Two- and three-body dissociations of C3H6 isomer dications investigated by 4 keV/u Ar8+ impact.

The fragmentation dynamics of two isomers of C3H6, cyclopropane and propene, induced by 4 keV/u Ar8+ are investigated employing a reaction microscope. Four two-body and two three-body dissociation channels of C3H6 2+ dications are identified for each isomer, among which the channels involving CC bond breaking are found to be much more favored than H3 + and H2 + formation channels. The observation of the CH3 + or H3 + formation channels from cyclopropane are direct evidence of the proton migration within the carbon skeleton before dissociation. Obvious isomer effects are revealed by comparing the relative branching ratios of different channels of the two isomers. Moreover, it was shown that a sequential dissociation mechanism with H elimination prior to CC bond cleavage may be dominant for the two three-body dissociation channels for both isomers.

Photoluminescence and magnetism integrated multifunctional black phosphorus probes through controllable PO bond orbital hybridization.

Biological probes with integrated photoluminescence and magnetism characteristics play a critical role in modern clinical diagnosis and surgical protocols combining fluorescence optical imaging (FOI) with magnetic resonance imaging (MRI) technology. However, traditional magnetic semiconductors can easily generate a spin splitting at the Fermi level and half-metallic electronic occupation, which will sharply reduce the radiation recombination efficiency of photogenerated carriers. To overcome this intrinsic contradiction, we propose a controllable oxidation strategy to introduce some particular PO bonds into black phosphorus nanosheets, in which the p orbital hybridization between P and O atoms not only provides some carrier recombination centers but also leads to a room-temperature spin polarization. As a result, the coexistence of photoluminescence and magnetism is realized in multifunctional black phosphorus probes with excellent biocompatibility. This work provides a new insight into integrating photoluminescence and magnetism together by intriguing atomic orbital hybridization.

Temperature-Induced Lifshitz Transition and Possible Excitonic Instability in ZrSiSe.

The nodal-line semimetals have attracted immense interest due to the unique electronic structures such as the linear dispersion and the vanishing density of states as the Fermi energy approaching the nodes. Here, we report temperature-dependent transport and scanning tunneling microscopy (spectroscopy) [STM(S)] measurements on nodal-line semimetal ZrSiSe. Our experimental results and theoretical analyses consistently demonstrate that the temperature induces Lifshitz transitions at 80 and 106 K in ZrSiSe, which results in the transport anomalies at the same temperatures. More strikingly, we observe a V-shaped dip structure around Fermi energy from the STS spectrum at low temperature, which can be attributed to co-effect of the spin-orbit coupling and excitonic instability. Our observations indicate the correlation interaction may play an important role in ZrSiSe, which owns the quasi-two-dimensional electronic structures.

The giant planar Hall effect and anisotropic magnetoresistance in Dirac node arcs semimetal PtSn4.

Topological semimetals (TSMs) present intriguing quantum states and have attracted much attention in recent years because of exhibiting various anomalous magneto-transport phenomena. Theoretical prediction shows that some novel phenomena, such as negative magnetoresistance (MR) and the planar Hall effect (PHE), originate from the chiral anomaly in TSMs. In this work, high-field (33 T) Shubnikov-de Haas (SdH) oscillations are obtained to reveal the topology of PtSn4. Giant PHE and anisotropic magnetoresistance (AMR) are observed in Dirac node arcs of semimetal PtSn4. First, a non-zero transverse voltage can be acquired while tilting the in-plane magnetic field. Moreover, the amplitude of PHE sharply increases at T * ∼ 50 K with decreasing temperature, which is suggested to be related to the Fermi surface reconstruction observed in PtSn4. Subsequently, the field-dependent amplitudes of the PHE show an abnormal behavior around 50 K, which is thought to stem from the complex correlation between the chiral charge and electric one in PtSn4 driving the system into different coupling states due to the complicated band structure. On the other hand, the relative AMR is negative and up to -98% at 8.5 T. Our work proves that the PHE measurements are a convincing transport fingerprint feature to confirm the chiral anomaly in TSMs.

Low plasma miR-25 expression is a favorite prognosis factor in non-small cell lung cancer.

