Emergence of the isotropic Kitaev honeycomb latticeα-RuCl3and its magnetic properties.

We present a comprehensive investigation of the crystal and magnetic structures of the van der Waals antiferromagnetα-RuCl3using single crystal x-ray and neutron diffraction. The crystal structure at room temperature is a monoclinic (C2/m). However, with decreasing temperature, a remarkable first-order structural phase transition is observed, leading to the emergence of a rhombohedral (R3-) structure characterized by three-fold rotational symmetry forming an isotropic honeycomb lattice. On further cooling, a zigzag-type antiferromagnetic order develops belowTN=6∼6.6K. The critical exponent of the magnetic order parameter was determined to beß=0.11(1), which is close to the two-dimensional Ising model. Additionally, the angular dependence of the magnetic critical field of the zigzag antiferromagnetic order for the polarized ferromagnetic phase reveals a six-fold rotational symmetry within theab-plane. These findingsreflect the symmetry associated with the Ising-like bond-dependent Kitaev spin interactions and underscore the universality of the Kitaev interaction-dominated antiferromagnetic system.

Serum anti-Müllerian hormone levels are negatively related to Follicular Output RaTe (FORT) in normo-cycling women undergoing controlled ovarian hyperstimulation.

BACKGROUND: Since in rodents anti-Müllerian hormone (AMH) has been shown to inhibit antral follicle responsiveness to FSH, we aimed at verifying whether a relationship exists between serum AMH levels and antral follicle responsiveness to exogenous FSH in normo-cycling women. METHODS: Serum AMH, estradiol (E(2)) and FSH levels were prospectively measured on cycle day 3 in patients undergoing controlled ovarian hyperstimulation (COH) with a time-release GnRH agonist and standardized FSH doses. In 162 patients, follicles were counted after pituitary suppression and before FSH administration (baseline; small antral follicles; 3-8 mm), and on the day of hCG (dhCG; pre-ovulatory follicles; 16-22 mm). Antral follicle responsiveness to FSH was estimated by the Follicular Output RaTe (FORT), determined by the ratio pre-ovulatory follicle count on dhCG × 100/small antral follicle count at baseline. RESULTS: Serum AMH levels were positively correlated with the number of small antral follicles at baseline (r = 0.59; P < 0.0001) and pre-ovulatory follicles on dhCG (r = 0.17; P < 0.04). Overall, FORT was 47.5 ± 1.4% and failed to be influenced by the woman's age, BMI or basal E(2) and FSH level. Conversely, multiple regression analysis showed that FORT was negatively correlated with AMH levels (r = -0.30; P < 0.001), irrespective of duration of COH and total FSH dose. CONCLUSIONS: The percentage of follicles that effectively respond to FSH by reaching pre-ovulatory maturation is negatively and independently related to serum AMH levels. Although the mechanisms underlying this finding remain unclear, it is in keeping with the hypothesis that AMH inhibits follicle sensitivity to FSH.

Tadalafil for Endometrial Growth in Clomiphene Citrate stimulated cycles in an IUI programma: A pilot study.

AIM OF THE STUDY: The objective of this study was to assess the impact of tadalafil on endometrial growth, the uterine artery pulsatility index (PI) and the uterine artery resistance index (RI) in patients under clomiphene ovarian stimulation for intrauterine insemination (IUI). METHODS: This randomized crossover study included 30 patients with a normal endometrium over 53 cycles, and 46 of those cycles in 23 patients were included in the analysis. In group A the patients were under 100 mg clomiphene daily for five days (2-6) and 5 mg tadalafil daily for 7 days (4-10). For Group B (control) the patients only received clomiphene. Measurements of the endometrium, PI, RI and estradiol determinations were taken on cycle days 4, 8 and 10. RESULTS: We observed a better endometrial growth in Group A compared to Group B: 7.5 ± 2.1 mm vs 5.5 ± 1.2 mm, P < 0.0002 and 8.9 ± 1.8 mm vs 6.3 ± 1.8 mm, P < 0.0002 on days 8 and 10, respectively. Additionally, a progressive decrease in the RI was observed in Group A but not in Group B from day 8 (0.77 ± 0.15 vs 0.85 ± 0.18, P = 0.059) to day 10 (0.74 ± 0.20 vs 0.87 ± 0.14, P < 0.017). However, no differences were observed in PI or serum estradiol between Group A and Group B. CONCLUSION: The use of tadalafil improved endometrial growth in patients under clomiphene ovarian stimulation with no significant effect on the uterine artery Pulsatility Index and serum estradiol.

