High-temperature superconductivity in ternary clathrate YCaH12 under high pressures

Binary hydrogen-rich compounds with H clathrate structures can serve as high-temperature superconductors under high pressures. Here, a novel ternary clathrate structure YCaH₁₂ with space group Pm-3m is uncovered at high pressure using ab initio methods. It is predicted that YCaH₁₂ can be stable above 180 GPa and decomposes into YH₆ and CaH₆ above 257 GPa. Our calculations show that YCaH₁₂ is a potential high-temperature superconductor with T _c of 230 K at 180 GPa owing to the strong electron-phonon coupling related to the optical phonon softening of H-cages. The pre-eminent pressure-induced superconductive behavior under attainable pressure is encouraging in the ternary hydrides.

[Effects of SMP-30 overexpression on apoptosis of human lens epithelial cells induced by ultraviolet B irradiation]

Objective: This study was to observe the effect of SMP-30 on ultraviolet B (UVB)-induced apoptosis of human lens epithelial cells(HLE-B3) in vitro. Methods: Experimental study. The SMP-30 cDNA was amplified by PCR and inserted into the pRFP-N1 expressing vector which had been double digested by XhoI/HindIII. HLE-B3 cells were cultured and divided into three groups: normal group, pRFP-N1 vector plasmid group and pRFP-N1-SMP-30 plasmid group (SMP-30). Then cells were exposed to UVB and the survival rate of cells was detected by MTT assay. The effects of SMP-30 on UVB-induced HLE-B3 apoptosis were measured by the Cell Death Detection ELISA kit. Meanwhile, the influence of SMP-30 on UVB-induced apoptosis-relative protein expression in HLE-B3 cells was tested by Western blots. Moreover, 2', 7'-Dichlorofluorescin diacetate staining was performed to monitor the protective effects of SMP-30 on UVB-induced HLE-B3 reactive oxygen species(ROS). One-way analysis of variance combined with Dunnett's statistical method were performed to analyze the data. Results: The full length of PSF cDNA fragment was correctly inserted into the pRFP-N1 vector, which was confirmed by DNA sequencing. The SMP-30 fragment was inserted to the plasmid pRFP-N1 correctly, which was also confirmed by DNA sequencing. The PRFP-N1-SMP-30 plasmid was transfected into HLE-B3 successfully. SMP-30 expression was up-regulated in the transfection group, compared with the control group. Data showed that the survival rate of HLE-B3 after the pRFP-N1-SMP-30 plasmid transfection was 0.90±0.14, while the apoptosis rate was 0.43±0.06 and the ROS production was 0.52±0.02, showing significant difference in comparison with the vector plasmid group and the normal group(t=5.830, 9.934, 12.19, P<0.05). In the meantime, SMP-30 overexpression down-regulated the levels of Bax and cleav-caspase-3, but up-regulated the Bcl-2 and Pro-caspase-3 expression levels under UVB irradiation. Conclusion: SMP-30 overexpression plays a protective role in UVB-induced apoptosis via regulating the expression of apoptosis-related proteins and inhibiting the production of ROS in HLE-B3 cells. (Chin J Ophthalmol, 2017, 53: 835-841).

Metallic and anti-metallic properties of strongly covalently bonded energetic AlN5 nitrides

High pressure can stimulate numerous novel physical effects which are not observed under ambient conditions, such as the electronic redistribution and delocalization phenomenon in strongly covalently bonded nitrides. Through first principles simulations, we report a new N-rich aluminum nitride AlN5, which crystallizes with the space group P1[combining macron] at 20 GPa and then transforms into the I4[combining macron]2d phase at 60 GPa. We have identified and proved the delocalization effects of π electrons in the strongly covalent Lewis poly-nitrogen structure via the one-dimensional particle in a box mechanism, which contributes to the metallization and stability of the system. This implies that not all strongly covalently bonded systems with highly localized electrons exhibit nonmetallic properties in III-V main group nitrides. Furthermore, pressure results in the hybridization configuration mutation from sp2 in the P1[combining macron] phase to a mixture of sp2 and sp3 hybridization in the I4[combining macron]2d phase, which leads to phase transition from metal to insulator. With increasing pressure, the band gap increases abnormally, exhibiting anti-metallization induced by the strong hybridization. Interestingly, the P1[combining macron] and I4[combining macron]2d structures are simultaneously accompanied by a high energy density and hardness, which enable them to have a greater ability to resist elasticity, plastic deformation and external force destruction in potential applications. Their energy density and hardness are up to 3.29 kJ g-1 and 15.2 GPa in the P1[combining macron] phase but especially 6.14 kJ g-1 and 31.7 GPa in the I4[combining macron]2d phase.