OBJECTIVE: Circulating microRNAs (miRNAs) are promising biomarkers for the diagnosis and prognosis prediction of cancer. In the study, we aimed to investigate the potential clinical significance of the plasma miR-25 in non-small cell lung carcinoma (NSCLC). PATIENTS AND METHODS: We first compared the miRNAs expression pattern between NSCLC tissues and adjacent normal tissues then, bioinformatic analysis of the downstream targets of miR-25 was performed. The diagnostic and prognostic value of the plasma miR-25 in NSCLC was then evaluated. RESULTS: The expression level of miR-25 was increased in NSCLC tissues compared to the adjacent normal tissues. In addition, bioinformatic analysis of the downstream-targeted genes of miR-25 revealed that many gene ontology functions and pathways were associated with cancer progression. The levels of plasma miR-25 were significantly upregulated in NSCLC patients compared to normal controls. In addition, the plasma miR-25 levels were especially higher in NSCLC patients with positive lymph node metastasis, poorly differentiation or advanced clinical stage. Subsequently, we found that the plasma miR-25 expression levels were dramatically decreased in 45 NSCLC patients after receiving surgical treatment. The receiver operating characteristic (ROC) curve analysis indicated that the plasma miR-25 exhibited high diagnostic sensitivity and specificity to discriminate NSCLC cases from healthy subjects. More interestingly, the combination of the plasma miR-25 and carcinoembryonic antigen (CEA) could effectively enhance the accuracy for distinguishing NSCLC patients from normal controls. Moreover, the plasma miR-25 overexpression was closely correlated with aggressive clinical characteristics and poor survival. Finally, the plasma miR-25 was identified as an independent prognostic marker for the overall survival of NSCLC. CONCLUSIONS: Collectively, our findings demonstrated that the plasma miR-25 might serve as a novel promising biomarker in the diagnosis and prognosis prediction of NSCLC.

LncRNA SNHG20 promotes tumorigenesis and cancer stemness in glioblastoma via activating PI3K/Akt/mTOR signaling pathway.

Long noncoding RNAs (lncRNAs) play crucial roles in the development of human cancers. LncRNA small nucleolar RNA host gene 20 (SNHG20) has been reported to be an oncogene in several cancers, whereas the specific role of SNHG20 in glioblastoma is unclear. In this study, we found that SNHG20 was significantly upregulated in glioblastoma tissues and cell lines. Survival analysis suggested that high expression of SNHG20 indicated the low overall survival rate of glioblastoma patients. Subsequently, gain or loss-of-function assays were carried out to examine the effect of SNHG20 on glioblastoma cell proliferation and apoptosis. We found that SNHG20 knockdown obviously suppressed cell proliferation, increased cell apoptosis and impaired stem properties, while SNHG20 overexpression led to the opposite results. In vivo experiment demonstrated that knockdown of SNHG20 efficiently suppressed cell growth in vivo. Furthermore, western blotting demonstrated that the PI3K/Akt/mTOR signaling pathway was activated by SNHG20 in glioblastoma cells. At last, rescue assays validated that PI3K/Akt/mTOR signaling pathway involved in the glioblastoma progression mediated by SNHG20. Taken together, this study revealed that SNHG20 regulated PI3K/Akt/mTOR signaling pathway to promote tumorigenesis and stemness of glioblastoma.

Multicentre study of Y chromosome microdeletions in 1,808 Chinese infertile males using multiplex and real-time polymerase chain reaction.

Azoospermia factor (AZF) genes on the long arm of the human Y chromosome are involved in spermatogenesis, and microdeletions in the AZF region have been recognised to be the second major genetic cause of spermatogenetic failure resulting in male infertility. While screening for these microdeletions can avoid unnecessary medical and surgical treatments, current methods are generally time-consuming. Therefore, we established a new method to detect and analyse microdeletions in the AZF region quickly, safely and efficiently. In total, 1,808 patients with spermatogenetic failure were recruited from three hospitals in southern China, of which 600 patients were randomly selected for screening for Y chromosome microdeletions in AZF regions employing real-time polymerase chain reaction with a TaqMan probe. In our study, of 1,808 infertile patients, 150 (8.3%) were found to bear microdeletions in the Y chromosome using multiplex PCR, while no deletions were found in the controls. Among the AZF deletions detected, two were in AZFa, three in AZFb, 35 in AZFc, three in AZFb+c and two in AZFa+b+c. Our method is fast-it permits the scanning of DNA from a patient in one and a half hours-and reliable, minimising the risk of cross-contamination and false-positive and false-negative results.

Spin-orbit coupling enhanced superconductivity in Bi-rich compounds ABi3 (A = Sr and Ba).

