Psychological support and the COVID-19 - A short report.

OBJECTIVE: The World Health Organization reported a cluster of cases of pneumonia of unknown cause detected on December 31, 2019 in China. Unfortunately, a 34-year-old Italian nurse has committed suicide after testing positive for coronavirus. It was the second case of suicide by a nurse in an Italian hospital and occurred only a few days after the first suicide. These consecutive suicides have aroused concern, and it is necessary to investigate the psychological issues of the medical staff in Italy regarding the COVID-19.

Relationship between inflammatory factors and arrhythmia and heart rate variability in OSAS patients.

OBJECTIVE: Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by recurrent upper airway obstruction, apnea, and hypopnea, associated with decreased oxygen saturation and disturbed sleep structure during sleep. It was found that OSAS was associated with a variety of arrhythmia and conduction disorders, but the relationship between multiple types of arrhythmia and the severity of OSAS, and its possible mechanism remain unclear. The purpose of this study was to observe the main types of arrhythmia and the condition of heart rate variability (HRV) in patients with OSAS, to detect the levels of multiple inflammatory factors in serum of OSAS patients, and to observe the correlation between polysomnographic parameters or inflammatory factors, and arrhythmia or HRV, as well as its possible mechanisms. PATIENTS AND METHODS: 141 patients with suspected OSAS were collected in the Second Affiliated Hospital of Soochow University and Xinghua People's Hospital from February 2016 to February 2018. According to the sleep apnea hypopnea index (AHI), they were divided into control group (AHI <5, n = 34), mild-moderate OSAS group (5≤ AHI <30, n = 48), and severe OSAS group (AHI ≥30, n = 59). Clinical data such as gender and age were collected. All patients completed polysomnography (PSG), 24-hour Holter monitoring and blood routine, biochemical indexes and serum hs-CRP, TNF-α, IL-6, and IL-1ß testing. The indicators in the three groups were compared, and the correlation between PSG parameters, HRV and inflammatory biomarkers was investigated. RESULTS: Compared with control group, there were significant differences in age, sex ratio, BMI, uric acid, TC, and TG in the mild-moderate OSAS group (p<0.05), and in age, sex ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL in severe OSAS group (p<0.05). There were significant differences in gender ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL between mild-moderate OSAS group and severe OSAS group (p<0.05). Heart rate variability (HRV) parameters include SDNN, SDNN index, RMSSD, PNN50, LF, HF, and LF/HF. SDNN, PNN50, and HF in severe OSAS group and mild-moderate OSAS group were significantly lower than those in control group (p<0.05). LF/HF was significantly higher than that of control group (p<0.05). There was a significant difference in PNN50, HF, and LF/HF between severe OSAS group and mild-moderate OSAS group (p<0.05). In terms of inflammation, serum hs-CRP was significantly higher in mild-moderate OSAS group and severe OSAS group than that in control group (p<0.05). Serum IL-1ß was significantly higher in mild-moderate OSAS group than that in severe OSAS group (p<0.05). There was no significant difference in other indicators (p>0.05). There was a significant positive correlation between hs-CRP and oxygen reduction index (ODI) (r=0.209, p=0.013) and a significant negative correlation with PNN50 (r=-0.188, p=0.025). There is no significant correlation between other indicators. CONCLUSIONS: Systemic inflammatory reactions existed in patients with OSAS. With the increase of OSAS, inflammation was aggravated, especially serum hs-CRP. Hs-CRP was significantly and negatively correlated with PNN50 and positively correlated with ODI. The results suggested that the inflammatory response was involved in the occurrence of heart rate variability in OSAS patients.

Topologically Entangled Rashba-Split Shockley States on the Surface of Grey Arsenic.

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at Γ[over ¯] is topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).

Comparative Raman study of Weyl semimetals TaAs, NbAs, TaP and NbP.

We report a comparative polarized Raman study of Weyl semimetals TaAs, NbAs, TaP and NbP. The evolution of the phonon frequencies with the sample composition allows us to determine experimentally which atoms are mainly involved for each vibration mode. Our results confirm previous first-principles calculations indicating that the A1, B1(2), E(2) and E(3) modes involve mainly the As(P) atoms, the B1(1) mode is mainly related to Ta(Nb) atoms, and the E(1) mode involves both kinds of atoms. By comparing the energy of the different modes, we establish that the B1(1), B1(2), E(2) and E(3) become harder with increasing chemical pressure. This behaviour differs from our observation on the A1 mode, which decreases in energy, in contrast to its behaviour under external pressure.

