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PubMed1997

Reliability of comparative molecular field analysis models: effects of data scaling and variable selection using a set of human synovial fluid phospholipase A2 inhibitors.

The effects of data pretreatment, data scaling, and variable selection on three-dimensional quantitative structure-activity relationships derived by comparative molecular field analysis (CoMFA) using the GRID energy function were studied in detail for a set of inhibitors of the human synovial fluid phospholipase A2 (HSF-PLA2). The quality of the models was evaluated for predictive power and ability to map the receptor binding site by (a) comparison of predicted and experimental activities using cross-validation and external validation sets and (b) comparison of the regions selected in space in the CoMFA models with a crystal structure of a HSF-PLA2-inhibitor complex, with optimized comparative binding energy analysis (COMBINE) models (Ortiz et al., 1995) and with structure-activity relationships derived previously for different sets of compounds. It is found that (1) data scaling and dielectric modeling strongly influence CoMFA results. Unscaled data and a uniform dielectric constant of 4 are well suited to GRID-CoMFA studies for the present compound set. (2) The GOLPE and Q2-GRS variable selection methods select variables in roughly the same regions in Cartesian space, but they produce different models in chemometric space and differ in their sensitivity to data scaling and pretreatment and their tendency to overfitting. (3) CoMFA models are consistent with COMBINE models in that they identify approximately the same intermolecular interactions as relevant for activity. Our study provides support for the qualitative receptor-mapping properties of CoMFA models and for the validity of variable selection when applied with care and also provides guidelines for how to evaluate the quality of CoMFA models.

Enzyme Inhibitors↗

PubMed1990

Renal transplant diet recommendations: results of a survey of renal dietitians in the United States.

A survey of dietitians at renal transplant centers in the United States was conducted to identify diet modifications currently used for nondiabetic adults after kidney transplantation. The survey focused on the diet recommended for the first 21 days after successful transplantation. Questionnaires were mailed to 100 centers randomly selected from a comprehensive list obtained through the Organ Transplant Coordinating Office of the Texas Medical Center, Houston. A 66% response rate was obtained. The results of the survey showed that dietitians were most frequently recommending 1.2 to 1.5 gm protein per kg body weight, 40% to 50% of total energy as carbohydrate, a fat intake of less than 30% of total energy, and an energy level consistent with achieving or maintaining desirable body weight. Sodium intake was most commonly restricted to 2 to 4 gm, whereas potassium and phosphorus intakes were individualized according to the patient's serum values. Comments on the returned questionnaires indicated that many institutions were reviewing and updating their transplant diet to include a polyunsaturated fat to saturated fat ratio and restrictions of cholesterol and simple sugars. The findings of the survey indicated that the renal transplant diet should focus on optimal protein and energy intake as well as restriction of simple sugars, total fat, cholesterol, and saturated fat to restore nitrogen balance and minimize clinical symptoms of post-transplant diabetes and hyperlipidemia.

Cholesterol, Dietary↗

PubMed1984

Optimization of in vitro protein synthesis by isolated mouse adrenal mitochondria.

The requirements for in vitro mitochondrial protein synthesis have been studied using isolated mitochondria from cultured adrenal Y-1 tumor cells from mice. By reducing the reaction volume to 50 microliter we were able to assay in replicate the requirements for various reaction components using trichloroacetic acid (TCA)-precipitable counts for a quantitative evaluation with time of incubation. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis followed by autoradiography was also used for a qualitative and quantitative evaluation of the translation products. With the optimized system, 1 to 3% of added [35S]methionine was incorporated. The products of mitochondrial protein synthesis range from 70,000 to 5000 molecular weight. Major autoradiographic bands were observed at 38,000, 31,000, 23,000, 20,000, and 5600 molecular weight as separated on 10 to 20% gradient SDS-polyacrylamide gels; however, 20 to 30 protein products of various molecular weights were discernible. Mitochondrial concentrations of 0.8 to 1.4 mg/ml of incubation gave the better incorporation of [35S]methionine per milligram of protein. Total [35S]methionine incorporated into mitochondrial protein was greatest at 25 degrees C after 90 min. Chloramphenicol at 10 micrograms/ml inhibited mitochondrial protein synthesis by more than 50% and at 100 micrograms/ml inhibited incorporation by more than 95%. Cycloheximide had no effect on incorporation at less than 1.0 mg/ml. Magnesium and ATP in a molar ratio of one to one at 5 mM gave optimal incorporation. Other energy generating systems using oxidative phosphorylation to supply ATP for protein synthesis were not as effective as ATP and 5 mM phosphoenol pyruvate, 20 micrograms/ml pyruvate kinase and 5 mM a-ketoglutarate. In contrast to in vitro yeast mitochondrial protein synthesis, no enhancement of in vitro adrenal cell mitochondrial protein synthesis was found with GTP or its analogs. The buffers N,N-bis(2-hydroxyethyl)glycine, N-(tris(hydroxymethyl)methyl)glycine, and N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid were superior to Tris-HCl for mitochondrial protein synthesis. Optimal pH for [35S]methionine incorporation into mitochondrial proteins was pH 7.0 to 7.6. Potassium at 50 to 90 mM gave the best incorporation of [35S]methionine, and the higher molecular weight products of translation were enhanced at these concentrations. Sodium at 10 to 40 mM had no effect; however, 100 mM sodium inhibited label incorporation by 30%. Calcium at 100 microM inhibited mitochondrial protein synthesis by approximately 50%, and at 1.0 mM little if any incorporation occurred.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphate↗