Recently, Bi-based compounds have attracted attentions because of the strong spin-orbit coupling (SOC). In this work, we figured out the role of SOC in ABi3 (A = Sr and Ba) by theoretical investigation of the band structures, phonon properties, and electron-phonon coupling. Without SOC, strong Fermi surface nesting leads to phonon instabilities in ABi3. SOC suppresses the nesting and stabilizes the structure. Moreover, without SOC the calculation largely underestimates the superconducting transition temperatures (Tc), while with SOC the calculated Tc are very close to those determined by measurements on single crystal samples. The SOC enhanced superconductivity in ABi3 is due to not only the SOC induced phonon softening, but also the SOC related increase of electron-phonon coupling matrix elements. ABi3 can be potential platforms to construct heterostructure of superconductor/topological insulator to realize topological superconductivity.

MicroRNA-122 is involved in oxidative stress in isoniazid-induced liver injury in mice.

Many studies have shown that the pathogenesis of liver injury includes oxidative stress. MicroRNA-122 may be a marker for the early diagnosis of drug-induced liver injury. However, the relationship between microRNA-122 and oxidative stress in anti-tuberculosis drug-induced liver injury remains unknown. We measured changes in tissue microRNA-122 levels and indices of oxidative stress during liver injury in mice after administration of isoniazid, a first-line anti-tuberculosis drug. We quantified microRNA-122 expression and indices of oxidative stress at 7 time points, including 1, 3, and 5 days and 1, 2, 3, and 4 weeks. The tissue microRNA-122 levels and oxidative stress significantly changed at 3 and 5 days, suggesting that isoniazid-induced liver injury reduces oxidative stress and microRNA-122 expression compared to in the control group (P < 0.05). Notably, over the time course of isoniazid-induced liver injury, mitochondrial ribosome protein S11 gene, the target of microRNA-122, began to change at 5 days (P < 0.05). The tissue microRNA-122 profile may affect oxidative stress by regulating mitochondrial ribosome protein S11 gene during isoniazid-induced liver injury, which may contribute to the response mechanisms of microRNA-122 and oxidative stress.

Efficacy and safety of echinocandins versus triazoles for the prophylaxis and treatment of fungal infections: a meta-analysis of RCTs.

Echinocandins and triazoles were proven to be effective antifungal drugs against invasive fungal infections (IFI), which may cause significant morbidity and mortality in immunocompromised patients. The aim of this study was to compare the efficacy and safety between echinocandins and triazoles for the prophylaxis and treatment of fungal infections. PubMed, Embase, and the Cochrane Library were searched to identify relevant randomized controlled trials (RCTs) up to July 2014. The quality of trials was assessed with the Jadad scoring system. The primary outcomes of interest were treatment success, microbiological success, breakthrough infection, drug-related adverse events (AEs), withdrawals due to AEs, and all-cause mortality. Ten RCTs, involving 2,837 patients, were included, as follows: caspofungin versus fluconazole (n = 1), caspofungin versus itraconazole (n = 1), anidulafungin versus fluconazole (n = 1), micafungin versus fluconazole (n = 4), micafungin versus voriconazole (n = 2), and micafungin versus itraconazole (n = 1). Echinocandins and triazoles showed similar effects in terms of favorable treatment success rate [relative risk (RR) = 1.02, 95% confidence interval (CI), 0.97-1.08], microbiological success rate (RR = 0.98, 95% CI, 0.90-1.15), breakthrough infection (RR = 1.09; 95% CI, 0.59-2.01), drug-related AEs (RR = 0.94; 95% CI, 0.71-1.15), and all-cause mortality (RR = 0.85; 95% CI, 0.66-1.10) in the prophylaxis and treatment of fungal infections. Additionally, echinocandins were more effective than triazoles for prophylaxis in patients undergoing hematologic malignancies or those who received hematopoietic stem cell transplantation (HSCT; RR = 1.08; 95% CI, 1.02-1.15). Echinocandins significantly decreased the AE-related withdrawals rate compared with triazoles (RR = 0.47; 95% CI, 0.33-0.67). This meta-analysis revealed that echinocandins are as effective and safe as triazoles for the prophylaxis and treatment of patients with fungal infections.

Henoch Schonlein Purpura in children: clinical analysis of 120 cases.

