A new mathematical approach to finding global solutions of the magnetic structure determination problem.

Determination of magnetic structure is an important analytical procedure utilized in various fields ranging from fundamental condensed-matter physics and chemistry to advanced manufacturing. It is typically performed using a neutron diffraction technique; however, finding global solutions of the magnetic structure optimization problem represents a significant challenge. Generally, it is not possible to mathematically prove that the obtained magnetic structure is a truly global solution and that no solution exists when no acceptable structure is found. In this study, the global optimization technique called semidefinite relaxation of quadratic optimization, which has attracted much interest in the field of applied mathematics, is proposed to use as a new analytical method for the determination of magnetic structure, followed by the application of polarized neutron diffraction data. This mathematical approach allows avoiding spurious local solutions, decreasing the amount of time required to find a tentative solution and finding multiple solutions when they exist.

Cluster-Based Haldane State in an Edge-Shared Tetrahedral Spin-Cluster Chain: Fedotovite K_{2}Cu_{3}O(SO_{4})_{3}.

Fedotovite K_{2}Cu_{3}O(SO_{4})_{3} is a candidate of new quantum spin systems, in which the edge-shared tetrahedral (EST) spin clusters consisting of Cu^{2+} are connected by weak intercluster couplings forming a one-dimensional array. Comprehensive experimental studies by magnetic susceptibility, magnetization, heat capacity, and inelastic neutron scattering measurements reveal the presence of an effective S=1 Haldane state below T≅4 K. Rigorous theoretical studies provide an insight into the magnetic state of K_{2}Cu_{3}O(SO_{4})_{3}: an EST cluster makes a triplet in the ground state and a one-dimensional chain of the EST induces a cluster-based Haldane state. We predict that the cluster-based Haldane state emerges whenever the number of tetrahedra in the EST is even.

Coulomb Correlations Intertwined with Spin and Orbital Excitations in LaCoO_{3}.

We carried out temperature-dependent (20-550 K) measurements of resonant inelastic x-ray scattering on LaCoO_{3} to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantified the renomalized crystal-field excitation energies and spin-state populations. We show that the screening of the effective on-site Coulomb interaction of 3d electrons is orbital selective and coupled to the spin-state crossover in LaCoO_{3}. The results establish that the gradual spin-state crossover is associated with a relative change of Coulomb energy versus bandwidth, leading to a Mott-type insulator-to-metal transition.

Hydrogen release reactions of Al-based complex hydrides enhanced by vibrational dynamics and valences of metal cations.

Hydrogen release from Al-based complex hydrides composed of metal cation(s) and [AlH4]- was investigated using inelastic neutron scattering viewed from vibrational dynamics. The hydrogen release followed the softening of translational and [AlH4]- librational modes, which was enhanced by vibrational dynamics and the valence(s) of the metal cation(s).

Spin-orbit fluctuations in frustrated heavy-fermion metal LiV(2)O(4).

Spin fluctuations were studied over a wide momentum (ℏQ) and energy (E) space in the frustrated d-electron heavy-fermion metal LiV_{2}O_{4} by time-of-flight inelastic neutron scattering. We observed the overall Q-E evolutions near the characteristic Q=0.6 Å^{-1} peak and found another weak broad magnetic peak around 2.4 Å^{-1}. The data are described by a simple response function, a partially delocalized magnetic form factor, and antiferromagnetic short-range spatial correlations, indicating that heavy-fermion formation is attributable to spin-orbit fluctuations with orbital hybridization.

Emergence of highly degenerate excited states in the frustrated magnet MgCr2O4.

High degeneracy in ground states leads to the generation of exotic zero-energy modes, a representative example of which is the formation of molecular spin-liquid-like fluctuations in a frustrated magnet. Here we present single-crystal inelastic neutron scattering results for the frustrated magnet MgCr(2)O(4), which show that a common set of finite-energy molecular spin excitation modes is sustained in both the liquid-like phase above magnetic ordering temperature T(N) and an ordered phase with an extremely complex magnetic structure below T(N). Based on this finding, we propose the concept of high degeneracy in excited states, which promotes local resonant elementary excitations. This concept is expected to have ramifications on our understanding of excitations in many complex systems, including not only spin but also atomic liquids, complex order systems, and amorphous systems.