PubMed2005

Enhanced sampling near the native conformation using statistical potentials for local side-chain and backbone interactions.

In the preceding article in this issue of Proteins, an empirical energy function consisting of 4 statistical potentials that quantify local side-chain-backbone and side-chain-side-chain interactions has been demonstrated to successfully identify the native conformations of short sequence fragments and the native structure within large sets of high-quality decoys. Because this energy function consists entirely of interactions between residues separated by fewer than 5 positions, it can be used at the earliest stage of ab initio structure prediction to enhance the efficiency of conformational search. In this article, protein fragments are generated de novo by recombining very short segments of protein structures (2, 4, or 6 residues), either selected at random or optimized with respect this local energy function. When local energy is optimized in selected fragments, more efficient sampling of conformational space near the native conformation is consistently observed for 450 randomly selected single turn fragments, with turn lengths varying from 3 to 12 residues and all 4 combinations of flanking secondary structure. These results further demonstrate the energetic significance of local interactions in protein conformations. When used in combination with longer range energy functions, application of these potentials should lead to more accurate prediction of protein structure.

Computational Biology↗

PubMed1998

Amino acid and energy interrelationships in growing beef steers: II. Effects of energy intake and metabolizable lysine supply on growth.

We conducted three experiments to determine the optimal metabolizable Lys:net energy ratio for growth of beef calves. The single basal diet fed contained corn (56.1%), soybean hulls (18%), cottonseed hulls (15%), animal fat (4.25%), and corn gluten meal (5.6%). In Exp. 1, 54 steers were individually fed the basal diet at 1.5, 2.25, and 3.0 times NEm requirement; rations were top-dressed with 3.4 g of rumen-stable (RS) Met and either 0, 2, 4, 6, 8, or 12 g of RS-Lys daily. An additional 18 steers were fed the same three levels of energy and supplemented with 125 g of blood meal per steer. In Exp. 2, 68 crossbred steers were subjected to the same experimental protocol, with the exception that only the two highest levels of energy were used. Of these steers, 48 were fed individually and received the RS-Lys treatments; the remaining 20 steers received 125 g of blood meal per steer. No interaction (P > .10) was detected between level of supplemental Lys and energy intake in Exp. 1 or 2. Supplementation with RS-Lys improved (P < .01) ADG in Exp. 1, but it had no effect (P > .10) on growth in Exp. 2. The Lys requirement estimates were 44.3 and 51.3 g/d, corresponding to maximal growth rates of 1.21 and 1.64 kg/d for the 2.25 and 3.0 times maintenance treatments, respectively. Comparing the growth rates of steers fed supplemental Lys with those of steers fed blood meal in Exp. 1 and 2 revealed an ADG advantage (P < .03) with blood meal supplementation. To confirm the blood meal response, Exp. 3 used 75 crossbred steers fed the basal diet at 3.0 times NEm requirement plus either 3.4 g RS-Met, 3.4 g RS-Met and 12 g RS-Lys, or 125 g of blood meal per steer. Blood meal supplementation improved (P < .01) growth of steers over those fed supplemental Met or Met plus Lys. Although a distinct relationship between amino acid requirements and energy supply may exist, Lys and Met were not first-limiting in these experiments, or selective supplementation with undegradable protein may have provided some factor that enhanced performance beyond that detected with Lys and Met alone.

