Association between amino acids and recent osteoporotic fracture: a matched incident case-control study.

Context: Osteoporotic fracture is a major public health issue globally. Human research on the association between amino acids (AAs) and fracture is still lacking. Objective: To examine the association between AAs and recent osteoporotic fractures. Methods: This age and sex matched incident case-control study identified 44 recent x-ray confirmed fracture cases in the Second Hospital of Jilin University and 88 community-based healthy controls aged 50+ years. Plasma AAs were measured by high performance liquid chromatography coupled with mass spectrometry. After adjusting for covariates (i.e., body mass index, milk intake >1 time/week, falls and physical activity), we conducted conditional logistical regression models to test the association between AAs and fracture. Results: Among cases there were 23 (52.3%) hip fractures and 21 (47.7%) non-hip fractures. Total, essential, and non-essential AAs were significantly lower in cases than in controls. In the multivariable conditional logistic regression models, after adjusting for covariates, each standard deviation increase in the total (odds ratio [OR]: 0.304; 95% confidence interval [CI]: 0.117-0.794), essential (OR: 0.408; 95% CI: 0.181-0.923) and non-essential AAs (OR: 0.290; 95%CI: 0.107-0.782) was negatively associated with recent fracture. These inverse associations were mainly found for hip fracture, rather than non-hip fractures. Among these AAs, lysine, alanine, arginine, glutamine, histidine and piperamide showed the significantly negative associations with fracture. Conclusion: There was a negative relationship between AAs and recent osteoporotic fracture; such relationship appeared to be more obvious for hip fracture.

Differential expression of plasma­derived exosomal miRNAs in polycystic ovary syndrome as a circulating biomarker.

Identifying biomarkers with high sensitivity and stability is helpful for the timely and accurate diagnosis, and effective management of polycystic ovary syndrome (PCOS), a long-term, progressive endocrine disorder. Circulating microRNAs (miRNAs/miRs) are being increasingly recognized as promising biomarkers given the stability and enrichment of miRNAs in exosomes. The high sensitivity of the reverse transcription-quantitative PCR (RT-qPCR) has enabled accurate quantification of miRNAs and small fragments, present in a low abundance, in the circulation. In the present study, the potential of miRNAs in the diagnosis of PCOS was evaluated. Exosomal miRNAs were extracted and screened, and three miRNAs (miR-4488, miR-151a-5p, and miR-223-3p) were found to be differentially expressed between the PCOS group and age-matched controls by sequencing analysis. RT-qPCR was performed on a clinically confirmed PCOS cohort (n=107) and a non-PCOS control cohort (n=101) from South China to validate the PCOS-related RNA sequencing results. miR-151a-5p and miR-4488 expression levels were significantly upregulated, and miR-223-3p expression was downregulated in the PCOS cohort compared with the control cohort (P<0.05). The areas under the receiver operating characteristic curve were 0.889, 0.871, and 0.664 for miR-4488, miR-151a-5p, and miR-223-3p, respectively. Combining anti-Müllerian hormone levels with the three miRNAs resulted in an AUC of 0.967, and higher sensitivity and specificity. These results suggest that miRNAs may prove useful in the early diagnosis and effective management of PCOS, and that these three miRNAs may be involved in the pathogenesis of PCOS. In addition, bioinformatics analysis showed that these three exosomal miRNAs were involved in key signaling pathways related to cancer.

Zinc Oxide Nanoparticles Foliar Application Effectively Enhanced Zinc and Aroma Content in Rice (Oryza sativa L.) Grains.

