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Objectives: To investigate the natural courses of mild, moderate and severe idiopathic oligozoospermia, and which factors or semen variables were of utmost importance in predicting the courses. Methods: A total of 208 men (age 29–47 years) who were diagnosed with mild, moderate and severe idiopathic oligozoospermia in a 9-year-period between January 2000 and December 2008 were followed up for more than 6 months. Results: Overall, 16 (24.6%) of 65 patients with severe oligozoospermia developed azoospermia, whereas two (3.1%) patients with moderate oligozoospermia developed azoospermia and none of the patients with mild oligozoospermia developed azoospermia. Initial follicle stimulating hormone level and testicular volume between the subgroups were significantly different (P = 0.0071 and 0.0039, respectively). The subgroup of patients who became azoospermic (n = 18) showed statistically significant differences in terms of body mass index and the level of prolactin (PRL) from the subgroup that maintained the initial lingering sperm count (n = 190; P = 0.0086 and 0.0154, respectively). As the vitality of semen variables increased 1%, the risk of progression to azoospermia diminished by 0.892-fold, according to Cox's proportional hazards model analysis. A receiver operating characteristic curve analysis showed that the area under the curve was 0.755 and the sperm concentration value with the highest sensitivity and specificity was the reference value of 3–5 million/mL, with a sensitivity of 0.746 and specificity of 0.711 (P = 0.01). Conclusions: Patients with severe oligozoospermia should be warned of the possibility of becoming azoospermic and hence sperm freezing should be encouraged as early as possible.

Most couples with severe male factor infertility are treated with assisted reproduction technology and little has been known about the prognosis of severe male factor infertility itself. We investigated the prognosis of infertile male patients with severe oligozoospermia. Thirty-nine patients with severe nonobstructive oligozoospermia were followed more than 6 months without any medical or surgical intervention. Retrospective analyses of the natural sequence of the condition and influences on the future fertility potential of the study participants were conducted. Sperm concentration, motility, and morphology between first semen analysis and last semen analysis were not significantly different. However, during the follow-up period, 5 (12.8%) patients became azoospermic. In 7 (17.9%) patients, the sperm count declined to a severe level that could be detected only after centrifugation. Three patients underwent microdissection testicular sperm extraction (TESE) for sperm retrieval after confirmation of azoospermia. The sperm retrieval was successful only in 1 of the 3 patients. Therefore, male patients diagnosed with severe oligozoospermia should be informed about possible aggravation of their residual spermatogenesis function and the necessity of intermittent follow-up semen analyses. If follow-up semen tests show a declining tendency, sperm cryopreservation may be recommended for these patients. If azoospermia develops during the follow-up period, early TESE procedure should be considered to improve the chance of sperm retrieval.

We present an experimental and theoretical investigation of the temperature dependence of the threshold current for double quantum well GaInNAs-GaAs lasers in the temperature range 10 degC-110 degC. Pulsed measurements of the threshold current have been performed on broad and narrow ridge wave guide (RWG) lasers. The narrow RWG lasers exhibit high characteristic temperatures (T0) of 200 K up to a critical temperature (Tc), above which T0 is reduced by approximately a factor of 2. The T0-values for broad RWG lasers are significantly lower than those for the narrow RWG lasers, with characteristic temperatures on the order of 100 (60) K below (above) Tc. Numerical simulations, using a model that accounts for lateral diffusion effects, show good agreement with experimental data and reveal that a weakly temperature dependent lateral diffusion current dominates the threshold current for narrow RWG lasers.

A state-of-the-art laser diode simulation tool has been used to investigate how phonon reflection at epitaxial interfaces impacts upon the performance of high-power 980 nm ridge waveguide lasers. Due to the inclusion of phonon reflection, a 0.5 K increase in quantum well temperature and a reduction in front facet output power of up to 0.6 mW is observed. The results demonstrate that whilst this effect is relatively small, a first order correction should be made to obtain accurate simulation results.

