Transfer learning guided discovery of efficient perovskite oxide for alkaline water oxidation.

Perovskite oxides show promise for the oxygen evolution reaction. However, numerical chemical compositions remain unexplored due to inefficient trial-and-error methods for material discovery. Here, we develop a transfer learning paradigm incorporating a pre-trained model, ensemble learning, and active learning, enabling the prediction of undiscovered perovskite oxides with enhanced generalizability for this reaction. Screening 16,050 compositions leads to the identification and synthesis of 36 new perovskite oxides, including 13 pure perovskite structures. Pr0.1Sr0.9Co0.5Fe0.5O3 and Pr0.1Sr0.9Co0.5Fe0.3Mn0.2O3 exhibit low overpotentials of 327 mV and 315 mV at 10 mA cm-2, respectively. Electrochemical measurements reveal coexistence of absorbate evolution and lattice oxygen mechanisms for O-O coupling in both materials. Pr0.1Sr0.9Co0.5Fe0.3Mn0.2O3 demonstrates enhanced OH- affinity compared to Pr0.1Sr0.9Co0.5Fe0.5O3, with the emergence of oxo-bridged Mn-Co conjugate facilitating charge redistribution and dynamic reversibility of Olattice/VO, thereby slowing down Co dissolution. This work paves the way for accelerated discovery and development of high-performance perovskite oxide electrocatalysts for this reaction.

The meso-substituent electronic effect of Fe porphyrins on the electrocatalytic CO2 reduction reaction.

We report Fe porphyrins bearing different meso-substituents for the electrocatalytic CO2 reduction reaction (CO2RR). By replacing two and four meso-phenyl groups of Fe tetraphenylporphyrin (FeTPP) with strong electron-withdrawing pentafluorophenyl groups, we synthesized FeF10TPP and FeF20TPP, respectively. We showed that FeTPP and FeF10TPP are active and selective for CO2-to-CO conversion in dimethylformamide with the former being more active, but FeF20TPP catalyzes hydrogen evolution rather than the CO2RR under the same conditions. Experimental and theoretical studies revealed that with more electron-withdrawing meso-substituents, the Fe center becomes electron-deficient and it becomes difficult for it to bind a CO2 molecule in its formal Fe0 state. This work is significant to illustrate the electronic effects of catalysts on binding and activating CO2 molecules and provide fundamental knowledge for the design of new CO2RR catalysts.

Upregulation of HBXIP contributed to the anti-DND by ginsenoside Rg1 after global cerebral ischemia-reperfusion.

OBJECTIVES: Ginsenoside Rg1 (Rg1) has been well-documented to be effective against ischemic/reperfusion (I/R) injury. However, whether it has therapeutic effect on delayed neuronal death is still unclear. The aim of this study is to investigate the effect of Rg1 on delayed neuronal death and elucidate its underlying mechanism. METHODS: Delayed neuronal death model was prepared by global cerebral ischemia-reperfusion in rats, Rg1 was intravenously administered once a day. Nissl and Fluoro Jade B staining were carried out to evaluate the effect of Rg1 on delayed neuronal death. Western blot and qPCR were used to investigate the levels of HBXIP and Survivin. HBXIP/Survivin complex was observed by co-immunoprecipitation. AAV-CMV-shRNA (HBXIP) was used to observe the role of HBXIP on delayed neuronal death improved by Rg1. KEY FINDINGS: Rg1 attenuated delayed neuronal death at the dose of 20 mg/kg, which also improved the mRNA and protein levels of HBXIP, as well as Survivin. Moreover, administration of Rg1 promoted the formation of HBXIP/Survivin complex, which contributed to the reduction of caspases signaling pathway. Knockdown of HBXIP abolished the alleviation of DND and inhibition of caspase cascade induced by Rg1. CONCLUSIONS: Rg1 alleviated delayed neuronal death by promoting anti-apoptosis effect by HBXIP/Survivin complex.

Non-destructive detection and classification of textile fibres based on hyperspectral imaging and 1D-CNN.

