Serotonin regulates osteoblast proliferation and function in vitro

The monoamine serotonin (5-hydroxytryptamine, 5-HT), a well-known neurotransmitter, also has important functions outside the central nervous system. The objective of this study was to investigate the role of 5-HT in the proliferation, differentiation, and function of osteoblasts in vitro. We treated rat primary calvarial osteoblasts with various concentrations of 5-HT (1 nM to 10 µM) and assessed the rate of osteoblast proliferation, expression levels of osteoblast-specific proteins and genes, and the ability to form mineralized nodules. Next, we detected which 5-HT receptor subtypes were expressed in rat osteoblasts at different stages of osteoblast differentiation. We found that 5-HT could inhibit osteoblast proliferation, differentiation, and mineralization at low concentrations, but this inhibitory effect was mitigated at relatively high concentrations. Six of the 5-HT receptor subtypes (5-HT_1A, 5-HT_1B, 5-HT_1D, 5-HT_2A, 5-HT_2B, and 5-HT_2C) were found to exist in rat osteoblasts. Of these, 5-HT_2A and 5-HT_1B receptors had the highest expression levels, at both early and late stages of differentiation. Our results indicated that 5-HT can regulate osteoblast proliferation and function in vitro.

X-ray parametric down-conversion in the Langevin regime

We experimentally and theoretically study the coincidence count rate for down-converted x-ray photons. Because of photoionization, parametric down-conversion at x-ray wavelengths generally involves loss and the theoretical description requires a Langevin approach. By working in a transmission geometry (Laue) rather than in the Bragg geometry of previous experiments, we obtain an improvement in the signal-to-noise ratio of 12.5, and find agreement between experiment and theory.

A prospective comparative study of kyphoplasty using the Jack vertebral dilator and balloon kyphoplasty for the treatment of osteoporotic vertebral compression fractures

This study prospectively compared the efficacy of kyphoplasty using a Jack vertebral dilator and balloon kyphoplasty to treat osteoporotic compression fractures between T10 and L5. Between 2004 and 2009, two groups of 55 patients each underwent vertebral dilator kyphoplasty and balloon kyphoplasty, respectively. Pain, function, the Cobb angle, and the anterior and middle height of the vertebral body were assessed before and after operation. Leakage of bone cement was recorded. The post-operative change in the Cobb angle was significantly greater in the dilator kyphoplasty group than in the balloon kyphoplasty group (-9.51 degrees (sd 2.56) vs -7.78 degrees (sd 1.19), p < 0.001)). Leakage of cement was less in the dilator kyphoplasty group. No other significant differences were found in the two groups after operation, and both procedures gave equally satisfactory results in terms of all other variables assessed. No serious complications occurred in either group. These findings suggest that vertebral dilator kyphoplasty can facilitate better correction of kyphotic deformity and may ultimately be a safer procedure in reducing leakage of bone cement.

Generation and compression of chirped biphotons

We describe an experiment demonstrating the radarlike technique of "chirp and compress." Chirped biphotons are generated using a quasi-phase-matched nonlinear crystal where the phase-matched frequency varies linearly with position. Sum frequency generation is used to measure the amplitude of the biphoton wave function. As compared to a nonchirped crystal, compression and an increase in summing efficiency of a factor of 5 is observed.

Hiding single photons with spread spectrum technology

We describe a proof-of-principal experiment demonstrating the use of spread spectrum technology at the single photon level. We show how single photons with a prescribed temporal shape, in the presence of interfering noise, may be hidden and recovered.

Observation of nonlocal modulation with entangled photons

We demonstrate a new type of quantum mechanical correlation where phase modulators at distant locations, acting on the photons of an entangled pair, interfere to determine the apparent depth of modulation. When the modulators have the same phase, the modulation depth doubles; when oppositely phased, the modulators negate each other.

Resonant sum frequency generation with time-energy entangled photons

We describe a technique for enhancing the efficiency of sum frequency generation using entangled signal and idler photons. By resonating the sum frequency field, we observe that the generated power varies linearly with input power and is increased by a factor of 12.