Searching for Atmospheric Bioindicators in Planets around the Two Nearby Stars, Proxima Centauri and Epsilon Eridani-Test Cases for Retrieval of Atmospheric Gases with Infrared Spectroscopy

We tested the ability of thermal infrared spectroscopy to retrieve assumed atmospheric compositions for different types of planets orbiting Proxima Centauri and Epsilon Eridani. Six cases are considered, covering a range of atmospheric compositions and some diversity in the bulk composition (rocky, water ocean, hydrogen rich) and the spectral type of the parent star (M and K stars). For some cases, we applied coupled climate chemistry, or climate-only calculations; for other cases, we assumed the atmospheric composition, ground temperature, and surface reflectivity. The IR emission was then calculated from line-by-line radiative transfer models and used to investigate retrieval of input atmospheric species. For the six cases considered, no false positive of the triple bioindicator (H₂O, CO₂, and O₂, in specified conditions) was found. In some cases, results show that the simultaneous acquisition of a visible spectrum would be valuable, for example, when CO₂ is very abundant and its 9.4 μm satellite band hides the 9.6 μm O₃ band in the IR. In each case, determining the mass appears mandatory to identify the planet's nature and have an idea of surface conditions, which are necessary when testing for the presence of life.

Unique Phase Diagram and Superconductivity of Calcium Hydrides at High Pressures

Structure prediction studies on Ca-H binary systems under high pressures were carried out, and the structures of calcium hydrides in earlier works were reproduced. The previously unreported composition of CaH₉ was found to be stable and experienced the phase transition series Cm → P2₁/ m → C2/ m from 100 to 400 GPa. To the best of our knowledge, CaH₉ may be the only alkaline earth hydride with an odd H content. At 400 GPa, the metastable R3̅ m-CaH₁₀ phase shares the same space group with the R3̅ m-SrH₁₀ phase with puckered honeycomb H layers. The C2/ m phase of CaH₉ and the R3̅ m phase of CaH₁₀ are excellent superconductors with T_c values of about 240-266 and 157-175 K at 300 and 400 GPa, respectively. The high contributions of H-derived states at the Fermi level play an important role in the superconductivity of calcium hydrides.

Unusual interfacial magnetic interactions for τ-MnAl with Fe(Co) atomic layers

The interfacial magnetic interaction and coupling mechanism for τ-MnAl with Fe(Co) atomic layers have been studied using first principles calculations. The stable surface and interface were firstly determined by the surface energy of τ-MnAl and interface energy of τ-MnAl/Fe(Co) films, respectively. Their magnetic coupling interactions were investigated by varying the Fe(Co) atomic layer numbers. It is noted that both Fe and Co exhibited ferromagnetic coupling with τ-MnAl. Interestingly, an unusual oscillation phenomenon of magnetic coupling for τ-MnAl with Fe(Co) atomic layers was observed depending on the layer thickness of Fe(Co). Moreover, Fe and Co showed different oscillation modes. The energy difference between antiferromagnetic and ferromagnetic states is larger for τ-MnAl/Fe and τ-MnAl/Co when the Fe(Co) layer numbers are even and odd, respectively. Their mechanisms were analyzed based on the band structures and the confinement of electrons in quantum wells. It is found that the magnetic coupling oscillation in τ-MnAl/Fe originated from both the spin up Δ1 band and spin down Δ5 band at the [capital Gamma, Greek, macron] points. Comparatively, the oscillation of τ-MnAl/Co is due to the spin up band at the X[combining macron] point. The present results could provide insight to further understand interfacial exchange interactions among magnetic layers.