The search for an effective zinc fertilizer and its application method to effectively increase zinc content and enhance aroma in rice grains is a crucial objective. In this study, a 2-year field plot experiment was conducted to investigate the influence of ZnO NPs foliar spraying on rice quality, grain zinc and aroma content, along with exploring the physiological mechanisms underlying these effects. Our results demonstrated that the rice breakdown value and taste value of foliar spraying zinc oxide nanoparticles were improved by 31.0-41.7% and 8.2-13.0% compared with CK (control treatment involved spraying water), improving the tasting and steaming quality of rice. While Fe and Cu content in grains decreased for the application of zinc oxide nanoparticles, zinc oxide nanoparticles foliar spraying significantly increased the zinc content and accumulation of grains by 33.6-65.1% and 37.8-74.7%, respectively. Further analysis showed that the sprayed zinc oxide nanoparticles achieved effective enrichment of zinc in edible parts and increased the final bioavailability of Zn. In addition, foliar spraying of zinc oxide nanoparticles significantly increased activities of nitrate reductase and glutamine synthetase in leaves, which elevated nitrogen content in leaves and grains, and ultimately enhanced 2-acetyl-1-pyrroline (2-AP) content in grains at maturity by 6.1-21.4% compared to CK. Our findings indicated that zinc oxide nanoparticles can be practically applied as a foliar fertilizer at the gestation for quality improvement, zinc enrichment and aroma enhancement of rice grains.

Genotypic characterization of a Proteus mirabilis strain harboring blaKPC-2 on the IncN plasmid isolated from a patient with bloodstream infection in China.

BACKGROUND: Carbapenemase is the predominant enzyme in the mechanism leading to Enterobacterales resistance to carbapenems, and the rapid spread of the blaKPC gene is a major public health concern. Here, we describe a carbapenem-resistant Proteus mirabilis strain XH983, which harbored a blaKPC-2-producing IncN plasmid, isolated from a bloodstream infection. METHODS: Whole-genome sequencing and bioinformatics analysis were performed to assess the genetic environment of P. mirabilis XH983. Conjugation and transfer experiments were performed and the corresponding strains were confirmed by antimicrobial susceptibility testing. Phylogenetic and comparative genomic analysis were performed to explore the characteristics of carbapenem-resistant P. mirabilis isolates worldwide. RESULTS: P. mirabilis XH983 was isolated from the blood of a patient in Hangzhou, China. The genome of XH983 contained one 4128,916 bp circular chromosome and one 24,225 bp IncN plasmid harboring blaKPC-2. P. mirabilis XH983 had multiple resistance genes, conferring resistance to aminoglycosides [aph(3')-Ia, aph(3'')-Ib, aph(6)-Id, aac(3)-IId, aadA5, aadA1], ß-lactams (blaKPC-2, blaTEM-1B), phenicol (cat, catA1), sulphonamide/trimethoprim (drfA1, drfA17, sul1, sul2) and tetracycline [tet(J)]. The phylogenetic tree showed that XH983 was present in a cluster of 30 isolates, all of which carried blaKPC-2 and most of them came from the same hospital as XH983, indicating the clonal spread of the cluster. CONCLUSION: We characterized carbapenem-resistant P. mirabilis clinical isolate XH983. The genome sequence of P. mirabilis XH983 provides information about resistance mechanisms of P. mirabilis carrying the blaKPC-2 plasmid and the potential spread of blaKPC-2.

Population Structure and Genetic Diversity of Chinese Honeybee (Apis Cerana Cerana) in Central China.

Central China has a rich terrain with a temperate monsoon climate and varied natural environments for the Chinese honeybee (Apis cerana cerana). However, little comprehensive research on population genetic diversity has been done in this area. A population survey of the structure and genetic diversity of Apis cerana cerana in this area is deeply needed for understanding adaptation to variable environments and providing more references for the protection of honeybee biodiversity. In this study, we present a dataset of 72 populations of Chinese honeybees collected from nine sites by whole genome sequencing in Central China. We obtained 2,790,214,878 clean reads with an average covering a depth of 22×. A total of 27,361,052 single nucleotide polymorphisms (SNPs) were obtained by mapping to the reference genome with an average mapping rate of 93.03%. Genetic evolution analysis was presented via the population structure and genetic diversity based on the datasets of SNPs. It showed that Apis cerana cerana in plains exhibited higher genetic diversity than in mountain areas. The mantel test between Apis cerana cerana groups revealed that some physical obstacles, especially the overurbanization of the plains, contributed to the differentiation. This study is conducive to elucidating the evolution of Apis cerana in different environments and provides a theoretical basis for investigating and protecting the Chinese honeybee.