Observation of optical precursors at the biphoton level

We describe the observation of a sharp leading-edge spike in a biphoton wave packet that is produced using slow light and measured by two-photon correlation. Using the stationary-phase approximation we characterize this spike as a Sommerfeld-Brillouin precursor resulting from the interference of low- and high-frequency spectral components.

Electro-optic modulation of single photons

We use the Stokes photon of a biphoton pair to set the time origin for electro-optic modulation of the wave function of the anti-Stokes photon thereby allowing arbitrary phase and amplitude modulation. We demonstrate conditional single-photon wave functions composed of several pulses, or instead, having Gaussian or exponential shapes.

Subnatural linewidth biphotons with controllable temporal length

This Letter describes the generation of biphotons with a temporal length that can be varied over the range of 50-900 ns, with an estimated subnatural linewidth as small as 0.75 MHz. We make use of electromagnetically induced transparency and slow light in a two-dimensional magneto-optical trap with an optical depth as high as 62. We report a sharp leading edge spike that is a Sommerfeld-Brillouin precursor, as observed at the biphoton level.

Four-wave mixing and biphoton generation in a two-level system

We find that in a two-level system there are two kinds of four-wave mixing processes which destructively contribute to the third-order nonlinear susceptibility. In a paired-photon generation scheme by using a single retroreflected pump beam, these two processes occur with definite time orders. The biphoton temporal correlation, which is measured with a back-to-back geometry in a laser-cooled two-level atomic ensemble, shows a damped Rabi oscillation and photon antibunching. Without suppressing the background of Rayleigh scattering, the upper limit of Cauchy criteria is estimated.

Molecular modulation in a hollow fiber

We report the extension of the technique of molecular modulation to a deuterium-filled optical fiber. Using driving lasers at 807 and 1064 nm, each with a pulse energy of several millijoules and a 200 microm diameter fiber with a length of 22.5 cm, we generate 12 sidebands with wavelengths spanning 1.56 microm to 254 nm.

Generation of narrow-bandwidth paired photons: use of a single driving laser

We describe a generator of narrow-band paired photons. A single retroreflected Ti:sapphire laser is used to cool, render transparent, and parametrically pump a cloud of (87)Rb atoms. We attain a paired-photon generation rate into opposing fibers of 600 counts/s with an intensity correlation function that has a width of 5 ns, and violates the Cauchy-Schwartz criteria by a factor of 2000.

Coherent control of laser-induced breakdown

We demonstrate coherent control of laser-induced optical breakdown in Ar and Xe with a femtosecond time-scale pulse train. By using a genetic algorithm to set the relative phases of seven optical sidebands that span two octaves of bandwidth, we enhance or suppress the probability of breakdown, vary the onset time of the spark, and to some extent, vary the position of the spark and the timing of the laser-produced shock wave.

Generation of paired photons with controllable waveforms

We describe experiments and theory showing the generation of counterpropagating paired photons with coherence times of about 50 ns and waveforms that are controllable at a rudimentary level. Using cw lasers, electromagnetically induced transparency and cold 87Rb atoms we generate paired photons into opposing single-mode optical fibers at a rate of approximately 12 000 pairs per second.

Generation of a single-cycle optical pulse

We make use of coherent control of four-wave mixing to the ultraviolet as a diagnostic and describe the generation of a periodic optical waveform where the spectrum is sufficiently broad that the envelope is approximately a single-cycle in length, and where the temporal shape of this envelope may be synthesized by varying the coefficients of a Fourier series. Specifically, using seven sidebands, we report the generation of a train of single-cycle optical pulses with a pulse width of 1.6 fs, a pulse separation of 11 fs, and a peak power of 1 MW.

Frequency mixing using electromagnetically induced transparency in cold atoms

We report the first experimental demonstration of four-wave mixing using electromagnetically induced transparency in cold atoms. Backward-wave, phase-matched difference-frequency conversion is achieved at optical powers of a few nanowatts and at energies of less than a picojoule.

Quasiperiodic Raman technique for ultrashort pulse generation

We report the experimental demonstration of a new Raman technique that produces 200 sidebands, ranging in wavelength from 3 microm to 195 nm. By studying multiphoton ionization of nitric oxide (NO) molecules, we show mutual phase coherence among 15 visible sidebands covering 0.63 octaves of bandwidth.

