Developing a low-cost, simple, and efficient method to prepare excellent bifunctional electrocatalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical in ...rechargeable zinc-air batteries. Non-stoichiometric M
0.85
Se (M = Ni or Co) nanoparticles are synthesized and modified on nitrogen-doped hollow carbon sphere (NHCS). The NHCS loaded Ni
0.85
Se (Ni
0.85
Se-NHCS) with rich Ni
3+
presents higher OER activity, whereas the NHCS-loaded Co
0.85
Se (Co
0.85
Se-NHCS) with abundant Co
2+
displays better ORR activity, respectively. When Co
0.85
Se-NHCS is mixed with Ni
0.85
Se-NHCS in a mass ratio of 1 : 1, the resulting mixture (Ni
0.85
Se/Co
0.85
Se-NHCS-2) shows better ORR and OER dual catalytic functions than a single selenide. Moreover, zinc-air batteries equipped with Ni
0.85
Se/Co
0.85
Se-NHCS-2 as the oxygen electrode catalyst exhibit excellent charge and discharge performance as well as improved stability over precious metals. This work has developed a simple and effective method to prepare excellent bifunctional electrocatalysts for ORR and OER, which is beneficial for the practical large-scale application of zinc-air batteries.
The mixture Ni
0.85
Se/Co
0.85
Se-NHCS-2 displayed superior electrocatalytic performance to that of Ni
0.85
Se-NHCS or Co
0.85
Se-NHCS alone. This provided a simple approach to develop ORR/OER bifunctional electrocatalysts for zinc-air batteries.
The outbreak of COVID-19 has led to international concern. We aimed to establish an effective screening strategy in Shanghai, China, to aid early identification of patients with COVID-19.
We did a ...multicentre, observational cohort study in fever clinics of 25 hospitals in 16 districts of Shanghai. All patients visiting the clinics within the study period were included. A strategy for COVID-19 screening was presented and then suspected cases were monitored and analysed until they were confirmed as cases or excluded. Logistic regression was used to determine the risk factors of COVID-19.
We enrolled patients visiting fever clinics from Jan 17 to Feb 16, 2020. Among 53 617 patients visiting fever clinics, 1004 (1·9%) were considered as suspected cases, with 188 (0·4% of all patients, 18·7% of suspected cases) eventually diagnosed as confirmed cases. 154 patients with missing data were excluded from the analysis. Exposure history (odds ratio OR 4·16, 95% CI 2·74–6·33; p<0·0001), fatigue (OR 1·56, 1·01–2·41; p=0·043), white blood cell count less than 4 × 109 per L (OR 2·44, 1·28–4·64; p=0·0066), lymphocyte count less than 0·8 × 109 per L (OR 1·82, 1·00–3·31; p=0·049), ground glass opacity (OR 1·95, 1·32–2·89; p=0·0009), and having both lungs affected (OR 1·54, 1·04–2·28; p=0·032) were independent risk factors for confirmed COVID-19.
The screening strategy was effective for confirming or excluding COVID-19 during the spread of this contagious disease. Relevant independent risk factors identified in this study might be helpful for early recognition of the disease.
National Natural Science Foundation of China.
The extracellular matrix surrounding oligodendrocytes plays an important role during myelination and remyelination in the brain. In many cases, the microenvironment surrounding demyelination lesions ...contains inhibitory molecules, which lead to repair failure. Accordingly, blocking the activity of these inhibitory factors in the extracellular matrix should lead to more successful remyelination. In the central nervous system, oligodendrocytes form the myelin sheath. We performed primary cell culture and found that a natural increase in fibronectin promoted the proliferation of oligodendrocyte progenitors during the initial stage of remyelination while inhibiting oligodendrocyte differentiation. Poly-L-ornithine blocked these inhibitory effects without compromising fibronectin's pro-proliferation function. Experiments showed that poly-L-ornithine activated the Erk1/2 signaling pathway that is necessary in the early stages of differentiation, as well as PI3K signaling pathways that are needed in the mid-late stages. When poly-L-ornithine was tested in a lysolecithin-induced animal model of focal demyelination, it enhanced myelin regeneration and promoted motor function recovery. These findings suggest that poly-L-ornithine has the potential to be a treatment option for clinical myelin sheath injury.
The three-component sequential reaction of alpha,beta-unsaturated aldehydes, amines, and enaminones proceeded smoothly to give 1,3,4-trisubstituted 1,4-dihydropyridines in aqueous DMF. Moreover, the ...unexpected regioselective formation of 1,2-dihydropyridines has been observed for the first time in such an approach. On the basis of a systematic study, the novel regioselectivity could be assigned both to steric and electronic effects originating from the amine partner.
Several polygenic risk scores (PRSs) have been developed to predict the risk of colorectal cancer (CRC) in European descendants. We used genome‐wide association study (GWAS) data from 22 702 cases ...and 212 486 controls of Asian ancestry to develop PRSs and validated them in two case‐control studies (1454 Korean and 1736 Chinese). Eleven PRSs were derived using three approaches: GWAS‐identified CRC risk SNPs, CRC risk variants identified through fine‐mapping of known risk loci and genome‐wide risk prediction algorithms. Logistic regression was used to estimate odds ratios (ORs) and area under the curve (AUC). PRS115‐EAS, a PRS with 115 GWAS‐reported risk variants derived from East‐Asian data, validated significantly better than PRS115‐EUR derived from European descendants. In the Korea validation set, OR per SD increase of PRS115‐EAS was 1.63 (95% CI = 1.46‐1.82; AUC = 0.63), compared with OR of 1.44 (95% CI = 1.29‐1.60, AUC = 0.60) for PRS115‐EUR. PRS115‐EAS/EUR derived using meta‐analysis results of both populations slightly improved the AUC to 0.64. Similar but weaker associations were found in the China validation set. Individuals among the highest 5% of PRS115‐EAS/EUR have a 2.52‐fold elevated CRC risk compared with the medium (41‐60th) risk group and have a 12% to 20% risk of developing CRC by age 85. PRSs constructed using results from fine‐mapping and genome‐wide algorithms did not perform as well as PRS115‐EAS and PRS115‐EAS/EUR in risk prediction, possibly due to a small sample size. Our results indicate that CRC PRSs are promising in predicting CRC risk in East Asians and highlights the importance of using population‐specific data to build CRC risk prediction models.