Endoscopic- versus x-ray-guidance for placement of nasojejunal tubes in critically ill patients: a systematic review and meta-analysis of randomized controlled trials.

Nasojejunal tubes (NJTs) are increasingly used in critically ill patients. NJT insertion with endoscopic- or x-ray-guidance can be achieved with success rates above 90%. This systematic review and meta-analysis of randomized controlled trials (RCTs) compares the efficiency and safety of these two methods in critically ill patients. We searched Chinese and English databases for RCTs comparing endoscopy- and x-ray-guided NJT placement published up to July 5, 2021. Meta-analyses were performed using RevMan5 software to compute mean differences (MDs) and odds ratios (ORs). Eleven RCTs (n=676) were included. The endoscopic group had a higher procedure success rate (OR=2.14, 95% CI [1.19, 3.85], Z=2.52, P=0.01) and shorter insertion time (MD=-3.70 min, 95% CI [-6.90, -0.50], Z=2.27, P=0.02) than the x-ray group. NJT indwelling time and post-insertion complications were similar between groups. The x-ray group had fewer complications during placement (OR=8.08, 95% CI [3.58, 18.22], Z=5.03, P<0.00001]; on subgroup analysis, only gastrointestinal non-bleeding adverse events differed significantly between groups (OR=2.78, 95% CI [1.43, 5.39], Z=3.03, P=0.002). Visual analog scale discomfort scores were better in the x-ray group (MD=4.10, 95% CI [3.57, 4.63], Z=15.07, P<0.00001). Compared with x-ray-guided NJT placement, endoscopy-guided placement was faster, had a higher success rate, and was associated with fewer gastrointestinal non-bleeding adverse events and less discomfort during insertion. Endoscopic guidance is recommended for NJT placement in critically ill patients to improve placement efficiency. X-ray guidance is a good alternative, depending on the hospital setting, as it is convenient, economical, and potentially safer.

Linking microbial community composition to farming pattern in selenium-enriched region: Potential role of microorganisms on Se geochemistry.

Selenium (Se) is an essential micronutrient for lives. Indigenous microbial communities play an important role on Se geochemistry in soils. In this study, the microbial community composition and functions of 53 soil samples were investigated using high-throughput sequencing. Samples were divided into 3 groups with different farming types based on the measured geochemical parameters and microbial functional structures. Results indicated that putative Se related bacteria Bacillus, Dyella, Paenibacillus, Burkholderia and Brevibacillus were dominant in dryland plantation soils which were characterized with higher available Se and low contents of H2O, total organic carbon (TOC), NH4+ and NO2-. In contrast, the putative denitrifier Pseudomonas dominated in flooded paddy soils with higher TOC, NO3- and organic Se, whereas genera Rhizobium, Nitrosospira, and Geobacter preferred woodland soils with higher oxidation-reduction potential (ORP), pH, NH4+ and Fe. Farming patterns resulted in distinct geochemical parameters including moisture, pH, ORP, TOC, and contents of soluble Fe, NO2- and NH4+, shaping the microbial communities, which in turn affected Se forms in soils. This study provides a valuable insight into understanding of Se biogeochemistry in soils and prospective strategy for Se-rich agriculture production.

Value of pretreatment serum lactate dehydrogenase as a prognostic and predictive factor for small-cell lung cancer patients treated with first-line platinum-containing chemotherapy.

