Practical, modular, and general synthesis of 3-coumaranones through gold-catalyzed intermolecular alkyne oxidation strategy

A gold-catalyzed intermolecular alkyne oxidation for the preparation of 3-coumaranones has been developed. Using 8-isopropylquinoline N-oxides as oxidants, the reactions of o-ethynylanisoles afford versatile 3-coumaranones in moderate to good isolated yields. The synthetic utility of this chemistry is also indicated by the synthesis of the natural product sulfuretin.

Investigating conversion of endplate chondrocytes induced by intermittent cyclic mechanical unconfined compression in three-dimensional cultures

Mechanical stimulation is known to regulate the calcification of endplate chondrocytes. The Ank protein has a strong influence on anti-calcification by transports intracellular inorganic pyrophosphate (PPi) to the extracellular matrix. It is known that TGF-β1 is able to induce Ank gene expression and protect chondrocyte calcification. Intermittent cyclic mechanical tension (ICMT) could induce calcification of endplate chondrocytes by decrease the expression of Ank gene. In this study, we investigated the relation of intermittent cyclic mechanical unconfined compression (ICMC) and Ank gene expression. We found that ICMC decreased the Ank gene expression in the endplate chondrocytes, and there was an decreased in the TGF-β1 expression after ICMC stimulation. The Ank gene expression significantly increased when treated by transforming growth factor alpha 1 (TGF-β1) in a dose-dependent manner and decreased when treated by SB431542 (ALK inhibitor) in a dose-dependent manner. Our results implicate that ICMC-induced downregulation of Ank gene expression may be regulated by TGF-β1 in end-plate chondrocytes.

Flexible and practical synthesis of 3-oxyindoles through gold-catalyzed intermolecular oxidation of o-ethynylanilines

A novel gold-catalyzed intermolecular oxidation of o-ethynylanilines has been developed, which provides a reliable access to synthetically useful 3-oxyindoles. Importantly, this gold-catalyzed oxidative process outcompetes the typical indole formation.

Gold-catalyzed intermolecular oxidation of o-alkynylbiaryls: an easy and practical access to functionalized fluorenes

A novel gold-catalyzed intermolecular oxidation of o-alkynylbiaryls has been developed. A variety of functionalized fluorenes are readily accessed by utilizing this non-diazo approach, thus providing a viable alternative to synthetically useful fluorenes.

Generation of gold carbenes in water: efficient intermolecular trapping of the α-oxo gold carbenoids by indoles and anilines

The efficient intermolecular reaction of gold carbene intermediates, generated via gold-catalyzed alkyne oxidation, with indoles and anilines has been realized in aqueous media.

Gold-catalyzed intermolecular oxidation of chiral homopropargyl sulfonamides: a reliable access to enantioenriched pyrrolidin-3-ones

A gold-catalyzed intermolecular oxidation of chiral homopropargyl sulfonamides has been developed, which provides a reliable access to synthetically useful chiral pyrrolidin-3-ones with excellent ee by combining the chiral tert-butylsulfinimine chemistry and gold catalysis.

Force-induced optical nonlinearity and Kerr-like coefficient in opto-mechanical ring resonators

This paper demonstrates the optical nonlinearity in opto-mechanical ring resonators that consist of a bus waveguide and two ring resonators, which is induced by the optical gradient force and characterized by the Kerr-like coefficient. Each ring resonator has a free-hanging arc that is perpendicularly deformable by an optical gradient force and subsequently this deformation changes the effective refractive index (ERI) of the ring resonator. The change of the ERI induces optical nonlinearity into the system, which is described by an equivalent Kerr coefficient (Kerr-like coefficient). Based on the experimental results, the Kerr-like coefficient of the ring resonator system falls in the range from 7.64 × 10(-12) to 2.01 × 10(-10) m(2)W(-1), which is at least 6-order higher than the silicon's Kerr coefficient. The dramatically improved optical nonlinearity in the opto-mechanical ring resonators promises potential applications in low power optical signal processing, modulation and bio-sensing.