Raman self-focusing at maximum coherence

We demonstrate a type of Raman self-focusing and -defocusing that is inherent in operation at maximum coherence. In this regime the two-photon detuning from the Raman resonance controls the refractive index of the medium.

Rotational Raman generation with near-unity conversion efficiency

We demonstrate collinear generation of equidistant rotational sidebands in low-pressure molecular hydrogen with near-unity conversion efficiency. The spectrum consists of 37 coherent sidebands covering over 20, 000 cm(-1) of spectral bandwidth and ranging from 1.37mum to 352 nm in wavelength.

Femtosecond light source for phase-controlled multiphoton ionization

We describe a femtosecond Raman light source with more than an octave of optical bandwidth. We use this source to demonstrate phase control of multiphoton ionization under conditions where ionization requires eleven photons of the lowest frequency of the spectrum or five photons of the highest frequency. The nonlinearity of the photoionization process allows us to characterize the light source. Experiment-to-theory comparison implies generation of a near single-cycle waveform.

Optical frequency conversion by a rotating molecular wave plate

We demonstrate efficient four-wave mixing in low-pressure molecular deuterium without the need for phase matching. We use two laser fields with opposite circular polarizations to produce a strong excitation of a rovibrational transition at a frequency of 3167 cm(-1) . The coherent molecular motion, in turn, modulates a third laser field (also circularly polarized) and results in highly efficient single-sideband conversion.

Raman generation by phased and antiphased molecular states

We use molecular deuterium and two driving lasers to demonstrate collinear generation of mutually coherent equidistant sidebands, covering 50 000 cm(-1) of spectral bandwidth and ranging from 2.94 microm to 195 nm in wavelength. The essential idea is the adiabatic preparation of a single, highly coherent (|rho(ab)| = 0.33) molecular eigenstate.

Efficient nonlinear frequency conversion in an all-resonant double- lambda system

We demonstrate efficient, pulsed, gas-phase, nonlinear frequency conversion in a quadruply resonant, double- Lambda system and, simultaneously, verify theoretical predictions of Rabi-frequency matching unique to absorbing nonlinear media. This system is used to up-convert ultraviolet light at 233 nm to the vacuum ultraviolet at 186 nm in atomic Pb vapor with small-signal conversion efficiencies exceeding 30% and with modest atomic density-length (NL) products (scale 10(14) cm(-2)) and optical power densities (10-100 kW/cm(2)).

Efficient gas-phase generation of coherent vacuum ultraviolet radiation

We report the demonstration of a pulsed atomic lead (Pb) vapor-based vacuum ultraviolet frequency converter from 233 to 186 nm with unity photon-conversion efficiency. This conversion is attained without phase matching.

Efficient self-seeding of a pulsed Ti3+:Al2O3 laser

We describe the design considerations and operating characteristics of a compact, widely tunable, narrow-linewidth, megawatt-class pulsed laser system based on Ti(3+):Al(2)O(3) (Ti:sapphire) pumped by the second harmonic of a 1.06-microm Nd:YAG laser. The system delivers 10 mJ in a 5-ns near-transform-limited single-longitudinal-mode (SLM) pulse with a threshold of 20 mJ and a slope efficiency greater than 40%. By the technique of self-seeding, in which a portion of the gain medium's spontaneous fluorescence is coupled back to the laser cavity, SLM operation may be obtained across the entire gain profile of Ti:sapphire with a minimum number of optical components and without external seeding.

[Clinical study on the piweiping capsule in treating patients with metaplasia of gastric mucosa]

