The nature of spin excitations in the one-third magnetization plateau phase of Ba3CoSb2O9

Magnetization plateaus in quantum magnets—where bosonic quasiparticles crystallize into emergent spin superlattices—are spectacular yet simple examples of collective quantum phenomena escaping classical description. While magnetization plateaus have been observed in a number of spin-1/2 antiferromagnets, the description of their magnetic excitations remains an open theoretical and experimental challenge. Here, we investigate the dynamical properties of the triangular-lattice spin-1/2 antiferromagnet Ba₃CoSb₂O₉ in its one-third magnetization plateau phase using a combination of nonlinear spin-wave theory and neutron scattering measurements. The agreement between our theoretical treatment and the experimental data demonstrates that magnons behave semiclassically in the plateau in spite of the purely quantum origin of the underlying magnetic structure. This allows for a quantitative determination of Ba₃CoSb₂O₉ exchange parameters. We discuss the implication of our results to the deviations from semiclassical behavior observed in zero-field spin dynamics of the same material and conclude they must have an intrinsic origin.

Frustrated magnetic materials attract significant interest because their properties can become dominated by quantum fluctuations. Here the authors show that excitations in the plateau phase of a quantum magnet can be understood semiclassically even though the ground state involves strong quantum effects.

[Safety and efficacy of rotational atherectomy in the interventional treatment of coronary chronic total occlusion lesions]

Objective: To investigate the safety and efficacy of rotational atherectomy in the interventional treatment of coronary chronic total occlusion lesions. Methods: In this retrospective study,a total of 31 consecutive patients with coronary chronic total occlusion(CTO) lesions underwent rotational atherectomy in our hospital from February 2004 to December 2016 were enrolled,and the clinical features were analyzed. Coronary atherectomy was performed if balloon failed to cross the CTO lesions or balloon could not be fully dilated in the CTO lesions after wire crossing. The definition of procedure success was defined as residual stenosis less than 20% after implantation of drug eluting stent and rotational atherectomy. After the procedure, the patients were followed up to observe major adverse cardiac and cerebral vascular events which including cardiogenic death, myocardial infarction, cerebrovascular accident, and target lesion revascularization. Results: The 1.25 mm diameter burr was firstly selected in 80.6% (25/31) patients,and 96.8%(30/31) patients used only 1 burr to complete the rotational atherectomy procedure. The complication rate was 9.8% (3/31) including 1 patient with coronary dissection and 3 patients with slow flow or no flow. There was 1 patent with both coronary dissection and slow flow. The procedure success rate was 96.8%(30/31). Interventional treatment related myocardial infarction occurred in 3 patients during hospitalization.The 30 patients with procedure success were followed up 36(11, 96) months. The incidence rate of major adverse cardiac and cerebral vascular events was 13.3% (4/30), of which the cardiogenic death rate was 3.3% (1/30), the myocardial infarction rate was 6.7% (2/30), cerebrovascular accident rate was 3.3%(1/30),and the target lesion revascularization rate was 6.7% (2/30). Conclusion: Rotational atherectomy is safe and effective in the interventional treatment of coronary CTO lesions.

Network meta-analysis of Chinese herb injections combined with FOLFOX chemotherapy in the treatment of advanced colorectal cancer

WHAT IS KNOWN AND OBJECTIVE

Research has indicated that some Chinese herb injections (CHIs) might be beneficial in combination with chemotherapy, including remedies that might be used as effective chemosensitizers and radiosensitizers, or as palliative therapy. Here, we carried out a network meta-analysis to assess the clinical efficacy and safety of CHIs combined with oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) for advanced colorectal cancer (CRC).

METHODS

PubMed, EMBASE.com, the Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Biomedical Literature Database (CBM), Wanfang Database and Chinese Journal Full-text Database were searched from inception to 31 December 2014, to identify relevant randomized controlled trails (RCTs). The risk of bias in included RCTs was evaluated according to the Cochrane Handbook version 5.1.0. Standard pairwise meta-analysis and Bayesian network meta-analysis were performed to compare the efficacy and safety of different CHIs combined with FOLFOX. Data were analysed using STATA 12.0 and WinBUGS1.4 software.

RESULTS AND DISCUSSION

We identified 63 eligible studies (with 4837 patients in total), involving 9 CHIs. Pairwise meta-analysis showed that compared with FOLFOX alone, combinations with Aidi injection and compound matrine injection could significantly improve the overall response rate and quality of life and reduce the incidence of nausea and vomiting (III-IV), diarrhoea (III-IV), thrombocytopenia (III-IV), leukopenia (III-IV) and peripheral neurotoxicity (III-IV). According to results of indirect comparison, there were no statistically significant differences for most of comparison groups. Aidi+FOLFOX, shenqifuzheng+FOLFOX and compound matrine+FOLFOX had the greatest probability of being the best treatment in clinical efficacy and safety, considering the small sample size.