BACKGROUND: The current study aimed to evaluate the serum pretreatment lactate dehydrogenase (LDH) and overall survival (OS) in small cell lung cancer (SCLC) patients who received first-line platinum-containing chemotherapy. METHODS: A total of 234 SCLC patients, who received first-line platinum-based chemotherapy between 2013 and 2018, were retrospectively analyzed. The data of hematological characteristics, age, gender, ECOG score, staging, metastatic site, smoking history, chemotherapy cycle, thoracic radiotherapy and hyponatremia were collected. Overall survival was calculated using the Kaplan-Meier method. The statistically significant factors in the univariate analysis were selected for the multivariate COX model analysis. RESULTS: Age, ECOG score, stage, thoracic radiotherapy, hyponatremia, liver metastasis, brain metastasis, bone metastasis, LDH, NSE and neutrophil-to-lymphocyte ratio (NLR) were closely correlated to OS in the univariate analysis. Furthermore, the multivariate analysis revealed that age (<65 years), ECOG score (<2 points), limited-stage (LD), thoracic radiotherapy and LDH <215.70 U/L were the independent prognostic factors for survival. The median OS time was worse for patients with LDH ≥215.70 U/L. In the subgroup analysis, LDH ≥215.70 U/L was significant for survival in both limited and extensive disease. Patients who achieved CR + PR in the first-line treatment had lower initial LDH levels. It was found that the pretreatment LDH increased the incidence of patients with liver metastasis. CONCLUSIONS: Positive independent prognostic factors for SCLC patients were age < 65 years old, ECOG score < 2 points, LD-SCLC, and pretreatment LDH <215.70 U/L. These factors may be useful for stratifying patients with SCLC for treatment approaches. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: Age < 65 years old, ECOG score < 2 points, LD-SCLC, and pretreatment LDH <215.70 U/L are the positive independent prognostic factors for SCLC patients. WHAT THIS STUDY ADDS: The current study provided more references for SCLC diagnosis and treatment and determined more factors for stratifying patients with SCLC for treatment approaches.

Anti-Müllerian Hormone Accelerates Pathological Process of Insulin Resistance in Polycystic Ovary Syndrome Patients.

Insulin resistance (IR) is one of the most common features of polycystic ovary syndrome (PCOS), which is related to obesity. Whether increased anti-Müllerian hormone (AMH) levels in PCOS are involved in the pathogenesis of insulin resistance remains unclear. We investigated serum levels of leptin and AMH along with basic clinical and metabolic parameters in 114 PCOS patients and 181 non-PCOS women. PCOS patients presented higher fasting blood glucose, insulin concentrations and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) in addition to body mass index (BMI), lipids profiles and hormone levels. HOMA-IR showed a positive correlation with BMI, AMH, leptin, and low-density lipoprotein-cholesterol (LDL-c) levels. Interestingly, AMH is strongly positively correlated with HOMA-IR and insulin concentrations for 1st and 2nd hours of glucose treatment after fasting. Among PCOS women with BMI≥25 kg/m2, high AMH level group showed an increased HOMA-IR when compared to normal AMH level. However, among PCOS women with normal BMI, women with high AMH presented an elevated fasting insulin levels but not HOMA-IR when compared to normal AMH group. In vitro treatment of isolated islet cells with high concentration of leptin (200 ng/ml) or high leptin plus high concentration of AMH (1 ng/ml) significantly enhanced insulin secretion. Importantly, co-treatment of AMH plus leptin upregulates the expression of pro-apoptotic proteins, such as Bax, caspase-3, and caspase-8 after incubating with a high level of glucose. These results suggest that AMH may involve in the pathological process of pancreatic ß-cells in obese PCOS women.

Dual Covalent Cross-Linking Networks in Polynorbornene: Comparison of Shape Memory Performance.