Animals↗

PubMed2004

Effect of energy on propylene glycol aerosols using the capillary aerosol generator.

The CAG is being developed for pulmonary drug delivery. Liquids are pumped, heated and vaporized by the CAG, whence they nucleate and condense to form aerosols. This study characterized the effect of energy on the aerosolization process. With increasing energy, the CAG produced an increasing fine particle fraction (FPF) until "optimal aerosolization" was achieved between 40 and 45 J; this energy range agreed with that theoretically required to vaporize the dose of PG. Further increases in energy above this optimal range did not improve PG's aerosolization efficiency. Based on the energy, FPF and temperature profiles, it was possible to deduce the nature of the liquid flow-boiling during aerosol generation. The aerosol particle size went through a minimum, as energy was increased through the "optimal range." In the "energy excess" region, where additional energy increased PG vapor temperature and velocity, droplet sizes were increased primarily due to changes in the nucleation rates and supersaturation ratios affecting the nucleation and condensation processes occurring within the vapor jet. The in vitro MMAD of the PG aerosol changed as a function of the applied energy, suggesting that for any pharmaceutical application, the choice of applied energy is critical to deposition profile of the aerosol.

Administration, Inhalation↗

PubMed2004

Vision-based force measurement.

This paper demonstrates a method to visually measure the force distribution applied to a linearly elastic object using the contour data in an image. The force measurement is accomplished by making use of the result from linear elasticity that the displacement field of the contour of a linearly elastic object is sufficient to completely recover the force distribution applied to the object. This result leads naturally to a deformable template matching approach where the template is deformed according to the governing equations of linear elasticity. An energy minimization method is used to match the template to the contour data in the image. This technique of visually measuring forces we refer to as vision-based force measurement (VBFM). VBFM has the potential to increase the robustness and reliability of micromanipulation and biomanipulation tasks where force sensing is essential for success. The effectiveness of VBFM is demonstrated for both a microcantilever beam and a microgripper. A sensor resolution of less than +/- 3 nN for the microcantilever and +/- 3 mN for the microgripper was achieved using VBFM. Performance optimizations for the energy minimization problem are also discussed that make this algorithm feasible for real-time applications.

Algorithms↗

PubMed1995

Dietary intakes of students.

This paper relies on 24-h dietary recall data from a nationally representative sample of approximately 3350 students to analyze the dietary intakes of students. Most US students eat at least five times during the day, and nearly all eat at least three times per day. The average daily intake of vitamins and minerals at least meets the recommended dietary allowances (RDAs). Overall, students consume more food energy on average than recommended, suggesting that some may be at risk of consuming more food energy than is optimal. Students also consume more protein, total fat, saturated fat, and sodium than is recommended for good health. National School Lunch Program (NSLP) participants' mean intakes of most nutrients at lunch meet the program goal of at least one-third of the RDA. NSLP participants, however, consume more fat, saturated fat, and sodium than is recommended. School Breakfast Program (SBP) participants' mean intakes of most nutrients at breakfast also exceed the program goal of one-fourth of the RDA. However, their breakfast intakes of saturated fat as a percentage of food energy, cholesterol, and sodium exceed dietary recommendations.

Adolescent↗

PubMed2005

The mechanics of sound production in Panacanthus pallicornis (Orthoptera: Tettigoniidae: Conocephalinae): the stridulatory motor patterns.