Alterations in Brain Metabolites in Patients with Epilepsy with Impaired Consciousness: A Case-Control Study of Interictal Multivoxel 1H-MRS Findings

BACKGROUND AND PURPOSE

Previous studies have shown perfusion abnormalities in the thalamus and upper brain stem in patients with epilepsy with impaired consciousness. We hypothesized that these areas associated with consciousness will also show metabolic abnormalities. However, metabolic abnormalities in those areas correlated with consciousness has not been characterized with multiple-voxel ¹H-MRS. In this study, we investigated the metabolic alterations in these brain regions and assessed the correlation between seizure features and metabolic alterations.

MATERIALS AND METHODS

Fifty-seven patients with epilepsy and 24 control subjects underwent routine MR imaging and 3D multiple-voxel ¹H-MRS. Patients were divided into 3 subgroups: focal impaired awareness seizures (n = 18), primary generalized tonic-clonic seizures (n = 19), and secondary generalized tonic-clonic seizures (n = 20). The measured metabolite alterations in NAA/Cr, NAA/(Cr + Cho), and Cho/Cr ratios in brain regions associated with the consciousness network were compared between the patient and control groups. ROIs were placed in the bilateral inferior frontal gyrus, supramarginal gyrus, cingulate gyrus, precuneus, thalamus, and upper brain stem. Correlations between clinical parameters (epilepsy duration and seizure frequency) and metabolite alterations were analyzed.

RESULTS

Significantly lower NAA/Cr and NAA/(Cho + Cr) ratios (P < .05 and < .01, respectively) were observed in the bilateral thalamus and upper brain stem in all experimental groups, and significantly high Cho/Cr ratios (P < .05) were observed in the right thalamus in the focal impaired awareness seizures group. There were no significant differences in metabolite ratios among the 3 patient groups (P > .05). The secondary generalized tonic-clonic seizures group showed a negative correlation between the duration of epilepsy and the NAA/(Cr + Cho) ratio in the bilateral thalamus (P < .05).

CONCLUSIONS

Metabolic alterations were observed in the brain stem and thalamus in patients with epilepsy with impaired consciousness.

Computed tomography-quantified body composition predicts short-term outcomes after gastrectomy in gastric cancer

Background

Malnutrition is a common and critical problem that influences outcome in cancer patients. Body composition reflects a patient's metabolic profile and physiologic reserves, which might be the true determinant of prognosis. In the present study, which aimed to identify valuable new prognostic indicators, we investigated the association between computed tomography-quantified body composition and short-term outcomes after gastrectomy for gastric cancer.

Methods

Skeletal muscle index, mean muscle attenuation, and ratio of visceral-to-subcutaneous adipose tissue area (vsr) were calculated from preoperative computed tomography images. Low skeletal muscle index, low mean muscle attenuation, and high vsr were respectively termed "sarcopenia," "myosteatosis," and "visceral obesity." The association of body composition with postoperative complications and serum markers of nutrition and inflammation after radical gastrectomy were analyzed.

Results

The overall complication rate was significantly higher in the sarcopenia (62.5% vs. 27.3%, p = 0.001) and myosteatosis groups (38.2% vs. 4%, p = 0.002). Patients with visceral obesity had a higher incidence of inflammatory complications (20.3% vs. 6.5%, p = 0.01). Multivariate logistic regression analysis demonstrated that sarcopenia (p = 0.013), myosteatosis (p = 0.017), and low serum retinol-binding protein (p = 0.019) were independent risk factors for overall complications. Compared with control subjects, patients with sarcopenia had lower postoperative levels of serum retinol-binding protein (p = 0.007), and patients with visceral obesity had higher levels of C-reactive protein (p = 0.026).

Conclusions

Sarcopenia, myosteatosis, and visceral obesity were significantly associated with increased rates of postoperative complications and affected the postoperative nutrition and inflammation status of patients with gastric cancer.

