosides, 0.8% by weight, given for 2 weeks, on gut growth and maturation in 20 weanling rats. Mucosal protein and DNA in the proximal intestinal segment were 50% and 77% higher, respectively, in the DN-supplemented group (n = 10; p less than 0.05). Villus height based on cell count was 25% greater in the DN group (p less than 0.05). Maltase activity was significantly greater in proximal, middle, and distal intestinal segments, and the largest increase, 87%, was seen in the proximal gut mucosa. The maltase/lactase ratio was also higher in this segment. Increases in sucrase were less prominent. Lactase was minimally affected. The pattern of change in disaccharidase activity suggests that DN may enhance gut growth and maturation of the intestine in the weanling rat, the effects being more pronounced in the proximal segment. Diets free of nucleosides and nitrogenous bases may have adverse effects on the gut.

Severe pseudomembranous enterocolitis in a child: case report and literature review

Antibiotic-associated pseudomembranous enterocolitis (PMC), an inflammatory gastrointestinal disease mediated by toxins produced by Clostridium difficile, is increasingly recognized in the pediatric population. We report a case of fulminant PMC in an otherwise normal 2 1/2-year-old child after antibiotic therapy given for a routine childhood illness. The patient had debilitating colitis marked by severe diarrhea, a generalized electrolyte derangement, an extreme protein-losing enteropathy state, rectal prolapse, ascites, pleural effusion, varicella and multiple relapses. The child required specific antimicrobial therapy as well as aggressive supportive care to achieve recovery. A review of the literature for pediatric cases of PMC revealed reported cases in all age groups; the youngest was 5 days old. There were 9 deaths in 43 cases for a mortality rate of about 20%. All but 2 of the cases were associated with antibiotic therapy. The antibiotics most frequently implicated were ampicillin (15), penicillin (11), cephalosporins (7), amoxicillin (6) and clindamycin (5). The onset of symptoms of PMC can begin at any time while the child is taking an antibiotic or up to 21 days after it is discontinued. Children with underlying gastrointestinal motility disorders such as Hirschsprung's disease are predisposed to PMC. Fulminant PMC is a serious but uncommon infectious disease of infancy and childhood, occurring as a complication of routine antibiotic therapy for common childhood illnesses.

Growth-hormone-releasing factor immunoreactivity in human endocrine tumors

Seventy-three human tumors and adjacent nonneoplastic tissues were analyzed immunohistochemically for the presence of growth-hormone-releasing factor (GRF). Four of 9 pancreatic endocrine tumors, 2 of 3 appendiceal carcinoids, and 1 of 5 cecal carcinoids were immunoreactive for GRF. One of the GRF-containing pancreatic tumors was associated with acromegaly. Histologically, the growth patterns of these tumors were variable, and the distribution of immunoreactive cells was patchy and irregular. There were no normal cells that contained GRF. These results indicate that GRF production by human tumors is more common than previously thought, although clinical acromegaly may not be apparent in patients who harbor such neoplasms.

Effects of a commercial starch blocker preparation on carbohydrate digestion and absorption: in vivo and in vitro studies

We have tested the effectiveness of a commercial starch blocker on the digestion and absorption of dietary carbohydrates in six normal, healthy volunteers. The effectiveness of the starch blocker to attenuate or block the digestion of carbohydrate was assessed against a placebo by the measurement of end tidal breath hydrogen, plasma glucose, and insulin responses to a constant test meal. There were no significant differences in breath hydrogen, or plasma glucose and insulin responses. In vitro enzyme inhibition studies assessed the ability of the brush border enzyme maltase/glucoamylase to degrade starch in the presence of the starch blockers. A highly purified solution of rat and human maltase/glucoamylase was capable of degrading a starch solution, while 40 mM Tris-HCl (a known maltase/glucoamylase inhibitor) completely abolished the enzyme activity. These data challenge the claims that starch blocker preparations are effective in reducing or attenuating the absorption of carbohydrates or calories from a mixed meal. The ineffectiveness in vivo could be explained, in part, by the ability of the brush border enzyme maltase/glucoamylase to hydrolyze starch in the presence of starch blockers.