Synthesis and antiviral activity of 11-azapentacyclo[6.2.1.0.0.0]decane.

11-Azapentacyclo[6.2.1.0.0.0]decane (6a) as well as its 6,7-dimethyl derivative 6b was synthesized by a novel, four-step sequence that holds promise for the construction of a variety of cage compounds with bridging nitrogen atoms. The hydrochloride salt of 6a was shown to possess no antiviral activity against either the influenza virus A/Victoria/3/75 or the herpes simplex viruses HSV-1 and HSV-2.

An unexpected Paternò-Büchi reaction in the crystalline state.

[reaction: see text]. The solution and solid-state photochemistry of a series of aryl 1-phenylcyclopentyl ketones (1) was investigated. While typical Norrish type I products were formed in solution, irradiation of crystals of 1 afforded the novel oxetanes 3 and 4 regiospecifically. The formation of the oxetanes is believed to occur through Norrish type I cleavage and hydrogen abstraction, producing an alkene and an aldehyde, followed by a Paternò-Büchi reaction within the crystal lattice cage.

Enantio- and diastereodifferentiating cis,trans-photoisomerization of 2beta,3beta-diphenylcyclopropane-1alpha-carboxylic acid derivatives in organized media.

[reaction: see text] Four methods of asymmetric induction in the cis, trans-photoisomerization of 2beta, 3beta-diphenylcyclopropane-1alpha-carboxylic acid derivatives were studied. Best results (ca. 80% de) were obtained by irradiation of chiral esters, amides, and salts in NaY and LiY zeolites and in the pure crystalline state.

Genes controlling circadian rhythm are widely distributed in cyanobacteria.

The kaiABC gene cluster is important for maintaining circadian rhythms in the cyanobacterium Synechococcus PCC 7942. An extensive PCR-based survey of phylogenetically diverse cyanobacteria was conducted using degenerate primers designed to identify the presence of the kaiC gene. Hybridization and sequence analyses showed that the observed amplification products had a high degree of similarity to kaiC. Forty cyanobacterial strains possessed kaiC related sequences, suggesting that a clock system is universal among cyanobacteria.

Chemical polymorphism of the essential oils from populations of Thymus caespititius grown on the island S. Jorge (Azores).

The compositions of the essential oils obtained from ten populations of Thymus caespititius grown on S. Jorge (Azores) were studied by GC and GC-MS. All the oils analysed were dominated by their monoterpene fraction (69-9%). The sesquiterpene fraction was rather small (4-17%) and consisted mainly of oxygen-containing compounds (3-13%). Enantiomeric ratio of sabinene and alpha-terpineol was investigated in the oils from some populations. (+)-Sabinene was detected with high enatiomeric purity (96 99%). Although ( +)-alpha terpineol was the predominant enantiomer, its purity varied considerably (66-97%). Cluster analysis of all identified components grouped the oils into four main clusters that corresponded with their major components: alpha-terpineol (43-68%), carvacrol (32-52%), thymol (44-58%) and sabinene (41%). The essential oil from Th. caespititius showed a clear chemical polymorphism, that was particularly evident among four populations growing along a 200 m distance at Pico Verde.

Essential oils from Azorean Laurus azorica.

The essential oils isolated from leaves of ten and from unripe berries of eight populations of Laurus azorica (Seub.) Franco, collected on five islands of the Azorean archipelago, were analysed by GC and GC-MS. All oil samples were dominated by their monoterpene fraction (60-94%), alpha-pinene (15-37%) and 1,8-cineole (12-31%) being the main components of the leaf oils, while trans-beta-ocimene (27-45%) and alpha-pinene (12-22%) were the main components of the oils from the berries. The sesquiterpene fractions of the oils ranged from 3 to 17% and the main components were beta-caryophyllene (traces-8%) and beta-elemene (traces-3%) both in the leaf and berry oils. Some phenylpropanoid components were also present, in total amounting to 17%, trans-cinnamyl acetate (215% of the leaf oils) being the main component of this fraction. Cluster analysis of the enantiomeric composition of alpha- and beta-pinene in the oils from the leaves clearly showed two groups, one constituted by the two populations growing on the island S. Jorge, and the other constituted by the remaining populations.