Stable structures and superconductivity of an At-H system at high pressure

The phase diagram, electronic properties and superconductivity of an At-H system at high pressure are investigated through first principles calculation considering the effect of spin-orbit coupling (SOC). The Cmcm-AtH2, Pnma-AtH2, P6/mmm-AtH4, and Cmmm-AtH4 phases are uncovered above 50 GPa. Metallization is realized at 50 GPa for AtH2 and 60 GPa for AtH4, with Tc values of approximately 5-10 K and 30-50 K, respectively. In P6/mmm-AtH4, phonon softening induced by Fermi surface nesting occurs as the pressure increases, which is closely related to the structural phase transition of P6/mmm → Cmmm and plays a crucial role in the superconductivity of the P6/mmm phase. In addition, the spin-orbit coupling effect considerably influences the energy of ground states, pressure points of phase transitions, electronic structures, and even the electron-phonon coupling of the At-H system. Such an influence may also occur in other heavy atomic hydrides.

Effects of Ziyin Jianghuo Ningxin decoction plus dehydroepiandrosterone and femoston in treatment of patients with menopausal symptoms

OBJECTIVE

To determine the therapeutic effect of Ziyin Jianghuo Ningxin Decoction (ZYJHNXD) plus dehydroepiandrosterone (DHEA) and menopausal hormone therapy (MHT) in patients suffering from menopausal symptoms identified as, in terms of Traditional Chinese Medicine, symptom pattern of Yin deficiency with hyperactive fire.

METHODS

Totally 180 postmenopausal women aged 40 to 60 years were assigned into four groups and accepted femoston, femoston with ZYJHNXD, femoston with DHEA, femoston with ZYJHNXD and DHEA therapies, respectively, for three months. Common questionnaire-based measure instruments included modified Kupperman index (MKI), Hamilton Rating Scale for Anxiety (HAMA), and Hamilton Rating Scale for Depression (HAMD). Follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), 5-hydroxyindole-3-acetic acid (5-HIAA), norepinephrine (NE), dopamine (DA), bone mineral density (BMD), and sleep quality were evaluated before and three months after the treatments.

RESULTS

In all four groups, the scores of MKI, HAMA, HAMD and the levels of FSH, LH decreased significantly (P < 0.05) after the treatment, while the levels of E2, 5-HIAA, NE, and DA showed obvious elevation (P < 0.05). The group receiving ZYJHNXD and DHEA combined with femoston had superiority in the preservation of bone mineral density and improvement of total sleep time and nighttime sleep time over the other three groups.

CONCLUSION

ZYJHNXD and DHEA combined with MHT therapy have a favorable outcome in managing menopausal symptoms, restoring hormone levels, preventing skeletal rarefaction or osteoporosis, and improving sleep quality for postmenopausal women.

Insights into Antibonding Induced Energy Density Enhancement and Exotic Electronic Properties for Germanium Nitrides at Modest Pressures

Here, the electronic and bonding features in ground-state structures of germanium nitrides under different components that not accessible at ambient conditions have been systematically studied. The forming essence of weak covalent bonds between the Ge and N atom in high-pressure ionic crystal Fd-3 m-Ge₃N₄ is induced by the binding effect of electronic clouds originated from the Ge_ p orbitals. Hence, it helps us to understand the essence of covalent bond under high pressure, profoundly. As an excellent reducing agent, germanium transfer electrons to the antibonding state of the N₂ dimer in Pa-3-GeN₂ phase at 20 GPa, abnormally, weakening the bonding strength considerably than nitrogen gap (N≡N) at ambient pressure. Furthermore, the common cognition that the atomic distance will be shortened under the high pressures has been broken. Amazingly, with a lower range of synthetic pressure (∼15 GPa) and nitrogen contents (28%), its energy density is up to 2.32 kJ·g^-1, with a similar order of magnitude than polymeric LiN₅ (nonmolecular compound, 2.72 kJ·g^-1). It breaks the universal recognition once again that nitrides just containing polymeric nitrogen were regarded as high energy density materials. Hence, antibonding induced energy density enhancement mechanism for low nitrogen content and pressure has been exposed in view of electrons. Both the highest occupied molecular orbitals (HOMO) and the lowest unoccupied molecular orbitals (LUMO) are usually the separated orbitals of N_π* and N_σ*, which are the key to stabilization. Besides, the sp² hybridizations that exist in N₄ units are responsible for the stability of the R-3 c-GeN₄ structure and restrict the delocalization of electrons, exhibiting nonmetallic properties.