A systematic study of the dependence of the optical gain on the injection current and temperature in InGaAsN/GaAs lasers has been performed. The amplified spontaneous emission has been measured from a series of both facet-coated and uncoated 1.3 μm edge-emitting double quantum well lasers. The net gain, modal gain, cavity loss, quasi-Fermi level separation and width of the gain spectra have been extracted using Cassidy's method. The peak gain was found to shift 0.41 nm/K between 300 K and 340 K and 0.60 nm/K between 340 K and 380 K. The value of the peak gain was found to decrease with temperature at a rate of 0.26 cm−1/K. The increase in the full at width half maxima of the gain spectra was determined to be 0.35 nm/K. These values are all comparable to those found for the more traditional 1.3 μm InP-based devices, suggesting that InGaAsN/GaAs lasers are a viable alternative to replace such InP-based devices, in particular for uncooled access network applications. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A theoretical investigation into the impact of the thermal boundary resistance on the performance of uncooled edge-emitting 1.3μm InGaAsN/GaAs quantum well lasers has been performed. A state-of-the-art 2D laser diode simulation tool has been extended to accurately model the thermal resistance due to the acoustic material mismatch and defect scattering at epitaxial interfaces. A small, but noticeable, increase in quantum well temperature is observed. The results clearly highlight the need for the inclusion of thermal boundary resistance in device simulation tools. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The net modal gain, effective group index and linewidth enhancement factor (LWEF) in edge-emitting InGaAsN/GaAs lasers have been determined as a function of both temperature and injection current from experimentally amplified spontaneous emission spectra. The shift of the peak gain with temperature was found to be 0.49 nm/K. Values of effective group index between 3.52 and 3.59 were measured, suggesting a relatively high refractive index of 3.75 for a dilute nitride quantum well. LWEF values between 1.87 and 2.84 were measured.

The simulation of double quantum well (QW) GalnNAs ridge-waveguide (RW) lasers is performed over a wide range of cavity lengths and operating temperatures using a comprehensive in-house 2D laser simulator that takes into account all of the major device physics, including current spreading, capture escape processes, drift diffusion in the QW, 2D optical modes and fully resolved lasing spectra. The gain data used by the simulator were fitted to experimental gain spectra measured by the segmented contact method. The gain model includes the band-anticrossing model for the conduction band and a 4 x 4 kldrp model for the valence band. Using a carrier density-dependent and temperature-dependent linewidth broadening parameter, a good fit with experiment over a temperature range of 300-350 K was obtained. A Shockley-Read-Hall (SRH) lifetime of 0.5 ns and an Auger recombination coefficient of 1 x 10-28 cm6/ s, were extracted from the calibration of the laser simulator to experimental device characteristics of broad-area (BA) devices. Using the same set of parameters for BA devices, except for a reduced SRH lifetime of 0.45 ns underneath the etch, 2D simulation results were found to agree well with the measured RW laser operating characteristics. The impact of the various recombination processes in the RW laser at threshold has also been identified using the calibrated laser simulator.

This paper presents a model for simulating the impact of external optical feedback on large-optical cavity high-brightness diode lasers. The simulations are performed with our 2.5D simulation tool for high-brightness laser diodes. The external cavity is modelled using commercial coherent ray tracing software. We consider the impact of the optical feedback on the excitation of amplified spontaneous emission in the parasitic vertical modes.

Using a quantitatively calibrated imaging system and specially fabricated tapered lasers with windowed n-contacts, the authors image the spontaneous emission distribution inside two different laser cavities as a function of injection current. In the first device, an array of narrow-angle index-guided tapered lasers, significant thermal and electrical coupling between the emitters was observed. In the second device, a wide-angle gain-guided tapered laser, significant spatial hole burning was observed above threshold. The spontaneous emission distributions of this wide-angle device have been compared with simulation results from a 2.5D laser simulator and show good quantitative agreement in the quantum well carrier density.

As-deposited CoFeAlO films have been prepared by reactive RF magnetron sputtering at input power of 300 W. The X-ray diffraction (XRD) results exhibit a multi-phase structure, which could be consisting of major phases: α-CoFe (1 1 0) and α-CoFe(2 1 1), and minor phase CoFe-oxides with Al2O3 as the amorphous matrix were formed. Moreover, it has also been demonstrated that a nanocrystalline CoFe alloy was obtained and the evaluated sizes were below 15 nm. The thickness effects on the high-frequency characteristics of as-deposited CoFeAlO soft magnetic thin films have been studied in the range of 50 to 1200 nm. The coercivity ( H c ) and anisotropy field ( H k ) of these films increases largely with decrease in the film thickness. It is explained to be the result of the change in the film composition and surface roughness. The electrical resistivity ( ρ ) also increases with decreases in the film thickness. The effective permeability of a CoFeAlO thin film is larger than 1000 and remained constant up to 700 MHz with film thickness below 1000 nm. A CoFeAlO film exhibits excellent high-frequency characteristics, which results from softness properties, high ρ , high H k .