Molecular spin resonance in the geometrically frustrated magnet MgCr2O4 by inelastic neutron scattering.

We measured two magnetic modes with finite and discrete energies in an antiferromagnetic ordered phase of a geometrically frustrated magnet MgCr2O4 by single-crystal inelastic neutron scattering, and clarified the spatial spin correlations of the two levels: one is an antiferromagnetic hexamer and the other is an antiferromagnetic heptamer. Since these correlation types are emblematic of quasielastic scattering with geometric frustration, our results indicate instantaneous suppression of lattice distortion in an ordered phase by spin-lattice coupling, probably also supported by orbital and charge. The common features in the two levels, intermolecular independence and discreteness of energy, suggest that the spin molecules are interpreted as quasiparticles (elementary excitations with energy quantum) of highly frustrated spins, in analogy with the Fermi liquid approximation.

Primary carcinoid of the testis associated with carcinoid syndrome.

Testicular carcinoid is a rare disease accounting for less than 1% of all testicular neoplasms. It rarely manifests symptoms of carcinoid syndrome. Recent reports have noted that only 1.1-3.1% of testicular carcinoid tumors are complicated by carcinoid syndrome. In general, large tumor size and the presence of carcinoid syndrome are features associated with a malignant course. In the present case, pathological findings revealed pure carcinoid of the testis without metastasis. Moreover, watery diarrhea due to carcinoid syndrome disappeared and the serum serotonin level normalized following orchiectomy. The patient was followed up for 12 months with whole body computed tomography scan and assessment of serotonin levels. To date, there is no evidence of tumor recurrence. These findings suggest that monitoring serum serotonin levels may be useful as a marker during follow up of this type of tumor.

Cloning and nucleotide sequence of the pullulanase gene of Thermus thermophilus HB8 and production of the enzyme in Escherichia coli.

A 3.4-kb SphI fragment carrying the pullulanase gene of Thermus thermophilus HB8 was cloned. Based on the nucleotide sequence of it and the flanking region analyzed by direct sequencing of the inverse PCR product, an expression vector was constructed. The E. coli cells harboring the plasmid produced an about 80-kDa protein having pullulanase activity, the optimum temperature of which was 70 degrees C.

Differential metabolism of human VLDL according to content of ApoE and ApoC-III.

We studied the metabolism of very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) particles that did or did not have apolipoprotein E (apoE) in 12 normolipidemic women by endogenously labeling plasma apolipoprotein B. The plasma was separated into bound (E+) and unbound (E-) fractions by use of a monoclonal antibody (1D7), and the fractions were ultracentrifuged to yield E+ and E- subfractions of light and dense VLDL and IDL. VLDL E+ and IDL E+ were produced mainly by the liver. VLDL E+ and IDL E+ had lower fractional catabolic rates and much higher apolipoprotein C-III (apoC-III) content than did the corresponding E- particles. Most light VLDL apoE+ underwent lipolysis to dense VLDL E+ with reduced apoC-III content, which was removed from the circulation without conversion to IDL. In contrast, most light VLDL apoE-, poor in apoC-III, was removed from the circulation, and a smaller proportion underwent lipolysis to dense VLDL E-. Most dense VLDL E- underwent lipolysis to IDL E-. The rate constant for lipolysis of dense VLDL to IDL was greater for E- than for E+, and the rate constant for clearance from plasma was greater for dense VLDL E+ than for E-. In conclusion, metabolism of human VLDL particles is influenced by their content of apoE, further modulated by the coexistence of apoC-III.

Transurethral holmium laser resection of the prostate.