Textile fibre is very common in daily life, and its classification and identification play an important role in textile recycling, archaeology, public security, and other industries. However, traditional identification methods are time-consuming, laborious, and often destructive to the samples. In order to quickly, accurately, and nondestructively classify and recognize textile fibres, this study established a textile fibre classification and recognition method based on hyperspectral imaging (HSI) and a one-dimensional convolutional neural network (1D-CNN) model. Hyperspectral images of 25 kinds of commercial textile fibres were collected and denoised by pixel fusion. Four traditional machine learning classification models, k-nearest neighbors (KNN), support vector machine (SVM), random forest (RF), and partial least squares-discriminant analysis (PLS-DA), were used to identify the data. The results show that RF has the highest classification accuracy, reaching 91.4%. Then a back propagation neural network (BPNN) model and a one-dimensional convolutional neural network (1D-CNN) model were constructed and compared with the traditional machine learning methods. The results show that the 1D-CNN models have 97.9% and 98.6% accuracy on the training and test sets, respectively. The precision (Pr), sensitivity (Se), specificity (Sp), and F1 score (F1 score) of the models reached 98.7%, 98.6%, 99.9%, and 98.6%, respectively, which were significantly better than the four traditional machine learning models. It seems that 1D-CNN combined with the HSI technique may be a potential method in the detection and classification of textile fibres.

Combination of monoammonium glycyrrhizinate and cysteine hydrochloride protects mice against acetaminophen-induced liver injury via Keap1/Nrf2/ARE pathway.

OBJECTIVES: Acetaminophen (APAP) overdose has been the primary cause of drug-induced liver injury (DILI) in western countries. Monoammonium glycyrrhizinate (MG) is a primary active ingredient from glycyrrhiza. Cysteine hydrochloride (CH) is a component of glutathione (GSH). The study aimed to explore the therapeutical effect of MG-CH against DILI incurred by intragastric APAP. METHODS: Mice were randomized into eight groups: control, APAP, three groups accepted APAP and the combination of MG and CH (15, 30, 60 mg/kg), two groups accepted APAP and MG (40 mg/kg) or CH (20 mg/kg), moreover, one group received MG-CH (60 mg/kg) without APAP. After pretreatment with MG-CH or MG and CH alone for 3 days, mice were administered APAP by oral gavage. The serum and tissue were collected to detect the activities of liver enzymes and evaluate the change of histomorphology and explore the possible mechanism of MG-CH in protecting against DILI. KEY FINDINGS: MG-CH pretreatment remarkably alleviated hepatic injury and decreased the activities of ALT, AST, ALP and LDH. The hepatic ROS and MDA contents were decreased, and the level of GSH and GSH-PX activities was increased in the serum. Furthermore, MG-CH improved the expression of Nrf2, HO-1, GCLM and NQO1 to increase antioxidant ability and induce detoxification. The expression of IL-10 suppressing excessive inflammatory responses was enhanced. CONCLUSION: The study demonstrated that MG-CH had protective effects against DILI induced by APAP and the potential mechanisms were based on inhibiting oxidative stress and activating the Keap1/Nrf2/ARE pathway.

Classification modeling method for hyperspectral stamp-pad ink data based on one-dimensional convolutional neural network.

In the questioned document, the examination of stamp-pad ink is crucial scientific evidence to discern the difference between genuine and forged documents. In this study, a new method for rapid and non-destructive identification of types of stamp-pad inks by combining hyperspectral imaging (HSI) technology and deep learning was developed. Twenty stamp-pad inks of different brands and models were collected and numbered in turn, and then, each of them was sealed six times repeatedly on the A4 printing paper for the test. After that, the hyperspectral imager was used to collect the hyperspectral images and the reflectance spectral data were obtained after pixel fusion. Principal component analysis (PCA) and non-negative matrix factorization (NMF) were used to deal with the dataset, but visual results were not good. Then, back propagation neural network (BPNN) and one-dimensional convolutional neural network (1D-CNN) were constructed and their merits and drawbacks were compared. The final loss function of the BPNN of training set and validation set was stable at 0.27 and 0.42, and the classification accuracy of the training set and validation set reached 90.02% and 83.99%, respectively. Compared with the BPNN, the 1D-CNN had better stability and efficiency for the classification. The loss function of the training set and validation set was as low as 0.068 and 0.075, and the final classification accuracy reached 98.30% and 97.94%, respectively. Therefore, the combination of hyperspectral imaging technology and 1D-CNN represents a potentially simple, non-destructive, and rapid method for stamp-pad inks detection and classification.