WHAT IS NEW AND CONCLUSIONS

Most of the included studies were of low quality, and there was a scarcity of eligible trials and numbers of participants. Based on currently limited evidence, aidi, shenqifuzheng and compound matrine were superior to other CHIs in patients receiving FOLFOX chemotherapy for advanced CRC. More studies are required to confirm the efficacy of CHIs in combination with FOLFOX for advanced CRC.

Impact of haematologic deficiencies on recurrent aphthous ulceration: a meta-analysis

BACKGROUND

Recurrent aphthous ulceration (RAU) is one of the most common oral mucosal diseases, some of which may be secondary to haematologic deficiencies. This meta-analysis aims to evaluate the association between haematologic deficiencies and RAU.

MATERIALS AND METHODS

Case control studies were identified using a predefined search strategy that compared the difference in haematologic deficiencies between a RAU group and a control group. A meta-analysis was performed to estimate the combined odds ratios (ORs) and 95% confidence intervals (95% CIs) in a fixed-effects model and a random-effects model, as appropriate.

RESULTS

In this meta-analysis, nine case control studies, including total 710 cases in RAU groups and 602 cases in control groups, were considered eligible for inclusion. Overall, the combined results based on all studies showed that the rate of haematinic deficiencies was significantly high in the RAU group (vitamin B12: OR=3.75, 95% CI: 2.38-5.94; folic acid: OR=7.55, 95% CI: 3.91-14.60; ferritin: OR=2.62, 95% CI: 1.69-4.06; and haemoglobin: OR=1.77, 95% CI: 1.12-2.80).

CONCLUSION

This meta-analysis suggests that haematologic deficiencies could be a significant risk factor for RAU. Thus, screening and treating any haematologic deficiencies may play an important role in preventing the occurrence of RAU.

The HIV/AIDS epidemic among young people in China between 2005 and 2012: results of a spatial temporal analysis

OBJECTIVES

Despite a recent increase in the HIV/AIDS epidemic among young people in China, youth-specific HIV data are limited.

METHODS

In total, 56 621 individuals with HIV/AIDS, aged 15-24 years, registered in the Case Reporting System of China between 2005 and 2012 and having complete spatial information were included in the present analysis. Spatial autocorrelation (general and local) and space-time scanning were performed using the ArcGIS 10.2 and SaTScan 9.3 software, respectively.

RESULTS

During 2005-2012, the number of reported HIV/AIDS cases and the proportion of HIV cases increased while the proportion of AIDS cases decreased. Sexual contact became the predominant route of transmission in later years. Spatial analysis showed marked geographical variations in HIV infection among young people throughout China during 2005-2012. The number of new hotspots increased over time. They were mainly localized to southeastern coastal areas, southwestern frontier provinces or autonomous regions (of Guangxi, Yunnan and Sichuan) and Beijing municipality. Later these hotspots disappeared and new hotspots were found in the northeast of the country. Significant clusters of HIV-positive cases were identified in three different time periods, which indicated high HIV transmission among young Chinese people in the recent past. The risk of HIV infection was highest in the first cluster (2009-2012; this cluster was the largest in size) covering the provinces of Guizhou and Yunnan, the Chongqing municipality, Guangxi, and the province of Sichuan. The second cluster (2010-2012) was mostly located in Shanghai, South Jiangsu, Zhejiang and South Anhui, while the third cluster (2010-2012) was located in Beijing and Tianjin.

CONCLUSIONS

Target-specific comprehensive behavioural interventions are urgently needed to contain the HIV epidemic among young people.

[Characteristics of HIV infections among over 50-year-olds population in China]

OBJECTIVE

To analyze the characteristics on demographical, spatial distribution and transmission mode of HIV infections among 50-year-old population.

METHODS

Related information on demography, spatial distribution, high risk behavioral and history of HIV infections among 50-year-old population were collected and analyzed. Possible time of infection based on their first CD4 testing results right after the HIV diagnoses, was estimated.