BACKGROUND: Henoch Schonlein Purpura (HSP) is a systemic vasculitic disease which is common in children. It is very important to understand the clinical features of this disease for doctors and nurses. OBJECTIVES: To study the clinical characteristics of HSP in children. METHODS: Collect the clinical data of the HSP children, and analyze the clinical characteristics of these HSP patients. RESULTS: The ratio of M:F was 1.9:1. The mean age was 6.6 ± 1.6 years. The typical onset seasons were spring, winter and autumn. Infection and food allergy were the main etiological factors. The first symptom was skin purpura and these purpura mainly concentrated the lower extremities and buttocks. The dominant digestive clinical features were abdominal pains and vomiting. The knee joint and ankle joint were most frequently affected. The typical kidney symptoms were microscopic hematuria and albuminuria. An increased ESR was reported in 68 patients (56.7%). Serum C3 decreased in 13 cases (10.8%). ASO titer was higher in 57 children (47.5%). CONCLUSION: There were gender, season and area differences for the HSP patients. The etiological factors were diverse. HSP patients could have various clinical symptoms and rare complications.

A new molecular diagnostic approach to assess Y chromosome microdeletions in infertile men.

OBJECTIVE: A key cause of spermatogenetic failure in infertile males is microdeletions in the azoospermia factor (AZF) regions of the Y chromosome. This study screened for microdeletions in the AZF regions using suspension array technology and compared the results with those from polymerase chain reaction (PCR). METHODS: Patients with spermatogenetic failure (n=507) and healthy control sperm donors (n=100) were recruited. DNA samples were analysed using both multiplex PCR with gel electrophoresis and suspension array technology. RESULTS: The suspension array method identified 45 infertile males with Y chromosome microdeletions, while none was found in the controls. Amongst the AZF subregions, two cases had deletions in AZFa, three in AZFb, 35 in AZFc, three in AZFbc and two in AZFabc. The results from 507 patients were identical when analysed with either suspension array or multiplex PCR, however suspension array technology offered improved sensitivity, may be more accurate and could give time and cost savings. CONCLUSIONS: Suspension array technology offers a rapid and high-throughput method for Y chromosome microdeletion screening in infertile men.

Energy gaps in Bi(2)Sr(2)CaCu(2)O(8+δ) cuprate superconductors.

The relationship between the cuprate pseudogap (Δ(p)) and superconducting gap (Δ(s)) remains an unsolved mystery. Here, we present a temperature- and doping-dependent tunneling study of submicron Bi(2)Sr(2)CaCu(2)O(8+δ) intrinsic Josephson junctions, which provides a clear evidence that Δ(s) closes at a temperature T(c) (0) well above the superconducting transition temperature T(c) but far below the pseudogap opening temperature T*. We show that the superconducting pairing first occurs predominantly on a limited Fermi surface near the node below T(c) (0), accompanied by a Fermi arc due to the lifetime effects of quasiparticles and Cooper pairs. The arc length has a linear temperature dependence, and as temperature decreases below T(c) it reduces to zero while pairing spreads to the antinodal region of the pseudogap leading to a d-wave superconducting gap on the entire Fermi surface at lower temperatures.

Characterization of the expression of macrophage inflammatory protein-1α (MIP-1α) and C-C chemokine receptor 5 (CCR5) after kainic acid-induced status epilepticus (SE) in juvenile rats.

AIMS: To identify the potential role of macrophage inflammatory protein-1α (MIP-1α) with its C-C chemokine receptor 5 (CCR5) in epileptogenic brain injury, we examined their expression in juvenile rat hippocampus and explored the potential link between MIP-1α, CCR5 and neuropathological alterations after status epilepticus (SE) induced by intracerebroventricular (i.c.v.) kainic acid (KA) injection. METHODS: Based on the determination of the development of spontaneous seizures initiated by SE in developing rat brain, we firstly examined hippocampal neurone damage through Nissl and Fluoro-Jade B staining, and evaluated microglial reaction during the early phase following KA-induced SE in 21-day-old rats. MIP-1α and CCR5 protein were quantified by ELISA and Western blot respectively following mRNA by real-time PCR. We also mapped MIP-1α and CCR5 expression in the hippocampus by immunohistochemistry and identified their cellular sources using double-labelling immunofluorescence. RESULTS: In juvenile rats, KA caused characteristic neurone damage in the hippocampal subfields, with accompanying microglial accumulation. In parallel with mRNA expression, MIP-1α protein in hippocampus was transiently increased after KA treatment, and peaked from 16 to 72 h. Double-labelling immunofluorescence revealed that MIP-1α was localized to microglia. Up-regulated CCR5 remained prominent at 24 and 72 h and was mainly localized to activated microglia. Further immunohistochemistry revealed that MIP-1α and CCR5 expression were closely consistent with microglial accumulation in corresponding hippocampal subfields undergoing degenerative changes. CONCLUSIONS: Our data indicated that MIP-1α as a regulator, linking with the CCR5 receptor, may be involved within the early stages of the epileptogenic process following SE by i.c.v. KA injection.

