Quantum spin liquid emerging in two-dimensional correlated Dirac fermions.

At sufficiently low temperatures, condensed-matter systems tend to develop order. A notable exception to this behaviour is the case of quantum spin liquids, in which quantum fluctuations prevent a transition to an ordered state down to the lowest temperatures. There have now been tentative observations of such states in some two-dimensional organic compounds, yet quantum spin liquids remain elusive in microscopic two-dimensional models that are relevant to experiments. Here we show, by means of large-scale quantum Monte Carlo simulations of correlated fermions on a honeycomb lattice (a structure realized in, for example, graphene), that a quantum spin liquid emerges between the state described by massless Dirac fermions and an antiferromagnetically ordered Mott insulator. This unexpected quantum-disordered state is found to be a short-range resonating valence-bond liquid, akin to the one proposed for high-temperature superconductors: the possibility of unconventional superconductivity through doping therefore arises in our system. We foresee the experimental realization of this model system using ultra-cold atoms, or group IV elements arranged in honeycomb lattices.

[Biography of Moody Meng].

Moody Meng(1897-1983) was a pioneer of pharmacy in China. He was the main editor of the first Chinese Pharmacopoeia, the first president of the National College of Pharmacy (now China Pharmaceutical University), the first director of Chongqing Union Pharmaceutical Factory during the Anti-Japanese War and the first director of the China National Institute for the Control of Pharmaceutical and Biological Products. He made important contributions in many fields of pharmacy in China.

A case of acute renal failure due to hydroxyethyl starch.

A 73-year-old nephrotic female developed acute renal failure (ARF) with serum creatinine to 586 umol/l after 4 days of therapy with hydroxyethyl starch (HES). Renal biopsy demonstrated that the histopathological appearance was mesangioproliferative glomerulonephritis with tubulointerstitial changes resembling acute tubulointerstitial nephritis. "Pulse" therapy with methylprednisolone, hemodialyses and other symptomatic treatment were performed in the patient during the oliguric phase of the disease. There was no worsening of her renal function, and subsequently it recovered fully. After 6 months of follow-up she had a serum creatinine of 112 umol/l, proteinuria had declined to 0.18 g/day and she is now doing well. Our findings suggest that an immune disease due to a hapten induced by HES may be a possible factor in the pathogenesis of ARF. Therefore, it is important for clinicians to bear in mind the possibility of ARF due to HES and it has been proposed that, whenever possible, HES should not be used in idiopathic nephritic syndrome patients to avoid severe complications.

Vertical distributions of SO(2) and NO(2) in the lower atmosphere in Beijing urban areas, China.

Measurements of SO(2) and NO(2) were conducted from January to March 2001 and August 2003 at a 325 m meteorological tower in Beijing. The concentrations of SO(2) and NO(2) observed by passive samplers at ten heights showed complex vertical distributions in winter and summer. The vertical profiles of pollutants were influenced by source emissions, meteorological conditions, urban canopy and other factors. The comparison analysis of winter and summer pollutant concentrations suggests that the decrease in SO(2) concentration was significant in summer, and the reduction of NO(2) was relatively not distinctive. Domestic heating and industrial sources were major sources of SO(2) in urban areas of Beijing. Differing from SO(2,) urban NO(2) was closely related to traffic emission. Meteorological evidence suggests that strong temperature inversions influence vertical distribution of air pollutants over urban Beijing. The high levels of SO(2) and NO(2) concentrations were due to the accumulation of pollutants resulting from the stable atmosphere prevalent during the measurement period. The vertical distributions of air pollutants were controlled and affected by atmospheric dynamical characteristics.

[Immunogenicity of inacitivated quadrivalent influenza vaccine in adults aged 18-64 years: A systematic review and Meta-analysis].

Objective: To evaluate the immunogenicity of inactivated quadrivalent influenza vaccine (QIV) in adults aged 18-64 years, through a Meta-analysis. Methods: Literature was retrieved by searching the Medline, Cochrane Library, Science Direct in the past decade. All the studies were under random control trial (RCT) and including data related to immunogenicity which involving sero-protection rate (SPR) and sero-conversion rate (SCR) of the QIV, versus inactivated trivalent influenza vaccine (TIV) in the population aged 18 to 64. Revman 5.3 software was employed to manipulate the pooled date of the included literature. Result: A total of 8 studies for the SPR and SCR of the shared strains (two A lineage and one B lineage) were included. There appeared no significant differences in the response rates between the two vaccines. As for QIV versus TIV (B/Yamagata), the pooled RR of the SPR for B/Victoria was 1.28 (95%CI: 1.08-1.51, P<0.05), with the pooled RR of the SCR for B/Victoria as 1.94 (95%CI: 1.50-2.50, P<0.05). For QIV versus TIV (B/Victoria), the pooled RR of the SPR for B/Yamagata as 1.10 (95%CI: 1.02-1.18, P<0.05), and the pooled RR of SCR for B/Yamagata as 1.99 (95%CI: 1.34-2.97, P<0.05). Conclusion: In the population aged 18-64 years, inactivated QIV was equivalently immunogenic against the shared three strains included in the activated TIV while a superior immunogenic effect was noticed in the vaccine strain which did not include the inactivated QIV.

Pharmacokinetics and metabolism of 1,5-dicaffeoylquinic acid in rats following a single intravenous administration.