RESULTS

Since 2008, the number of new HIV/AIDS cases among the over-50-year-olds was reported increasing annually. The number of aged 50 and above in 2014 was 4.2 times than the number in 2008. 50-year-old or older population were infected mainly through heterosexual behavior (88.0%). Among these cases, 83.9% self-reported as having histories on extramarital sex intercourse and the number was increasing yearly. Among male cases who admitted as having heterosexual experience, 95.1% of them reported as having histories of extramarital sex intercourse while 53.4% of the female cases reported as having the same experiences. 46.6% of spouses of the females or with fixed partners were HIV positive. Through estimating the time of infection and the time interval between infection and diagnosis, we found that the proportion was 15.5%, from infection to diagnosis as 3 years among the 50 and older age groups, but the proportion of 8 years from infection to diagnosis was 43.6%. We estimated that 66.5% of the new HIV cases who were at age 50 and over, were infected when they were at that age span. The average time from infection and being tested was (6.8 ± 2.7) years.

CONCLUSION

The increasing number of being diagnosed on HIV among the 50-year-olds population might be related to both high risk exposure and belated diagnoses among this population, calling for the necessity of deriving the sources of HIV infection and tailoring the HIV prevention strategies in this population.

Features of Stroke in Chinese Diabetes Patients: A Hospital-based Study

In this study, demographic characteristics, risk factors, stroke subtypes and outcome were compared in 2532 patients with and without diabetes hospitalized for first-ever stroke. Diabetes was present in 471 (18.6%) of the patients. Patients with diabetes presented more frequently with ischaemic stroke (92.1% versus 71.3%), especially lacunar infarction (41.2% versus 35.2%), compared with non-diabetics. Cerebral haemorrhage was less frequent in diabetics than non-diabetics (4.2% versus 18.1%). In-hospital mortality rates from ischaemic stroke were similar in the two groups (18.2% in diabetics and 16.9% in non-diabetics). Predictors of in-hospital mortality in diabetic patients included decreased consciousness, congestive heart failure and atrial fibrillation. In conclusion, stroke in diabetic patients was different to stroke in non-diabetic patients: in diabetics the frequency of cerebral haemorrhage was lower and the rate of lacunar infarct syndrome was higher, but in-hospital mortality from ischaemic stroke was not increased. Clinical factors evident at the onset of stroke have a major influence on in-hospital mortality and may help clinicians provide a more accurate prognosis.

Bosonic Condensation and Disorder-Induced Localization in a Flat Band

We report on the engineering of a nondispersive (flat) energy band in a geometrically frustrated lattice of micropillar optical cavities. By taking advantage of the non-Hermitian nature of our system, we achieve bosonic condensation of exciton polaritons into the flat band. Because of the infinite effective mass in such a band, the condensate is highly sensitive to disorder and fragments into localized modes reflecting the elementary eigenstates produced by geometric frustration. This realization offers a novel approach to studying coherent phases of light and matter under the controlled interplay of frustration, interactions, and dissipation.

Comparison of antioxidant activities of different parts from snow chrysanthemum (Coreopsis tinctoria Nutt.) and identification of their natural antioxidants using high performance liquid chromatography coupled with diode array detection and mass spectrometry and 2,2'-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt-based assay

Snow chrysanthemum (Coreopsis tinctoria Nutt.), a world-widely well-known flower tea material, has attracted more and more attention because of its beneficial health effects such as antioxidant activity and special flavor. In this study, a high performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) and 2,2'-azinobis(3-ethylbenzthiazoline-sulfonic acid)diammonium salt (ABTS) based assay was employed for comparison and identification of antioxidants in different samples of snow chrysanthemum. The results showed that snow chrysanthemum flowers possessed the highest while stems presented the lowest antioxidant capacities. Fourteen detected peaks with antioxidant activity were temporarily identified as 3,4',5,6,7-pentahydroxyflavanone-O-hexoside, chlorogenic acid, 2R-3',4',8-trihydroxyflavanone-7-O-glucoside, flavanomarein, flavanocorepsin, flavanokanin, quercetagitin-7-O-glucoside, 3',5,5',7-tetrahydroxyflavanone-O-hexoside, marein, maritimein, 1,3-dicaffeoylquinic acid, coreopsin, okanin and acetyl-marein by comparing their UV spectra, retention times and MS data with standards or literature data. Antioxidants existed in snow chrysanthemum are quite different from those reported in Chrysanthemum morifolium, a well-known traditional beverage in China, which indicated that snow chrysanthemum may be a promising herbal tea material with obvious antioxidant activity.