Sources of ambient volatile organic compounds and their contributions to photochemical ozone formation at a site in the Pearl River Delta, southern China

The Positive Matrix Factorization (PMF) receptor model and the Observation Based Model (OBM) were combined to analyze volatile organic compound (VOC) data collected at a suburban site (WQS) in the PRD region. The purposes are to estimate the VOC source apportionment and investigate the contributions of these sources and species of these sources to the O(3) formation in PRD. Ten VOC sources were identified. We further applied the PMF-extracted concentrations of these 10 sources into the OBM and found "solvent usage 1", "diesel vehicular emissions" and "biomass/biofuel burning" contributed most to the O(3) formation at WQS. Among these three sources, higher Relative Incremental Reactivity (RIR)-weighted values of ethene, toluene and m/p-xylene indicated that they were mainly responsible for local O(3) formation in the region. Sensitivity analysis revealed that the sources of "diesel vehicular emissions", "biomass/biofuel burning" and "solvent usage 1" had low uncertainties whereas "gasoline evaporation" showed the highest uncertainty.

Pure angular momentum generator using a ring resonator

This paper reports a pure angular momentum generator using a ring resonator surrounded by a group of nano-rods. The evanescent waves of the circulating light in the ring are scattered by the nano-rods and generate a rotating electromagnetic field, which has only angular momentum but no linear momentum along the axis of rotation. The angular order is determined by the difference between the order of Whispering Gallery mode and the number of the rods, the rotating frequency is equal to the light frequency divided by the angular order. The maximum amplitude of the rotating electromagnetic fields can be 10 times higher than the amplitude of the input field when there are 36 rods (R(rod) = 120 nm, nr = 1.6). The pure angular momentum generator provides a new platform for trapping and rotation of small particles.

Effect of traffic rule breaking behavior on pedestrian counterflow in a channel with a partition line

In this paper a partition line is used in the counterflow system to present the default (conventional) traffic rule: pedestrians prefer to walk on a certain side on the road during movement, e.g., the right-hand side in China or the left-hand side in Japan. Based on the counterflow model of Takimoto (model A), we introduced two modified models, i.e., model B and C, to study the effects of a partition line in the consideration of people who do not obey the default traffic rule. Model B represents that factor in time scale, while model C in space scale. In model B, there are pedestrians who cross the partition line but choose not to obey the default traffic rule with a probability p(nor), while in model C, if a pedestrian crosses the partition line and goes away from it further than a certain nonobeying-rule threshold distance d(t), he will not obey the traffic rule. It is found that the behavior of traffic rule breaking influences much the counterflow when it is at the choking flow state rather than at the free moving or stopped state. Furthermore, it is shown that the default traffic rule is not always positive to the counterflow in all situations. It depends on the game result of these two opposite sides: to use the channel width as much as possible and to avoid the interference from the other group as far as possible.

Cellular automaton simulation of pedestrian counter flow considering the surrounding environment

This paper presents a cellular automaton model without step back to simulate the pedestrian counter flow in a channel. The consideration of the surrounding environment when people make judgments on moving directions is added to a random walker model also without step back. Two types of walkers: the right walkers going to the right and the left walkers going to the left are taken into account. The characteristics of counterflow are clarified. Influences of the different interaction radius values and system sizes on movement are studied. Phase transition from free moving to jamming is observed with the increase of entrance density. It is found that the critical entrance density pc at the transition point does not depend on the system size when the interaction radius value is large. Simulation results are represented as a comparison with the random walker model.

[HOE642 (Cariporide) reduces the intracellular calcium overload of isolated immature rabbit ventricular myocytes induced by anoxia/reoxygenation]

AIM

To observe the effects of HOE642 (Cariporide) on intracellular free calcium in isolated immature rabbit ventricular myocytes induced by anoxia/reoxygenation, and to search the protective mechanism of the Na+/H+ exchange inhibitor on immature rabbit hearts.