In this work, tetrakis(dimethyllamino)ethylene (TDAE) plasticized polynorbornene (PNB) was used as the matrix, sulfur (S) and dicumyl peroxide (DCP) were simultaneously used as crosslinking agents to construct dual covalent cross-linking networks in PNB. The effects of different amounts of cross-linkers on the crosslinking degree, mechanical property, glass transition temperature, and PNB shape memory performance were investigated. Two crosslinking mechanisms were examined by Fourier transform infrared spectrometer and Raman spectrometer. The results showed that sulfur-rich cross-linked PNB exhibited a higher crosslinking degree, tensile strength, and slightly higher glass transition temperature than the DCP-rich system. Cross-linked PNB presented better shape memory performance than the uncross-linked one. Sulfur-rich cross-linked PNB showed even better shape memory behavior than the DCP-rich system, both with a shape fixation ratio of over 99% and a shape recovery ratio of over 90%. The reaction mechanism of sulfur and DCP in cross-linking PNB was different. Sulfur reacted with the α-H in PNB to form monosulfide bonds, disulfide bonds, and polysulfide bonds in PNB and the number of polysulfide bonds increased with increased amounts of sulfur. DCP reacted with the double bonds in PNB to form C-C covalent bond crosslinking networks. The crosslinking mechanism revealed that the sulfur-containing cross-linked bonds, especially polysulfide bonds, were more flexible and bore large deformation, which gave the PNB excellent mechanical properties and ensured a higher shape entropy elastic recovery ratio.

Two new selenite reducing bacterial isolates from paddy soil and the potential Se biofortification of paddy rice.

Selenium (Se) is an essential element for human health. Se-enriched agricultural products can promote people's intake of Se. Microorganisms play an important role in Se cycling. In this study, two new bacterial strains were isolated from paddy soil and were identified as Chitinophaga sp. and Comamonas testosteroni, respectively. More than 44% and 39% of 1.0 mM selenite were reduced in 84 h by them using yeast extract as carbon source, respectively. Scanning electron microscope (SEM) and Energy dispersive X-ray spectrometry (EDS) results indicated that the reduction product of selenite was nanometer Se. These strains could promote the available Se in soil and the content of Se in rice plants in pot experiments. Organic combined Se in soils was increased up to 35%, accompanied by the 92% and 130% increase of Se in rice plants. To our best knowledge, this is the first report of Se reduction by Chitinophaga. This work might provide a prospective strategy for microbial fortification of Se in corps.

Impacts and socioeconomic exposures of global extreme precipitation events in 1.5 and 2.0 °C warmer climates.

The rise of global mean temperature has aroused wide attention in scientific communities. To reduce the negative climate change impact, the United Union's Intergovernmental Panel on Climate Change (IPCC) set a goal to limit global warming to 1.5 °C relative to pre-industrial levels based on the previous 2.0 °C target in October 2018. To understand the necessity of more stringent emission reduction, this study investigates the impacts of additional 0.5 °C global warming from 1.5 to 2.0 °C on global extreme precipitation, and especially its socioeconomic consequences. The extreme precipitation is represented by extreme precipitation frequency (R95pF), extreme precipitation percentage (R95pT), and maximum one-day precipitation (RX1day) as indicators, calculated based on daily precipitation data extracted from 29 Coupled Model Inter-comparison Project Phase 5 (CMIP5) global climate models (GCMs) under two representative concentration pathways: RCP4.5 and RCP8.5. The exposures of economy and population to extreme precipitation events are also computed and compared for two warming levels by using the Shared Socioeconomic Pathways (SSPs). The results show that most regions in the world are likely to suffer from increasing extreme precipitation hazards in a warming climate, with ascending gross domestic product (GDP) and population being exposed to extreme dangers with an additional 0.5 °C warming. R95pT and RX1day are projected to increase overwhelmingly throughout all continents, directly leading to intensified precipitation extremes and flash floods. In middle and low latitudes, the annual total wet-day precipitation (PRCPTOT) shows a rich-get-richer trend and R95pF decreases, which will reinforce the intensified trend of the magnitude of extreme precipitation. The exposures of GDP and population in regions with extensive exposure to extreme precipitation events at the 1.5 °C warming increase more remarkably with the additional 0.5 °C warming. In particular, Asia and Africa show lager sensitivity to global warming than other regions. These findings could provide information for mitigation and adaptation policymaking.

[Analysis of Correlation between TTF-1 and Sensitivity to First-line Chemotherapy and Prognosis in Patients with Small Cell Lung Cancer].