Neuronal chemokine-like-factor 1 (CKLF1) up-regulation promotes M1 polarization of microglia in rat brain after stroke.

The phenotypic transformation of microglia in the ischemic penumbra determines the outcomes of ischemic stroke. Our previous study has shown that chemokine-like-factor 1 (CKLF1) promotes M1-type polarization of microglia. In this study, we investigated the cellular source and transcriptional regulation of CKLF1, as well as the biological function of CKLF1 in ischemic penumbra of rat brain. We showed that CKLF1 was significantly up-regulated in cultured rat cortical neurons subjected to oxygen-glucose deprivation/reoxygenation (ODG/R) injury, but not in cultured rat microglia, astrocytes and oligodendrocytes. In a rat model of middle cerebral artery occlusion, we found that CKLF1 was up-regulated and co-localized with neurons in ischemic penumbra. Furthermore, the up-regulated CKLF1 was accompanied by the enhanced nuclear accumulation of NF-κB. The transcriptional activity of CKLF1 was improved by overexpression of NF-κB in HEK293T cells, whereas application of NF-κB inhibitor Bay 11-7082 (1 µM) abolished it, caused by OGD/R. By using chromatin-immunoprecipitation (ChIP) assay we demonstrated that NF-κB directly bound to the promoter of CKLF1 (at a binding site located at -249 bp to -239 bp of CKLF1 promoter region), and regulated the transcription of human CKLF1. Moreover, neuronal conditional medium collected after OGD/R injury or CKLF1-C27 (a peptide obtained from secreted CKLF1) induced the M1-type polarization of microglia, whereas the CKLF1-neutralizing antibody (αCKLF1) or NF-κB inhibitor Bay 11-7082 abolished the M1-type polarization of microglia. Specific knockout of neuronal CKLF1 in ischemic penumbra attenuated neuronal impairments and M1-type polarization of microglia caused by ischemic/reperfusion injury, evidenced by inhibited levels of M1 marker CD16/32 and increased expression of M2 marker CD206. Application of CKLF1-C27 (200 nM) promoted the phosphorylation of p38 and JNK in microglia, whereas specific depletion of neuronal CKLF1 in ischemic penumbra abolished ischemic/reperfusion-induced p38 and JNK phosphorylation. In summary, CKLF1 up-regulation in neurons regulated by NF-κB is one of the crucial mechanisms to promote M1-type polarization of microglia in ischemic penumbra.

Discrimination of phenethylamine regioisomers and structural analogues by Raman spectroscopy.

In this study, the Raman spectra of 21 phenethylamines were obtained using far-red excitation (785 nm). The distinguishing ability of Raman for phenethylamines, especially for phenethylamine regioisomers and structural analogues, was investigated. Here, the evaluation of a cross section of Raman spectra demonstrated that all types of phenethylamines were distinguishable, even for certain structural analogues with high spectrum similarity. Raman exhibited high distinguishing ability for phenethylamine regioisomers that differ in the substitution position of halogen, methoxy, alkyl, or other substituted groups; as well as for structural analogues containing different groups, such as furanyl, 2,3-dihydrofuranyl, halogen, and alkyl substituted at the same position. The Raman spectra for homologues with differences in only a methyl group were found to be highly similar; however, their spectra demonstrated small but detectable differences. Four analogue mixtures and 59 seized samples were also analyzed to study the practical use of the Raman method in forensic field. 95% of the seized samples were correctly identified, which significantly validated the ability of Raman method in identifying the correct isomers. Accordingly, this study provides a non-destructive, high-throughput and minimal sample preparation technique for the discrimination of phenethylamines.

Low corticosterone levels attenuate late life depression and enhance glutamatergic neurotransmission in female rats.