Assay of 2,3-dihydroxybenzoic acid and related compounds in plant materials by high-performance liquid chromatography.

Salicylic acid and its putative biosynthetic precursors were assayed isocratically by RP-HPLC with UV detection at 280 nm. Optimum resolution was provided by an HPLC mobile phase consisting of MeOH-1% aqueous HOAc (40:60, v/v), at pH 4. Furthermore, for the analysis of 2,3-dihydroxybenzoic acid (2,3-DHBA) in Catharanthus roseus cell cultures after elicitation, a mobile phase consisting of acetonitrile-1% aqueous HCOOH containing 0.25% trichloroacetic acid (1:5, v/v), at pH 2, was used. The recovery for the free form of 2,3-DHBA was about 80% after a one-step extraction of the cells. The detection limit of 2,3-DHBA was 3 microg by using saligenin as an internal standard.

Antimicrobial activities of some Ocimum species grown in Rwanda.

The essential oils of four Ocimum species grown in Rwanda, i.e. O. canum, O. gratissimum, O. trichodon and O. urticifolium (synonym O. suave) including some chemotypes, were screened for antimicrobial activities. Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Trichophyton mentagrophytes var. interdigitale were used as test organisms. Different techniques were applied in the screening, such as the biogram and agar overlay techniques and a dilution technique yielding maximum inhibitory dilution (MID) values. Also some growth curves were determined. Although the results obtained by the diffusion techniques were rather different for some of the oil samples, all samples were found to be antimicrobially active.

Cardiovascular effects of Tabernaemontana pandacaqui.

Intravenous injection of ethanolic extracts of the stem, leaf and flower of Tabernaemontana pandacaqui caused hypotension in pentobarbital anesthetized rats. At high doses (100-300 mg/kg), the flower extract showed a transient hypertensive effect preceeding hypotensive activity. The effects of the extracts on the heart rate of anesthetized rats correlated well with the negative chronotropic and inotropic activity observed with isolated atrium. The hypotensive activity was not inhibited by antihistaminic and antimuscarinic agents. The extracts had no effect on the pressor effects induced by norepinephrine or dual carotid occlusion. These results suggest that the hypotensive action of the extracts is not mediated through histaminic and muscarinic receptors stimulation, alpha-adrenoceptor blockade or interference of sympathetic transmission.

Hippocratic screening of ethanolic extracts from two Tabernaemontana species.

Ethanolic extracts of roots, stems, leaves and flowers of Tabernaemontana divaricata and T. pandacaqui were studied by an observational (hippocratic) screening method in rats. Extracts of all plant parts caused sedation, decreased respiration and decreased skeletal muscle tone. Except for the leaf extract of T. pandacaqui, the extracts caused vasodilatation of ear vasculature. Analgesic activity was found for all extracts of both Tabernaemontana species, except for the flower extract of T. divaricata. Lethal doses of the extracts caused the animals to die from respiratory paralysis. Intensity of pharmacological activities was greater with the root and stem extracts. The extracts of T. pandacaqui were more potent than those of T. divaricata.

Cardiovascular activity of the crude alkaloidal fraction from Tabernaemontana pandacaqui in the rat.

The effects of a crude alkaloidal (CA) fraction from the stem of Tabernaemontana pandacaqui Poir. on the blood pressure and heart rate were investigated in conscious as well as anesthetized rats. The CA fraction exerted a hypotensive activity in both experimental models. In pentobarbital anesthetized rats, an intravenous administration of the CA fraction caused two consecutive hypotensive and bradycardiac responses. In order to investigate the mechanism of the responses, the effect of the CA fraction on the blood pressure and the heart rate was tested in various experimental animals such as pithed rats, reserpinized rats under pentobarbital anesthesia and atropine- or chlorpheniramine-treated rats under pentobarbital anesthesia. The results obtained suggest that the hypotensive and bradycardiac responses of the first phase might involve cholinergic and central mechanisms, whereas those of the second phase involve mechanisms which are mediated by central, biogenic amines, acetylcholine and histamine.

Neuropharmacological activities of the crude alkaloidal fraction from stems of Tabernaemontana pandacaqui Poir.