PURPOSE: We evaluated the efficacy of the holmium:YAG laser for transurethral endoscopic prostatectomy for benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: We treated 103 patients with BPH with holmium:YAG laser resection of the prostate. A high power holmium laser generating a maximum of 60 or 81 W. was used in a pulsed mode, applying energy directly to prostatic tissue via a forward firing 550 micron. fiber transurethrally under direct vision. Treatment outcome was evaluated by the International Prostate Symptom Score, quality of life score, maximum flow rate and post-void residual urine volume. We also compared holmium laser surgery and transurethral resection of the prostate for operative factors, such as surgical duration, bleeding volume and catheterization time. RESULTS: Average symptom score, quality of life score, peak flow rate and post-void residual significantly improved at 1 week, 1 month and 3 months postoperatively, with improvement maintained up to 36 months postoperatively in the holmium:YAG group. Intraoperative bleeding volume was significantly lower and catheterization time was significantly shorter for holmium:YAG than for transurethral prostatic resection. Use of the holmium laser caused no complications. CONCLUSIONS: Because of its effectiveness and safety holmium:YAG resection is a viable potential surgical alternative for symptomatic BPH. The holmium:YAG laser has been verified to be useful for many purposes in urology.

Direct intra-cardiomuscular transfer of beta2-adrenergic receptor gene augments cardiac output in cardiomyopathic hamsters.

In chronic heart failure, down-regulation of beta-adrenergic receptor (beta-AR) occurs in cardiomyocytes, resulting in low catecholamine response and impaired cardiac function. To correct the irregularity in the beta-AR system, beta-AR gene was transduced in vivo into failing cardiomyocytes. The Epstein-Barr virus (EBV)-based plasmid vector carrying human beta2-AR gene was injected into the left ventricular muscle of Bio14.6 cardiomyopathic hamsters whose beta-AR is down-regulated in the cardiomyocytes. The echocardiographic examinations revealed that stroke volume (SV) and cardiac output (CO) were significantly elevated at 2 to 4 days after the beta2-AR gene transfer. Systemic loading of isoproterenol increased the cardiac parameters more significantly on day 2 to day 7, indicating that the adrenergic response was augmented by the genetic transduction. The same procedure did not affect the cardiac function of normal hamsters. Immunohistochemical examinations demonstrated human beta2-AR expression in failing cardiomyocytes transduced with the gene. RT-PCR analysis detected mRNA for the transgene in the heart but not in the liver, spleen, or kidney. The procedures may provide a feasible strategy for gene therapy of severe heart failure. Gene Therapy (2000) 7, 2087-2093.

Endoscopic lithotripsy with the holmium:YAG laser.

BACKGROUND AND OBJECTIVE: The holmium:YAG (Ho:YAG) laser can be used not only for soft tissue but also for hard tissue such as urinary calculi. The objective of this study was to assess the usefulness of the Ho:YAG laser for endoscopic lithotripsy in patients with urinary tract stone. STUDY DESIGN/MATERIASL AND METHODS: Of 102 procedures performed among 96 patients, 88 were transurethral ureterolithotripsy (TUL), seven were percutaneous nephrolithotripsy, and seven were transurethral cystolithotripsy. Six patients had bilateral stones. The fragments were reduced as much as possible with the Ho:YAG laser. RESULTS: The efficacy rate of the 102 lithotripsy procedures was 93%. With respect to the effect of TUL, the efficacy rates of 40 procedures for the proximal ureter, 18 procedures for the midureter, and 30 procedures for the distal ureter were 85%, 94%, and 100%, respectively. CONCLUSION: The Ho:YAG laser produced a sufficiently strong lithotripsy force on all stones. The results of this study indicate that lithotripsy of urinary tract stones with the Ho:YAG laser can achieve a clinical outcome equivalent to or exceeding that of pulsed dye laser lithotripsy. The Ho:YAG laser is a multipurpose laser and thus is a cost effective and very useful means for endoscopic lithotripsy of urinary tract stones.

Inhibitory effect of tea flavonoids on the ability of cells to oxidize low density lipoprotein.