One hundred and forty-three patients were diagnosed as chronic superficial atrophic gastritis of gastric antrum or with metaplasia by means of gastroscopic observation with pathological biopsy examination. They were divided into 4 types (the Spleen-Stomach Cold-Deficiency type, Disharmonious of Liver and Stomach type, Spleen-Stomach Yin Deficiency type and Spleen Deficiency with Qi-Stagnation type) and subdivided according to treatment into two groups, 75 patients of treatment group of above-mentioned 4 types were treated with Piweiping capsule (PWPC) I, II, III, IV respectively, 68 patients of control group were all treated with Sanjiu Weitai (SJWT). After 3-6 months of treatment, the improvement of gastric mucosa cyclic adenosine monophosphate, deoxyribonucleic acid, 3H-thymopyrimidine nucleoside and lymphocyte transformation of treatment group were all superior to that of control group, P < 0.05-0.001. The curative rate and total effective rate of symptomatic effect of treatment group were 49.3% and 92.0%, while at intestinal metaplasia of treatment group were 45.3% and 62.7%. As in control group, they were 29.4%, 67.6%, 10.3% and 29.4% respectively. The difference between two groups was significant, P < 0.001. These results suggested that the PWPC could reverse the intestinal metaplasia through improving the gastric cAMP, DNA and strengthening the cellular immunity and the effect would be enhanced when the treatment was based on syndrome differentiation.

Pulsed Ti:sapphire laser seeded off the gain peak

An external-cavity diode laser is used to seed a pulsed Ti:sapphire laser from 839 to 860 nm. Because this wavelength range is off the gain peak of Ti:sapphire, a bandpass filter is used in the cavity to permit seeded operation. We describe a tunable, wide-field-of-view birefringent filter especially suited for use in seeded lasers. Measurements of the ratio of unseeded to seeded output as a function of seed power are also presented and demonstrate an approximately reciprocal dependence on the seed power.

Mouse Brca1: localization sequence analysis and identification of evolutionarily conserved domains

The human genes BRCA1, conferring susceptibility to early-onset breast and ovarian cancer, has recently been isolated. Here we describe isolation of cDNAs, sequence analysis, and genomic localization of the murine homolog, Brac1. The mouse cDNA sequence predicts a protein of 1812 amino acids; a number of small gaps account for the 51 fewer residues in the mouse protein relative to human BRCA1. While the predicted mouse and human proteins display on the whole a high level of homology (58% identity, 73% similarity), the regions of greatest homology are at the respective amino and carboxyl termini. Most reported disease-associated missense mutations in human BCRA1 occurred within these more highly conserved terminal regions. A predicted zinc-building RING finger domain near the amino terminus lies within a 50 amino acid stretch that is perfectly conserved in both species. The strong conservation during mammalian evolution argues for the importance of this domain, perhaps mediating a role for BRCA1 in DNA and/or protein binding. We have also identified a conserved highly acidic domain in the carboxyl terminal half of the BCRA1 protein resembling acidic transactivation domains of certain transcription factors. Using an interspecific backcross panel, Brca1 was mapped to a region of mouse chromosome 11 that exhibits conserved linkage with 17q21. The sequence and isolated cDNAs will provide useful reagents for studying the expression of Brca1 in the mouse, and for testing the importance of the evolutionarily conserved domains.

[Study on mitochondrial ultrastructure, trace elements and correlative factors of gastric mucosa in patients with spleen deficiency syndrome]

Eighty-eight gastropathic patients with Spleen deficiency syndrome by using transmission electron microscope (TEM), X-ray energy disperse analysis system (EDAX), histochemical staining and radioimmuno methods were examined. The authors found that the gastric mucosa cAMP, SOD level, the quantity of mitochondria and its crista, the ratio of diameter between ventricle and cavity of mitochondria and the content of Zn, Cu of mitochondria were reduced in the trend of healthy control group, Spleen Qi deficiency group, Spleen deficiency with Qi stagnation group; chronic superficial gastritis group, chronic atrophic gastritis group, gastric cancer group: complete small intestinal metaplasia group, incomplete small intestinal metaplasia group, complete colonic intestinal metaplasia group, incomplete colonic intestinal metaplasia group (P < 0.05-0.001). While the degeneration rate of mitochondria, the Cu/Zn ratio of mitochondria, the metaplasia rate of gastric, the rate of incomplete colonic intestinal metaplasia and the content of serum LPO were increased in the above turn. It is suggested that the comprehensive effect of the degeneration of mitochondria and the quantitative changes of its correlative factors is the physiopathologic base for inducing Spleen deficiency disease, gastric mucosa metaplasia and canceration. Much attention must be paid in clinic to the cancerization trend of gastric disease with Spleen deficiency syndrome.