Sustained elevation of corticosterone (CORT) is one of the common causes of aging and major depression disorder. However, the role of elevated CORT in late life depression (LLD) has not been elucidated. In this study, 18-month-old female rats were subjected to bilateral adrenalectomy or sham surgery. Their CORT levels in plasma were adjusted by CORT replacement and the rats were divided into high-level CORT (H-CORT), low-level CORT (L-CORT), and Sham group. We showed that L-CORT rats displayed attenuated depressive symptoms and memory defects in behavioral tests as compared with Sham or H-CORT rats. Furthermore, we showed that glutamatergic transmission was enhanced in L-CORT rats, evidenced by enhanced population spike amplitude (PSA) recorded from the dentate gyrus of hippocampus in vivo and increased glutamate release from hippocampal synaptosomes caused by high frequency stimulation or CORT exposure. Intracerebroventricular injection of an enzymatic glutamate scavenger system, glutamic-pyruvic transmine (GPT, 1 µM), significantly increased the PSA in Sham rats, suggesting that extracelluar accumulation of glutamate might be the culprit of impaired glutamatergic transmission, which was dependent on the uptake by Glt-1 in astrocytes. We revealed that hippocampal Glt-1 expression level in the L-CORT rats was much higher than in Sham and H-CORT rats. In a gradient neuron-astrocyte coculture, we found that the expression of Glt-1 was decreased with the increase of neural percentage, suggesting that impairment of Glt-1 might result from the high level of CORT contributed neural damage. In sham rats, administration of DHK that inhibited Glt-1 activity induced significant LLD symptoms, whereas administration of RIL that promoted glutamate uptake significantly attenuated LLD. All of these results suggest that glutamatergic transmission impairment is one of important pathogenesis in LLD induced by high level of CORT, which provide promising clues for the treatment of LLD.

New qualitative analysis strategy for illicit drugs using Raman spectroscopy and characteristic peaks method.

Performing fast qualitative identification of seized illegal drugs by Raman spectroscopy is challenging due to fluorescence interference as well as chemical complexity. Spectrometers with 785-nm excitation, 1,064-nm excitation, and sequentially shifted excitation (SSE) were compared for their effect on fluorescence reduction. The characteristic peaks method, which is independent of cutting agents, was tested as a new strategy to broaden the application of the Raman technique. The suitability of the characteristic peaks method was fully examined by analyzing a large amount of seized illegal drugs, including 72 methamphetamine hydrochloride (concentration range of 13.9%-99.4%), 68 ketamine hydrochloride (17.7%-99.8%), 176 heroin hydrochloride (5.2%-79.5%), 51 cocaine hydrochloride (21.1%-94.5%), and 33 cocaine base (30.9%-92.5%) samples. The results showed that seized methamphetamine, ketamine, and cocaine samples had no or little fluorescence. Hence, in regard to detection of these samples, the advantage of using 1,064-nm excitation and SSE compared with 785-nm excitation was quite limited. Regarding the heroin samples, a significant improvement of the "high" confident positive detected rate was evident for 1,064 nm excitation (60.8%) and SSE (61.4%), compared with 785-nm excitation (13.1%). However, it was also seen that even if 1,064-nm excitation and SSE were applied, the fluorescence of heroin samples was still unable to be fully overcome. By using the characteristic peaks method, low LOD results of 5%-20% were acquired for 40 types of drug mixtures, and lower LODs were obtained for the 60% of the drug mixtures compared with library searching method. Raman spectroscopy in conjunction with the characteristic peaks method was shown to be fast, simple, accurate, and sensitive in the qualitative analysis of seized drug samples.

[Research Progress on Forensic Toxicology of Z-drugs].

The Z-drugs (zolpidem, zopiclone, and zaleplon), as the innovative hypnotics, have an improvement over the traditional benzodiazepines in the management of insomnia. Z-drugs have significant hypnotic effects by reducing sleep latency and improving sleep quality, though duration of sleep may not be significantly increased. As benzodiazepines, Z-drugs exert their effects through increasing the transmission of γ-aminobutyric acid. Z-drugs overdose are less likely to be fatal, more likely would result in poisoning. Z-drugs can be detected in blood, urine, saliva, and other postmortem specimens through liquid chromatography-mass spectrometry techniques. Zolpidem and zaleplon exhibit significant postmortem redistribution. Z-drugs have improved pharmacokinetic profiles, but incidence of neuropsychiatric sequelae, poisoning, and death may prove to be similar to the other hypnotics. This review focuses on the pharmacology and toxicology of Z-drugs with respect to their adverse effect profile and toxicity and toxicology data in the field of forensic medicine.

