Assisted hatching in mouse embryos using a noncontact Ho:YSGG laser system

PurposeA noncontact holmium:yttrium scandium gallium garnet (Ho:YSGG) laser system has been designed and tested for the micromanipulation of mammalian embryos. The purpose of this preliminary investigation was to determine the effectiveness of this laser for assisted hatching and evaluate its impact on embryo viability. The Ho:YSGG system, utilizing 250-microsecond pulses at a wavelength of 2.1 microns and 4 Hz, was used to remove a portion of the zona pellucida (ZP) of two- to four-cell FVB mouse embryos.ResultsIn the first experiment there was no difference in blastocyst production or hatching rates following laser or conventional assisted hatching (LAH or AH, respectively) in contrast to control embryos cultured in a 5% CO2 humidified air incubator at 37 degrees C. In the second experiment a blastocyst antihatching culture model was employed and LAH-treated embryos were cultured in a serum-free HTF medium (HTF-o). Blastocyst formation was not influenced by LAH treatment and hatching was increased (P < 0.01) from 4 to 60% compared to HTF-o control group.ConclusionsThese preliminary data demonstrate the utility and nontoxic properties of the Ho:YSGG laser system for quick and precise ZP drilling

New insights on structure and stratigraphic interpretation for assessing the hydrocarbon potentiality of the offshore Nile Delta basin, Egypt

The study area lies around the petroleum provinces of the Egyptian Offshore Nile Delta basin. The existing exploration data are sparse, and any effort made on the strati-structural interpretation is challenging for exploratory drilling campaigns, even with meager well control. Keeping in view the issues and major challenges, the authors propose new methodologies, tools and new insights into the interpretation of the existing data and information, to make the study area more attractive for investors and detailed exploration studies. The published geological work existing within the vicinity of the study area is an added value to the new insights of current interpretation and knowledge acquisition. Pliocene–Pleistocene section is the main target in the study area, since it has quality reservoirs, holding commercial hydrocarbons. Pre-salt source rocks may have charged the reservoirs in the study area. Structural complexities and heterogeneities at target levels are likely to impact the seismic wavelet property intricacies and thus the data processing qualities. Post- and pre-salt tectonics in the northern part of Sinai, the Nile Cone, and how they affect the structural framework and the seismic interpretation work in the study area are described. For the purpose of understanding the combinational trapping mechanism, stratigraphic features and the structural geology are integrated using new tools and technologies. Several strati-structural plays are interpreted in the study area that support the detailed exploration campaigns, and the existing major hydrocarbon plays associated within shelf, slope and deep-marine geological events in nearby offshore regions. Diapir salt, rotated fault blocks and growth faults within syn-sediment systems are other plays to be investigated. The study is an effort of compiled work from many published sources, putting all ideas into a positive perspective and has better understanding of new opportunities, leads and prospects for investment purposes in the Nile Delta offshore basin

Hydrodynamic model for ultra-short pulse ablation of hard dental tissue

A computational model for the ablation of tooth enamel by ultra-short laser pulses is presented. The role of simulations using this model in designing and understanding laser drilling systems is discussed. Pulses of duration 300 fsec and intensity greater than 10{sup 12} W/cm{sup 2} are considered. Laser absorption proceeds via multi-photon initiated plasma mechanism. The hydrodynamic response is calculated with a finite difference method, using an equation of state constructed from thermodynamic functions including electronic, ion motion, and chemical binding terms. Results for the ablation efficiency are presented. An analytic model describing the ablation threshold and ablation depth is presented. Thermal coupling to the remaining tissue and long-time thermal conduction are calculated. Simulation results are compared to experimental measurements of the ablation efficiency. Desired improvements in the model are presented

Comparison of soft and hard tissue ablation with sub-ps and ns pulse lasers

Tissue ablation with ultrashort laser pulses offers several unique advantages. The nonlinear energy deposition is insensitive to tissue type, allowing this tool to be used for soft and hard tissue ablation. The localized energy deposition lead to precise ablation depth and minimal collateral damage. This paper reports on efforts to study and demonstrate tissue ablation using an ultrashort pulse laser. Ablation efficiency and extent of collateral damage for 0.3 ps and 1000 ps duration laser pulses are compared. Temperature measurements of the rear surface of a tooth section is also presented

A clinical evaluation of an ex vivo organ culture system to predict patient response to cancer therapy

IntroductionEx vivo organ cultures (EVOC) were recently optimized to sustain cancer tissue for 5 days with its complete microenvironment. We examined the ability of an EVOC platform to predict patient response to cancer therapy.MethodsA multicenter, prospective, single-arm observational trial. Samples were obtained from patients with newly diagnosed bladder cancer who underwent transurethral resection of bladder tumor and from core needle biopsies of patients with metastatic cancer. The tumors were cut into 250 μM slices and cultured within 24 h, then incubated for 96 h with vehicle or intended to treat drug. The cultures were then fixed and stained to analyze their morphology and cell viability. Each EVOC was given a score based on cell viability, level of damage, and Ki67 proliferation, and the scores were correlated with the patients’ clinical response assessed by pathology or Response Evaluation Criteria in Solid Tumors (RECIST).ResultsThe cancer tissue and microenvironment, including endothelial and immune cells, were preserved at high viability with continued cell division for 5 days, demonstrating active cell signaling dynamics. A total of 34 cancer samples were tested by the platform and were correlated with clinical results. A higher EVOC score was correlated with better clinical response. The EVOC system showed a predictive specificity of 77.7% (7/9, 95% CI 0.4–0.97) and a sensitivity of 96% (24/25, 95% CI 0.80–0.99).ConclusionEVOC cultured for 5 days showed high sensitivity and specificity for predicting clinical response to therapy among patients with muscle-invasive bladder cancer and other solid tumors