The crude alkaloidal (CA) fraction from the stem of Tabernaemontana pandacaqui Poir. was studied for its pharmacological activity on the central nervous system (CNS) of animals. The CA fraction was found to produce symptoms of CNS depression in conscious rats and mice, viz. reduction in spontaneous motility, potentiation of pentobarbital sleeping time, prolongation of latency of convulsions induced by pentylenetetrazole and antinociception. However, the fraction could not antagonize oxotremorine-induced tremor. The observations suggest that the CA fraction possesses a CNS depressant activity.

Anti-inflammatory, antipyretic and antinociceptive activities of Tabernaemontana pandacaqui Poir.

Studies on carrageenin-induced rat paw edema, yeast-induced hyperthermia in rat and writhing response induced by acetic acid in mice showed that the alcoholic extract of stems of Tabernaemontana pandacaqui (T. pandacaqui) has significant anti-inflammatory, antipyretic and antinociceptive activities. These activities are due to alkaloidal components since they were also observed when the crude alkaloidal (CA) fraction separated from alcoholic extract was tested in the same models.

[Role of thrombolytic treatment in thrombosis of valvular prostheses. Apropos of 2 cases and review of the world literature]. / Place du traitement thrombolytique dans les thromboses des prothèses valvulaires. A propos de 2 cas et revue de la littérature mondiale.

The authors report 2 cases of thrombolytic therapy by Urokinase at the dose of 4 500 U/kg/hour, for 24 hours, in patients with thrombosis of a Bjork aortic and Lillehei mitral valve prostheses, and assess the efficacy with a review of the world literature. The first case was a 65 year old woman who received a Bjork No 25 aortic valve prosthesis for aortic regurgitation. Two years later oral anti-vitamin K anticoagulants were replaced by an association of Aspirin-Persantine. She developed acute pulmonary oedema secondary to thrombosis of her valve during the fifth postoperative year. Treatment with Urokinase was successful (4 500 U/kg/hour for 24 hours). The second cases was a 33 year old woman who received a Lillehei No 27 mitral valve prosthesis for mitral regurgitation due to infective endocarditis. Six years later, during a period of apparently ineffective oral anticoagulation, she developed subacute pulmonary oedema due to thrombosis of her prosthesis. Urokinase therapy was successful after 4 hours, but the valve surface area on cardiac catheterisation was decreased and elective reoperation to change the prosthesis was decided upon. Prosthetic valve thrombosis is a serious complication with an operative mortality of 68.6% (35 deaths out of 51 reoperations in the worl literature) whilst the efficacy of thrombolytic therapy would appear to be about 80%. When thrombosis is progressive, the valve has to be changed surgically, but when it is secondary, thrombolytic therapy at least helps the patient survive the acute phase.

[Bracket graft arthrodesis in the surgical treatment of spondylolisthesis]. / L'arthrodèse console dans le traitement chirurgical des spondylolisthésis

A technique of anterior lumbosacral arthrodesis is described in which a tibial graft is inserted into the sacrum and acts as a bracket against the anterior surface of the fifth lumbar vertebral body. Eighteen patients were treated. There was non-union in four but only two had unsatisfactory clinical results. The technique can be applied to moderate displacement but is particularly appropriate in grade III spondylolisthesis. It does not decrease the stability of the spine. The functional results depend on fusion and are not affected by persistent displacement.

The contribution of DNA to the disaster victim identification (DVI) effort.

As part of the disaster victim identification (DVI) response to the 2009 Victorian bushfires disaster, a number of scientific disciplines contributed to the human identification process--forensic pathology, anthropology and odontology, as well as fingerprinting and DNA profiling. The DNA laboratory received 182 post-mortem (PM) samples from 120 DVI cases and 236 reference samples corresponding to 163 missing persons (and two non-DVI cases). DNA analysis yielded full DNA profiles for 102 DVI cases and 190 ante-mortem (AM) samples (relating to all 163 missing persons), respectively. Subsequent comparison of DNA profiles, through direct and kinship matching, resulted in the submission of 76 DNA reports to the DVI Reconciliation Centre which assisted in the identification of 67 deceased. This paper describes the contribution of DNA analysis towards the DVI response to the 2009 Victorian bushfires disaster.