METHODS

The ventricular cardiomyocytes isolated from six New Zealand immature rabbit hearts were divided into three groups of each heart, which were attained by mean of collagenase (type II, 0.28 mg/ml) perfusion. All cells were incubated with calcium fluorescence indicator Fluo-3/AM, and then the intracellular free calcium was measured under the laser scanning confocal microscopy. As well as the creatine phosphokinase (CK) and lactic dehydrogenase (LDH) were measured. The baseline was measured after isolation without anoxia/reoxygenation. The control group received anoxic conditions for 60 minutes and reoxygenation for 30 minutes, then measured. The experiment group received the same conditions as control group with addition of HOE642 (1 micromol/L).

RESULTS

After anoxia/reoxygenation, the intracellular free calcium of isolated immature rabbit ventricular myocytes and CK, LDH in control group increased significantly than baseline (P < 0.01), there were no significant difference of immature myocardial [Ca+]i and CK, LDH between experiment group and baseline (P > 0.05), and the experiment group myocardial [Ca2+]i and CK, LDH reduced significantly than control (P < 0.01).

CONCLUSION

HOE642 (Cariporide) may reduce intracellular calcium overload and the enzymes level (CK, LDH) in isolated immature rabbit ventricular myocytes induced by anoxia/reoxygenation, so the protective mechanism of HOE642 on immature rabbit heart may be by inhibition of the intracellular free calcium overload.

[The effect of ischemic preconditioning on adenosine phosphate content after spinal cord ischemia in rabbits]

AIM

To study the effect of ischemic preconditioning (IP) on adenosine phosphate content after spinal cord ischemia in rabbits.

METHODS

We established a lumbar spinal cord ischemia model by inflating the balloon of a 4F Swan-Ganz catheter positioned in the abdominal aorta of the rabbits. All rabbits were divided into sham-operated group, ischemic group and IP group. Adenosine phosphate content in spinal cord of all rabbits was determined at 4 hours, 2 days and 5 days after spinal cord ischemia by using reverse phase HPLC.

RESULTS

ATP content in lumbar spinal cord of rabbits in ischemic group was markedly reduced (P < 0.01 vs sham-operated group). But in IP group, it was obviously elevated at each time point compared with ischemic group (P < 0.01).

CONCLUSION

IP can significantly elevated ATP content in postischemic lumbar spinal cord in rabbits. This may be one of the mechanisms that IP can protect spinal cord from ischemic injury.

Effect of dl-praeruptorin A on calcium current in ventricular cells of guinea pig

With patch clamp technic (whole cell recording), the effect of dl-praeruptorin A (Pra), an ingredient of Peucedanum praeruptorum Dunn on calcium current (ICa) in the single ventricular cells of guinea pig was studied. Results showed that under Cs/Cs condition, when the holding potential was -40 mV and in the presence of Pra (1, 10, 100 mumol.L-1), ICa was decreased dose-dependently from 2.02 +/- 0.24, 2.00 +/- 0.12, 2.12 +/- 0.33 nA (control) to 1.60 +/- 0.24, 1.32 +/- 0.08, 1.16 +/- 0.43 nA, respectively, and their inhibitory rates were 21%, 33.5%, 45%, respectively. The current-voltage relation curve showed that the reversal potential of ICa was +60 mV; the potential producing peak value of ICa was about 0 mV. The results indicated that Pra had a Ca2+ channel blocking effect.

Electron microscopic observations of tegumental damage in adult Schistosoma japonicum after in vivo treatment with levo-praziquantel

The in vivo effects of a single dose of levo-praziquantel, 75 mg/kg in PEG 400, on the tegumental surface of adult S. japonicum were compared with the effects of a single dose (150 mg/kg) of the mixed isomer preparation, using scanning and transmission electron microscope. Worms were recovered from mice at 10 min, 30 min, 1 hr, 4 hr, 12 hr, 24 hr and 48 hr after treatment. After 10 min exposure to either compound, the tegumental folds and sensory organelles were swollen and the tegument vacuolated. After 12-24 hr, the surface was eroded and exfoliated with exposure of intrategumental and/or subtegumental tissues and attachment of leukocytes to the denuded areas. Vehicle controls were normal throughout the time period examined. These studies demonstrate that the levo isomer of praziquantel causes acute structural damage to the tegument similar to that seen with the mixed isomer preparation.