Quantum phase diffusion in a small underdamped Josephson junction.

Quantum phase diffusion in a small underdamped Nb/AlO(x)/Nb junction (∼0.4 µm(2)) is demonstrated in a wide temperature range of 25-140 mK where macroscopic quantum tunneling (MQT) is the dominant escape mechanism. We propose a two-step transition model to describe the switching process in which the escape rate out of the potential well and the transition rate from phase diffusion to the running state are considered. The transition rate extracted from the experimental switching current distribution follows the predicted Arrhenius law in the thermal regime but is greatly enhanced when MQT becomes dominant.

Observation of the large magnetocaloric effect in an orbital-spin-coupled system MnV(2)O(4).

The magnetocaloric effect (MCE) in an orbital-spin-coupled spinel vanadate MnV(2)O(4) is investigated by magnetization measurement. MnV(2)O(4) has ferrimagnetic ordering occurring at T(C) = 57 K. The maximum magnetic entropy change reaches 14.8 and 24.0 J kg(-1) K(-1) for field changes of 0-2 and 0-4 T, respectively. The maximum adiabatic temperature is about 2.9 K for a magnetic field change of 2 T. Except for the spin entropy change, the observed giant MCE is suggested to be related to the orbital entropy change due to the change of the orbital state of V(3+) induced by an applied magnetic field around T(C).

Enhanced Microwave Absorption Properties of Intrinsically Core/shell Structured La(0.6)Sr(0.4)MnO(3) Nanoparticles.

The intrinsically core/shell structured La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores have been prepared. The magnetic, dielectric and microwave absorption properties are investigated in the frequency range from 1 to 12 GHz. An optimal reflection loss of -41.1 dB is reached at 8.2 GHz with a matching thickness of 2.2 mm, the bandwidth with a reflection loss less than -10 dB is obtained in the 5.5-11.3 GHz range for absorber thicknesses of 1.5-2.5 mm. The excellent microwave absorption properties are a consequence of the better electromagnetic matching due to the existence of the protective amorphous shells, the ferromagnetic cores, as well as the particular core/shell microstructure. As a result, the La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores may become attractive candidates for the new types of electromagnetic wave absorption materials. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11671-009-9374-y) contains supplementary material, which is available to authorized users.

Flocculation behavior and mechanism of an exopolysaccharide from the deep-sea psychrophilic bacterium Pseudoalteromonas sp. SM9913.

Flocculation behavior and mechanism of the exopolysaccharide secreted by Pseudoalteromonas sp. SM9913 (EPS SM9913), a psychrophilic bacterium isolated from 1855m deep-sea sediment, has been studied in this paper. EPS SM9913 showed a peak flocculating activity of 49.3 in 1g/L kaolin suspension with 4.55mmol/L CaCl2 and the optimum pH range of 5-8. It appears that the flocculating activity of EPS SM9913 was stimulated by Ca2+ and Fe2+. This study found that EPS SM9913 showed a better flocculation performance than Al2(SO4)3 at salinity of 5-100 per thousand or temperatures of 5-15 degrees C. In addition, this EPS was effective to flocculate several other suspended solids. The measured zeta-potentials, the size of flocs formed during the flocculation process and the surface profile of flocs revealed by scan electron micrograph suggest that bridging is the main flocculation mechanism of the studied EPS. Deacetylation of EPS SM9913 resulted in a significant decrease in its flocculating activity indicating that the large number of acetyl groups in EPS SM9913 played an important role in its flocculation performance.

Critical behavior of double perovskite La(2)NiMnO(6).

The critical behavior of the double perovskite La(2)NiMnO(6) was investigated by measurement of the magnetization around the Curie temperature T(C). The magnetic data were analyzed in the critical region using the Kouvel-Fisher method to yield the critical exponents of ß = 0.408 ± 0.011 with T(C) = 270.50 (from the temperature dependence of the spontaneous magnetization below T(C)) and γ = 1.295 ± 0.015 with T(C) = 271.10 (from the temperature dependence of the inverse initial susceptibility above T(C)). The critical magnetization isotherm M(T(C),H) gives δ = 4.139 ± 0.090. The critical exponents obtained by this method obey the Widom scaling relation δ = 1+γ/ß, implying the critical exponents are reliable. The values of critical exponents are close to those predicted by the three-dimensional (3D) Heisenberg model with short-range interactions.