[The value of cardiac MRI in the risk stratification in patients with hypertrophic cardiomyopathy].

Objective: To explore the value of cardiac magnetic resonance imaging (CMR) in the risk stratification of hypertrophic cardiomyopathy (HCM). Methods: HCM patients who underwent CMR examination in Fuwai Hospital between March 2012 and May 2013 were retrospectively enrolled. Baseline clinical and CMR data were collected and patient follow-up was performed using telephone contact and medical record. The primary composite endpoint was sudden cardiac death (SCD) or and equivalent event. The secondary composite endpoint was all-cause death and heart transplant. Patients were divided into SCD and non-SCD groups. Cox regression was used to explore risk factors of adverse events. Receiver operating characteristic (ROC) curve analysis was used to assess the performance and the optimal cut-off of late gadolinium enhancement percentage (LGE%) for the prediction of endpoints. Kaplan-Meier and log-rank tests were used to compare survival differences between groups. Results: A total of 442 patients were enrolled. Mean age was (48.5±12.4) years and 143(32.4%) were female. At (7.6±2.5) years of follow-up, 30 (6.8%) patients met the primary endpoint including 23 SCD and 7 SCD equivalent events, and 36 (8.1%) patients met the secondary endpoint including 33 all-cause death and 3 heart transplant. In multivariate Cox regression, syncope(HR=4.531, 95%CI 2.033-10.099, P<0.001), LGE% (HR=1.075, 95%CI 1.032-1.120, P=0.001) and left ventricular ejection fraction (LVEF) (HR=0.956, 95%CI 0.923-0.991, P=0.013) were independent risk factors for primary endpoint; Age (HR=1.032, 95%CI 1.001-1.064, P=0.046), atrial fibrillation (HR=2.977, 95%CI 1.446-6.131, P=0.003),LGE% (HR=1.075, 95%CI 1.035-1.116, P<0.001) and LVEF (HR=0.968, 95%CI 0.937-1.000, P=0.047) were independent risk factors for secondary endpoint. ROC curve showed the optimal LGE% cut-offs were 5.1% and 5.8% for the prediction of primary and secondary endpoint, respectively. Patients were further divided into LGE%=0, 0

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission.

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Developmental Changes in Potassium Channels in Low Threshold Myelinated Ah-type Vagal Ganglion Neurons in Rats.

Myelinated Ah-type vagal ganglion neurons (VGNs) were specific subpopulation in adult females, rather than neonate and key players in sexual dimorphism in baroreflex afferent function and closely associated with estrogen. However, the gender related development changes in Ah-type VGNs remains unknown. To quantify the developmental changes in ion channels overtime, the whole-cell patch-clamp technique was performed and three afferent fiber types of VGNs were identified upon electrophysiological/pharmacological validations. The K+ currents were recorded with or without specific blockers from postnatal day 4-32 and adult in both sexes. The electrophysiological data conjugated with analysis of action potential (AP) trajectory strongly indicated that in male rats, Ah-types were likely to disappear or transform during development. The percentage of myelinated A-, Ah-, and unmyelinated C-type afferents in females remained relatively steady during the 4-32-day period. Conversely, Ah-type afferents in males declined from levels comparable with those in females at birth to near absence in adulthood at 32 days. The coordinated changes in the current density of certain ion channels may be the underlying mechanism of developmental changes in AP waveform and neuroexcitability. As expected, the coordinated change between the down-regulation of iberiotoxin-sensitive and up-regulation of 4-aminopyridine-sensitive K+ currents played a key role in shaping AP and neuroexcitability in Ah-types during development. Our results demonstrated that the myelinated Ah-type VGNs in males almost disappear at 4 weeks old where closes to adult and the correlative ion channel changes contribute to the sexual dimorphism in visceral afferent function.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite.

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

[The histopathological observation of rabbit corneas after small incision lenticule extraction].

OBJECTIVE: To evaluate the morphological changes during corneal wound healing after small incision lenticule extraction (SMILE). METHODS: Twenty-one New Zealand white rabbits were randomly divided into 2 groups (group A of 12 rabbits and group B of 9 rabbits) using the toss of a coin. All the right eyes were treated. Group A underwent SMILE, and group B underwent femtosecond laser-assisted in situ keratomileusis (LASIK), with the same refractive corrections of-6.00 DS/-1.00 DC. The surface regularity on the refractive corneal lenticules and flaps was evaluated by scanning electron microscopy. Light microscopy and transmission electron microscopy were applied to observe changes in the cornea on postoperative week 1, months 1 and 3. The contralateral eye of three rabbits served as control. RESULTS: All the operations were successful, and the postoperative corneal healing was uneventful in both groups. The recovery of corneas was faster in the SMILE group by slit-lamp examination. Light microscopy confirmed the mild edema of corneal stroma with a clear intrastromal crevice in the SMILE group and the adhesion of the flap and stromal bed in the LASIK group on postoperative week 1. The filling of epithelial cells at the flap margin and the irregular arrangement of collagens were demonstrated in both groups. On postoperative month 1, stromal edema was dissipated, and collagens became more regular in both groups. The intrastromal crevice in the SMILE group disappeared on postoperative month 3. Transmission electron microscopy also revealed the edema of keratocyte mitochondria within 1 month, and the keratocytes recovered to normal on month 3. The surface regularity of the front surface was better than that of the back. CONCLUSIONS: Smooth intrastromal lenticules can be safely prepared by femtosecond laser. The corneal healing in the SMILE group was better than that in the LASIK group. The intrastromal crevice in the early postoperative period after SMILE should be paid attention to clinically. (Chin J Ophthalmol, 2016, 52: 507-513).