Refeeding syndrome in a young woman with argininosuccinate lyase deficiency.

A severely chronically protein and calorie restricted young woman with argininosuccinate lyase deficiency developed transient refeeding syndrome (RFS) and hyperammonemia after modest diet liberalization following initiation of glycerol phenylbutyrate (GPB). The patient required IV supportive care and supplementation with potassium, magnesium and calcium. She is now doing well on GPB and an appropriate maintenance diet. Susceptibility to RFS should be considered in chronically nutritionally restricted patients with metabolic disorders after liberalization of diet.

Correlation-induced self-doping in the iron-pnictide superconductor Ba2Ti2Fe2As4O.

The electronic structure of the iron-based superconductor Ba2Ti2Fe2As4O (Tc(onset)=23.5 K) has been investigated by using angle-resolved photoemission spectroscopy and combined local density approximation and dynamical mean field theory calculations. The electronic states near the Fermi level are dominated by both the Fe 3d and Ti 3d orbitals, indicating that the spacer layers separating different FeAs layers are also metallic. By counting the enclosed volumes of the Fermi surface sheets, we observe a large self-doping effect; i.e., 0.25 electrons per unit cell are transferred from the FeAs layer to the Ti2As2O layer, leaving the FeAs layer in a hole-doped state. This exotic behavior is successfully reproduced by our dynamical mean field calculations, in which the self-doping effect is attributed to the electronic correlations in the 3d shells. Our work provides an alternative route of effective doping without element substitution for iron-based superconductors.

Angle-resolved photoemission spectroscopy observation of anomalous electronic states in EuFe2As(2-x)P(x).

We used angle-resolved photoemission spectroscopy to investigate the electronic structure and the Fermi surface of EuFe2As2, EuFe2As1.4P0.6 and EuFe2P2. We observed doubled core level peaks associated with the pnictide atoms. Using K atoms evaporated at the surface to affect the surface quality, we show that one component of these doubled peaks is related to a surface state. Nevertheless, strong electronic dispersion along the c-axis, especially pronounced in EuFe2P2, is observed for at least one band, thus indicating that the Fe states, albeit probably affected at the surface, do not form pure two-dimensional surface states. We determine the evolution of the Fermi surface as a function of the P content and reveal that the hole Fermi surface pockets enlarge with increasing P content. We also show that the spectral weight near the Fermi level of EuFe2P2 is reduced as compared to that of EuFe2As2 and EuFe2As1.4P0.6. Finally, we identify the electronic states associated with the Eu(2+) f states and show an anomalous jump in EuFe2P2.

Three dimensionality and orbital characters of the Fermi surface in (Tl,Rb)(y)Fe(2-x)Se2.

We report a comprehensive angle-resolved photoemission spectroscopy study of the tridimensional electronic bands in the recently discovered Fe selenide superconductor ((Tl,Rb)(y)Fe(2-x)Se2 (T(c)=32 K). We determined the orbital characters and the k(z) dependence of the low energy electronic structure by tuning the polarization and the energy of the incident photons. We observed a small 3D electron Fermi surface pocket near the Brillouin zone center and a 2D like electron Fermi surface pocket near the zone boundary. The photon energy dependence, the polarization analysis and the local-density approximation calculations suggest a significant contribution from the Se 4p(z) and Fe 3d(xy) orbitals to the small electron pocket. We argue that the emergence of Se 4p(z) states might be the cause of the different magnetic properties between Fe chalcogenides and Fe pnictides.

Functional reconstruction of maxilla with pedicled buccal fat pad flap, prefabricated titanium mesh and autologous bone grafts.

The aim of this study was to evaluate the use of pedicled buccal fat pad flap (PBFPF), prefabricated titanium mesh and autologous bone graft in maxillary reconstruction. Seventeen patients with a unilateral class I-III maxillary defect were involved. Preoperatively, a solid model was manufactured based on virtual maxillectomy and reconstruction of the abnormal maxilla. Intraoperatively, PBFPF was applied to repair the soft-tissue defect, serving as nasal lining and the receiving bed for bone grafts. Titanium mesh was prefabricated on the solid model and then, together with bone grafts from iliac crest, fixed to residual bones to reconstruct the hard-tissue defect. Postoperative aesthetic appearance and function were followed up. No exposure of titanium mesh, leakage or oronasal regurgitation occurred. Of the patients with a class I or II defect 91% (10/11) and of those with a class III defect 50% (3/6) gained a good appearance. Fifteen patients were articulate. Eleven patients received dental rehabilitation and had a normal diet. PBFPF with prefabricated titanium mesh and autologous bone grafts is a reliable option for reconstruction of unilateral maxillary defects of class I and II, but this method alone should be used cautiously in defects of class III and beyond.