Magnetic tunnel junctions(MTJ) are fabricated as a function of the input power of Al thin film. Al thin films have pseudo-crystalline structure at 30, 60, 90 W and transform into amorphous like smooth nanocrystalline state at 120 W. Junction resistance increases as the annealing temperature increases up to 250 􀀀 and decrease at 300 􀀀 at the pseudo-crystalline barrier. When the barrier has amorphous like nanocrystalline structure, optimum annealing temperature increases up to 300 􀀀 . The barrier characteristics are strongly related with the microstructure of AlOx barrier.

In this work, an ultracompact electro-optic modulator based on refractive index modulation by plasma dispersion effect in PhC all-optical gate (AOG) is proposed. The index modulation is achieved by applying a time-varying bias voltage across the electrical contacts of the AOG. The proposed modulator has potential for high-speed operation, with bandwidths in excess of 30GHz achievable.

We present results from measurements of the subthreshold lateral spontaneous emission profile in 1.3-mu m wavelength ridge waveguide InGaNAs quantum-well lasers using a scanning near-field optical microscopy technique. The measurements reveal the presence of significant lateral carrier diffusion which has a profound effect on the temperature dependence of the threshold current. This effect is frequently omitted when the characteristic temperature of the threshold current is considered.

CoFeAlN soft magnetic thin films were fabricated by radio frequency reactive magnetron sputtering in mixed Ar+N2 plasmas. The Al and N contents in films were varied by the number of Al chips placed on Co70Fe30 alloy target. We examined the effects of addition elements, such as Al and N, on magnetic properties of the CoFeAlN films, and we investigated the relationship between soft magnetic properties and microstructure. Under the optimum fabrication conditions the values of saturation magnetization ( 4 π M s ) of 16–19 kG, coercivity field ( H c ) less than 2 Oe, anisotropy field ( H k ) in the range of 40–60 Oe, electrical resistivity ( ρ ) larger than 160 μ Ω cm, when the total Al+N content in the range of 12–18% were obtained in CoFeAlN thin films.

The performance of high-brightness laser diode emitters and bars is often affected by external optical feedback from the modules and systems in which they are deployed. We report on the coupling of an advanced simulation tool for high-brightness laser diodes with commercial optical design software. The aim of this work is to create a software tool which can be applied to the design and optimisation of high-brightness diode laser modules and systems intended for use in industrial applications requiring the cutting and welding of sheet metal.

We report on the design and simulation of high-power, high-brightness laser diodes and bars. Bar level simulations are demonstrated revealing important consequences of current competition and thermal crosstalk. We also demonstrate bidirectional coupling with external cavity optics, with the aim of evaluating the performance of full laser systems.

In 2D and quasi-3D simulations, Fermi-level pinning of the surfaces has been found to result in the decoupling of the electron and hole populations, preventing numerical convergence to the correct solution. In this work, we report on the elimination of numerical underflow in the self-consistent solution of the Poisson and continuity equations in a 2D optoelectronic device simulator. The use of extended precision to represent the state variables eliminates the numerical underflow and consequently the decoupling of the electron and hole populations.

We describe passive phase-locking architectures based on external-cavity setups to improve the brightness of diode laser bars. Volume Bragg gratings are used to stabilize the lase line. Numerical modelling and experimental results will be presented., Comment: High Power Diode Lasers and Systems, Coventry : United Kingdom (2009)