BACKGROUND: Thyroid transcription factor-1 (TTF-1) has been widely studied in non-small cell lung cancer, which is considered as an independent prognostic factor in patiens with non-small cell lung cancer. However, there are few studies on the prognostic value of TTF-1 in small cell lung cancer (SCLC). The purpose of this study was to explore the relationship between the expression state of TTF-1 and the sensitivity to first-line chemotherapy and prognosis in patients with SCLC. METHODS: A retrospective analysis was made on 234 patients with SCLC who were diagnosed and treated in The Affiliated Hospital of Qingdao University and received platinum-based chemotherapy. The clinical characteristics, treatment and survival of the patients were followed up. Chi χ² test and Logistic regression model were used to analyze the relationship between TTF-1 expression and chemotherapy response rate. Kaplan-Meier method and Cox proportional hazard regression model were used to analyze the effect of TTF-1 expression on survival time of patients. RESULTS: Among the 234 patients, the positive expression of TTF-1 was 188 cases (80.3%), and the negative expression of TTF-1 was 46 cases (19.7%). The objective response rate (ORR) of first-line chemotherapy in patients with positive expression of TTF-1 was higher than that in patients with negative expression of TTF-1 (70.7% vs 47.8%) (χ²=8.681, P=0.003). Logistic regression multivariate analysis showed that the expression state of TTF-1 was an independent predictor of ORR in first-line chemotherapy (OR=0.216, 95%CI: 0.076-0.615, P=0.004), however this difference was only reflected in LS-SCLC. The median progression free survival (PFS) of patients with negative expression of TTF-1 was shorter than that of patients with positive expression (6.9 months vs 9.0 months) (χ²=9.357, P=0.002). The median OS in TTF-1 negative group was shorter than that in TTF-1 positive group (13.3 months vs 20.1 months)(χ²=12.082, P=0.001). CONCLUSIONS: TTF-1 expression is an independent predictor of first-line chemotherapy response rate and survival in patients with SCLC, and may become a biomarker to predict the efficacy and prognosis of SCLC.

Mindfulness, Meditation, and Belief in Free Will/Determinism.

Two experiments investigated the influence of mindfulness, meditation, and type of induction (free will, determinism, or neutral) on affect and beliefs in free will/determinism. In Experiment 1, it was found that high mindful participants reported experiencing more positive affect and less negative affect than low mindful participants. In the determinism induction condition in Experiment 2, high mindful participants scored higher on free will beliefs after they meditated, whereas low mindful participants scored lower on free will beliefs after they meditated. So it would seem that mindfulness can have differential effects for high and low mindful individuals. It was also found that high mindful participants (depending on the task and induction condition) sometimes had longer reaction times than low mindful participants. This could be an indication of high mindful participants having a higher decision boundary for some tasks or simply an indication that high mindful participants enjoyed some tasks more than others (i.e., processing fluency). In addition, the internal consistency of the questionnaires was compared to the internal consistency found for those questionnaires in previous research.

Squalene epoxidase promotes the proliferation and metastasis of lung squamous cell carcinoma cells though extracellular signal-regulated kinase signaling.

BACKGROUND: The biological function of squalene epoxidase (SQLE), an important rate-limiting enzyme in downstream cholesterol synthesis, is to convert squalene to 2-3 oxacin squalene. The expression of SQLE in lung cancer is abnormal. We conducted this study to investigate the effect of SQLE expression on lung squamous cell carcinoma (SCC) proliferation, migration, and invasion and its role in extracellular signal-regulated kinase (ERK) signaling. METHODS: Cell Counting Kit 8, wound healing, and Transwell assays; Western blotting; and quantitative real-time PCR were used to investigate the effect of SQLE in a lung SCC H520 cell line. Kaplan-Meier analysis was used to identify the prognostic significance of SQLE. RESULTS: Overexpression of SQLE promoted lung SCC cell proliferation, migration and invasion, whereas knockdown of SQLE expression showed the opposite effect. SQLE can interact with ERK to enhance its phosphorylation. SQLE may contribute to the pathogenesis of lung cancer by modulating ERK signaling. Further survival analysis indicated that high expression of SQLE indicated poor prognosis in lung SCC. CONCLUSION: Our study presents novel evidence of potential biomarkers or therapeutic targets for lung SCC therapy and prognosis.