Effects of Nitrogen Application Rate on the Yields, Nutritive Value and Silage Fermentation Quality of Whole-crop Wheat.

Whole-crop wheat (Triticum aestivum L.) as forage has been extensively used in the world. In this study, the effects of N application rates on the yields, nutritive value and silage quality were investigated. The N application rates were 0, 75, 150, 225, and 300 kg/ha. The research results indicated that the dry matter yield of whole-crop wheat increased significantly with increasing N rate up to 150 kg/ha, and then leveled off. The crude protein content and in vitro dry matter digestibility of whole-crop wheat increased significantly with increasing N up to 225 kg/ha, while they no longer increased at N 300 kg/ha. On the contrary, the content of various fibers tended to decrease with the increase of N application. The content of lactic acid, acetic acid and propionic acid in silages increased with the increase of N rate (p<0.05). The ammonia-N content of silages with higher N application rates (≥225 kg/ha) was significantly higher than that with lower N application rates (≤150 kg/ha). Whole-crop wheat applied with high levels of N accumulated more nitrate-N. In conclusion, taking account of yields, nutritive value, silage quality and safety, the optimum N application to whole-crop wheat should be about 150 kg/ha at the present experiment conditions.

Comparison of half- and standard-dose ticagrelor in Chinese patients with NSTE-ACS.

Ticagrelor is a novel direct-acting P2Y12 receptor antagonist used for preventing atherothrombotic events in patients with acute coronary syndromes (ACS). The current recommended dose is 90 mg bid, but a low dose of ticagrelor has not been previously studied in Chinese ACS patients. Therefore, we performed this study to observe the different effects of half- and standard-dose ticagrelor on platelet aggregation in Chinese patients with NSTE-ACS. Sixty-two NSTE-ACS subjects were assigned to half-dose ticagrelor (n = 20), standard-dose ticagrelor (n = 22) and clopidogrel (n = 20) groups. Five days after drug administration, VerifyNow P2Y12 assay was performed to test P2Y12 reaction units (PRU) and inhibition of platelet aggregation (IPA). High-platelet reactivity (HPR) was defined as a PRU > 208. The adverse events, including bleeding events and dyspnoea, were monitored throughout the study. PRU values in the half-dose (44.55 ± 32.88) and standard-dose (39.10 ± 40.02) ticagrelor were dramatically lower than those in the clopidogrel group (189.20 ± 65.22; P < 0.0001). The half-dose (84% ± 10%) and standard-dose (86% ± 13%) ticagrelor both showed greater IPA than clopidogrel (33% ± 20%; P < 0.0001). There were no significant differences in PRU and IPA between the two ticagrelor groups (P = 0.3085 and 0.4028, respectively). HPR rates were significantly lower in the two ticagrelor groups (0% for both) than those in the clopidogrel group (35%). In conclusion, half-dose ticagrelor had a similar inhibitory effect on platelet aggregation as standard-dose ticagrelor in Chinese patients with NSTE-ACS, which was significantly stronger than that of clopidogrel.

[Current status of HIV infection in Yunnan Province of China].

In cooperation with the Chinese Academy of Preventive Medicine and Yunnan Province Provincial Office for AIDS Control and Prevention, we studied the current status of HIV infection intravenous drug users (IVDUs) and other high risk groups in Yunnan province of China. As of the end of 1995, 1,807 HIV cases were officially reported (Positive rate was 0.6%), of which 1,278 (77.9%) were IVDUs, and 24 were their spouses. The majority of cases were found among the Dai minority male farmers near Ruili which borders on Myammar, but HIV also appears to be spreading among the Han people. HIV antibody positive rates among commercial sex workers, pregnant women and blood donors were 0.2%, 0.07% and 0.04%, respectively. A system for surveillance of HIV has been developed, but preventive strategies to cope with HIV epidemic are not sufficient. As HIV/AIDS is now a global issue, (1) the integration and coordination of such preventive strategies in cooperation with community health workers, (2) general health education for condom use promotion and (3) care of psychological vulnerable person such as IVDUs, should be developed.

PIP: In cooperation with the Chinese Academy of Preventive Medicine and the Yunnan Provincial Office for AIDS Control and Prevention, the authors studied the current status of HIV infection among intravenous drug users (IVDUs) and other high-risk groups in Yunnan province, China. As of the end of 1995, 1807 HIV cases had been officially reported (positive rate was 0.6%), of which 1278 (77.9 %) were IVDUs and 24 were their spouses. The majority of cases were found among the Dai minority male farmers near Ruili, which borders on Myanmar, but HIV also appears to be spreading among the Han people. HIV antibody positive rates among commercial sex workers, pregnant women, and blood donors were 0.2%, 0.07%, and 0.04%, respectively. A system for surveillance of HIV has been developed, but preventive strategies to cope with the HIV epidemic are not sufficient. As HIV/AIDS is now a global issue, the integration and coordination of such preventive strategies in cooperation with community health workers, general health education for condom use promotion, and care of psychologically vulnerable people such as IVDUs should be developed.