Detection of telomerase activity in saliva from oral squamous cell carcinoma patients.

Tumor markers have been detected in saliva from patients with oral cancers. In order to investigate the expression of telomerase in saliva and its clinical significance. Sixty-two saliva specimens were collected from 32 patients with oral squamous cell carcinoma and 30 normal persons, the telomerase activity was assayed by telomerase PCR-ELISA method. It was detected positively in 75.0% (24/32) of patients with oral squamous cell carcinoma, while it was positive in 6.67% (2/30) of normal persons, the statistical difference was significant with P < 0.001. But the difference of expression of telomerase activity between the patients in clinical early and late stage was not significant with P > 0.05, the same to that between the patients with and without lymph nodes metastasis with P > 0.05. The results suggest that the telomerase in saliva could be used as an assistant marker for oral squamous cell carcinoma, however, a larger study is encouraged to confirm the value of judgement on clinical stage and lymph nodes metastasis.

Evidence for changing of cosmic ray composition between 10(17) and 10(18) eV from multicomponent measurements

The average mass composition of cosmic rays with primary energies between 10(17) and 10(18) eV has been studied using a hybrid detector consisting of the High Resolution Fly's Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum and the muon density as a function of energy. The results show that the composition is changing from a heavy to lighter mix as the energy increases.

The radical cation of anti-tricyclooctadiene and its rearrangement products

The anti dimer of cyclobutadiene (anti-tricyclo[4.2.0.0(2.5)]octa-3,7-diene, TOD) is subjected to ionization by gamma-irradiation in Freon matrices, pulse radiolysis in hydrocarbon matrices, and photoinduced electron transfer in solution. The resulting species are probed by optical and ESR spectroscopy (solid phase) as well as by CIDNP spectroscopy (solution). Thereby it is found that ionization of anti-TOD invariably leads to spontaneous decay to two products, that is bicyclo[4.2.0]octa-2,4,7-triene (BOT) and 1,4-dihydropentalene (1,4-DHP), whose relative yield strongly depends on the conditions of the experiment. Exploration of the C8H8*+ potential energy surface by the B3LYP/6-31G* density functional method leads to a mechanistic hypothesis for the observed rearrangements which involves a bifurcation between a pathway leading to the simple valence isomer, BOT*+, and another one leading to an unprecedented other valence isomer, the anti form of the bicyclo[3.3.0]octa-2,6-diene-4,8-diyl radical cation (anti-BOD*+). The latter product undergoes a very facile H-shift to yield the radical cation of 1,3a-dihydropentalene (1,3a-DHP*+) which ultimately rearrranges by a further H-shift to the observed product, 1,4-DHP*+.

The radical cation of syn-tricyclooctadiene and its rearrangement products

The syn dimer of cyclobutadiene (tricyclo[4.2.0.0(2.5)]octa-3,7-diene, TOD) is subjected to ionization under different conditions and the resulting species are probed by optical and ESR spectroscopy. By means of quantum chemical modelling of the potential energy surfaces and the optical spectra, it is possible to assign the different products that arise spontaneously after ionization or after subsequent warming or illumination of the samples. Based on these findings, we propose a mechanistic scheme which involves a partitioning of the incipient radical cation of TOD between two electronic states. These two states engage in (near) activation-less decay to the more stable valence isomers, cyclooctatetraene (COT*+) and a bis-cyclobutenylium radical cation BCB*+. The latter product undergoes further rearrangement, first to tetracyclo[4.2.0.0(2,4).0(3,5]oct-7-ene (TCO*+) and eventually to bicyclo[4.2.0]octa-2,4,7-triene (BOT*+) which can also be generated photochemically from BCB*+ or TCO*+. The surprising departure of syn-TOD*+ from the least-motion reaction path leading to BOT*+ can be traced to strong vibronic interactions (second-order Jahn-Teller effects) which prevail in both possible ground states of syn-TOD*+. Such effects seem to be more important in determining the intramolecular reactivity of radical cations than orbital or state symmetry rules.