Photoinduced C-C Cross-Coupling of Aryl Chlorides and Inert Arenes

Here we report a facile, efficient, and catalyst-free method to realize C-C cross-coupling of aryl chlorides and inert arenes under UV light irradiation. The aryl radical upon homolytic cleavage of C-Cl bond initiated the nucleophilic substitution reaction with inert arenes to give biaryl products. This mild reaction mode can also be applied to other synthetic reactions, such as the construction of C-N bonds and trifluoromethylated compounds

Numerical studies towards practical large-eddy simulation

Large-eddy simulation developments and validations are presented for an improved simulation of turbulent internal flows. Numerical methods are proposed according to two competing criteria: numerical qualities (precision and spectral characteristics), and adaptability to complex configurations. First, methods are tested on academic test-cases, in order to abridge with fundamental studies. Consistent results are obtained using adaptable finite volume method, with higher order advection fluxes, implicit grid filtering and "low-cost" shear-improved Smagorinsky model. This analysis particularly focuses on mean flow, fluctuations, two-point correlations and spectra. Moreover, it is shown that exponential averaging is a promising tool for LES implementation in complex geometry with deterministic unsteadiness. Finally, adaptability of the method is demonstrated by application to a configuration representative of blade-tip clearance flow in a turbomachine

New Insights Into the Response of Metabolome of Escherichia coli O157:H7 to Ohmic Heating

The objective of this study was to investigate the effects of ohmic heating and water bath heating (WB) on the metabolome of Escherichia coli O157:H7 cells at the same inactivation levels. Compared to low voltage long time ohmic heating (5 V/cm, 8.50 min, LVLT) and WB (5.50 min), the high voltage short time ohmic heating (10 V/cm, 1.75 min, HVST) had much shorter heating time. Compared to the samples of control (CT), there were a total of 213 differential metabolites identified, among them, 73, 78, and 62 were presented in HVST, LVLT, and WB samples, revealing a stronger metabolomic response of E. coli cells to HVST and LVLT than WB. KEGG enrichment analysis indicated that the significantly enriched pathways were biosynthesis and metabolism of amino acids (alanine, arginine, aspartate, and glutamate, etc.), followed by aminoacyl-tRNA biosynthesis among the three treatments. This is the first metabolomic study of E. coli cells in response to ohmic heating and presents an important step toward understanding the mechanism of ohmic heating on microbial inactivation, and can serve as a theoretical basis for better application of ohmic heating in food products

LDA*: A robust and largescale topic modeling system

We present LDA*, a system that has been deployed in one of the largest Internet companies to fulfil their requirements of "topic modeling as an internal service"-relying on thousands of machines, engineers in different sectors submit their data, some are as large as 1.8TB, to LDA* and get results back in hours. LDA* is motivated by the observation that none of the existing topic modeling systems is robust enough-Each of these existing systems is designed for a specific point in the tradeoffspace that can be suboptimal, sometimes by up to 10×, across workloads. Our first contribution is a systematic study of all recently proposed samplers: AliasLDA, F+LDA, LightLDA, and WarpLDA. We discovered a novel system tradeoffamong these samplers. Each sampler has different sampling complexity and performs differently, sometimes by 5×, on documents with different lengths. Based on this tradeoff, we further developed a hybrid sampler that uses different samplers for different types of documents. This hybrid approach works across a wide range of workloads and outperforms the fastest sampler by up to 2×. We then focused on distributed environments in which thousands of workers, each with different performance (due to virtualization and resource sharing), coordinate to train a topic model. Our second contribution is an asymmetric parameter server architecture that pushes some computation to the parameter server side. This architecture is motivated by the skew of the word frequency distribution and a novel tradeoffwe discovered between communication and computation. With this architecture, we outperform the traditional, symmetric architecture by up to 2×. With these two contributions, together with a carefully engineered implementation, our system is able to outperform existing systems by up to 10×and has already been running to provide topic modeling services for more than six months.ISSN:2150-809

Successful treatment of periungual warts with local hyperthermia: report of two cases

Periungual warts are common warts that grow on the periungual or nail margin, and it’s challenging to remove them due to their particular location, causing its high recurrence rate and brings difficulties to the treatments. We successfully cured two cases of stubborn periungual warts by local hyperthermia. A male with warts on his hands and knees and a girl with periungual warts on her fingers received local hyperthermia of 44 °C for 30 min a time. One month after the last treatment, their lesions disappeared entirely and did not relapse during the follow-up period. These two cases showed that local hyperthermia might be a safe and effective method for treating periungual warts in patients with poor traditional treatment

Association Between Online Health Information–Seeking Behaviors by Caregivers and Delays in Pediatric Cancer: Mixed Methods Study in China