Objective To evaluate the effectiveness of liquid nitrogen (LN 2 ) vapor (indirect contact method) for the storage of human semen. Design Experimental study. Setting University hospital-based fertility center. Patient(s) We evaluated 150 patients with normal sperm parameters. Intervention(s) Human semen (N = 120) was mixed with Semen Freezing Medium, divided into two groups, frozen, and stored in LN 2 or LN 2 vapor. Frozen semen from each group (n = 40) was thawed after storage for 1 week, 1 month, or 3 months and then analyzed. In the second experiment, semen (n = 30) was divided into four groups, frozen, and stored in LN 2 or stored 7 cm, 12 cm, or 17 cm above the surface of LN 2 for 1 week. Main Outcome Measure(s) The motility and viability of sperm were evaluated by basic analysis, the morphology was analyzed with use of staining, the DNA integrity was assessed with use of terminal deoxyuridine triphosphate nick end-labeling assays, and active mitochondria were detected with use of rhodamine 123 staining. Result(s) The LN 2 and LN 2 vapor groups did not differ with regard to sperm motility, viability, morphology, DNA integrity, or active mitochondria when the cryostorage periods were compared. Furthermore, the quality of sperm stored within 17 cm of the surface of LN 2 for 1 week did not change. Conclusion(s) The storage of human semen in LN 2 vapor, without direct contact with LN 2 , may represent a useful alternative for the effective storage of human semen.

In conclusion, we have shown that it is possible to provide selective feedback to a particular lateral mode from the external cavity using an asymmetric feedback technique. The simulation and experiment show a good agreement with respect to spatial hole burning and the far-field distribution.

In this work, we have presented a description of our spectral laser model and performed spectroscopic simulations of a 975 nm tapered laser diode. To verify the ASE model, we checked the extracted gain using the variable stripe length method. A good agreement between the simulated and measured emission linewidth could be obtained using a spontaneous emission coupling factor of 1×10−16. The simulated red-shift in the peak emission wavelength with increasing bias is consistent with experiment and is attributed to self-heating effects.

A one dimensional spectral model of a self-organizing external cavity laser diode with a PR crystal in the external cavity was developed. The model combines the photon-carrier density coupled rate equations model and a plane wave PR crystal model. The model confirms that the self-organizing external cavity laser diode operates in a single longitudinal mode with an output power up to 0.55 W

We have demonstrated the simulation tool for both single and multiple emitters. Investigations of a model bar with a non-uniform temperature distribution showed that the hotter emitters at the centre of the bar drew more current and emitted higher powers, but also degraded faster than the cooler edge emitters. Similar behaviour has been observed experimentally. However, the simulation results for a real bar showed poor agreement with the observed power distribution. This was attributed to thermal crosstalk between the emitters and is being addressed by the introduction of a global thermal model to Barlase.

Dilute-nitride lasers with record performances have been used to build uncooled transceivers and failure free 10 Gb/s optical transmission was achieved over 815 m of multimode Corning InfiniCor fiber under the LRM standard.

In this work we have measured the lateral spontaneous emission profile for the lasers, using scanning near-field optical microscopy (SNOM). Since the near-field of the spontaneous emission maps the lateral carrier distribution in the active region, this measurement provides a way to directly measure the lateral diffusion. The obtained profile therefore represents the optical mode which is well confined beneath the ridge. Carriers that diffuse outside the ridge can hence not contribute to optical gain and are therefore associated with a leakage current.

A self-consistent model of a self-organizing external cavity high power laser is presented. The model consists of a photorefractive crystal model, which relies on the plane wave approximation, and of a spectral model of the tapered laser amplifier. The results show that the laser can operate in a single longitudinal mode.

Objective We aimed to investigate the prevalence of erectile dysfunction (ED) and the usage of phosphodiesterase type 5 (PDE5) inhibitors for ED treatment in infertile couples. Methods A total of 260 male partners in couples reporting infertility lasting at least 1 year were included in this study. In addition to an evaluation of infertility, all participants completed the International Index of Erectile Function (IIEF)-5 questionnaire to evaluate their sexual function. The participants were asked about their use of PDE5 inhibitors while trying to conceive during their partner's ovulatory period and about their concerns regarding the risks of PDE5 inhibitor use to any eventual pregnancy and/or the fetus. Results Based on the IIEF-5 questionnaire, 41.5% of the participants (108/260) were classified as having mild ED (an IIEF-5 score of 17-21), while 10.4% of the participants (27/260) had greater than mild ED (an IIEF-5 score of 16 or less). The majority (74.2%, 193/260) of male partners of infertile couples had a negative perception of the safety of using a PDE5 inhibitor while trying to conceive. Only 11.1% of men (15/135) with ED in infertile couples had used a PDE5 inhibitor when attempting conception. Conclusion ED was found to be common in the male partners of infertile couples, but the use of PDE5 inhibitors among these men was found to be very low. The majority of male partners were concerned about the risks of using PDE5 inhibitors when attempting to conceive. Appropriate counseling about this topic and treatment when necessary would likely be beneficial to infertile couples in which the male partner has ED.