1,5-Dicaffeoylquinic acid (1,5-DCQA) is a potentially important HIV-1 integrase inhibitor widely distributed in many plants. To characterize the pharmacokinetic and metabolic properties of 1,5-DCQA in rats following single intravenous administration (160 mg/kg), the plasma concentrations of 1,5-DCQA were measured by high-performance liquid chromatography (HPLC) and the metabolites formed in urine were identified by liquid chromatography-mass spectrometry (LC-MS) in parallel to diode-array detection (DAD). The results showed that the concentrations of 1,5-DCQA in plasma declined rapidly in a biphasic manner with a mean terminal half-life (t(1/2)) of 1.40 h. The mean clearance (CL) and the apparent volume of distribution (Vd(B)) of 1,5-DCQA were 0.44l/h/kg and 0.89l/kg, respectively. A total of 15 metabolites in rat urine were identified, including four isomeric O-mono-methylated (M1-M4), six isomeric O-di-methylated (M5-M10), one isomeric O-mono-methyl-glucuronidated (M11) and four isomeric O-di-methyl-glucuronidated (M12-M15) metabolites. The O-methylation positions of three important metabolites (M1, M2 and M5) were determined (3''-, 3'-, and 3',3''-) by comparing with synthesized standards. These results suggested that the disappearance of 1,5-DCQA from plasma was rapid, and that its quick urinary excretion and extensive metabolism, including methylation and glucuronidation, were two factors causing its rapid elimination from the circulation.

Mean-field embedding of the dual-fermion approach for correlated electron systems.

To reduce the rapidly growing computational cost of the dual-fermion lattice calculation with increasing system size, we introduce two embedding schemes. One is the real fermion embedding, and the other is the dual-fermion embedding. Our numerical tests show that the real fermion and dual-fermion embedding approaches converge to essentially the same result. The application on the Anderson disorder and Hubbard models shows that these embedding algorithms converge more quickly with system size as compared to the conventional dual-fermion method, for the calculation of both single- and two-particle quantities.

[Experimental studies on rabbit facial nerve regeneration in chitin tubes containing nerve growth factor].

OBJECTIVE: To evaluate the nerve regeneration after implantation of chitin tubes containing nerve growth factor(NGF) in the rabbit facial nerve. METHODS: Bilateral 8 mm defect of superior buccal divisions of the facial nerves were made in 16 New Zealand rabbits. Chitin tubes containing NGF were implanted into the gaps, and autologous nerves were implanted into the right gaps as control. The nerve regeneration was evaluated with electrophysiological and ultrastructural examination after 8 and 16 weeks of operation. RESULTS: Chitin tubes containing NGF successfully induced the nerve regeneration, regularly arranged myelinated and unmyelinated axons could be observed across the 8 mm gaps, and the myelin sheath was thick with clear lamellar structure at 8 weeks after operation, The regenerated nerve fibers increased and were more mature at 16 weeks after operation. There were no significant difference in electrical impulse conduction velocity through the neural regeneration between the experimental and control sides (P > 0.05). CONCLUSION: Chitin tubes containing NGF can provide optimal conditions for regeneration of rabbit facial nerve.

[Experimental study on osteoinduction of coral composited artificial bone].

OBJECTIVE: To improve the osteoinduction of coral and provide a perfect bone graft substitute for clinical bone defects. METHODS: By combining coral with collagen and recombinant human bone morphogenetic protein-2(rhBMP-2), coral/collagen/rhBMP-2 composite was obtained. The composite was implanted into the back muscle pouches of mice, and coral/collagen or coral/rhBMP-2 were implanted as control. The osteoinduction of the composite was assessed by histology and image analysis system. RESULTS: The chondrocyte differentiation and matrix formation were observed in local sites after one week, lamellar bone with bone marrow were formed after 4 weeks, and coral were absorbed partially. The quantity of osteoinduction was time-related and rhBMP-2 dose-related(P < 0.01). Coral/collagen and coral/rhBMP-2 implants did not show any bone or cartilage formation. CONCLUSION: The coral/collagen/rhBMP-2 composite possesses a superior osteoinduction and will be a new type of bone substitute to be used in orthopedic and maxillofacial surgery.

Steroidal saponins from Anemarrhena asphodeloides and their effects on superoxide generation.

A new steroidal saponin, timosaponin F, along with six known compounds was isolated from the rhizomes of Anemarrhena asphodeloides Bge. On the basis of chemical and spectroscopic evidence, the structure of timosaponin F was elucidated as (5beta, 25 S):-spirostan-3beta,15alpha,23alpha-triol-3-O-beta- glucopyranosyl-(1--->2)-beta-galactopyranoside. The six known compounds were anemarrhenasaponin I, anemarrhenasaponin Ia, timosaponin BI, timosaponin BII, timosaponin B, timosaponin AIII; their effects on superoxide generation are also reported.

[Clinical summary of relatively large dose of sodium morrhuate injection for the treatment of maxillofacial cavernous hemangionma:A report of 764 cases]

The result of relatively large dose of 5% sodium morrhuate injection(SIM) for the treatment of 764 cases in the cavernous hemangioma in orofacial region is presented.The curative rate was improved,Its cure and elementary cure rate were 89.27%.The dosage,course and practical approach were discussed,The relationship of factors listed above with the curative effect were mentioned.The reaction and complications might be influencing the recurrence rate.Hemangioma after SMI should be observed in order to consolidate its curative effect.