Dietary flavonoid intake has been reported to be inversely related to mortality from coronary heart disease, and the anti-atherosclerotic effect of flavonoids is considered to be due probably to their antioxidant properties. Oxidation of low density lipoprotein (LDL) has been reported to be induced by the constituent cells of the arterial wall. Accordingly, we examined the effect of pretreatment with tea flavonoids, such as theaflavin digallate, on the ability of cells to oxidize LDL. Theaflavin digallate pretreatment of macrophages or endothelial cells reduced cell-mediated LDL oxidation in a concentration- (0-400 microM) and time- (0-4 hr) dependent manner. This inhibitory effect of flavonoids on cell-mediated LDL oxidation was in the order of theaflavin digallate > theaflavin > or = epigallocatechin gallate > epigallocatechin > gallic acid. Further, we investigated the mechanisms by which flavonoids inhibited cell-mediated LDL oxidation using macrophages and theaflavin digallate. Theaflavin digallate pretreatment decreased superoxide production of macrophages and chelated iron ions significantly. These results suggest that tea flavonoids attenuate the ability of the cell to oxidize LDL, probably by reducing superoxide production in cells and chelating iron ions.

[A case of AIDS-associated primary CNS lymphoma difficult to differentiate from toxoplasmic encephalitis by clinical symptoms, neuroimages, and therapeutic responses].

We reported a 24-year-old Thai woman who developed primary CNS lymphoma (PCNSL) associated with acquired immunodeficency syndrome. It was difficult to distinguish PCNSL from toxoplamic encephalitis in this case by clinical symptoms, findings of CT and MRI, and therapeutic responses for toxoplasmosis. It is important to make a definite diagnosis of PCNSL by brain biopsy to treat appropriately, because this disorder could be fatal if it is not treated by corticosteroid, radiation, or other proper methods.

The role of 3-methylsulfonyl-2,2',4',5,5'-pentachlorobiphenyl, a metabolite of 2,2',4,5,5'-pentachlorobiphenyl, in the induction of hepatic microsomal drug-metabolizing enzymes by 2,2',4,5,5'-pentachlorobiphenyl in rats.

After the administration of 2,2',4,5,5'-pentachlorobiphenyl (2,2',4,5,5'-pentaCB) to intact rats, the concentration of 2,2',4,5,5'-pentaCB in liver gradually decreased, whereas 3-methylsulfonyl (3-MeSO(2))-2,2',4',5,5'-pentaCB appeared in liver and remained detectable in liver for 6 weeks. A single injection of 2,2',4,5,5'-pentaCB (342 µmol/kg) or 3-MeSO(2)-2,2',4',5,5'-pentaCB (0.5 µmol/kg) caused a significant increase both in the contents of cytochromes P450 and b(5) and in the activities of aminopyrine N-demethylase and benzo[a]pyrene hydroxylase, and the increased enzyme contents and activities continued for 6 weeks after the administration. The extent of both the hepatic accumulation of 3-MeSO(2)-2,2',4',5,5'-pentaCB and the induction of the enzymes for 6 weeks after the administration of 2,2',4,5,5'-pentaCB was similar to that after the administration of 3-MeSO(2)-2,2',4',5,5'-pentaCB. 3-MeSO(2)-2,2',4',5,5'-pentaCB was considered to play a principal role in the induction of microsomal drug-metabolizing enzymes by 2,2',4,5,5'-pentaCB. When 2,2',4,5,5'-pentaCB was injected i.p. into bile duct-cannulated rats, 3- and 4-MeSO(2)-2,2',4',5,5'-pentaCBs were not detected in liver. In antibiotic-treated rats dosed with 2,2',4,5,5'-pentaCB, the concentrations of 3- and 4-MeSO(2)-2,2',4',5,5'-pentaCBs in liver were markedly reduced. These findings suggest that the process in which 3- and 4-MeSO(2) metabolites of 2,2',4,5,5'-pentaCB are formed involves the biliary secretion of some precursors which will be subjected to metabolism by intestinal microflora. The increasing effects of 2,2',4,5,5'-pentaCB both on the content of cytochrome P450 and on the activity of aminopyrine metabolizing enzyme in hepatic microsomes were not observed in the bile duct-cannulated rats, in which the phenobarbital treatment enabled the drug-metabolizing enzymes to be induced. In antibiotic-treated rats, the increases both in the cytochrome P450 content and in the aminopyrine N-demethylase activity after the administration of 2,2',4,5,5'-pentaCB were smaller than those observed in the intact rats. These findings provide the evidence that the induction of some drug-metabolizing enzymes by 2,2',4,5,5'-pentaCB is due not to the action of 2,2',4,5,5'-pentaCB itself but to its 3-methylsulfonyl metabolite, 3-MeSO(2)-2,2',4',5,5'-pentaCB.