To examine whether sound production in katydids relies on an escapement mechanism similar to that of crickets we investigated the functional anatomy and mechanical properties of the stridulatory apparatus in the katydid Panacanthus pallicornis. Males of this species produce sustained pulses with a sharp low frequency peak of approximately approximately 5 kHz and a broad band spectrum between 15 and 25 kHz. Simultaneous recordings of movement and sound indicate that the entire stridulatory file is used for sound production and there is nearly a 1:1 correspondence between the number of cycles in a song and the number of teeth on the file. There is an overall tendency for both the spacing of teeth to increase along the file and the velocity of wing closure to increase as the scraper traverses the file. There is considerable variation, however, in the evenness of tooth spacing and in the instantaneous velocity of wing closure during sound production. The production of sustained pulses appears to depend on resonance in the right tegmen, with the left tegmen acting primarily as a damping element. This resonance is not strongly coupled to the scraper and, unlike crickets, the timing of file-scraper interactions, and therefore the phasing of energy input to wing oscillations, is variable. Similarly, the quality of the sound spectrum varies over the course of a single stridulatory wing-stroke. Based on measurements of tooth spacing on the stridulatory file and cycle-by-cycle frequency of sound output, we predicted the velocity of wing movement that would provide consistent phasing of file-scraper interactions with respect to sound-radiating wing oscillations and compared this with measurements of wing velocity. Acceleration of wing velocity during stridulation results in a closer match to the velocity required for optimal phasing during a portion of the call, and this corresponds with higher amplitudes of radiated sound and the excitation of higher order modes of vibration (evident as distinct harmonic peaks in spectrograms). Our results suggest that in katydid stridulation, the movement of the scraper along the file is not regulated by an escapement mechanism as it is in crickets. Instead, katydids that produce pure-tone songs sweep their wings over a range of velocities, within which some portion matches file tooth spacing to give optimal phasing of energy input to excite a resonance in the right tegmen.

Acoustics↗

PubMedDate not supplied

A transcutaneous energy and information transfer system for implanted medical devices.

During the last four decades there has been a rapid increase in the development and usage of medical devices. Currently, there are more than 500,000 devices on the market and 25,000 new devices enter the market each year. Many medical devices are now designed to be implantable (pacemakers, defibrillators, circulatory assist devices, artificial hearts, cochlear implants, neuromuscular stimulators, biosensors, etc.). Almost all of the active devices (those that perform work) and many of the passive devices (those that do not perform work) require a source of power. In addition, these devices need to be monitored and controlled, which can be accomplished by utilizing remote communication methods. A transcutaneous energy transfer system combined with a remote communications system has been developed and evaluated in vitro and in vivo (bovine, porcine, and human cadaver experiments). The energy transfer system can deliver up to 60 W with power transfer efficiencies between 60 and 83%. An automatically tuned, resonant frequency tracking method is used to obtain optimum power transfer over a range of operating conditions. The remote communications system can transfer digital data bidirectionally through intact skin at rates up to 9600 baud. The system transmits information by frequency modulating an 890 nm infrared carrier signal. The system has demonstrated satisfactory performance during multicenter evaluation with ventricular assist and total artificial heart devices. Design improvements have been identified, which will be implemented to produce an optimized system for energy transfer to and remote communications with various implantable medical devices.

Animals↗

PubMed2003

Structure and the energy of base pairing in non-natural bases of nucleic acids: the azaguanine-cytosine and azaadenine-thymine base pairs.

Watson-Crick optimized geometries and the energies of base pairing for the natural pairs of nucleic bases: adenine-thymine (AT) and guanine-cytosine (GC) have been recalculated by ab initio methods in order to compare results to those found for the non-natural azaadenine-thymine (AAT) and azaguanine-cytosine (AGC) pairs. Geometry optimizations carried out at the HF/6-31G** level and energies obtained at MP2/6-31G**, show that AAT and AGC have hydrogen bonding patterns similar to the natural AT and GC and that the interaction energies (DeltaH0int) for the former are ca. 7 kcal/mol more stable than the latter. Accordingly, the pairs based on azapurines would be favored with respect to the natural pairs. Some possible explanations why nature does not use extensively the azabases in base pairing are given.

Azaguanine↗

PubMed2004

Ab initio molecular orbital study of structures and energetics of Si(3)H(2), Si(3)H(2) (+), and Si(3)H(2) (-).