Myocardial protection of cold crystalloid and warm blood cardioplegia. A comparative study

Twenty patients undergoing open-heart valvular operations were divided randomly into two groups. Intermittent perfusion of cold crystalloid (St. Thomas Hospital solution) with hypothermic cardiopulmonary bypass (CPB) in the hypothermic group and continuous administration of warm blood cardioplegia with normothermic CPB in the normothermic group were used respectively. The results of warm blood cardioplegia were superior to those of cold crystalloid. 70% of patients treated with the warm technique had spontaneous return of normal sinus rhythm shortly after removal of the aortic cross-clamp, compared with only 10% of the hypothermic group (P < 0.05). The extracorporeal support time from releasing of aortic clamp to the weaning of CPB was significantly shorter in the normothermic group (33.50 +/- 3.78 min vs. 25.00 +/- 4.64 min, P < 0.05). The postoperative ventilation support time was also much shorter than that of the hypothermic group (19.84 +/- 1.11 h vs. 38.98 +/- 16.55 h, P < 0.05). More atrial beating occurred in the normothermic group (80% vs. 20%, P < 0.05) during aortic clamping, and it is showed that continuous warm blood cardioplegia might not efficiently prevent the atrium from damage.

Whole-cell patch clamp measurements and berberine inhibition of hyperpolarization-activated inward current in rabbit sinoatrial node cells

Single rabbit sinoatrial node (SAN) cells were isolated by means of an enzymatic dispersion procedure and used for the whole-cell patch clamp experiment. At a holding potential of -40 mV, a time- and voltage-dependent inward current, I(f), was activated at different hyperpolarization potentials from -60 mV to -110 mV. The current-voltage relation curve showed that I(f) was activated at potential more negative than -40 mV. Five min after treatment by CsCl 2 mmol.L-1-containing Tyrode solution, I(f) was almost completely blocked. At a hyperpolarization potential of -110 mV, I(f) was reduced from 1.7 +/- 0.2 nA of the control to 1.2 +/- 0.4 nA after superfusing with Tyrode solution containing berberine (Ber) 1 mumol.L-1 for 5 min. And it was difficult to wash out this action. Ber also had inhibitory effects on other currents to a certain extent. The results indicate that I(f) is a Cs(+)-sensitive current and that the negative chronotropic effect of Ber may be due to the inhibition of I(f) that functions as an important pacemaking modulator for the spontaneous depolarization of SAN tissue.

[A pathological analysis of 51 cases of renal osteodystrophy]

Renal osteodystrophy is a metabolic bone disease of chronic renal failure. The long-standing alterations in mineral metabolism generated by renal failure have a profound effect on the skeleton and induce severe systemic metabolic bone disease. Iliac crest biopsy was performed in 51 patients of chronic renal failure and examined with microscopy. The histological bone changes are characterized by ostitis fibrosa, increased resorption of bone and number of osteoclasts, increased osteoid volume (osteoblastic osteoid and acellular osteoid), active remodelling of bone and aluminum deposition in bone. According to the histological appearance, advanced renal bone disease can be subdivided into three major histological groups: secondly hyperparathyroid bone disease (high turnover uremic osteodystrophy), osteomalacia (low turnover uremic osteodystrophy) and mixed uremic osteodystrophy consisting of mild to moderate hyperparathyroid bone disease and defective mineralization. Aluminum-related bone changes can be seen in varying degrees in all these groups. Even though these groups do not fully represent separate entities and transformation from one form to another can occur, it is essential to distinguish them since therapy can be tailored according to the predominant histologic findings.