Holmium laser resection of the prostate.

A total of 35 patients with benign prostatic hyperplasia (BPH) were treated with the Ho: YAG laser using a new technique termed holmium laser resection of the prostate or HoLRP. The laser energy was applied directly to prostatic tissue exclusively through the use of a standard 550 micron end-firing fiber. A high-powered holmium laser was used and was set at 2.4 J per pulse at 25 pulses per second for an average power of 60 W. The mean preoperative AUA Symptom Score was 24. Postoperatively, the score dropped to 10.9, 8.2, 5.2, and 4.6 at 1 week, 1 month, 3 months, and 6 months, respectively. The peak urine flow rate improved from 6.3 mL/sec preoperatively to 15.1, 15.3 and 16 mL/sec at 1 week, 1 month, 3 months, and 6 months. A foley catheter was removed within 24 hours of completion of the operation in 31 patients (89%), and voiding was improved. The HoLRP technique was bloodless, and the short-term results were satisfactory. Most importantly, the defect produced by HoLRP is identical to that of a conventional transurethral resection. These initial results demonstrate that HoLRP is a useful surgical alternative in the treatment of patients with obstructive BPH.

Effects of soy protein isolate (SPI) and casein on the postprandial lipemia in normolipidemic men.

To elucidate the effects of soybean protein and casein on postprandial lipemia, oral fat load tests were performed before and 3 weeks after the administration of soy protein isolate (SPI) and casein supplement to normolipidemic men. Eleven normolipidemic male subjects on otherwise identical controlled diets were assigned to either a 20 g/d soy protein isolate (SPI) dietary supplement or a casein dietary supplement for three weeks in a crossover design. Fat load tests with 40 g/m2 of bovine milk fat were carried out before and after 3 weeks on the experimental dietary supplements. Fasting plasma concentrations of lipids and apolipoproteins were not significantly different from baseline levels before or after the administration of SPI or casein supplemented diets. Neither SPI nor casein supplement affected the fasting plasma concentrations of lipids and apolipoproteins. The areas under the incremental curve (AUIC) of triglyceride (TG) and remnant-like particles triglyceride (RLP-TG) after both experimental diets were not significantly different from those before the experimental diets. However, the AUIC of remnant-like particles cholesterol (RLP-C) showed a tendency (p = 0.07) to decrease after administration of the diet supplemented with SPI than before the diet. The AUIC of RLP-C was significantly (p < 0.05) lower after the diet supplemented with SPI than after administration of the diet supplemented with casein. These results suggest that 3 weeks of 20 g/d SPI dietary supplement favorably affects the postprandial remnant lipoprotein response as compared to the casein dietary supplement.

Gene transfer in vitro and in vivo with Epstein-Barr virus-based episomal vector results in markedly high transient expression in rodent cells.

The EBV-based plasmid vectors, which carry oriP and EBNA1 gene from EBV genome, can be retained in the nucleus and replicate in human cells. Rodent cells are not permissive for the EBV plasmids, in terms of the plasmid replication. However, the EBV vector facilitates not only the long term maintenance of the plasmid but also high level gene expression at a transient phase after transfection. It has not been elucidated if rodent cells show this high level transient expression. We demonstrate that rodent cells transfected with an EBV vector expressed a marker gene more intensively than those with a conventional plasmid vector did. The high marker gene expression was also seen in rat myocardium injected in vivo with the EBV plasmid. The present data indicate that the EBNA1-oriP system functions in "non-permissive" rodent cells at transient phase, and may require different cellular factor(s) for the transient expression and plasmid replication.