[Effect of zhuchun pill on immunity and endocrine function of elderly with kidney-yang deficiency]

After randomly dividing 45 elderly males with Kidney-Yang Deficiency into Zhuchun Pill (ZCP) group and placebo (starch capsule) group by single blind method, and treating them for 3 months, we found that ZCP could greatly improve the main symptoms of Kidney-Yang Deficiency, P < 0.01 by comparison with control group: the 3H-TdR lymphocyte transformation (3H-TdR LCT) rate, level of serum C3, IgA, IgD, IgG & IgM went up (P < 0.01); contents of plasma adrenocortical hormone (ACTH), testosterone (T) and cyclic adenosine monophosphate (cAMP) increased (P < 0.01-0.001): the level of superoxide dismutase (SOD) in serum also increased while lipid peroxide (LPO) in plasma decreased (P < 0.01). But for control group, there were no remarkable changes after treatment, so it revealed that the improvement of Kidney-Yang Deficiency by ZCP is realized through regulating the organism's immunity and endocrine function as well as through scavenging the free radical agents.

The developmental pattern of Brca1 expression implies a role in differentiation of the breast and other tissues

We have examined the developmental expression of the murine breast and ovarian cancer susceptibility gene, Brca1, to investigate its role in the control of cell growth and differentiation. Specifically, we have analysed Brca1 expression during embryonic development, in adult tissues, and during postnatal mammary gland development, particularly in response to ovarian hormones. Our results suggest that Brca1 is expressed in rapidly proliferating cell types undergoing differentiation. In the mammary gland, Brca1 expression is induced during puberty, pregnancy, and following treatment of ovariectomized animals with 17 beta-estradiol and progesterone. These observations imply that Brca1 is involved in the processes of proliferation and differentiation in multiple tissues, notably in the mammary gland in response to ovarian hormones.

Observation of electromagnetically induced phase matching

We report the observation of electromagnetically induced phase matching in collisionally broadened Pb vapor. At a critical intensity at which the Rabi frequency of a dressing 1064-nm laser overcomes the Doppler broadening of the vapor, the generated four-frequency-mixing signal at 283 nm increases in a steplike manner by a factor of 59.

[Research on the fundamental factors and conditions of gallstone formation]

The authors applied scanning electron microscope with synchronization of EDAX to detect the ultrastructure of gallbladder mucosa, metallic elements and their oxides, to observe the bacteria of the core of the gallstone; applied cholecystokinin to observe the effects of abnormal gallbladder contraction on stone formation; applied biochemical, immunological criteria to determine the association between liver and gallbladder diseases and gallstone; applied scanning electron microscope to compare the analysis of mechanical structure of gallstone. According to the results of research, the authors conclude: (1) The basic condition of the formation of the gallstone was the disturbance of physiological reaction of "integration" and "homeostasis" of liver-biliary system. (2) The essential factor of the formation of gallstone was the infection of liver-biliary system. (3) The formation of the gallstone structure was caused by changed physical and chemical mechanics of bile. (4) The synchronization treatment of liver-biliary was the principle of preventing and treating gallstone.

Observation of super Coster-Kronig-pumped gain in Zn III

We report the observation of laser gain in the vacuum ultraviolet pumped by super Coster-Kronig decay. Using a 5-J, 300-psec pump pulse of 1064-nm radiation, we have observed gain on transitions in Zn III at 127.0, 130.6, and 131.9 nm with total gains of exp(2.4), exp(5.1), and exp(3.2), respectively. The large branching ratios of the rapid super Coster-Kronig decay into a small number of final levels makes high-efficiency operation possible.

Low-energy pumping of a 108.9-nm xenon Auger laser

We report extensive measurements of gain in the Xe III system initially observed by Kapteyn et al. [Phys. Rev. Lett. 57, 2939 (1986)]. The dependence of this gain on pressure, pumping-pulse length, and pump energy is presented. By optimizing these parameters we have achieved a gain of exp(3.2) by using only 0.56 J of 1064-nm energy on target, representing an efficiency improvement of nearly 100. Total gains as high as exp(6.6) have been measured when using higher energies. Our data indicate that effective laser-produced plasmas can be created with applied power densities as low as 5 x 10(10) W cm(-2).