Inverse relationship between serum osteocalcin levels and visceral fat area in Chinese men.

OBJECTIVE: The relationship between serum osteocalcin levels and body fat distribution remains unclear. This study aimed to investigate the association between serum osteocalcin levels and visceral fat area (VFA) in Chinese men. DESIGN: Total serum osteocalcin levels were measured in 1768 Chinese men (22-75 yr old) by electrochemiluminescence immunoassay. VFA was quantified via magnetic resonance imaging. Correlation analyses were carried out for serum osteocalcin levels and clinical parameters. Subgroup analysis was carried out to confirm the correlations using subjects with normal glucose tolerance and normal body mass index chosen from the entire study population. RESULTS: Increased serum osteocalcin levels were accompanied by a decreasing trend in all anthropometric indices of obesity, systolic blood pressure, blood glucose, insulin resistance index, triglycerides, free fatty acid, and C-reactive protein levels (all P < 0.05). The 50-75th (osteocalcin level: 16.18-19.88 ng/ml) and 75th (≥19.89 ng/ml) percentile groups had lower VFA than the 25th (≤13.11 ng/ml) and 25-50th (13.12-16.17 ng/ml) percentile groups (96.0 ± 44.4 and 89.8 ± 44.4 cm(2) vs. 108.1 ± 41.9 and 102.9 ± 44.9 cm(2), P < 0.05). A decreasing trend in serum osteocalcin levels was found to accompany the increase in VFA. Multiple stepwise regression analysis showed that VFA, as an independent factor, was inversely associated with serum osteocalcin levels both in the entire study population and subgroup population (all P < 0.01). CONCLUSIONS: Serum osteocalcin levels were inversely correlated with VFA in Chinese men.

Determination of amphetamines in hair by GC/MS after small-volume liquid extraction and microwave derivatization.

We report here on the results of a procedure for the determination of amphetamine drugs in hair. The procedure is simple and sensitive. The results from the procedure using small-volume extraction matches perfectly with those either from using the derivatization method or selected ion monitoring (SIM) detection. We validated our method using four different amine drugs, including amphetamine, methamphetamine, methylenedioxy-amphetamine and methylenedioxy-methamphetamine. The detection limit for these drugs is about 50 +/- 7.5 pg/mg in hair and the intra-day and inter-day reproducibility are within 15% at most drug concentrations. Moreover, we also showed the utility of the procedure in analyses of authentic hair samples taken from amphetamine abusers, and demonstrated that the method meets the requirement for the analysis of a trace amounts of amphetamines in human hair.

Pregnancy after liver transplantation: four-year follow-up of the first case in mainland China.

The safety and feasibility of pregnancy following liver transplantation (LT) have been accredited in a series of LT center. The first case in mainland China is reported. The follow-up data of a 22-year-old pregnant patient with end-stage liver disease undergone orthotopic liver transplantation were analyzed retrospectively. After surgery, the patient was uneventfully recovered and became pregnant 33 mo after LT. The patient was closely monitored and treated with a standard and individualized triple-drug immunosuppressive therapy throughout her pregnancy. Caesarean section was performed in March 18, 2004, and a health live-born infant was delivered. After the delivery, a 4-year follow-up period indicated that the patient was satisfactory with her condition and her baby was healthy. Our case shows that a successful pregnancy following LT is possible and safe in women with end-stage liver diseases under close monitoring. Three factors including mother, baby, and transplanted liver function must be considered for the safety of high-risk pregnancies.

[Determination of amphetamines in human hair using dynamic liquid-phase microextraction and gas chromatography/selected ion monitoring-mass spectrometry after microwave derivatization].