In this work, we optimize the thermal performance of a double quantum well GalnNAs ridge waveguide laser using an accurate in-house 2D electro-opto-thermal laser simulator. The simulator has shown good agreement with experiments after a detailed calibration procedure. Using calibrated material parameters, we investigate the influence of the p-cladding doping concentration on the heat generation within the laser. It is found that due to the competition between Joule and free carrier absorption heating, an optimum p-cladding doping concentration/profile exists.

The magneto-optical properties and penetration depth of Ta/Cu/NiFe/CoFe/Cu/CoFe/NiFe/FeMn/Cu spin valve are studied. The samples are deposited on Si (100) substrate at room temperature by reactive RF magnetron sputtering technique. The electrical properties and penetration depth of the spin valve, the volume magnetic characteristic, and the near-surface hysteresis loops of the samples are measured using transverse Kerr effect spectrometer, vibrating sample magnetometer (VSM), and surface magneto-optical Kerr effect, respectively.

A SRAM-like embedded DRAM compiler with 0.13um technology was designed using two novel circuit schemes. Firstly, Dual Asymmetric bit line Sensing Scheme is proposed to implement VDD bit line pre-charge scheme without any reference cells and half charge generator. Therefore, we overcame the risk of failure caused by defects in reference cells and simplified embodying VDD bit line pre-charge scheme, enjoying privileges of VDD bit line pre-charge scheme such as fast sensing speed (tRC:7ns, tAC:6.7ns in this work) and stable sensing operation at low voltage and low temperature. Secondly, we propose circuit idea for quiet unselected IO lines. Unselected IO lines are not developed by bit line data during READ/WRITE operation. This scheme has advantage in the architecture with wide IO and various IO multiplexing options like a memory compiler.

This paper describes new design schemes for a telecommunication management network (TMN) agent for man machine language (MML)-managed network elements (NE), especially for ATM networks. Most of the currently developed ATM switches have simple MML interfaces for local operator crafts. This means that most operations, administration, maintenance, and provisioning (OAM&P) functions reside within the NE itself, and designing a TMN agent as a proxy is considered to be most appropriate in that more intelligent event correlation and filtering can be done in the NE itself. In TMN environment, proxy-based management expects an agent to have a functionality of a Q adaptation function (QAF), rather than a network element function (NEF) itself. In contrast with NEF, QAF can be simplified by focusing on the message conversion, namely adaptation and mediation, between standard CMIP messages and proprietary MML messages or any kind of management messages. Based on this observed fact, this paper proposes several design schemes for a Q3 agent and its companion gateway function, so that a Q3 agent, as a proxy, can rather be lightweight and mediation-insensitive. The design schemes proposed in this paper are listed in the following: designing management protocol-insensitive schema for an NE-embedded database (DB), mapping of a management information base (MIB)/management instances tree (MIT) accesses to DB queries and making direct use of DB queries, minimizing the retained information on MIT/MIB, and using GDMO/ASN.1-based MML mediation capabilities with various message adaptation capabilities.

The thesaurus is widely used in information indexing and retrieval for vocabulary control and concept search. Conceptual relationships are usually reciprocal and many-to-many, and can hardly be described precisely. To comply with the imprecise nature of the thesaurus, we have proposed and developed a fuzzy multilinkage thesaurus builder. The builder maintains a fuzzy membership degree for each relationship. The relationships are extensible and have an inheritance capability. The applications of the fuzzy multilinkage thesaurus builder to expand the query terms for multimedia information retrieval are presented.