The geometric structures, isomeric stabilities, and potential energy profiles of various isomers and transition states in Si(3)H(2) neutral, cation and anion are investigated at the coupled-cluster singles, doubles (triples) level of theory. For the geometrical survey, the basis sets used are of the Dunning's correlation consistent basis sets of triple-zeta quality (cc-pVTZ) for the neutral and cation and the Dunning's correlation consistent basis sets of double-zeta quality with diffuse functions (aug-cc-pVDZ) for the anion. For the final energy calculations, the aug-cc-pVTZ: Dunning's correlation consistent basis sets of triple-zeta quality with diffuse functions and cc-pVQZ: Dunning's correlation consistent basis sets of quadruple-zeta quality basis sets are used for the neutral and the aug-cc-pVTZ ones for the cation and anion. The global minimum neutral (I-1: (1)A(1)) has the same framework as that (cyclopropenylidene) of the C(3)H(2) molecule. Other low-lying three isomers (I-2, I-3, and I-4) are also predicted to be within 20 kJ/mol. Five transition states are optimized and their energy relationships with the isomers are clarified. The geometric structure of the global minimum cation (C-1: (2)A(1)) has the same framework as that of the neutral, but that of the anion (A-1: (2)A(')) differs very much from those of the neutral and cation. The calculated vertical and adiabatic ionization potentials from the global minimum neutral (I-1) are 7.85 and 7.77 eV, respectively. The adiabatic electron affinity of the neutral I-1 and the electron detachment energy of the global minimum anion (A-1) are predicted to be 1.21 and 1.92 eV, respectively. The two-electron three-centered bond is widely observed in the present Si(3)H(2) neutral, cation, and anion. The contour plots of their localized molecular orbitals clearly show the existence of such nonclassical chemical bonds.

Journal Article↗

PubMed2005

Ab initio molecular-orbital study of structures and energetics of Si3H3 neutral and anion.

The geometric structures and isomeric stabilities of various stationary points in Si(3)H(3) neutral and its anion are investigated at the coupled-cluster singles, doubles (triples) [CCSD(T)] level of theory. For geometrical surveys, the basis sets used are of the Dunning's correlation consistent basis sets of triple-zeta quality for the neutral. To the anions, the Dunning's correlation consistent basis sets of double-zeta quality with diffuse functions are applied. For the three lower-lying anion isomers, the Dunning's correlation consistent basis sets of triple-zeta quality with diffuse functions (aug-cc-pVTZ) are also used. The final energies for the optimized stationary points are calculated at the CCSD(T) level of theory with the aug-cc-pVTZ basis sets. The basis sets of 6-311++G(3df,2pd) were also used for the lower-lying anion isomers. The Gaussian-2 method was performed only for the lower-lying anion isomers to clarify the relative stabilities. The global minimum neutral 1 (C(1):(2)A) has an unsymmetrical hydrogen-bridged bond; the conformer 2 in C(s) symmetry is a saddle point connecting the two equivalent isomers 1. Two lower-lying isomers (3 and 4) are also predicted within the energy range of 20 kJmol. In the anion, however, the conformer 4 (C(s):(1)A(')) with five formal valence electrons is a global minimum. Two more isomers (2 and 3) lie within 20 kJmol as in the neutral; the conformer 1 converts to the isomer 2. The quartets for the neutrals and diradical triplets for the anions were further studied; lower-lying quartets and triplets, competing with the corresponding doublet and singlet, respectively, were not found in the present systems. The vertical and adiabatic electron affinities of the global minimum neutral 1, producing the second lowest-lying anion isomer 2, amount to 2.18 and 2.35 eV, respectively, at the CCSD(T)/aug-cc-pVTZ level of theory. The electron addition to the third lowest-lying neutral isomer 4 produces the largest vertical electron affinities of 2.48 eV. The D(3h) structure, being the global minimum in the corresponding Si(3)H(3) (+) cation (trisilacyclopropenyl cation), converts to the isomer 8 (C(s)) or 11 (C(2)) due to the Jahn-Teller effect in the Si(3)H(3) neutral.

Anions↗

PubMed2004

Experimental energy response verification of XR type T radiochromic film.

This short note investigates the energy response characteristics of a relatively new high sensitivity radiochromic film (XR type T) and compares it to other radiochromic and radiographic films and thermoluminescent dosimeters. Results show that the energy response of the new XR type T film is relatively large over the range of therapeutic energies from 50 kVp superficial x-ray treatment to 18 MV high energy radiotherapy treatment. When normalized to 1 at a standard 6 MV radiotherapy x-ray energy the XR type T film produced a normalized dose response of approximately 6 in the energy range of 30 keV to 70 keV thus representing an increase in sensitivity at lower energies similar to that observed for radiographic x-ray films. This is quite different from previous versions of Gafchromic film where the energy response of the film decreases at lower energies down to levels approximately 0.6-0.7 for the same effective energies. This type of film has been optimized for use in diagnostic energy ranges producing a relatively uniform dose response in the 30 keV to 70 keV range.