What's new?
Several polygenic risk scores (PRS) have been developed to predict colorectal cancer risk in European‐ancestry populations. Using data from large genome‐wide association studies, here the authors developed and validated PRSs for colorectal cancer risk prediction in East Asians. The PRS derived from this study showed a similar discriminatory ability in classifying cases and controls as that previously reported in European‐ancestry populations. The findings support the utility of PRSs in identifying high‐risk individuals for colorectal cancer prevention in Asians and highlight the importance of using population‐specific data to build colorectal cancer risk prediction models.
Lisianthus (Eustoma grandiflorum) is an important ornamental plant ranking in the top 10 cut flowers worldwide. During 2016-2017, root and stem rot was a major problem that limited the production of ...lisianthus in Fujian Province, China. Disease symptoms include yellowing of the leaves and root and stem rot leading to wilting. The aim of this study was to isolate and identify the causal pathogen. Based on symptoms on host plants, morphological characteristics, sequence analysis of the internal transcribed spacer rRNA region (ITS) and the gene encoding translation elongation factor-1α (TEF), and pathogenicity tests, the pathogen was identified as Fusarium solani (Mart.) Sacc. Isolates recovered from inoculated, diseased lisianthus plants had a similar morphology to the fungal isolates used to inoculate the plants, which completed Koch's postulates. To our knowledge, this is the first report of F. solani causing root and stem rot on lisianthus in China.
Summary
The aim of the present study was to evaluate the role of placental apoptosis in mediating the reproductive and developmental toxicity of caffeine in rodents.
Female Kunming mice were treated ...with caffeine (60, 120 and 240 mg/kg per day) before and during pregnancy. The conception rate, maternal bodyweight gain, placental weight and indices of fetal developmental, including the rate of intrauterine growth retardation (IUGR; i.e. the actual number of fetuses exhibiting IUGR as a percentage of the total number of fetuses), were determined on gestational day (GD) 18.
Female Wistar rats were treated with caffeine (20, 60 and 180 mg/kg per day) from GD11 to GD20. The IUGR rate, maternal plasma angiotensin (Ang) II and prolactin concentrations, placental pathology, expression of angiotensin AT1 and AT2 receptors and apoptosis‐related proteins were measured on GD20.
In mice, caffeine treatment dose‐dependently reduced the total conception rate, delayed conception and decreased maternal bodyweight gain, placental weight, fetal bodyweight and fetal body and tail lengths, whereas the IUGR rate was increased.
In rats, caffeine treatment dose‐dependently decreased placental weight and fetal bodyweight and increased the IUGR rate. Abnormal placental structures and decreased maternal plasma prolactin concentrations were observed following 180 mg/kg per day caffeine treatment, which resulted in increases in renin–angiotensin system (RAS) activity, including maternal plasma AngII concentrations and placental AT1B and AT2 receptor expression, and Bax and p53 expression, but decreases in placental Bcl‐2 expression.
On the basis of the results of the present study, it appears that caffeine ingestion has detrimental effects on the reproductive system and fetal development in rodents that are associated with chronic activation of the maternal and placental RAS, and induction of p53‐dependent placental apoptosis.
The first multicomponent synthesis of tetrahydropyrimidinthiones has been realized via the four-component assembly of aromatic aldehyde, enaminone, aromatic amine, and thiourea. The reaction was ...performed at room temperature and the products were obtained in excellent diastereoselectivity.
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To investigate the protective effects of squid ink in chemotherapy, BALB/c mice were used as animal models of injuries induced by cyclophosphamine, a well known chemotherapeutic drug. The mice were ...randomly divided into five groups with the same number of males and females in each group. At the end of the experiment, animals were sacrificed to investigate organ indexes and antioxidant ability of the spleen, peripheral blood profile and quantities of bone marrow nucleated cells. Results showed that the hemopoietic function of mice was injured by cyclophosphamine, as indicated by decreases of contents of erythrocytes, leukocytes, hemoglobin and bone marrow nucleated cells (P<0.01), while platelets were not affected (P>0.05), as well as modification of organ indexes (P<0.05) and spleen antioxidant ability (P<0.05 or P<0.01), whereas sepia extract markedly increased the levels of erythrocytes, leukocytes, hemoglobin and bone marrow nucleated cells (P<0.01), but not platelets (P>0.05), and reversed the effects of cyclophosphamine on organ indexes and antioxidant ability of spleen (P<0.01 or P<0.05). In addition, squid ink extract did not change marrow hemopoiesis but improved the antioxidant ability of spleen in the animals. The data suggest that squid ink extract can protect the hemopoietic system from chemotherapeutic injury and could be employed to develop cell-protective drugs for use in clinical treatment of tumours.
A palladium-catalyzed domino Heck reaction and dealkylation for the preparation of 2-substituted indoles is described. This novel transformation is based on an intramolecular Heck reaction followed ...by dealkylation.
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