Chinese herbal formulas for postmenopausal osteoporosis: A review of preclinical evidence on animal studies and molecular mechanism

Whether Chinese herbal formulas are effective in treatment of postmenopausal osteoporosis remains unclear. The aim of this study is to explore the experimental evidence of both in vitro and in vivo preclinical studies using Chinese herbal formulas in postmenopausal osteoporosis. Searches were applied to various databases with relevant keywords. Original in vivo and in vitro studies using Chinese herbal formulas to treat postmenopausal osteoporosis, and with full text available, were included. Er-Xian Decoction, Bu-Shen-Ning-Xin Decoction, Qing E Formula, Liuwei Dihuang Wan, and Xian-Ling-Gu-Bao Decoction, the most commonly studied formulas, were selected from the pool of Chinese medicine. The preclinical data indicated the potential use of Chinese herbal formulas in postmenopausal osteoporosis. The underlying mechanisms included bone morphogenetic protein (BMP), Wnt/[Formula: see text]-catenin, extracellular-signal-regulated kinase/c-Jun [Formula: see text] terminal kinase/mitogen-activated protein kinase (ERK/JNK/MAPK), estrogen receptor (ER), and osteoprotegerin/receptor activator of nuclear factor [Formula: see text]B ligand (OPG/RANKL) signaling pathways. This study demonstrated the anti-osteoporotic effect of Chinese herbal formulas targeting different pathways in bone metabolism. Further study with adequate sample size and follow-up time, appropriate controls, and optimal blinding is required.

Charge-patching method for the calculation of electronic structure of polypeptides

Based on the CPM method, the charge densities of polypeptides can be generated and their electronic structure can be further calculated.

[Clinical application of combined hepatic artery resection and reconstruction in surgical treatment for hilar cholangiocarcinoma]

Objective: To clarify whether the surgical treatment for hilar cholangiocarcinoma combined with artery reconstruction is optimistic to the patients with hilar cholangiocarcinoma with hepatic artery invasion. Methods: There were 384 patients who received treatment in the First Affiliated Hospital to Army Medical University from January 2008 to January 2016 analyzed retrospectively. There were 27 patients underwent palliative operation, 245 patients underwent radical operation, radical resection account for 63.8%. Patients were divided into four groups according to different operation method: routine radical resection group(n=174), portal vein reconstruction group (n=47), hepatic artery reconstruction group (n=24), palliative group(n=27). General information of patients who underwent radical operation treatment was analyzed by chi-square test and analysis of variance. The period of operation time, blood loss, the length of hospital stay and hospitalization expenses of the radical operation patients were analyzed by one-way ANOVA. Comparison among groups was analyzed by LSD-t test. Results: The follow-up ended up in June first, 2016. Each of patients followed for 6 to 60 months, the median follow-up period was 24 months. 1-, 3-, and 5-year survival rates were 81.3%, 44.9% and 13.5% of routine radical operation group, and were 83.0%, 44.7% and 15.1% of portal vein reconstruction group, and were 70.8%, 27.7% and 6.9% of hepatic artery reconstruction group, respectively. And 1-, 3-, and 5-year survival rates of hepatic artery reconstruction group was lower than routine radical group and portal vein reconstruction group significantly (P<0.05). However, the rate of postoperative complications of the hepatic artery reconstruction group and the routine radical operation group and the portal vein reconstruction group were 62.5%(15/24), 55.3%(96/174) and 51.5%(24/47), respectively. There was no significant difference among them (P>0.05). The data shows that the ratio of lymphatic metastasis in hepatic artery reconstruction group (70.8%) is much higher than them in routine radical operation group (20.1%) and portal vein reconstruction group (19.1%) significantly (P<0.05). The presented data also indicate that hepatic artery resection prolongs survival time comparing with patients undergoing palliative therapy for hilar cholangiocarcinoma. Cox regression analysis indicate that hepatic artery resection and reconstruction is a protective factor compare with palliative therapy (RR=0.38, 95%CI: 0.22-0.67). The significant reason for shorter survival time is a positive correlation between hepatic artery invasion and lymph node metastasis. Conclusion: Hepatic artery resection and reconstruction has beneficial impact on oncologic long-term outcome in patients with advanced stage hilar cholangiocarcinoma.