Dose-Response Relationship, Radiation↗

PubMed1986

Catheter-mediated electrical ablation: the relation between current and pulse width on voltage breakdown and shock-wave generation.

Barotrauma from arc induced shock waves may result in dangerous sequelae during ablation of arrhythmogenic foci. In this report, maximum pulse amplitude and pulse width determinations were made to assess avoidance of shock-wave generation using rectangular constant current pulses. Energy delivery appears to be optimal between 80-100 microseconds. If higher energies are required, multiple pulses will be needed to avoid barotrauma.

Animals↗

PubMed1993

Efficiency of energy conversion from metabolic substrates to ATP and mechanical and chemiosmotic energy.

The free energy available from substrate oxidation is a largely invariable figure in biological systems. The extent to which this energy is conserved in high-energy intermediates appears to be optimized during evolution to high efficiency. Since energy transformation by enzymatic and transport processes take place largely with fixed stoichiometrics, high efficiency can only be achieved by adapting free energy levels rather than by adapting turnover (number of molecules synthesized/hydrolyzed, etc.) The relatively small steps (equivalent with high efficiency) in free energy of various metabolic steps implicitly mean that changes in free energy leading to abolition of these steps (e.g., reduction of free energy of ATP) abolish the driving force and interrupt the (net) reaction. However, in the myocardium under limited energy supply (hypoxia) various protective mechanisms appear to be involved which keep free energy levels high for surviving of the cell but for the cost of function (contraction). Those mechanisms might play a role in the phenomena of hibernating and stunning.

Adenosine Triphosphate↗

PubMed1997

How might 12 (R) HETE cause the inhibition of Na,K-ATPase?

PURPOSE: 12 (R) hydroxy 5,8,10,14-eicosatetraenoic acid [12 (R) HETE] is a potent inhibitor of Na,K-ATPase. This study was an attempt to determine how the eicosanoid might inhibit the enzyme by using molecular modeling. METHODS: Models were generated using the program HyperChem 2.0 for Windows. Models of 12 (R) HETE, 12 (S) HETE (the "S" isomer of 12 (R) HETE), and 8 (R) hydroxy-hexadecatrienoic acid [8 (R) HHDTrE, a catabolic isomer of 12 (R) HETE] were formed and docked with phosphatidyl choline and the H3-H4 peptide of the alpha-subunit of Na,K-ATPase. In addition, models of 12 (R) HETE, and related compounds, were formed and complexed with calcium, and then docked with phosphatidyl choline. The energies of stabilization were calculated for each optimal docking. RESULTS: Optimal steric fitting and calculated energies of stabilization indicated that 12 (R) HETE and 8 (R) HHDTrE had the best fits when bound to the fatty acid portions of phosphatidyl choline. However, when Ca-HETE complexes were modeled, it was found that they formed even more stable complexes when bound to phosphatidyl choline. Calculated energies of 12 (S) HETE, whether complexed to calcium or not, were less favorable than the other HETE compounds. CONCLUSIONS: The results of the study indicate that plasma membrane lipids rather than Na,K-ATPase itself are more likely to be bound by 12 (R) HETE and its related compounds. Moreover, it was found that the calcium complexes of 12 (R) HETE and 8 (R) HHDTrE are even more likely to dock with plasma membrane lipids. This suggests that such complexes may be able to transport calcium into the cell and make it available for the inhibition of Na, K-ATPase at the enzyme's sodium binding site.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

PubMed2004

Theoretical design for the optimization of a material's geometry in diode-pumped high-energy Yb3+:YAG lasers and its experimental validation at 0.5-1 J.

The geometry of ytterbium-doped active media in diode-pumped lasers can be calculated with the help of a few analytic expressions for the optimization of high-energy and high-efficiency Q-switched lasers. The first step in the optimization consists in the definition of a basic three-level model with which to estimate the energy to be extracted. In the second step, for validation purposes we use a side-pumped Yb3+:YAG slab at 2-kW peak pump power in the long-pulse mode of operation up to 1 J, and we Q switch it at reduced energies up to 100 mJ. The final step of this study provides fairly general relationships devoted the geometric sizing of optimized slabs that will be of some interest for the design of higher-energy ytterbium-doped Q-switched lasers.

Journal Article↗