Advantages of Serum Anti-Müllerian Hormone as a Marker for Polycystic Ovarian Syndrome.

OBJECTIVE: To evaluate the advantages of using anti-Müllerian hormone (AMH) in the diagnosis of polycystic ovary syndrome (PCOS). METHODS: We compared data from 56 Han Chinese patients with PCOS and 52 female control Han Chinese individuals in terms of biochemical markers and the antral follicle count (AFC). Then, the correlation between serum AMH levels and various endocrine and metabolic factors was analyzed. We generated receiver operating characteristic (ROC) curves to assess the usefulness of AMH, AFC, the luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio, and testosterone (T), to discriminate between the PCOS and control groups. RESULTS: The LH/FSH ratio, homeostatis model assessment of insulin resistance (HOMA-IR), testosterone (T), blood glucose (Glu), triglyceride (TG), body mass index (BMI), AFC and, in particular, serum AMH level were significantly higher in the PCOS group than in the control group (P <.05; P <.001). The serum AMH level had a significant positive effect on the likelihood of AFC changes in patients with PCOS and control-group women. The areas under the ROC curve (AUC) of AMH, AFC, LH/FSH ratio, and T were 0.952, 0.778, 0.760, and 0.665, respectively. The best cutoff point for AMH was 6.09 ng per mL, with sensitivity of 88% and specificity of 88%.

Interface self-assembly preparation of multi-element doped carbon nanobowls with high electrocatalysis activity for oxygen reduction reaction.

Developing an efficient, stable and low cost oxygen reduction reaction electrocatalyst is desirable for fuel cells and metal-air batteries. Here, we have successfully prepared multi-element doped carbon nanobowls by simply mixing the porous carbon nanobowls and sulfur doped graphitic carbon nitride quantum dots in FeCl3 solution and subsequent high temperature treatment processes. Compared with the commercial Pt/C electrocatalyst, the multi-element doped carbon nanobowls display a comparable half-wave potential of 0.82 V, much larger limiting diffusion current density (0.4-0.8 V), better methanol-tolerance and higher long-term stability for the oxygen reduction reaction in alkaline media. The robust three-dimensional porous structure of carbon nanobowls and multiple active centers derived from Fe, N, S and O co-doping are responsible for the excellent performance. This work suggests that such multi-element doped carbon nanobowls can be a promising alternative for Pt-based catalysts in fuel cells.

Hyaluronidase Enzyme-responsive Targeted Nanoparticles for Effective Delivery of 5-Fluorouracil in Colon Cancer.

PURPOSE: In this study, we have successfully prepared the hyaluronic acid (HA)-conjugated mesoporous silica nanoparticles loaded with 5-fluorouracil (5-FU) to increase the anticancer efficacy in colon cancers. METHODS: The particles were nanosized and perfectly spherical. In vitro release kinetics clearly showed the enzyme-sensitive release of 5-FU from HA-conjugated 5-FU loaded mesoporous silica nanoparticles (HA/FMSN). RESULTS: The presence of HA on the surface of nanoparticles targeted the CD44 receptors overexpressed in the colon cancer cells In vitro cell viability and apoptosis assay clearly showed the superior anticancer effect of HA/FMSN in HT29 colon cancer cells. HA/FMSN exhibited a remarkably higher 43% of cells in early apoptosis phase and 55% of cells in late apoptosis phase indicating the superior anticancer effect of HA/FMSN. HA/FMSN exhibited a significant reduction in the tumor burden compared to that of any group. HA/FMSN was 3-fold more effective than free drug and 2-fold more effective than -FU loaded mesoporous silica nanoparticles (FMSN). CONCLUSIONS: Overall, results suggest that the novel delivery strategy could hold enormous potential in colon cancer targeting.