Revealing unusual rigid diamond net analogues in superhard titanium carbides

We found three diamond net analogues in titanium carbides firstly, including hard TiC₂, superhard TiC₃ and TiC₄. Their hardness mainly originates from the strong covalent interactions of diamond-like C-layers.

Insulin-like growth factor I reduces the occurrence of necrotizing enterocolitis by reducing inflammatory response and protecting intestinal mucosal barrier in neonatal rats model

OBJECTIVE

To observe the effect of enteral supplement of insulin-like growth factor I (IGF-1) on dynamic changes of TLR4, NF-κB, IL-6, SIgA and MUC2 in intestinal tissues of neonatal rats, and to investigate the protective effects and possible mechanisms of IGF-1 on necrotizing enterocolitis (NEC).

MATERIALS AND METHODS

Specific pathogen free (SPF) neonatal Sprague Dawley (SD) rats aged 3 days old were randomly divided into 3 groups, namely, normal control group, NEC model group and IGF-1 intervention group. In NEC group, the neonatal NEC rat models were established using artificial feeding, hypoxia and cold stimulation. In IGF-1 intervention group, the models were established by means of artificial feeding plus hypoxia and cold stimulation, and IGF-1 (22 ug/L) at a physiological concentration similar to the breast milk was added to milk replacer for intervention. The rats in the three groups were killed after the blood was collected from the heart at 24, 48 and 72 h, respectively, following the establishment of models; then, 3 cm of the terminal ilea were dissected and used for histopathological examination, RT-PCR and ELISA studies after hematoxylin and eosin (HE) staining.

RESULTS

Symptoms in IGF-1 intervention group were significantly relieved, and the incidence rate of NEC was lowered remarkably. In NEC model group, the peak expression of TLR4 mRNA occurred later than that of NF-κB mRNA and IL-6, and the expressions of TLR4 mRNA, NF-κB mRNA and IL-6 were decreased at 72 h after IGF-1 intervention. In NEC model group, the expression of MUC2 showed a transient decrease, the expression of SIgA was on the decline, but the expressions of MUC2 and SIgA were increased after IGF-1 intervention.

CONCLUSIONS

The enteral administration of IGF-1 at a physiological concentration can ameliorate the clinical symptoms in neonatal NEC rat models and decrease the occurrence rate. The possible mechanism is that IGF-1 down-regulates the TLR4 mRNA expression to inhibit the production of inflammatory mediators, and it up-regulates the expressions of MUC2 and SIgA to protect the mechanical and immuno-barrier functions of the intestinal mucous.

The association between MICA/MICB polymorphism and respiratory syncytial virus infection in children

MICA/MICB gene polymorphisms are related to several cancers and infectious diseases, but there are no reports on the association between MICA/MICB gene polymorphisms and respiratory syncytial virus (RSV) infection. To clarify the association between MICA/MICB gene polymorphisms and infection of RSV in children, we collected fresh blood samples from paediatric patients with and without pneumonia after RSV infection. The MICA/MICB alleles were characterized by PCR sequence-specific primers (PCR-SSP) and PCR sequence-based genotyping (PCR-SBT), and then, the frequency of the MICA/MICB alleles and haplotypes was calculated. The results showed that the frequencies of MICA*002:01 and MICA-A9 in RSV-infected patients were significantly lower than in controls (9% vs. 20%, pc = 0.04). The allele frequency of MICA*002:01 in pneumonia patients (8%) and nonpneumonia patients (9%) was significantly lower than in controls (20%, pc = 0.02). MICA*002:01-MICB*008(Δrel = 0.616), MICA*009-MICB*016 (Δrel = 0.506), and MICA*045-MICB*014 (Δrel = 0.700) showed linkage disequilibrium in patients infected with RSV. The haplotype frequency of MICA*002:01-MICB*005:02 in RSV-infected patients was significantly lower than in controls (10% vs. 16%, pc = 0.033). In conclusion, allele MICA*002:01/A9 and haplotype MICA*002:01-MICB*005:02 were negatively associated with RSV respiratory tract infections.