We report on the simulation of high-power laser bars and the emulation of their ageing behaviour, using simulation tools originally developed for single emitter laser diodes. Simulations of a simplified bar indicated that the hotter emitters located at the centre of the bar emit more power than their cooler neighbours, while degradation emulations showed that the centre emitters degrade faster. Although the degraded emitters produced less light, they drew an increasingly large fraction of the total current. These insights into the operation and degradation of the bar motivated new experimental investigations, which confirmed the predicted behaviour.

High-resolution x-ray diffraction (HRXRD) and photoreflectance (PR) spectroscopy were used to independently determine the In and N concentrations in GaInNAs alloys grown by solid-source molecular beam epitaxy (SSMBE). The lattice constant and bandgap energy can be expressed as two independent equations in terms of the In and N concentrations, respectively. The HRXRD measurement provided the lattice constant and the PR measurement extracted the bandgap energy. By simultaneously solving these two equations, we have determined the In and N concentrations with the error as small as 0.001.

A robust opto-electronic device simulation tool is extended to model the phonon bottleneck in edge-emitting 1.3µm InGaAsN double quantum well (QW) laser diodes. Both the steady state operation and the transient response of the phonon bottleneck are examined as a function of injection current and heatsink temperature. It is found that the hot phonon population can raise the electron and hole temperatures in the QW active region by up to 7K above the equilibrium lattice temperature at moderate injection currents. At high injection currents, it is found that the phonon bottleneck can significantly decrease the optical power.

Alternating- and direct-current electrical characteristics of rabbit corneal endothelium were studied under varying experimental conditions. The measurements were performed by sending a 10-microA current (AC or DC) across the tissue layer. Maximal values of transendothelial potential difference and resistance were 1.3 +/- 0.1 mV and 73 +/- 6 omega . cm2, respectively. The short-circuit current was estimated from the potential and resistance values. Impedance loci were obtained for the frequency range 0.5-100 kHz. A capacitive reactance (C = 0.63 +/- 0.02 microF/cm2) was observed in the 100 Hz-100 kHz range. To relate the impedance data to the electrical parameters of the cell membranes, the voltage-divider ratio was determined by sending square pulse across the tissue and measuring voltage responses across the apical and basal membranes with an intracellular microelectrode. The intracellular potential difference was on the average -61 +/- 1 mV, and the voltage-divider ratio was found to be between 0.33 and 4. Impedance data were fit by a computer to an equivalent circuit representing a "lumped" model, and the agreement between the model and the data was satisfactory. The results are discussed in terms of both the morphological characteristics and properties of the fluid transport mechanism across the preparation.

Four peaks were observed in the differential primary weight loss with temperatures up to 1,000 C. The first and second peaks correspond to the loss of water and the volatilization of protein. The third peak results from the carbonate. The fourth peak, which occurs at 700 to 800 C, probably is related to the transformation of hydroxyapatite to β-tricalcium phosphate. A zero order of reaction was assumed, and the activation energies in vacuum were determined to be 10.2 and 12.5 kcal/mol for loss of water and protein, respectively.

The dielectric constant of natural tendon in the frequency range of 200 Hz to 100 kHz has been determined as a function of temperature (300-450 degrees K) for water concentrations ranging from about 6 to 16% by weight. The results compare well with the approach taken by Haggis and his coworkers. Based on the assumption that at low concentration of water the probability of water-water bonding is small and hence may be disregarded, a structure for water in the collagen matrix is proposed in which the water is either bonded in one of four possible states to the polar groups of the polypeptide chains, or is unbound. In determining the distribution of the water among these states an approach similar to that of Haggis and his co-workers, in conjunction with the order-disorder theory of Bragg and Williams, is used. The number of water molecules per unit volume is then determined experimentally by relating it to weight loss as a function of temperature, as determined by thermogravimetric analysis. The dispersion which is normally found in dipolar substances has not been found for tendon. A maximum in the value of the dielectric constant is observed to occur between 25 and 80 degrees C, the temperature depending upon the heating rate.

Lawrence Livermore Laboratory is developing an assessment procedure to evaluate the effectiveness of a potential nuclear facility licensee’s material control (MC) system. The purpose of an MC system is to prevent the theft of special nuclear material such as plutonium and highly enriched uranium. The key in the assessment procedure is the generation and analysis of the adversary event sets by a directed graph and fault-tree methodology. The methodology is described step-by-step and its application illustrated by an example.