Streptozotocin induced cardiomyopathy in diabetic rats

Microscopic quantitative cardiomyopathy was previously reported in spontaneous diabetic biobreeding (BB) rats, but the nature of the lesions remains obscure. To further study the specificity of cardiomyopathy in streptozotocin-diabetic rats and discuss the existence of diabetic heart disease, we compared 40 streptozotocin-diabetic rats (D group) with 40 normal control rats (C group) at various durations in plasma glucose, fructosamine, plasma lipid, left ventricular enzyme contents and alterations of myocardial cells and coronary artery tree under electron and light microscope respectively. In 4 weeks, D rats showed myocardial mitochondrial swelling and degeneration, whereas at 8 weeks, myocardial enzyme contents markedly decreased, and myocardial lesions were more conspicuous with disruption of myocardial cells, formation of myocardial contraction bands, dilatation of intercalated discs, deposition of glycogen granules, etc. At 11 weeks, microscopic changes were essentially similar, whereas the decrease of enzyme contents became more conspicuous. During the 11 weeks, persistent and marked hyperglycemia and elevation of fructosamine were observed, however, no abnormalities were found along the coronary artery tree in the D rats. The results indicated that cardiomyopathy is diabetes specific, and exists independently as one of the three important components of diabetic heart disease.

[Aluminum in renal osteodystrophy]

To evaluate the relationship between aluminum and renal osteodystrophy, iliac bone biopsies and bone aluminum staining were studied in 51 patients with end-stage renal failure. In 27 of 51 cases were measured PTH, 1.25 (OH)2D3 levels and bone aluminum contents. We found that the incidence of renal osteodystrophy was 100%. The positive rate of bone aluminum staining was 12%. The rate was highest in low-turnover osteomalacia. Serum aluminum and bone aluminum contents were significantly higher than controls in three types of renal osteodystrophy on hemodialysis. Bone aluminum correlated with the duration of hemodialysis (r = 0.704), also with the serum calcium (r = 0.341). The duration of hemodialysis and bone aluminum contents were markedly longer and higher in positive group of bone aluminum staining than that of negative group (P < 0.001, respectively). Our data suggested that: (1) aluminum accumulation in bone was related to duration of hemodialysis, (2) aluminum may play important roles in the intervention of bone mineralization.

Survey of 160 centenarians in Shanghai

One hundred and sixty centenarians were discovered and followed up for 7 years (1982-88) in Shanghai. The proportion of centenarians in the population was non-significantly greater in the urban than in the rural area and centenarians were in general increasing in both areas over the years. The factors promoting longevity were good medical care and benevolent attention from family members. Autopsy was performed in eight centenarians revealing the main causes of death as pneumonia and cancer.

[Re-open heart surgery in congenital heart disease. An analysis of 23 cases]

The authors reported 23 cases of re-open heart surgery in 1473 patients with congenital heart disease treated surgically in the last ten years. The incidence was 1.6%. In 13 cases of the 23 re-open heart procedure was performed before closing the chest during the operation because of missed diagnosis in 5, incomplete correction of the anomaly in 5, and injure to important organ in 3. All of the 13 patients were recovered and discharged. Of the 23 cases re-open heart surgery was performed during the early postoperative period in 8 cases, including 4 cases of misdiagnosis, and 4 incomplete correction. 1 patient with VSD had still residual ventricular septal shunt post reintervention and died of circulatory failure. Re-open heart surgery was performed during the late postoperative period in 2 of the 23 cases. There was 1 missed diagnosis, and another incomplete correction. 1 patient died of massive bleeding during the reoperation. The anthers pointed out that accurate diagnosis and error-free operation is of most importance in avoiding re-open heart surgery. Through exploration to the heart after resuscitation during the operation and positive re-opening of the heart when necessary were emphasized. Indication of early and late postoperative re-open heart surgery and methods to prevent its complication were listed.

[Surgical treatment of mitral prolapse with chordae plasty]

Surgical treatment of 8 cases of anterior mitral leaflet prolapse was reported. Of the 8 cases, chordae elongation was occurred in 2, chordae rupture in 6, and congenital in 6, rheumatic in 2. Chordae reimplanting was performed in 5 cases, chordae shortening in 2, chordae prosthesis with surgical suture in 1, and combined annuloplasty in 7 of the 8 cases. The result of mitral plasty was better in congenital mitral prolapse. Indications of this technique and postoperative management were listed.