[The preventive effect of four drugs on acute mountain sickness: a Bayesian network meta-analysis].

Objective: To compare and predict the preventive effects of acetazolamide and other drugs on acute mountain sickness(AMS). Methods: Following the retrieval strategy of PRISMA statement of systematic review and meta-analysis, we searched the databases of PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang, etc. from January 1, 1980 to November 30, 2020, and randomized controlled trials (RCT) consistent with drug prevention of AMS were conducted. Using R and other statistical software, Markov chain-Monte Carlo method was carried out for network meta-analysis under Bayesian framework, and node separation method was performed to check the consistency of closed-loop research. Results: Twenty-three literatures (25 studies) were included to compare the preventive effects of 4 drugs on AMS. Bayesian network meta-analysis showed that the incidence of AMS in acetazolamide group (ACE), dexamethasone group (DEX), ginkgo biloba extract group (GBE) and rhodiola group (RHO) was lower than that in placebo group (PLA). In the comparison of drug groups, the incidence of AMS in ACE, DEX and RHO was lower than that in GBE. There was no statistically significant difference in the incidence of AMS among ACE, DEX and RHO groups. Eight of these studies reported the effects of two drugs on pulse oxygen saturation (SpO2) in people entering the target altitude. Bayesian network meta-analysis showed that SpO2 in RHO was higher than that in ACE and PLA, but there was no statistically significant difference in SpO2 between ACE and PLA. The probability ranking of prevention AMS effect grade showed that the rank 5th probability of AMS in ACE, DEX, GBE, RHO and PLA was 45.72%, 48.80%, 0, 5.48% and 0, respectively. The probability ranking of improving the SpO2 level of the target altitude population showed that the probability of the ACE, RHO and PLA ranking 1st in improving the SpO2 effect at the target altitude was 2.27%, 97.66% and 0.07%, respectively; the results of direct comparison were in good agreement with those of Bayesian prediction model indirectly, and there was no statistical difference. Conclusions: Acetazolamide and dexamethasone can effectively prevent AMS, and should be the first choice for related supplementary research in the future. Rhodiola not only improves the SpO2 of people entering high altitude, but also reduces the incidence of AMS, which needs more attention. Ginkgo biloba extract is not as effective as the above three drugs in preventing AMS and should be used depending on clinical situations.

[Clinical characteristics and outcome of patients with dilated-hypertrophic cardiomyopathy].

OBJECTIVE: To define the clinical characteristics and outcome of patients with dilated-hypertrophic cardiomyopathy (D-HCM). METHODS: Clinical data of HCM patients hospitalized from January 2002 to December 2015 in our hospital were retrospectively analyzed. Patients were divided into D-HCM and classic HCM patients. The D-HCM patients were followed up by phone. RESULTS: A total of 616 consecutive HCM patients were evaluated. Twenty one patients (3.4%) were diagnosed with D-HCM (average age(58.8±10.4) years, 13 males). It took (14.2±7.1)years for classic HCM patients to develop D-HCM. Compared to classic HCM patients, D-HCM patients were younger at the time of first HCM diagnosis ((39.7±10.4) years old vs. (48.5±9.5) years old, P<0.001) and had higher ratio of sudden cardiac death family history (19.0%(4/21) vs. 2.5%(14/558), P=0.003), more patients of future D-HCM patients had ventricular tachycardia (38.1%(8/21) vs. 5.7%(32/558), P<0.001) and higher Troponin-I(66.7%(14/21) vs. 9.3%(52/558), P<0.001) before the left ventricular cavity enlargement. Moreover, MLVWH ((24.8±4.2) mm vs. (17.2±3.5) mm, P<0.001) was significantly thicker and LAD ((39.8±5.9) mm vs. (35.2±3.3) mm, P<0.001) was significantly larger in D-HCM patients than in classical HCM patients. During the(3.8±1.9) years follow up period, 12 out of 21 D-HCM patients died (57.1%), 5 cases(23.8%)died of severe heart failure and 7 cases(33.3%) died of sudden cardiac death. One patient received heart transplantation. CONCLUSIONS: Few classical HCM patients progressed into D-HCM in this cohort. Patients diagnosed as HCM at young age, HCM patients with abnormal Troponin I and ventricular tachycardia are at higher risk of developing D-HCM. The prognosis of D-HCM is very poor, and heart failure and sudden cardiac death are the main causes of death.

Electronic structure and characteristics of Fe 3d valence states of Fe(1.01)Se superconductors under pressure probed by x-ray absorption spectroscopy and resonant x-ray emission spectroscopy.