Human hair is an important specimen for drug abuse analysis owing to its easy collection, long surveillance time window and good correlation between the "degree of addiction" and actual drug concentration. A simple method for determination of 4 amphetamines in human hair was developed. The hair was digested under basic condition, and the drugs in it were extracted using microvolume of chloroform. The organic layer was then transferred into another tube to be derivatized with N-methyl-bis (trifluoroacetamide) (MBTFA) by microwave heating. Finally the reacted solution was detected by gas chromatography/selected ion monitoring-mass spectrometry (GC/SIM-MS) directly. 2-Methyl-phenyl ethylamine was used as an internal standard. Good linearities were obtained for 4 amphetamines with correlation coefficients better than 0.996. The limits of detection, based on a signal-to-noise ratio (S/N) of 3:1, were all about 50 pg/mg for amphetamine (AM) , methamphetamine (MAM), methylenedioxy-amphetamine (MDA), and methylenedioxy-methamphetamine (MDMA) in hair. The reproducibility of the method was satisfactory, with the relative standard deviations of 6.0% for AM, 13.9% for MAM, 10.2% for MDA and 9.2% for MDMA. Some real hair from the drug abusers was analyzed with this method. The minimal hair is less than 5 mg (about 20 cm). The method is highly sensitive, easy to operate, time-saving and economic, which can be used for trace analysis of amphetamines in human hair.

Effects of human umbilical cord serum on proliferation and insulin content of human fetal islet-like cell clusters.

BACKGROUND: Type 1 diabets is an autoimmune disease caused by the destruction of pancreatic beta-cell with an increased incidence worldwide in the closing decades of the 20th century. This study was to investigate the effects of human umbilical cord serum (UCS) on the proliferation and function of human fetal islet-like cell clusters (ICCs) in vitro. METHODS: Eight fresh pancreatic glands obtained after induction of labor with water bag were mildly exposed to collagenase V, and the digested cells were cultured in a RPMI-1640 medium plus 10% pooled UCS or fetal calf serum (FCS) to permit cells attachment and outgrowth of ICCs. RESULTS: In 8 consecutively explanted glands, development and proliferation of ICCs were observed. In the presence of FCS, the outgrowth of ICC took place on the top of a fibroblast monocellular layer. UCS affected less growth of fibroblasts and increased the formation of ICCs about four-fold compared with explants from the same glands maintained in FCS. In both UCS and FCS, the insulin content of the medium was variable to a certain extent and progressively declined from day 2 to day 6. Dithizone-stained ICCs in UCS suggested that most cell clusters were islet cells (beta-cells), and the purity of islets was estimated 80%-90%. The ultrastructure of the cultured cells showed a large number of granule-containing cells, most of which were identified as beta-cells. CONCLUSION: We conclude that in comparison with explants with FCS, the yield of ICCs and purification of islet cells are markedly increased by UCS and may facilitate the proliferation of pancreatic beta-cells intended for islet transplantation.

A CASSCF/MR-CI study toward the understanding of wavelength-dependent and geometrically memorized photodissociation of formic acid.

The S(0), T(1), and S(1) potential energy surfaces for the HCOOH dissociation and isomerization processes have been mapped with different ab initio methods. The wavelength-dependent mechanism for the HCOOH dissociation was elucidated through the computed potential energy surfaces and the surface crossing points. The HCOOH molecules in S(1) by excitation at 248 nm mainly decay to the ground state via the S(0) and S(1) vibronic interaction, followed by molecular eliminations in the ground state. The S(1) direct dissociation to HCO((2)A') + OH((2)Pi) is the dominant pathway upon photoexcitation at 240-210 nm. Meanwhile, there is a slight probability that the system relaxes to the ground state via the S(0) and S(1) vibronic interaction at these wavelengths. After irradiation of HCOOH at 193 nm, the S(1) direct dissociation into HCO((2)A') + OH((2)Pi) is energetically the most favorable pathway. In view of high IC efficiency at the S(0)/S(1) conical crossing, the S(1) --> S(0) internal conversion via the S(0)/S(1) point can occur with considerable efficiency. In addition, the S(1) isomerization probably plays a dominant role in the partially conformational memory of the HCOOH photodissociation, which has been discussed in detail.