Biological and bactericidal properties of Ag-doped bioactive glass in a natural extracellular matrix hydrogel with potential application in dentistry

The aim of this study was the fabrication and evaluation of a novel bioactive and bactericidal material, which could have applications in dentistry by supporting tissue regeneration and killing oral bacteria. Our hypothesis was that a new scaffold for pulp-dentin tissue engineering with enhanced antibacterial activity could be obtained by associating extracellular matrix derived from porcine bladder with an antibacterial bioactive glass. Our study combines in vitro approaches and ectopic implantation in scid mice. The novel material was fabricated by incorporating a sol-gel derived silver (Ag)-doped bioactive glass (BG) in a natural extracellular matrix (ECM) hydrogel in ratio 1:1 in weight % (Ag-BG/ECM). The biological properties of the Ag-BG/ECM were evaluated in culture with dental pulp stem cells (DPSCs). In particular, cell proliferation, cell apoptosis, stem cells markers profile, and cell differentiation potential were studied. Furthermore, the antibacterial activity against Streptococcus mutans and Lactobacillus casei was measured. Moreover, the capability of the material to enhance pulp/dentin regeneration in vivo was also evaluated. Our data show that Ag-BG/ECM significantly enhances DPSCs' proliferation, it does not affect cell morphology and stem cells markers profile, protects cells from apoptosis, and enhances in vitro cell differentiation and mineralisation potential as well as in vivo dentin formation. Furthermore, Ag-BG/ECM strongly inhibits S. mutans and L. casei growth suggesting that the new material has also anti-bacterial properties. This study provides foundation for future clinical applications in dentistry. It could potentially advance the currently available options of dental regenerative materials.

Effect of interwall interaction on the electronic structure of double-walled carbon nanotubes

Through this study, the results of density functional theory calculations within the local density approximation of the electronic structure of zigzag-zigzag double-walled carbon nanotubes (DWCNTs), with chiral indices (n, 0)@(m, 0) for n = 7-15, and m = 15-26, has been presented and the effects of interwall interaction and orbital hybridization on the electronic structure of these systems has been discussed. It was observed that the electronic band gap of the aforementioned DWCNTs depends on the interwall distance only for metallic-semiconductor configurations and on the intrinsic properties of the constituent tubes in all other combinations. It was also observed that the calculated band gap for most of the metallic-metallic DWCNTs was smaller than semiconductor-metallic, metallic-semiconductor, and semiconductor-semiconductor configurations. Metallic-semiconductor DWCNTs were found to be desirable for band gap tuning applications because of their dependence on interwall distance, opening up the possibility of using such systems in electronic device applications, such as transistors. Other applications include the use of DWCNTs in macroscopic carbon nanotube conducting wires, for which metallic-metallic and semiconducting-metallic zigzag-zigzag DWCNTs were found to be the most desirable configurations due to their small band gaps.

Peroxisome proliferator-activated receptorβ/δ activation is essential for modulating p-Foxo1/Foxo1 status in functional insulin-positive cell differentiation

Peroxisome proliferator-activated receptors (PPARs) participate in energy homeostasis and play essential roles in diabetes therapy through their effects on non-pancreas tissues. Pathological microenvironment may influence the metabolic requirements for the maintenance of stem cell differentiation. Accordingly, understanding the mechanisms of PPARs on pancreatic β-cell differentiation may be helpful to find the underlying targets of disrupted energy homeostasis under the pancreatic disease condition. PPARs are involved in stem cell differentiation via mitochondrial oxidative phosphorylation, but the subtype member activation and the downstream regulation in functional insulin-positive (INS⁺) cell differentiation remain unclear. Here, we show a novel role of PPARβ/δ activation in determining INS⁺ cell differentiation and functional maturation. We found PPARβ/δ expression selectively upregulated in mouse embryonic pancreases or stem cells-derived INS⁺ cells at the pancreatic mature stage in vivo and in vitro. Strikingly, given the inefficiency of generating INS⁺ cells in vitro, PPARβ/δ activation displayed increasing mouse and human ES cell-derived INS⁺ cell numbers and insulin secretion. This phenomenon was closely associated with the forkhead box protein O1 (Foxo1) nuclear shuttling, which was dependent on PPARβ/δ downstream PI3K/Akt signaling transduction. The present study reveals the essential role of PPARβ/δ activation on p-Foxo1/Foxo1 status, and in turn, determining INS⁺ cell generation and insulin secretion via affecting pancreatic and duodenal homeobox-1 expression. The results demonstrate the underlying mechanism by which PPARβ/δ activation promotes functional INS⁺ cell differentiation. It also provides potential targets for anti-diabetes drug discovery and hopeful clinical applications in human cell therapy.

Mussel-inspired nanofibrous sheet for suture-less stomach incision surgery

We report a dopamine-based crosslinker-conjugated gelatin/polycaprolactone nanofibrous sheet. The nanosheet was then employed to treat stomach incisions without sutures during surgery.