The electronic structure and characteristics of Fe 3d valence states of iron-chalcogenide Fe(1.01)Se superconductors under pressure were probed with x-ray absorption spectroscopy and resonant x-ray emission spectroscopy (RXES). The intensity of the pre-edge peak at ~7112.7 eV of the Fe K-edge x-ray absorption spectrum of Fe(1.01)Se decreases for pressure from 0.5 GPa increased to 6.9 GPa. The satellite line Kß' was reduced in intensity upon applying pressure and became absent for pressure 52 GPa. Fe(1.01)Se shows a small net magnetic moment of Fe(2+), likely arising from strong Fe-Fe spin fluctuations. The 1s3p-RXES spectra of Fe(1.01)Se at pressures 0.5, 6.9, and 52 GPa recorded at the Fe K-edge reveal that unoccupied Fe 3d states exhibit a delocalized character, stemming from hybridization of Fe 3d and 4p orbitals arising from a local distortion around the Fe atom in a tetrahedral site. Application of pressure causes suppression of this on-site Fe 3d-Fe 4p hybridization, and thereby decreases the intensity of the pre-edge feature in the Fe K-edge absorption spectrum of Fe(1.01)Se. Compression enhances spin fluctuations at Fe sites in Fe(1.01)Se and increases the corresponding T(c), through a competition between nearest-neighbor ferromagnetic and next-nearest-neighbor antiferromagnetic superexchange interactions. This result aids our understanding of the physics underlying iron-based superconductors.

Core-level positive-ion and negative-ion fragmentation of gaseous and condensed HCCl3 using synchrotron radiation.

We investigated the dissociation dynamics of positive-ion and negative-ion fragments of gaseous and condensed HCCl(3) following photoexcitation of Cl 2p electrons to various resonances. Based on ab initio calculations at levels HF/cc-pVTZ and QCISD/6-311G∗, the first doublet structures in Cl L-edge x-ray absorption spectrum of HCCl(3) are assigned to transitions from the Cl (2P(3/2),(1/2)) initial states to the 10a(1)(∗) orbitals. The Cl 2p → 10a(1)(∗) excitation of HCCl(3) induces a significant enhancement of the Cl(+) desorption yield in the condensed phase and a small increase in the HCCl(+) yield in the gaseous phase. Based on the resonant photoemission of condensed HCCl(3), excitations of Cl 2p electrons to valence orbitals decay predominantly via spectator Auger transitions. The kinetic energy distributions of Cl(+) ion via the Cl 2p → 10a(1)(∗) excitation are shifted to higher energy ∼0.2 eV and ∼0.1 eV relative to those via the Cl 2p → 10e(∗) excitation and Cl 2p → shape resonance excitation, respectively. The enhancement of the yields of ionic fragments at specific core-excited resonance states is assisted by a strongly repulsive surface that is directly related to the spectator electrons localized in the antibonding orbitals. The Cl(-) anion is significantly reinforced in the vicinity of Cl 2p ionization threshold of gaseous HCCl(3), mediated by photoelectron recapture through post-collision interaction.

Multilineage differentiation of ectomesenchymal cells isolated from the first branchial arch.

Cranial neural crest-derived ectomesenchymal cells may be pluripotent stem cells that are capable of generating a range of phenotypes. The fate of these cells appears to be determined in part by intrinsic genetic programs and also by the influence of extracellular signals in the local environment. The extent of lineage determination once neural crest cells have migrated to the first branchial arch is not clear, although branchial arch pattern is not thought to be the result of crest predetermination. The aim of the present study was to test the hypothesis that ectomesenchymal cells of the first branchial arch show properties of pluripotent stem cells, the lineage of which may be directed by specific molecular signaling. Ectomesenchymal cells were enzymatically isolated from the mandibular processes of BALB/c mice and maintained in an undifferentiated state while cultured with leukemia inhibitory factor or induced to differentiate by lineage-specific induction factors or growth conditions, including transforming growth factor beta, forskolin, and a mineralization-promoting medium. Morphological observations and immunocytochemistry demonstrated that cells could be induced to differentiate into smooth muscle cells, glial cells, and osteoblasts, respectively. In the presence of the mineralization-promoting medium, alkaline phosphatase activity increased significantly and mineralization nodules formed. The data reported support the concept that many, although not all, first branchial arch-derived ectomesenchymal cells show properties of multipotent stem cells, the subsequent fate of which can be influenced by induction factors and growth conditions. Some cells, however, showed a degree of commitment with respect to their fate. The possible application of first branchial arch-derived stem cells to tissue engineering of the orofacial tissues should involve consideration of the developmental stage of cell harvesting and the desired cell fate.