BackgroundPediatric cancer patients in China often present at an advanced stage of disease resulting in lower survival and poorer health outcomes. One factor hypothesized to contribute to delays in pediatric cancer has been the online health information–seeking (OHIS) behaviors by caregivers. ObjectiveThis study aims to examine the association between OHIS behaviors by caregivers and delays for Chinese pediatric cancer patients using a mixed methods approach. MethodsThis study used a mixed methods approach, specifically a sequential explanatory design. OHIS behavior by the caregiver was defined as the way caregivers access information relevant to their children’s health via the Internet. Delays in pediatric cancer were defined as any one of the following 3 types of delay: patient delay, diagnosis delay, or treatment delay. The quantitative analysis methods included descriptive analyses, Student t tests, Pearson chi-square test, and binary logistic regression analysis, all performed using Stata. The qualitative analysis methods included conceptual content analysis and the Colaizzi method. ResultsA total of 303 pediatric cancer patient-caregiver dyads was included in the quantitative survey, and 29 caregivers completed the qualitative interview. Quantitative analysis results revealed that nearly one-half (151/303, 49.8%) of patients experienced delays in pediatric cancer, and the primary type of delay was diagnosis delay (113/303, 37.3%), followed by patient delay (50/303, 16.5%) and treatment delay (24/303, 7.9%). In this study, 232 of the 303 (76.6%) caregiver participants demonstrated OHIS behaviors. When those engaged in OHIS behaviors were compared with their counterparts, the likelihood of patient delay more than doubled (odds ratio=2.21; 95% CI 1.03-4.75). Qualitative analysis results showed that caregivers’ OHIS behaviors impacted the cancer care pathway by influencing caregivers’ symptom appraisal before the first medical contact and caregivers’ acceptance of health care providers’ diagnostic and treatment decisions. ConclusionsOur findings suggest that OHIS among Chinese pediatric caregivers may be a risk factor for increasing the likelihood of patient delay. Our government and society should make a concerted effort to regulate online health information and improve its quality. Specialized freemium consultations provided by health care providers via online health informatic platforms are needed to shorten the time for caregivers’ cancer symptom appraisal before the first medical contact

Transcutaneous electrical nerve stimulation regulates organ blood flow and apoptosis during controlled hypotension in dogs.

Transcutaneous electrical nerve stimulation (TENS) is commonly used in clinical practice for alleviating pains and physiological disorders. It has been reported that TENS could counteract the ischemic injury happened in some vital organs. To determine the protective effect of TENS on internal organs during CH in dogs, target hypotension was maintained for 60 min at 50% of the baseline mean arterial pressure (MAP). The perfusion to the brain, liver, stomach, and kidney was recorded and apoptosis within these organs was observed. Results showed that when arriving at the target MAP, and during the maintaining stage for 10 min, perfusion to the stomach and liver in the CH+TENS group was much higher than in the CH group (P<0.05). Perfusion to the cerebral cortex greatly declined in both the controlled pressure groups when compared with the general anesthesia (GA) group (P<0.05). After withdrawing CH, the hepatic blood flow in both the CH and CH+TENS groups, and the gastric and cerebral cortical blood flow in the CH+TENS group, were rapidly increased. By the end of MAP restoration, gastric blood flow in the CH group was still low. At 72 h after applying CH, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells in stomach and kidney tissue from the CH group were significantly increased compared with those in the GA group (P<0.05). There was no significant difference in TUNEL-positive cells in the liver and hippocampus among the three groups. Our results demonstrated that CH with a 50% MAP level could cause lower perfusion to the liver, stomach, cerebral cortex, and kidney, with apoptosis subsequently occurring in the stomach and kidney. TENS combined GA is able to improve the blood flow to the liver, stomach, and reduce the apoptosis in the stomach and kidney

Nε-Carboxymethyl-Lysine Negatively Regulates Foam Cell Migration via the Vav1/Rac1 Pathway

Background. Macrophage-derived foam cells play a central role in atherosclerosis, and their ultimate fate includes apoptosis, promotion of vascular inflammation, or migration to other tissues. Nε-Carboxymethyl-lysine (CML), the key active component of advanced glycation end products, induced foam cell formation and apoptosis. Previous studies have shown that the Vav1/Rac1 pathway affects the macrophage cytoskeleton and cell migration, but its role in the pathogenesis of diabetic atherosclerosis is unknown. Methods and Results. In this study, we used anterior tibiofibular vascular samples from diabetic foot amputation patients and accident amputation patients, and histological and cytological tests were performed using a diabetic ApoE-/- mouse model and primary peritoneal macrophages, respectively. The results showed that the atherosclerotic plaques of diabetic foot amputation patients and diabetic ApoE-/- mice were larger than those of the control group. Inhibition of the Vav1/Rac1 pathway reduced vascular plaques and promoted the migration of macrophages to lymph nodes. Transwell and wound healing assays showed that the migratory ability of macrophage-derived foam cells was inhibited by CML. Cytoskeletal staining showed that advanced glycation end products inhibited the formation of lamellipodia in foam cells, and inhibition of the Vav1/Rac1 pathway restored the formation of lamellipodia. Conclusion. CML inhibits the migration of foam cells from blood vessels via the Vav1/Rac1 pathway, and this process affects the formation of lamellipodia